day 8

.gitignore

@@ -1,3 +1,5 @@
-day1
-day1_input
-day1_test
+*.txt
+*.elf
+*.o
+blink.log
+compile_commands.json

Makefile

@@ -1,4 +1,27 @@
-all: day1
+FILES = $(wildcard ./*)
+SRCS  = $(filter %.c,$(FILES))
+BINS  = $(SRCS:%.c=%.elf)
 
-%: %.c
-	gcc-tree -o $@ -Wall -Werror -pedantic -D_GNU_SOURCE -std=gnu2y -O3 -g $<
+MUSLFILES = $(wildcard ./musl/*)
+MUSLOBJS  = $(filter %.o,$(MUSLFILES))
+
+CFLAGS = -Wall -Werror -pedantic -Wno-unused -std=gnu2y\
+		 -O3 -c -g -fno-stack-protector -fno-pie\
+		 -fno-semantic-interposition -fno-trapping-math\
+		 -march=x86-64 -mprefer-vector-width=128 -mpopcnt -malign-data=compat -malign-stringops
+
+LFLAGS = -Ttext=C475000 -static -nostdlib -no-pie
+
+all: $(BINS)
+
+%.elf: %.o start.o | %.c $(MUSLOBJS)
+	ld -o $@ $(LFLAGS) start.o $< $(MUSLOBJS)
+
+start.o: start.s
+	nasm -f elf64 -o $@ $<
+
+%.o: %.c | lib.h
+	gcc-tree -o $@ $(CFLAGS) $<
+
+clean:
+	rm -f *.elf *.o

day0.h

@@ -0,0 +1,91 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+ch input[] = {
+#embed "day0_input.txt"
+};
+
+static
+ch test[] = {
+#embed "day0_test.txt"
+};
+
+alignas(0x40) static
+struct {
+    line padstart[4];
+    struct { ch *s; num _extra[7]; };
+    union { line l; struct { ch s[16]; num n; }; } result;
+    line padend;
+} m;
+static_assert(offsetof(typeof(m),result) % 64 == 0);
+static_assert(offsetof(typeof(m),padend) % 64 == 0);
+
+static
+num do_part1(size_t file_len, ch file[file_len]) {
+    m = (typeof(m)){ };
+    m.s = file;
+    m.result.n = 0;
+
+#if DBG
+    print("\n");
+#endif
+
+do {
+    m.s++;
+} while (m.s != &file[file_len]);
+
+    return m.result.n;
+}
+
+static
+num do_part2(size_t file_len, ch file[file_len]) {
+    return 0;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 0
+#define RUN_TEST2 0
+#define RUN_PART2 0
+
+#define TEST1_EXPECT -1
+#define TEST2_EXPECT -1
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day1.c

@@ -1,15 +1,58 @@
-#include <stdio.h>
 #include <stdlib.h>
 #include <stdcountof.h>
+#include <stdint.h>
+#include <string.h>
 
-char input[] = {
-#embed "day1_input"
-};
+#define SYS_write 1
+#define SYS_exit_group 231
 
-char test[] = {
-#embed "day1_test"
-};
+#define STDOUT_FILENO 1
 
+static
+void write(uint64_t fileno, void *buffer, size_t len) {
+    uint64_t a,d;
+    asm volatile("syscall"
+        :"=a"(a),"=d"(d):"a"(SYS_write),"D"(fileno),"S"(buffer),"d"(len):"memory");
+}
+
+[[noreturn]] static
+void exit_group() {
+    asm volatile(
+        "syscall\n"
+        "ud2"
+        ::"a"(SYS_exit_group),"D"(0));
+    for (;;);
+}
+
+#define xstr(s) str(s)
+#define str(s) #s
+
+static
+void print_many_char(size_t len, char chars[len]) {
+    write(STDOUT_FILENO, chars, len);
+}
+
+#define print(string) print_many_char(sizeof(string)-1, string)
+
+static
+void printd(unsigned long v) {
+    if (!v) {
+        print("0");
+        return;
+    }
+    char buf[32];
+    char *p = buf+32;
+    unsigned count = 0;
+    while (v) {
+        p--;
+        *p = '0' + (v % 10);
+        v /= 10;
+        count++;
+    }
+    write(STDOUT_FILENO, p, count);
+}
+
+static
 unsigned grabnum(const char *s, const char **end) {
     unsigned r = 0;
     for (; *s >= '0' && *s <= '9'; s++)
@@ -18,6 +61,27 @@ unsigned grabnum(const char *s, const char **end) {
     return r;
 }
 
+#define DBG 1
+
+#define RUN_PART1 1
+#define RUN_PART2 1
+#define RUN_TEST1 1
+#define RUN_TEST2 1
+
+#define TEST1_EXPECT 3
+#define TEST2_EXPECT 6
+
+static
+char input[] = {
+#embed "day1_input.txt"
+};
+
+static
+char test[] = {
+#embed "day1_test.txt"
+};
+
+static
 unsigned long do_part1(size_t src_len, const char src[src_len]) {
     const char *s = src;
     unsigned long count = 0;
@@ -36,6 +100,7 @@ unsigned long do_part1(size_t src_len, const char src[src_len]) {
     return count;
 }
 
+static
 unsigned do_part2(size_t src_len, const char src[src_len]) {
     const char *s = src, *ns = s + 1;
     unsigned count = 0;
@@ -70,24 +135,40 @@ unsigned do_part2(size_t src_len, const char src[src_len]) {
     return count;
 }
 
-int main() {
-    printf("PART 1 TEST: ");
-    if (unsigned long v = do_part1(countof(test), test); v != 3) {
-        printf("FAILED (got %lu, expected 3)\n", v);
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (unsigned long v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
     } else {
-        printf("PASSED\n");
+        print("PASSED\n");
     }
+#endif
 
-    printf("PART 1 RESULT: %lu\n",
-        do_part1(countof(input), input));
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
 
-    printf("PART 2 TEST: ");
-    if (unsigned v = do_part2(countof(test), test); v != 6) {
-        printf("FAILED (got %u, expected 6)\n", v);
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (unsigned v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
     } else {
-        printf("PASSED\n");
+        print("PASSED\n");
     }
+#endif
 
-    printf("PART 2 RESULT: %u\n",
-        do_part2(countof(input), input));
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group();
 }

day2.c

@@ -0,0 +1,296 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+unsigned char input[] = {
+#embed "day2_input.txt"
+};
+
+static
+unsigned char test[] = {
+#embed "day2_test.txt"
+};
+
+
+struct id {
+    size_t len;
+    bcdint v;
+};
+
+static
+struct id next_palindrome_part1(struct id s) {
+    if (s.len % 2 == 1) {
+        size_t len = s.len + 1;
+        unsigned high_shift = (len / 2) * 4;
+
+        bcdint high = 1 << (high_shift - 4);
+
+        return (struct id) {
+            .len = len,
+            .v = (high << high_shift) | high
+        };
+    }
+
+    unsigned high_shift = (s.len / 2) * 4;
+    bcdint   low_mask = (1 << high_shift) - 1;
+
+    bcdint high = s.v >> high_shift;
+    bcdint low =  s.v & low_mask;
+
+    if (low > high)
+        high = bcdadd(high, 1);
+
+    return (struct id) {
+        .len = s.len,
+        .v = (high << high_shift) | high
+    };
+}
+
+static
+bcdint do_part1(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *src = file, *tmp;
+    bcdint result = 0;
+
+#if DBG
+    print("\n");
+#endif
+
+do {
+#if DBG
+    print_watch_ptr(src);
+    print("\t");
+    print(str(src) ":");
+    for (size_t i = 0; i < 2; i++) {
+        print(" ");
+        print_hex_char(src[i]);
+    }
+    print("\n");
+#endif
+
+    tmp = src;
+    bcdint rs = grabbcd(src, &src);
+    struct id first = {
+        .len = src - tmp,
+        .v = rs
+    };
+
+    src++;
+
+    tmp = src;
+    bcdint re = grabbcd(src, &src);
+
+    src++;
+
+#if DBG
+    printh(rs);
+    print(" to ");
+    printh(re);
+    print("\n");
+#endif
+
+struct id next = first;
+do {
+    next = next_palindrome_part1(next);
+    if (next.v <= re) {
+        result = bcdadd(result, next.v);
+#if DBG
+        print_watch_hex(next.v);
+        print("\t");
+        print_watch_hex(next.len);
+        print("\t");
+        print_watch_hex(result);
+        print("\n");
+#endif
+    }
+    bcdint tmp = bcdadd(next.v, 1);
+    for (bcdint chk = next.v; chk > 0; chk >>= 4) {
+        if ((chk & 0xF) != 9) goto no_len_change;
+    }
+    next.len++;
+no_len_change:
+    next.v = tmp;
+} while (next.v <= re);
+
+#if DBG
+    print("reached ");
+    printh(re);
+    print("\n");
+#endif
+
+} while (src != &file[file_len]);
+
+    return result;
+}
+
+static
+struct id next_palindrome_part2(struct id s) {
+    bcdint best = -1;
+
+    for (unsigned i = 2; i <= s.len; i++) {
+        if (s.len % i == 0) {
+            unsigned high_shift = (s.len / i) * 4;
+
+            bcdint high = s.v >> (high_shift * (i - 1));
+
+            for (int j = i - 2; j >= 0; j--) {
+                bcdint low = (s.v >> (high_shift * (j))) & ((1 << high_shift) - 1);
+
+                if (low < high) {
+                    break;
+                } else if (low > high) {
+                    high = bcdadd(high, 1);
+                    break;
+                }
+            }
+
+            bcdint next = 0;
+            for (unsigned j = 0; j < i; j++) {
+                next |= high << (high_shift * j);
+            }
+
+            if (next < best) {
+                best = next;
+            }
+        }
+    }
+
+    if (best != -1) {
+        return (struct id) {
+            .len = s.len,
+            .v = best
+        };
+    }
+
+    size_t len = s.len + 1;
+    unsigned high_shift = (len / 2) * 4;
+
+    bcdint high = 1 << (high_shift - 4);
+
+    return (struct id) {
+        .len = len,
+        .v = (high << high_shift) | high
+    };
+}
+
+static
+bcdint do_part2(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *src = file, *tmp;
+    bcdint result = 0;
+
+#if DBG
+    print("\n");
+#endif
+
+do {
+#if DBG
+    print_watch_ptr(src);
+    print("\t");
+    print(str(src) ":");
+    for (size_t i = 0; i < 2; i++) {
+        print(" ");
+        print_hex_char(src[i]);
+    }
+    print("\n");
+#endif
+
+    tmp = src;
+    bcdint rs = grabbcd(src, &src);
+    struct id first = {
+        .len = src - tmp,
+        .v = rs
+    };
+
+    src++;
+
+    tmp = src;
+    bcdint re = grabbcd(src, &src);
+
+    src++;
+
+#if DBG
+    printh(rs);
+    print(" to ");
+    printh(re);
+    print("\n");
+#endif
+
+struct id next = first;
+do {
+    next = next_palindrome_part2(next);
+    if (next.v <= re) {
+        result = bcdadd(result, next.v);
+#if DBG
+        print_watch_hex(next.v);
+        print("\t");
+        print_watch_hex(next.len);
+        print("\t");
+        print_watch_hex(result);
+        print("\n");
+#endif
+    }
+    bcdint tmp = bcdadd(next.v, 1);
+    for (bcdint chk = next.v; chk > 0; chk >>= 4) {
+        if ((chk & 0xF) != 9) goto no_len_change;
+    }
+    next.len++;
+no_len_change:
+    next.v = tmp;
+} while (next.v <= re);
+
+#if DBG
+    print("reached ");
+    printh(re);
+    print("\n");
+#endif
+
+} while (src != &file[file_len]);
+
+    return result;
+}
+
+#define RUN_TEST1 0
+#define RUN_PART1 0
+#define RUN_TEST2 0
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 0x1227775554l
+#define TEST2_EXPECT 0x4174379265l
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (bcdint v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printh(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printh(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (bcdint v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printh(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printh(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day2_plasl.c

@@ -0,0 +1,130 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+unsigned char input[] = {
+#embed "day2_input.txt"
+};
+
+static
+unsigned char test[] = {
+#embed "day2_test.txt"
+};
+
+uint64_t ipow(uint64_t a, uint64_t b) {
+    uint64_t m = a;
+    for (;b;b--) m += a;
+    return m;
+}
+
+static
+uint64_t range(uint64_t start, uint64_t end, uint64_t len) {
+#if DBG
+    print("==\n");
+    printd(start); print(" "); printd(end); print("\n");
+#endif
+
+    if ((len & 1) == 1) {
+        return 0;
+    }
+
+    uint64_t divisor = ipow(10, len / 2);
+
+    uint64_t first = (start + divisor - 1) / divisor;
+    uint64_t second = end / divisor;
+
+#if DBG
+    print("\n");
+    printd(divisor); print("\n");
+    printd(first); print(" "); printd(second); print("\n");
+#endif
+
+    uint64_t r = (((second + first) * (second + 1 - first)) / 2) * divisor;
+
+#if DBG
+    printd(r); print("\n");
+#endif
+
+    return r;
+}
+
+static
+uint64_t do_part1(size_t file_len, unsigned char file[file_len]) {
+    unsigned char buffer[65535];
+    memcpy(buffer, file, file_len);
+    size_t size = file_len;
+    buffer[file_len-1] = ',';
+
+    uint64_t out = 0;
+    uint64_t i = 0;
+
+    while (i < size) {
+#if DBG
+        print("--------------\n");
+#endif
+        uint64_t startlen = 0, endlen = 0;
+        uint64_t start = grabnum(buffer+i, NULL);
+
+        while (buffer[i] != '-') {
+            i++;
+            startlen++;
+        }
+        i++;
+
+        uint64_t end = grabnum(buffer+i, NULL);
+
+        while (buffer[i] != ',') {
+            i++;
+            endlen++;
+        }
+        i++;
+
+#if DBG
+        printd(startlen); print(" "); printd(start); print((char[]){ 10 });
+        printd(startlen); print(" "); printd(start); print((char[]){ 10 });
+#endif
+
+        if (endlen != startlen) {
+            out += range(start, ipow(10, startlen) - 1, startlen)
+                +  range(ipow(10, startlen), end, endlen);
+        } else {
+            out += range(start, end, startlen);
+        }
+
+#if DBG
+        print((char[]) { 10 });
+#endif
+    }
+
+    return out;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+
+#define TEST1_EXPECT 0x1227775554l
+
+void run() {
+    volatile uintptr_t s = (uintptr_t)&s;
+    printh(s);
+    print("\n");
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (uint64_t v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day2opt.c

@@ -0,0 +1,257 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+alignas(0x40) unsigned char input[] = {
+#embed "day2_input.txt"
+};
+
+struct id {
+    size_t len;
+    bcdint v;
+};
+
+static
+bcdint next_palindrome_len2(bcdint in) {
+    bcdint low  = in & 0xF;
+    bcdint high = in >> 4;
+
+    bcdint higher = high + 1;
+
+    bcdint high_pd =   0x11 * high;
+    bcdint higher_pd = 0x11 * higher;
+
+    return low > high ? higher_pd : high_pd;
+}
+
+static
+bcdint next_palindrome_len3(bcdint in) {
+    bcdint nib0  = in & 0xF;
+    bcdint nib1  = (in >> 4) & 0xF;
+    bcdint high  = in >> 8;
+
+    bcdint higher = high + 1;
+
+    bcdint high_pd =   0x111 * high;
+    bcdint higher_pd = 0x111 * higher;
+
+    if (nib1 < high) return high_pd;
+    return nib0 > high ? higher_pd : high_pd;
+}
+
+static
+bcdint next_palindrome_len4(bcdint in) {
+    bcdint nib0  = in & 0xF;
+    bcdint nib1  = (in >> 4) & 0xF;
+    bcdint nib2  = (in >> 8) & 0xF;
+    bcdint nib3  = in >> 12;
+
+    bcdint nib3er = nib3 + 1;
+
+    bcdint nib3_pd =   0x1111 * nib3;
+    bcdint nib3er_pd = 0x1111 * nib3er;
+
+    bcdint nib10 = in & 0xFF;
+    bcdint nib32 = in >> 8;
+
+    bcdint nib32er = bcdadd(nib32, 1);
+
+    bcdint nib32_pd   = 0x0101 * nib32;
+    bcdint nib32er_pd = 0x0101 * nib32er;
+
+    bcdint r = nib3er_pd;
+    if (nib3_pd > in) r = nib3_pd;
+    if (nib32er_pd > in) r = nib32er_pd;
+    if (nib32_pd > in) r = nib32_pd;
+
+    return r;
+}
+
+static
+bcdint next_palindrome_len6(bcdint in) {
+    bcdint nib0  = in & 0xF;
+    bcdint nib1  = (in >> 4)  & 0xF;
+    bcdint nib2  = (in >> 8)  & 0xF;
+    bcdint nib3  = (in >> 12) & 0xF;
+    bcdint nib4  = (in >> 16) & 0xF;
+    bcdint nib5  = in >> 20;
+
+    bcdint nib5er = nib5 + 1;
+
+    bcdint nib5_pd =   0x111111 * nib5;
+    bcdint nib5er_pd = 0x111111 * nib5er;
+
+    bcdint nib10 = in & 0xFF;
+    bcdint nib32 = (in >> 8) & 0xFF;
+    bcdint nib54 = in >> 16;
+
+    bcdint nib54er = bcdadd(nib54, 1);
+
+    bcdint nib54_pd   = 0x010101 * nib54;
+    bcdint nib54er_pd = 0x010101 * nib54er;
+
+    bcdint nib210 = in & 0xFFF;
+    bcdint nib543 = in >> 12;
+
+    bcdint nib543er = bcdadd(nib543, 1);
+
+    bcdint nib543_pd   = 0x001001 * nib543;
+    bcdint nib543er_pd = 0x001001 * nib543er;
+
+    bcdint r = nib5er_pd;
+    if (nib5_pd > in) r = MIN(r,nib5_pd);
+    if (nib54er_pd > in) r = MIN(r,nib54er_pd);
+    if (nib54_pd > in) r = MIN(r,nib54_pd);
+    if (nib543er_pd > in) r = MIN(r,nib543er_pd);
+    if (nib543_pd > in) r = MIN(r,nib543_pd);
+
+    return r;
+}
+
+static
+bcdint next_palindrome_len8(bcdint in) {
+    bcdint nib0  = in & 0xF;
+    bcdint nib1  = (in >> 4)  & 0xF;
+    bcdint nib2  = (in >> 8)  & 0xF;
+    bcdint nib3  = (in >> 12) & 0xF;
+    bcdint nib4  = (in >> 16) & 0xF;
+    bcdint nib5  = (in >> 20) & 0xF;
+    bcdint nib6  = (in >> 24) & 0xF;
+    bcdint nib7  = in >> 28;
+
+    bcdint nib7er = nib7 + 1;
+
+    bcdint nib7_pd =   0x11111111 * nib7;
+    bcdint nib7er_pd = 0x11111111 * nib7er;
+
+    bcdint nib10 = in & 0xFF;
+    bcdint nib32 = (in >> 8) & 0xFF;
+    bcdint nib54 = (in >> 16) & 0xFF;
+    bcdint nib76 = in >> 24;
+
+    bcdint nib76er = bcdadd(nib76, 1);
+
+    bcdint nib76_pd   = 0x01010101 * nib76;
+    bcdint nib76er_pd = 0x01010101 * nib76er;
+
+    bcdint nib3210 = in & 0xFFFF;
+    bcdint nib7654 = in >> 16;
+
+    bcdint nib7654er = bcdadd(nib7654, 1);
+
+    bcdint nib7654_pd   = 0x00010001 * nib7654;
+    bcdint nib7654er_pd = 0x00010001 * nib7654er;
+
+    bcdint r = nib7er_pd;
+    if (nib7_pd > in) r = MIN(r,nib7_pd);
+    if (nib76er_pd > in) r = MIN(r,nib76er_pd);
+    if (nib76_pd > in) r = MIN(r,nib76_pd);
+    if (nib7654er_pd > in) r = MIN(r,nib7654er_pd);
+    if (nib7654_pd > in) r = MIN(r,nib7654_pd);
+
+    return r;
+}
+
+static
+bcdint next_palindrome_part2(struct id s) {
+    if (s.len == 2)      return next_palindrome_len2(s.v);
+    else if (s.len == 3) return next_palindrome_len3(s.v);
+    else if (s.len == 4) return next_palindrome_len4(s.v);
+    else if (s.len == 6) return next_palindrome_len6(s.v);
+    else if (s.len == 8) return next_palindrome_len8(s.v);
+
+    unsigned len = s.len;
+    bcdint in = s.v;
+
+    bcdint best = -1;
+    for (unsigned i = 2; i <= len; i++) {
+        if (len % i == 0) {
+            unsigned high_shift = (len / i) * 4;
+
+            bcdint high = in >> (high_shift * (i - 1));
+
+            for (int j = i - 2; j >= 0; j--) {
+                bcdint low = (in >> (high_shift * (j))) & ((1 << high_shift) - 1);
+
+                if (low < high) {
+                    break;
+                } else if (low > high) {
+                    high = bcdadd(high, 1);
+                    break;
+                }
+            }
+
+            bcdint next = 0;
+            for (unsigned j = 0; j < i; j++) {
+                next |= high << (high_shift * j);
+            }
+
+            if (next < best) {
+                best = next;
+            }
+        }
+    }
+
+    return best;
+}
+
+static
+bcdint do_part2(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *src = file;
+    bcdint result = 0;
+
+    alignas(0x40) struct id ranges[128];
+    size_t range_count = 0;
+
+    do {
+        unsigned char *tmp;
+        bcdint rs = grabbcd(src, &tmp);
+        ranges[range_count * 2 + 0] = (struct id) {
+            .len = tmp - src,
+            .v = rs
+        };
+        src = tmp + 1;
+
+        bcdint re = grabbcd(src, &tmp);
+        ranges[range_count * 2 + 1] = (struct id) {
+            .v = re
+        };
+        src = tmp + 1;
+
+        range_count++;
+    } while (src != &file[file_len]);
+
+    do {
+        range_count--;
+        struct id next = ranges[range_count * 2 + 0];
+        bcdint re = ranges[range_count * 2 + 1].v;
+        do {
+            if (next.len == 1) {
+                next = (struct id) { .len = 2, .v = 0x11 };
+            } else {
+                next.v = next_palindrome_part2(next);
+            }
+            if (next.v <= re) {
+                result = bcdadd(result, next.v);
+            }
+            bcdint tmp = bcdadd(next.v, 1);
+            for (bcdint chk = next.v; chk > 0; chk >>= 4) {
+                if ((chk & 0xF) != 9) goto no_len_change;
+            }
+            next.len++;
+            no_len_change:
+            next.v = tmp;
+        } while (next.v <= re);
+    } while (range_count);
+
+    return result;
+}
+
+void run() {
+    print("PART 2 RESULT: ");
+    printh(do_part2(countof(input), input));
+    print("\n");
+
+    exit_group(0);
+}

day3.c

@@ -0,0 +1,125 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+unsigned char input[] = {
+#embed "day3_input.txt"
+};
+
+static
+unsigned char test_input[] = {
+#embed "day3_test.txt"
+};
+
+
+static
+unsigned long do_part1(size_t file_len, unsigned char file[file_len]) {
+    unsigned long result = 0;
+    unsigned char *s = file;
+
+    do {
+        unsigned char n0 = 0, n1 = 0;
+        unsigned char *n0p = NULL;
+        do {
+            if (s[0] > n0) {
+                n0 = s[0];
+                n0p = s;
+            }
+            s++;
+        } while (s[1] != '\n');
+        s = n0p+1;
+        do {
+            if (s[0] > n1) {
+                n1 = s[0];
+            }
+            s++;
+        } while (s[0] != '\n');
+        s++;
+        unsigned n = (n0 - '0') * 10 + (n1 - '0');
+        result += n;
+    } while(s < &file[file_len]);
+
+    return result;
+}
+
+static
+unsigned long do_part2(size_t file_len, unsigned char file[file_len]) {
+    unsigned long result = 0;
+    unsigned char *s = file;
+
+    do {
+        unsigned char n[12] = { };
+        unsigned char *np = NULL;
+        for (int i = 0; i < 12; i++) {
+            do {
+                if (s[0] > n[i]) {
+                    n[i] = s[0];
+                    np = s;
+                }
+                s++;
+            } while (s[11-i] != '\n');
+            s = np+1;
+        }
+        unsigned long v = 0;
+        for (int i = 0; i < 12; i++) {
+            v = v * 10 + (n[i] - '0');
+        }
+#if DBG
+        print("got ");
+        printd(v);
+        print("\n");
+#endif
+        result += v;
+        while (*s != '\n') s++;
+        s++;
+    } while(s < &file[file_len]);
+
+    return result;
+}
+
+#define RUN_TEST1 0
+#define RUN_PART1 0
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 357
+#define TEST2_EXPECT 3121910778619l
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (unsigned long v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (unsigned long v = do_part2(countof(test_input), test_input); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day4.c

@@ -0,0 +1,216 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+unsigned char input[] = {
+#embed "day4_input.txt"
+};
+
+static
+unsigned char test[] = {
+#embed "day4_test.txt"
+};
+
+alignas (0x40) static
+unsigned char buf[UINT16_MAX];
+
+static
+unsigned long do_part1(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *s = file, *d = buf;
+    unsigned long result = 0;
+
+#if DBG
+    print("\n");
+#endif
+
+    unsigned file_stride;
+    while (*s != '\n') s++;
+    file_stride = s - file + 1;
+    s = file;
+
+    unsigned line_count = file_len / file_stride;
+
+    unsigned line_stride = MAX(file_stride + 1, 0x40);
+
+    memset(d, 0, sizeof(buf));
+
+#if DBG
+    printh(file_stride); print("\n");
+    printh(line_stride * (line_count + 2)); print("\n");
+#endif
+
+#if DBG
+    printns(line_stride, d); print("\n");
+#endif
+    d += line_stride;
+    do {
+        memcpy(d + 1, s, file_stride - 1);
+#if DBG
+        printns(line_stride, d); print("\n");
+#endif
+        d += line_stride;
+        s += file_stride;
+    } while (s != &file[file_len]);
+#if DBG
+    printns(line_stride, d); print("\n");
+#endif
+
+    unsigned char *l = buf + line_stride + 1;
+    for (unsigned i = line_count; i; i--) {
+        d = l;
+        for (unsigned j = file_stride - 1; j; j--) {
+            if (*d == '@') {
+                unsigned neighbors = 0
+                    + (*(d - 1 - line_stride) == '@')
+                    + (*(d - 0 - line_stride) == '@')
+                    + (*(d + 1 - line_stride) == '@')
+                    + (*(d - 1 - 0) == '@')
+                    + (*(d + 1 - 0) == '@')
+                    + (*(d - 1 + line_stride) == '@')
+                    + (*(d - 0 + line_stride) == '@')
+                    + (*(d + 1 + line_stride) == '@')
+                    + (*(d - 1 - line_stride) == 'X')
+                    + (*(d - 0 - line_stride) == 'X')
+                    + (*(d + 1 - line_stride) == 'X')
+                    + (*(d - 1 - 0) == 'X')
+                    + (*(d + 1 - 0) == 'X')
+                    + (*(d - 1 + line_stride) == 'X')
+                    + (*(d - 0 + line_stride) == 'X')
+                    + (*(d + 1 + line_stride) == 'X');
+                if (neighbors < 4) {
+                    result++;
+                    *d = 'X';
+                }
+            }
+            d++;
+        }
+        l += line_stride;
+    }
+
+    return result;
+}
+
+static
+unsigned long do_part2(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *s = file, *d = buf;
+    unsigned long result = 0;
+
+#if DBG
+    print("\n");
+#endif
+
+    unsigned file_stride;
+    while (*s != '\n') s++;
+    file_stride = s - file + 1;
+    s = file;
+
+    unsigned line_count = file_len / file_stride;
+
+    unsigned line_stride = MAX(file_stride + 1, 0x40);
+
+    memset(d, 0, sizeof(buf));
+
+#if DBG
+    printh(file_stride); print("\n");
+    printh(line_stride * (line_count + 2)); print("\n");
+#endif
+
+#if DBG
+    printns(line_stride, d); print("\n");
+#endif
+    d += line_stride;
+    do {
+        memcpy(d + 1, s, file_stride - 1);
+#if DBG
+        printns(line_stride, d); print("\n");
+#endif
+        d += line_stride;
+        s += file_stride;
+    } while (s != &file[file_len]);
+#if DBG
+    printns(line_stride, d); print("\n");
+#endif
+
+    unsigned char *l = buf + line_stride + 1;
+    for (unsigned i = line_count; i; i--) {
+line_start:
+        d = l;
+        for (unsigned j = file_stride - 1; j; j--) {
+            if (*d == '@') {
+                unsigned neighbors = 0
+                    + (*(d - 1 - line_stride) == '@')
+                    + (*(d - 0 - line_stride) == '@')
+                    + (*(d + 1 - line_stride) == '@')
+                    + (*(d - 1 - 0) == '@')
+                    + (*(d + 1 - 0) == '@')
+                    + (*(d - 1 + line_stride) == '@')
+                    + (*(d - 0 + line_stride) == '@')
+                    + (*(d + 1 + line_stride) == '@');
+                if (neighbors < 4) {
+                    (*((volatile unsigned long *)&result))++;
+                    *(volatile unsigned char *)d = '.';
+                    if (i > line_count-1) {
+                        i = line_count;
+                        l = buf + line_stride + 1;
+                        goto line_start;
+                    } else {
+                        i += 1;
+                        l -= line_stride * 1;
+                        goto line_start;
+                    }
+                }
+            }
+            d++;
+        }
+        l += line_stride;
+    }
+
+    return result;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 0
+#define RUN_TEST2 1
+#define RUN_PART2 0
+
+#define TEST1_EXPECT 13
+#define TEST2_EXPECT 43
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (unsigned long v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (unsigned long v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day5.c

@@ -0,0 +1,236 @@
+#include "lib.h"
+#include <stdlib.h>
+
+#define DBG 0
+#define PRETTY 1
+
+static
+unsigned char input[] = {
+#embed "day5_input.txt"
+};
+
+static
+unsigned char test[] = {
+#embed "day5_test.txt"
+};
+
+#if PRETTY
+struct line {
+    union {
+        unsigned char l[64];
+        struct {
+            unsigned char s[16];
+            unsigned char pad0[4];
+            unsigned char e[16];
+            unsigned char pad1[4];
+            num sv;
+            num ev;
+        };
+    };
+};
+static_assert(sizeof(struct line) == 0x40);
+#else
+struct line {
+    num sv;
+    num ev;
+};
+#endif
+
+alignas(0x40) static
+struct line ranges[256];
+
+static
+int linecmp(const void *av, const void *bv) {
+    const struct line *a = av;
+    const struct line *b = bv;
+    if (a->sv < b->sv) return -1;
+    else if (a->sv > b->sv) return 1;
+    else return 0;
+}
+
+static
+unsigned long do_part1(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *s = file;
+    unsigned long result = 0;
+
+    memset(ranges, 0, sizeof(ranges));
+
+#if DBG
+    print("\n");
+#endif
+
+    struct line *d = ranges;
+    do {
+        unsigned char *tmp;
+        d->sv = grabbcd(s, &tmp);
+#if PRETTY
+        memcpy(d->s, s, tmp - s);
+#endif
+        s = tmp;
+        s++;
+        d->ev = grabbcd(s, &tmp);
+#if PRETTY
+        memcpy(d->e, s, tmp - s);
+#endif
+        s = tmp;
+        s++;
+        d++;
+    } while (*s != '\n');
+
+#if PRETTY
+    size_t range_cnt = d - ranges;
+    qsort(ranges, range_cnt, sizeof(*ranges), linecmp);
+#endif
+
+    d->sv = 0;
+    s++;
+
+    do {
+        bcdint id = grabbcd(s, &s);
+        for (d = ranges; d->sv; d++) {
+            bcdint ds = d->sv;
+            bcdint de = d->ev;
+            if (id >= ds && id <= de) {
+                result++;
+                goto next_id;
+            }
+        }
+next_id:
+        s++;
+    } while (s != &file[file_len]);
+
+    return result;
+}
+
+static
+unsigned long do_part2(size_t file_len, unsigned char file[file_len]) {
+    unsigned char *s = file;
+    unsigned long result = 0;
+
+    memset(ranges, 0, sizeof(ranges));
+
+#if DBG
+    print("\n");
+#endif
+
+    struct line *d = ranges;
+    do {
+        unsigned char *tmp;
+        d->sv = grabbcd(s, &tmp);
+#if PRETTY
+        snprinth(d->sv, sizeof(d->s), d->s);
+#endif
+        s = tmp;
+        s++;
+        d->ev = grabbcd(s, &tmp);
+#if PRETTY
+        snprinth(d->ev, sizeof(d->e), d->e);
+#endif
+        s = tmp;
+        s++;
+        d++;
+    } while (*s != '\n');
+
+    size_t range_cnt = d - ranges;
+    qsort(ranges, range_cnt, sizeof(*ranges), linecmp);
+
+    d->sv = 0;
+
+    outer:
+    for (struct line *di = ranges; di->sv; di++) {
+        bcdint dis = di->sv;
+        bcdint die = di->ev;
+        if (dis == -1) continue;
+        for (struct line *dj = di+1; dj->sv; dj++) {
+            bcdint djs = dj->sv;
+            bcdint dje = dj->ev;
+            if (djs == -1) continue;
+            if (djs > die) continue outer;
+            if (djs <= die && djs >= dis) {
+                djs = bcdadd(die, 1);
+            }
+            if (djs == dj->sv && dje == dj->ev)
+                continue;
+            if (dje < djs) {
+#if DBG
+                print("FOR: "); printd(dis); print(" "); printd(die); print("\n");
+                print("     "); printd(dj->sv); print(" "); printd(dj->ev); print("\n");
+                print("  -> "); printd(djs); print(" "); printd(dje); print(" BAD\n");
+#endif
+                dj->sv = -1;
+                dj->ev = -1;
+#if PRETTY
+                snprinth(dj->sv, sizeof(dj->s), dj->s);
+                snprinth(dj->ev, sizeof(dj->e), dj->e);
+#endif
+            } else {
+#if DBG
+                print("FOR: "); printd(dis); print(" "); printd(die); print("\n");
+                print("     "); printd(dj->sv); print(" "); printd(dj->ev); print("\n");
+                print("  -> "); printd(djs); print(" "); printd(dje); print("\n");
+#endif
+                dj->sv = djs;
+                dj->ev = dje;
+#if PRETTY
+                snprinth(dj->sv, sizeof(dj->s), dj->s);
+                snprinth(dj->ev, sizeof(dj->e), dj->e);
+#endif
+            }
+        }
+    }
+
+    for (struct line *di = ranges; di->sv; di++) {
+        if (di->sv == -1) continue;
+        unsigned long dis = bcdtonum(di->sv);
+        unsigned long die = bcdtonum(di->ev);
+        result += die - dis + 1;
+    }
+
+    return result;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 3
+#define TEST2_EXPECT 14
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (unsigned long v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (unsigned long v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day6.c

@@ -0,0 +1,228 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+ch input[] = {
+#embed "day6_input.txt"
+};
+
+static
+ch test[] = {
+#embed "day6_test.txt"
+};
+
+static
+num do_part1(size_t file_len, ch file[file_len]) {
+    ch *s = file;
+    num result = 0;
+
+    s = memchr(s, '\n', file_len);
+    num stride = s - file;
+
+    s = file;
+    while (*s != '+' && *s != '*') s += stride;
+    num heightb = (s - file);
+    num height  = (s - file) / stride;
+    ch *op = s;
+
+    // constructing a pointer more than 1 past the end of an array
+    // is UB, sadly, so we'll use offsets
+    num op_off = op - file;
+    s = file;
+    do {
+        num ledge_off = op_off - heightb;
+        if (s[op_off] == '+') {
+            num a = 0;
+            num rem = height;
+            do {
+                ch *t = s + ledge_off;
+                while (*t < '0') t++;
+                num b = grabnum(t, NULL);
+                a += b;
+                ledge_off += stride;
+                rem--;
+            } while (rem);
+            result += a;
+        } else if (s[op_off] == '*') {
+            num a = 1;
+            num rem = height;
+            do {
+                ch *t = s + ledge_off;
+                while (*t < '0') t++;
+                num b = grabnum(t, NULL);
+#if DBG
+                if (rem < height) { print("\t*\t"); }
+                printd(b);
+#endif
+                a *= b;
+                ledge_off += stride;
+                rem--;
+            } while (rem);
+            result += a;
+#if DBG
+            print("\t= "); printd(a); print("\n");
+#endif
+        }
+#if DBG
+        else {
+            print("INVALID OP\n");
+            exit_group(-1);
+        }
+#endif
+        op_off++;
+        while (op_off < file_len) {
+            if (s[op_off] == '+' || s[op_off] == '*')
+                break;
+            op_off++;
+        }
+    } while (op_off < file_len);
+
+    return result;
+}
+
+static
+num do_part2(size_t file_len, unsigned char file[file_len]) {
+    ch *s = file;
+    num result = 0;
+
+#if DBG
+    print("\n");
+#endif
+
+    s = memchr(s, '\n', file_len);
+    num stride = s - file;
+
+    s = file;
+    while (*s != '+' && *s != '*') s += stride;
+    num heightb = (s - file);
+    num height  = (s - file) / stride;
+    ch *op = s;
+
+#if DBG
+    print("STRIDE\t"); printd(stride); print("\n");
+    print("HEIGHT\t"); printd(height); print("\n");
+#endif
+
+    // constructing a pointer more than 1 past the end of an array
+    // is UB, sadly, so we'll use offsets
+    num fop_off = op - file;
+    num prev_op_off = fop_off + stride - 1;
+    s = file;
+    do {
+        // we don't need to do these in the same order as the example
+        // because both these operations are commutative.
+        // but you know what? we can anyway. for fun. and pretty output
+        num op_off = prev_op_off - 1;
+        while (s[op_off] != '+' && s[op_off] != '*' && s[op_off] != '\n')
+            op_off--;
+        num ledge_off = op_off - heightb;
+        num redge_off = (s[prev_op_off] == '\n' ? -1 : -2) + prev_op_off - heightb;
+        if (s[op_off] == '+') {
+            num a = 0;
+            num rem = redge_off - ledge_off + 1;
+            num frem = rem;
+            do {
+                num b = 0;
+                ch *t = s + redge_off;
+                for (num i = height; i; i--,t+=stride) {
+                    if (*t >= '0') {
+                        b *= 10;
+                        b += *t - '0';
+                    }
+                }
+#if DBG
+                if (rem < frem) { print("\t+\t"); }
+                printd(b);
+#endif
+                a += b;
+                redge_off--;
+                rem--;
+            } while (rem);
+            result += a;
+#if DBG
+            print("\t=\t"); printd(a); print("\n");
+#endif
+        } else if (s[op_off] == '*') {
+            num a = 1;
+            num rem = redge_off - ledge_off + 1;
+            num frem = rem;
+            do {
+                num b = 0;
+                ch *t = s + redge_off;
+                for (num i = height; i; i--,t+=stride) {
+                    if (*t >= '0') {
+                        b *= 10;
+                        b += *t - '0';
+                    }
+                }
+#if DBG
+                if (rem < frem) { print("\t*\t"); }
+                printd(b);
+#endif
+                a *= b;
+                redge_off--;
+                rem--;
+            } while (rem);
+            result += a;
+#if DBG
+            print("\t=\t"); printd(a); print("\n");
+#endif
+        }
+#if DBG
+        else {
+            print("INVALID OP\n");
+            exit_group(-1);
+        }
+#endif
+        prev_op_off = op_off;
+    } while (prev_op_off != fop_off);
+
+    return result;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 4277556
+#define TEST2_EXPECT 3263827
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day6pretty.c

@@ -0,0 +1,228 @@
+#include "lib.h"
+
+static
+ch input[] = {
+#embed "day6_input.txt"
+};
+
+static
+ch test[] = {
+#embed "day6_test.txt"
+};
+
+typedef struct { ch l[64]; } line;
+static_assert(sizeof(line) == 0x40);
+
+alignas(0x40) static
+struct {
+    line padstart[4];
+    struct { num pad[3]; num prev_op_off, op_off, ledge_off, redge_off, rem; };
+    union { line l; struct { ch s[16]; num op, pad0, pad1, v; }; } b;
+    union { line l; struct { ch s[16], pad0, sr[16], pad1; num v, vr; }; } a;
+    line padend;
+} m;
+static_assert(offsetof(typeof(m),b) % 64 == 0);
+static_assert(sizeof(m.b) == 64);
+static_assert(sizeof(m.a) == 64);
+static_assert(offsetof(typeof(m),padend) % 64 == 0);
+
+static
+num do_part1(size_t file_len, ch file[file_len]) {
+    ch *s = file;
+    m = (typeof(m)){ };
+
+    s = memchr(s, '\n', file_len);
+    const num stride = s - file;
+
+    s = file;
+    while (*s != '+' && *s != '*') s += stride;
+    const num heightb = (s - file);
+    const num height  = (s - file) / stride;
+    ch *const op = s;
+
+    // constructing a pointer more than 1 past the end of an array
+    // is UB, sadly, so we'll use offsets
+    m.op_off = op - file;
+    s = file;
+    do {
+        m.ledge_off = m.op_off - heightb;
+        if (s[m.op_off] == '+') {
+            m.a.v = 0;
+            m.rem = height;
+            m.b.op = '+' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+            do {
+                ch *t = s + m.ledge_off;
+                while (*t < '0') t++;
+                m.b.v = grabnum(t, NULL);
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v += m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.ledge_off += stride;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        } else if (s[m.op_off] == '*') {
+            m.a.v = 1;
+            m.rem = height;
+            m.b.op = '*' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+            do {
+                ch *t = s + m.ledge_off;
+                while (*t < '0') t++;
+                m.b.v = grabnum(t, NULL);
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v *= m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.ledge_off += stride;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        }
+        m.op_off++;
+        while (m.op_off < file_len) {
+            if (s[m.op_off] == '+' || s[m.op_off] == '*')
+                break;
+            m.op_off++;
+        }
+    } while (m.op_off < file_len);
+
+    return m.a.vr;
+}
+
+static
+num do_part2(size_t file_len, unsigned char file[file_len]) {
+    ch *s = file;
+    m = (typeof(m)){ };
+
+    s = memchr(s, '\n', file_len);
+    const num stride = s - file;
+
+    s = file;
+    while (*s != '+' && *s != '*') s += stride;
+    const num heightb = (s - file);
+    const num height  = (s - file) / stride;
+    ch *const op = s;
+
+    // constructing a pointer more than 1 past the end of an array
+    // is UB, sadly, so we'll use offsets
+    const num fop_off = op - file;
+    m.prev_op_off = fop_off + stride - 1;
+    s = file;
+    do {
+        // we don't need to do these in the same order as the example
+        // because both these operations are commutative.
+        // but you know what? we can anyway. for fun. and pretty output
+        {
+            num op_off = m.prev_op_off - 1;
+            while (s[op_off] != '+' && s[op_off] != '*' && s[op_off] != '\n')
+                op_off--;
+            m.op_off = op_off;
+        }
+        m.ledge_off = m.op_off - heightb;
+        m.redge_off = (s[m.prev_op_off] == '\n' ? -1 : -2) + m.prev_op_off - heightb;
+        if (s[m.op_off] == '+') {
+            m.a.v = 0;
+            m.rem = m.redge_off - m.ledge_off + 1;
+            const num frem = m.rem;
+
+            m.b.op = '+' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+
+            do {
+                m.b.v = 0;
+                ch *t = s + m.redge_off;
+                for (num i = height; i; i--,t+=stride) {
+                    if (*t >= '0') {
+                        m.b.v *= 10;
+                        m.b.v += *t - '0';
+                    }
+                }
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v += m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.redge_off--;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        } else if (s[m.op_off] == '*') {
+            m.a.v = 1;
+            m.rem = m.redge_off - m.ledge_off + 1;
+            const num frem = m.rem;
+
+            m.b.op = '*' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+
+            do {
+                m.b.v = 0;
+                ch *t = s + m.redge_off;
+                for (num i = height; i; i--,t+=stride) {
+                    if (*t >= '0') {
+                        m.b.v *= 10;
+                        m.b.v += *t - '0';
+                    }
+                }
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v *= m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.redge_off--;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        }
+
+        m.prev_op_off = m.op_off;
+    } while (m.prev_op_off != fop_off);
+
+    return m.a.vr;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 4277556
+#define TEST2_EXPECT 3263827
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day7.c

@@ -0,0 +1,178 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+ch input[32768] = {
+#embed "day7_input.txt"
+};
+
+static
+ch test[512] = {
+#embed "day7_test.txt"
+};
+
+typedef struct { ch l[64]; } line;
+static_assert(sizeof(line) == 0x40);
+
+alignas(0x40) static
+struct {
+    line padstart[4];
+    num file_stride;
+    num stride;
+    num _extra[6];
+    union { line l; struct { ch s[16]; num n; }; } result;
+    line padend;
+} m;
+static_assert(offsetof(typeof(m),result) % 64 == 0);
+static_assert(offsetof(typeof(m),padend) % 64 == 0);
+
+alignas(4096) ch buf1[256];
+alignas(4096) num buf[256];
+
+static
+num do_part1(size_t file_len, ch file[file_len]) {
+    m = (typeof(m)){ };
+    m.result.n = 0;
+#if DBG
+        pnl();
+#endif
+
+    memset(buf1, 0, sizeof(buf1));
+
+    m.file_stride = findc(file, '\n', file_len) - file;
+    num linecnt = (findc(file, 0, file_len) - file) / m.file_stride;
+#if DBG
+    print("stride "); printd(m.file_stride); pnl();
+    print("lines  "); printd(linecnt); pnl();
+#endif
+
+    num s_pos = findc(file, 'S', - 1) - 1 - file;
+    buf1[s_pos] = '|';
+    num line = 2;
+    do {
+        ch *l = file + line * m.file_stride;
+        for (num col = 0; col < m.file_stride - 1; col++) {
+            ch c = l[col];
+            if (c == '^') {
+                m.result.n += buf1[col] > 0;
+                buf1[col-1] |= buf1[col];
+                buf1[col+1] |= buf1[col];
+                buf1[col] = 0;
+            }
+        }
+#if DBG
+        for (num col = 0; col < m.file_stride; col++) {
+            if (buf1[col] == '|') print("|");
+            else if (l[col] == '^') print("^");
+            else print(" ");
+        }
+        pnl();
+#endif
+        line+=2;
+    } while (line < linecnt);
+
+    return m.result.n;
+}
+
+static
+num do_part2(size_t file_len, ch file[file_len]) {
+    m = (typeof(m)){ };
+#if DBG
+        pnl();
+#endif
+
+    memset(buf, 0, sizeof(buf));
+
+    m.file_stride = findc(file, '\n', file_len) - file;
+    num linecnt = (findc(file, 0, file_len) - file) / m.file_stride;
+#if DBG
+    print("stride "); printd(m.file_stride); pnl();
+    print("lines  "); printd(linecnt); pnl();
+#endif
+
+    num s_pos = findc(file, 'S', - 1) - 1 - file;
+    buf[s_pos] = 1;
+    num line = 2;
+    do {
+        ch *l = file + line * m.file_stride;
+        for (num col = 0; col < m.file_stride - 1; col++) {
+            ch c = l[col];
+            if (c == '^') {
+                buf[col-1] += buf[col];
+                buf[col+1] += buf[col];
+                buf[col] = 0;
+            }
+        }
+        for (num col = 0; col < m.file_stride; col++) {
+            num v = buf[col];
+#if DBG
+            if (l[col] == '^') print(" ");
+            else if (v >> 32) print("█");
+            else if (v >> 16) print("▓");
+            else if (v >>  8) print("▒");
+            else if (v >>  4) print("░");
+            else if (v >>  2) print("-");
+            else if (v >>  0) print(".");
+            else print(" ");
+#endif
+        }
+#if DBG
+        pnl();
+#endif
+        line+=2;
+    } while (line < linecnt);
+
+    m.result.n = 0;
+    for (num col = 0; col < m.file_stride; col++) {
+        m.result.n += buf[col];
+    }
+
+    return m.result.n;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 21
+#define TEST2_EXPECT 40
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

day8.c

@@ -0,0 +1,317 @@
+#include "lib.h"
+#include <stdlib.h>
+
+#define DBG 0
+
+static
+ch input[] = {
+#embed "day8_input.txt"
+};
+
+static
+ch test[] = {
+#embed "day8_test.txt"
+};
+
+
+typedef num point __attribute__((vector_size(4*sizeof(num))));
+
+alignas(64) static
+point positions[1000];
+
+alignas(64) static
+unsigned short circuits[1000];
+
+alignas(1024) static
+struct { num min_dist; unsigned short min_target; } targets[1000][1024];
+
+alignas(64) static
+unsigned short next_targets[1000];
+
+alignas(64) static
+num next_dists[1000];
+
+alignas(64) static
+unsigned short next_indices[1000];
+
+static
+int targetcompar(const void *a, const void *b) {
+    const num ad = ((typeof(**targets)*)a)->min_dist;
+    const num bd = ((typeof(**targets)*)b)->min_dist;
+    if (ad > bd) return 1;
+    else if (ad < bd) return -1;
+    else return 0;
+}
+
+static
+num do_part1(size_t file_len, ch file[file_len], bool istest) {
+    const num iters = istest ? 10 : 1000;
+    const num pointcount = istest ? 20 : 1000;
+    num iter = 0;
+#if DBG
+    pnl();
+#endif
+
+    // read in positions from file
+    { ch *s = file;
+    for (num i = 0; i < pointcount; i++) {
+        unsigned x = grabnum(s, &s);
+        s++;
+        unsigned y = grabnum(s, &s);
+        s++;
+        unsigned z = grabnum(s, &s);
+        s++;
+        positions[i] = (point){ x,y,z };
+    } }
+    // set up initial circuits
+    for (num i = 0; i < pointcount; i += 4) {
+        circuits[i+0] = i+0;
+        circuits[i+1] = i+1;
+        circuits[i+2] = i+2;
+        circuits[i+3] = i+3;
+    }
+    // find distances between all points
+    for (num i = 0; i < pointcount; i++) {
+        point pi = positions[i];
+        for (num j = 0; j < pointcount; j += 4) {
+            point pj0 = positions[j+0];
+            point pj1 = positions[j+1];
+            point pj2 = positions[j+2];
+            point pj3 = positions[j+3];
+
+            point dvp0 = (pi - pj0) * (pi - pj0);
+            point dvp1 = (pi - pj1) * (pi - pj1);
+            point dvp2 = (pi - pj2) * (pi - pj2);
+            point dvp3 = (pi - pj3) * (pi - pj3);
+
+            num d0 = dvp0[0] + dvp0[1] + dvp0[2] + dvp0[3];
+            num d1 = dvp1[0] + dvp1[1] + dvp1[2] + dvp1[3];
+            num d2 = dvp2[0] + dvp2[1] + dvp2[2] + dvp2[3];
+            num d3 = dvp3[0] + dvp3[1] + dvp3[2] + dvp3[3];
+
+            targets[i][j+0] = (typeof(**targets)) { d0, j+0 };
+            targets[i][j+1] = (typeof(**targets)) { d1, j+1 };
+            targets[i][j+2] = (typeof(**targets)) { d2, j+2 };
+            targets[i][j+3] = (typeof(**targets)) { d3, j+3 };
+        }
+        // sort targets. slow.
+        qsort(targets[i], pointcount, sizeof(**targets), targetcompar);
+    }
+    // set up initial next targets
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[i] = targets[i][1].min_target;
+        next_dists[i]   = targets[i][1].min_dist;
+        next_indices[i] = 1;
+    }
+
+    // FIXED JOIN ITERATIONS
+    do {
+        // find min dist
+        num min_dist = -1;
+        num min_i = 0;
+        for (num i = 0; i < pointcount; i++)
+            if (next_dists[i] < min_dist)
+                min_dist = next_dists[min_i = i];
+        num min_j = next_targets[min_i];
+        // -- join the pair --
+#if DBG
+        point ipos = positions[min_i];
+        point jpos = positions[min_j];
+        printd(ipos[0]); print(","); printd(ipos[1]); print(","); printd(ipos[2]);
+        print("\t->\t");
+        printd(jpos[0]); print(","); printd(jpos[1]); print(","); printd(jpos[2]);
+        pnl();
+#endif
+        // update circuits
+        unsigned old_circuit = circuits[min_j];
+        unsigned new_circuit = circuits[min_i];
+        if (old_circuit != new_circuit) {
+            for (num c = 0; c < pointcount; c++)
+                if (circuits[c] == old_circuit)
+                    circuits[c] = new_circuit;
+        }
+        // update targets
+        unsigned niidx = ++next_indices[min_i];
+        unsigned njidx = ++next_indices[min_j];
+        next_targets[min_i] = targets[min_i][niidx].min_target;
+        next_targets[min_j] = targets[min_j][njidx].min_target;
+        next_dists[min_i] = targets[min_i][niidx].min_dist;
+        next_dists[min_j] = targets[min_j][njidx].min_dist;
+
+        iter++;
+    } while(iter < iters);
+
+    // reuse next_targets to store circuit counts
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[i] = 0;
+    }
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[circuits[i]]++;
+    }
+    num circ0 = 0, circ1 = 0, circ2 = 0;
+    for (num i = 0; i < pointcount; i++) {
+        if (next_targets[i] > circ0) {
+            circ2 = circ1;
+            circ1 = circ0;
+            circ0 = next_targets[i];
+        } else if (next_targets[i] > circ1) {
+            circ2 = circ1;
+            circ1 = next_targets[i];
+        } else if (next_targets[i] > circ2) {
+            circ2 = next_targets[i];
+        }
+    }
+
+    return circ0 * circ1 * circ2;
+}
+
+static
+num do_part2(size_t file_len, ch file[file_len], bool istest) {
+    const num pointcount = istest ? 20 : 1000;
+#if DBG
+    pnl();
+#endif
+
+    // read in positions from file
+    { ch *s = file;
+    for (num i = 0; i < pointcount; i++) {
+        unsigned x = grabnum(s, &s);
+        s++;
+        unsigned y = grabnum(s, &s);
+        s++;
+        unsigned z = grabnum(s, &s);
+        s++;
+        positions[i] = (point){ x,y,z };
+    } }
+    // set up initial circuits
+    for (num i = 0; i < pointcount; i += 4) {
+        circuits[i+0] = i+0;
+        circuits[i+1] = i+1;
+        circuits[i+2] = i+2;
+        circuits[i+3] = i+3;
+    }
+    // find distances between all points
+    for (num i = 0; i < pointcount; i++) {
+        point pi = positions[i];
+        for (num j = 0; j < pointcount; j += 4) {
+            point pj0 = positions[j+0];
+            point pj1 = positions[j+1];
+            point pj2 = positions[j+2];
+            point pj3 = positions[j+3];
+
+            point dvp0 = (pi - pj0) * (pi - pj0);
+            point dvp1 = (pi - pj1) * (pi - pj1);
+            point dvp2 = (pi - pj2) * (pi - pj2);
+            point dvp3 = (pi - pj3) * (pi - pj3);
+
+            num d0 = dvp0[0] + dvp0[1] + dvp0[2] + dvp0[3];
+            num d1 = dvp1[0] + dvp1[1] + dvp1[2] + dvp1[3];
+            num d2 = dvp2[0] + dvp2[1] + dvp2[2] + dvp2[3];
+            num d3 = dvp3[0] + dvp3[1] + dvp3[2] + dvp3[3];
+
+            targets[i][j+0] = (typeof(**targets)) { d0, j+0 };
+            targets[i][j+1] = (typeof(**targets)) { d1, j+1 };
+            targets[i][j+2] = (typeof(**targets)) { d2, j+2 };
+            targets[i][j+3] = (typeof(**targets)) { d3, j+3 };
+        }
+        // sort targets. slow.
+        qsort(targets[i], pointcount, sizeof(**targets), targetcompar);
+    }
+    // set up initial next targets
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[i] = targets[i][1].min_target;
+        next_dists[i]   = targets[i][1].min_dist;
+        next_indices[i] = 1;
+    }
+
+    unsigned last_i = 0, last_j = 0;
+    // main iterations
+    do {
+        // find min dist
+        num min_dist = -1;
+        num min_i = 0;
+        for (num i = 0; i < pointcount; i++)
+            if (next_dists[i] < min_dist)
+                min_dist = next_dists[min_i = i];
+        num min_j = next_targets[min_i];
+        last_i = min_i;
+        last_j = min_j;
+        // -- join the pair --
+#if DBG
+        point ipos = positions[min_i];
+        point jpos = positions[min_j];
+        printd(ipos[0]); print(","); printd(ipos[1]); print(","); printd(ipos[2]);
+        print("\t->\t");
+        printd(jpos[0]); print(","); printd(jpos[1]); print(","); printd(jpos[2]);
+        pnl();
+#endif
+        // update circuits
+        unsigned old_circuit = circuits[min_j];
+        unsigned new_circuit = circuits[min_i];
+        if (old_circuit != new_circuit) {
+            bool done = true;
+            for (num c = 0; c < pointcount; c++) {
+                if (circuits[c] == old_circuit)
+                    circuits[c] = new_circuit;
+                if (circuits[c] != new_circuit)
+                    done = false;
+            }
+            if (done) break;
+        }
+        // update targets
+        unsigned niidx = ++next_indices[min_i];
+        unsigned njidx = ++next_indices[min_j];
+        next_targets[min_i] = targets[min_i][niidx].min_target;
+        next_targets[min_j] = targets[min_j][njidx].min_target;
+        next_dists[min_i] = targets[min_i][niidx].min_dist;
+        next_dists[min_j] = targets[min_j][njidx].min_dist;
+    } while(true);
+
+    return positions[last_i][0] * positions[last_j][0];
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 40
+#define TEST2_EXPECT 25272
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test, true); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input, false));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test, true); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input, false));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

lib.h

@@ -0,0 +1,288 @@
+#pragma once
+#include <stddef.h>
+#include <stdcountof.h>
+#include <stdint.h>
+#include <string.h>
+
+#define SYS_write 1
+#define SYS_exit_group 231
+
+#define STDOUT_FILENO 1
+
+static
+void write(uint64_t fileno, void *buffer, size_t len) {
+    uint64_t a,d;
+    asm volatile("syscall"
+        :"=a"(a),"=d"(d)
+        :"a"(SYS_write),"D"(fileno),"S"(buffer),"d"(len)
+        :"cc","memory","%rcx","%r11");
+}
+
+[[noreturn]] static
+void exit_group(uint64_t code) {
+    asm volatile(
+        "syscall\n"
+        "ud2"
+        ::"a"(SYS_exit_group),"D"(code));
+    for (;;);
+}
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+#define xstr(s) str(s)
+#define str(s) #s
+
+typedef uint64_t bcdint;
+typedef uint64_t num;
+typedef unsigned char ch;
+
+__attribute__((always_inline)) inline
+ch *findc(const ch *s, ch c, size_t n) {
+    uint64_t dispose;
+    void *d;
+    asm("repnz scasb":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
+    return d;
+}
+
+__attribute__((always_inline)) inline
+num *findnum(const num *s, num c, size_t n) {
+    uint64_t dispose;
+    void *d;
+    asm("repnz scasq":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
+    return d;
+}
+
+__attribute__((always_inline)) inline
+num *findnotnum(const num *s, num c, size_t n) {
+    uint64_t dispose;
+    void *d;
+    asm("repz scasq":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
+    return d;
+}
+
+static inline num alignnum(num v, num align) {
+    num extra = v % align;
+    num adjust = (align - extra) % align;
+    return v + adjust;
+}
+
+static
+void printns(size_t len, unsigned char chars[len]) {
+    write(STDOUT_FILENO, chars, len);
+}
+
+static 
+void printptr(uintptr_t v) {
+    char buf[sizeof(uintptr_t)*2] = { };
+    char *p = buf+countof(buf);
+    for (size_t i = 0; i < countof(buf); i++) {
+        p--;
+        if ((v & 0x0F) < 0xA) {
+            *p = '0' + (v & 0x0F);
+        } else {
+            *p = 'A' - 0xA + (v & 0x0F);
+        }
+        v >>= 4;
+    }
+    write(STDOUT_FILENO, p, countof(buf));
+}
+
+static
+void print_many_char(size_t len, char chars[len]) {
+    write(STDOUT_FILENO, chars, len);
+}
+
+#define print(string) print_many_char(sizeof(string)-1, string)
+#define pnl() print("\n")
+
+static
+void printd(unsigned long v) {
+    if (!v) {
+        print("0");
+        return;
+    }
+    char buf[32];
+    char *p = buf+32;
+    unsigned count = 0;
+    while (v) {
+        p--;
+        *p = '0' + (v % 10);
+        v /= 10;
+        count++;
+    }
+    write(STDOUT_FILENO, p, count);
+}
+
+static
+void snprintd(unsigned long v, size_t n, unsigned char d[n]) {
+    memset(d, 0, n);
+    if (!v) {
+        d[n-1] = '0';
+        return;
+    }
+    unsigned char *p = d+n;
+    unsigned count = 0;
+    while (v) {
+        p--;
+        *p = '0' + (v % 10);
+        v /= 10;
+        if (p == d) return;
+    }
+}
+
+static
+void printh(unsigned long v) {
+    if (!v) {
+        print("0");
+        return;
+    }
+    char buf[32];
+    char *p = buf+32;
+    unsigned count = 0;
+    while (v) {
+        p--;
+        if ((v & 0x0F) < 0xA) {
+            *p = '0' + (v & 0x0F);
+        } else {
+            *p = 'A' - 0xA + (v & 0x0F);
+        }
+        v >>= 4;
+        count++;
+    }
+    write(STDOUT_FILENO, p, count);
+}
+
+static
+void snprinth(unsigned long v, size_t n, unsigned char d[n]) {
+    memset(d, 0, n);
+    if (!v) {
+        d[n-1] = '0';
+        return;
+    }
+    unsigned char *p = d+n;
+    unsigned count = 0;
+    while (v) {
+        p--;
+        if ((v & 0x0F) < 0xA) {
+            *p = '0' + (v & 0x0F);
+        } else {
+            *p = 'A' - 0xA + (v & 0x0F);
+        }
+        v >>= 4;
+        if (p == d) return;
+    }
+}
+
+static
+void print_hex_char(unsigned char v) {
+    char buf[2];
+
+    if ((v >> 4) < 0x0A) {
+        buf[0] = '0' + (v >> 4);
+    } else {
+        buf[0] = 'A' - 0xA + (v >> 4);
+    }
+
+    if ((v & 0x0F) < 0xA) {
+        buf[1] = '0' + (v & 0x0F);
+    } else {
+        buf[1] = 'A' - 0xA + (v & 0x0F);
+    }
+
+    write(STDOUT_FILENO, buf, sizeof(buf));
+}
+
+static
+void print_pre_hex(size_t len, unsigned char prefix[len], unsigned long v) {
+    printns(len, prefix);
+    printh(v);
+}
+
+static
+void print_pre_ptr(size_t len, unsigned char prefix[len], void *ptr) {
+    printns(len, prefix);
+    printptr((uintptr_t)ptr);
+}
+
+#define print_watch_ptr(expr) print_pre_ptr(\
+        sizeof(#expr ": ")-1, (unsigned char*)(#expr ": "), expr)
+#define print_watch_hex(expr) print_pre_hex(\
+        sizeof(#expr ": ")-1, (unsigned char*)(#expr ": "), expr)
+
+static
+bcdint grabbcd(unsigned char *s, unsigned char **end) {
+    bcdint r = 0;
+    for (; *s >= '0' && *s <= '9'; s++)
+        r = (r << 4) + (*s - '0');
+    if (end) *end = s;
+    return r;
+}
+
+static
+unsigned long grabnum(unsigned char *s, unsigned char **end) {
+    unsigned long r = 0;
+    for (; *s >= '0' && *s <= '9'; s++)
+        r = r * 10 + (*s - '0');
+    if (end) *end = s;
+    return r;
+}
+
+// from wikipedia, the free encyclopedia
+// https://en.wikipedia.org/wiki/Binary-coded_decimal
+static bcdint bcdadd(bcdint a, bcdint b) {
+    bcdint t1, t2;
+    t1 = a + 0x0666666666666666;
+    t2 = t1 ^ b;
+    t1 = t1 + b;
+    t2 = t1 ^ t2;
+    t2 = ~t2 & 0x1111111111111110;
+    t2 = (t2 >> 2) | (t2 >> 3);
+    return t1 - t2;
+}
+
+// https://homepage.cs.uiowa.edu/~jones/bcd/bcd.html
+static bcdint bcdcomp(bcdint a) {
+    bcdint t1, t2, t3, t4, t5, t6;
+    t1 = 0xFFFFFFFFFFFFFFFF - a;
+    t2 = - a;
+    t3 = t1 ^ 0x0000000000000001;
+    t4 = t2 ^ t3;
+    t5 = ~t4 & 0x1111111111111110;
+    t6 = (t5 >> 2) | (t5 >> 3);
+    return t2 - t6;
+}
+
+static bcdint bcdsub(bcdint a, bcdint b) {
+    return bcdadd(a, bcdcomp(b));
+}
+
+static num bcdtonum(bcdint a) {
+    return 0
+        + ((a >>  0) & 0xF) * 1
+        + ((a >>  4) & 0xF) * 10
+        + ((a >>  8) & 0xF) * 100
+        + ((a >> 12) & 0xF) * 1000
+        + ((a >> 16) & 0xF) * 10000
+        + ((a >> 20) & 0xF) * 100000
+        + ((a >> 24) & 0xF) * 1000000
+        + ((a >> 28) & 0xF) * 10000000
+        + ((a >> 32) & 0xF) * 100000000
+        + ((a >> 36) & 0xF) * 1000000000
+        + ((a >> 40) & 0xF) * 10000000000
+        + ((a >> 44) & 0xF) * 100000000000
+        + ((a >> 48) & 0xF) * 1000000000000
+        + ((a >> 52) & 0xF) * 10000000000000
+        + ((a >> 56) & 0xF) * 100000000000000
+        + ((a >> 60) & 0xF) * 1000000000000000;
+}
+
+static bcdint numtobcd(num a) {
+    bcdint r = 0;
+    while (a) {
+        r <<= 4;
+        r |= (a % 10);
+        a /= 10;
+    }
+    return r;
+}

musl/COPYRIGHT

@@ -0,0 +1,193 @@
+musl as a whole is licensed under the following standard MIT license:
+
+----------------------------------------------------------------------
+Copyright © 2005-2020 Rich Felker, et al.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+----------------------------------------------------------------------
+
+Authors/contributors include:
+
+A. Wilcox
+Ada Worcester
+Alex Dowad
+Alex Suykov
+Alexander Monakov
+Andre McCurdy
+Andrew Kelley
+Anthony G. Basile
+Aric Belsito
+Arvid Picciani
+Bartosz Brachaczek
+Benjamin Peterson
+Bobby Bingham
+Boris Brezillon
+Brent Cook
+Chris Spiegel
+Clément Vasseur
+Daniel Micay
+Daniel Sabogal
+Daurnimator
+David Carlier
+David Edelsohn
+Denys Vlasenko
+Dmitry Ivanov
+Dmitry V. Levin
+Drew DeVault
+Emil Renner Berthing
+Fangrui Song
+Felix Fietkau
+Felix Janda
+Gianluca Anzolin
+Hauke Mehrtens
+He X
+Hiltjo Posthuma
+Isaac Dunham
+Jaydeep Patil
+Jens Gustedt
+Jeremy Huntwork
+Jo-Philipp Wich
+Joakim Sindholt
+John Spencer
+Julien Ramseier
+Justin Cormack
+Kaarle Ritvanen
+Khem Raj
+Kylie McClain
+Leah Neukirchen
+Luca Barbato
+Luka Perkov
+Lynn Ochs
+M Farkas-Dyck (Strake)
+Mahesh Bodapati
+Markus Wichmann
+Masanori Ogino
+Michael Clark
+Michael Forney
+Mikhail Kremnyov
+Natanael Copa
+Nicholas J. Kain
+orc
+Pascal Cuoq
+Patrick Oppenlander
+Petr Hosek
+Petr Skocik
+Pierre Carrier
+Reini Urban
+Rich Felker
+Richard Pennington
+Ryan Fairfax
+Samuel Holland
+Segev Finer
+Shiz
+sin
+Solar Designer
+Stefan Kristiansson
+Stefan O'Rear
+Szabolcs Nagy
+Timo Teräs
+Trutz Behn
+Will Dietz
+William Haddon
+William Pitcock
+
+Portions of this software are derived from third-party works licensed
+under terms compatible with the above MIT license:
+
+The TRE regular expression implementation (src/regex/reg* and
+src/regex/tre*) is Copyright © 2001-2008 Ville Laurikari and licensed
+under a 2-clause BSD license (license text in the source files). The
+included version has been heavily modified by Rich Felker in 2012, in
+the interests of size, simplicity, and namespace cleanliness.
+
+Much of the math library code (src/math/* and src/complex/*) is
+Copyright © 1993,2004 Sun Microsystems or
+Copyright © 2003-2011 David Schultz or
+Copyright © 2003-2009 Steven G. Kargl or
+Copyright © 2003-2009 Bruce D. Evans or
+Copyright © 2008 Stephen L. Moshier or
+Copyright © 2017-2018 Arm Limited
+and labelled as such in comments in the individual source files. All
+have been licensed under extremely permissive terms.
+
+The ARM memcpy code (src/string/arm/memcpy.S) is Copyright © 2008
+The Android Open Source Project and is licensed under a two-clause BSD
+license. It was taken from Bionic libc, used on Android.
+
+The AArch64 memcpy and memset code (src/string/aarch64/*) are
+Copyright © 1999-2019, Arm Limited.
+
+The implementation of DES for crypt (src/crypt/crypt_des.c) is
+Copyright © 1994 David Burren. It is licensed under a BSD license.
+
+The implementation of blowfish crypt (src/crypt/crypt_blowfish.c) was
+originally written by Solar Designer and placed into the public
+domain. The code also comes with a fallback permissive license for use
+in jurisdictions that may not recognize the public domain.
+
+The smoothsort implementation (src/stdlib/qsort.c) is Copyright © 2011
+Lynn Ochs and is licensed under an MIT-style license.
+
+The x86_64 port was written by Nicholas J. Kain and is licensed under
+the standard MIT terms.
+
+The mips and microblaze ports were originally written by Richard
+Pennington for use in the ellcc project. The original code was adapted
+by Rich Felker for build system and code conventions during upstream
+integration. It is licensed under the standard MIT terms.
+
+The mips64 port was contributed by Imagination Technologies and is
+licensed under the standard MIT terms.
+
+The powerpc port was also originally written by Richard Pennington,
+and later supplemented and integrated by John Spencer. It is licensed
+under the standard MIT terms.
+
+All other files which have no copyright comments are original works
+produced specifically for use as part of this library, written either
+by Rich Felker, the main author of the library, or by one or more
+contibutors listed above. Details on authorship of individual files
+can be found in the git version control history of the project. The
+omission of copyright and license comments in each file is in the
+interest of source tree size.
+
+In addition, permission is hereby granted for all public header files
+(include/* and arch/*/bits/*) and crt files intended to be linked into
+applications (crt/*, ldso/dlstart.c, and arch/*/crt_arch.h) to omit
+the copyright notice and permission notice otherwise required by the
+license, and to use these files without any requirement of
+attribution. These files include substantial contributions from:
+
+Bobby Bingham
+John Spencer
+Nicholas J. Kain
+Rich Felker
+Richard Pennington
+Stefan Kristiansson
+Szabolcs Nagy
+
+all of whom have explicitly granted such permission.
+
+This file previously contained text expressing a belief that most of
+the files covered by the above exception were sufficiently trivial not
+to be subject to copyright, resulting in confusion over whether it
+negated the permissions granted in the license. In the spirit of
+permissive licensing, and of not having licensing issues being an
+obstacle to adoption, that text has been removed.

musl/atomic.h

@@ -0,0 +1,333 @@
+#ifndef _ATOMIC_H
+#define _ATOMIC_H
+
+#include <stdint.h>
+
+#include "atomic_arch.h"
+
+#ifdef a_ll
+
+#ifndef a_pre_llsc
+#define a_pre_llsc()
+#endif
+
+#ifndef a_post_llsc
+#define a_post_llsc()
+#endif
+
+#ifndef a_cas
+#define a_cas a_cas
+static inline int a_cas(volatile int *p, int t, int s)
+{
+	int old;
+	a_pre_llsc();
+	do old = a_ll(p);
+	while (old==t && !a_sc(p, s));
+	a_post_llsc();
+	return old;
+}
+#endif
+
+#ifndef a_swap
+#define a_swap a_swap
+static inline int a_swap(volatile int *p, int v)
+{
+	int old;
+	a_pre_llsc();
+	do old = a_ll(p);
+	while (!a_sc(p, v));
+	a_post_llsc();
+	return old;
+}
+#endif
+
+#ifndef a_fetch_add
+#define a_fetch_add a_fetch_add
+static inline int a_fetch_add(volatile int *p, int v)
+{
+	int old;
+	a_pre_llsc();
+	do old = a_ll(p);
+	while (!a_sc(p, (unsigned)old + v));
+	a_post_llsc();
+	return old;
+}
+#endif
+
+#ifndef a_fetch_and
+#define a_fetch_and a_fetch_and
+static inline int a_fetch_and(volatile int *p, int v)
+{
+	int old;
+	a_pre_llsc();
+	do old = a_ll(p);
+	while (!a_sc(p, old & v));
+	a_post_llsc();
+	return old;
+}
+#endif
+
+#ifndef a_fetch_or
+#define a_fetch_or a_fetch_or
+static inline int a_fetch_or(volatile int *p, int v)
+{
+	int old;
+	a_pre_llsc();
+	do old = a_ll(p);
+	while (!a_sc(p, old | v));
+	a_post_llsc();
+	return old;
+}
+#endif
+
+#endif
+
+#ifdef a_ll_p
+
+#ifndef a_cas_p
+#define a_cas_p a_cas_p
+static inline void *a_cas_p(volatile void *p, void *t, void *s)
+{
+	void *old;
+	a_pre_llsc();
+	do old = a_ll_p(p);
+	while (old==t && !a_sc_p(p, s));
+	a_post_llsc();
+	return old;
+}
+#endif
+
+#endif
+
+#ifndef a_cas
+#error missing definition of a_cas
+#endif
+
+#ifndef a_swap
+#define a_swap a_swap
+static inline int a_swap(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, v) != old);
+	return old;
+}
+#endif
+
+#ifndef a_fetch_add
+#define a_fetch_add a_fetch_add
+static inline int a_fetch_add(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, (unsigned)old+v) != old);
+	return old;
+}
+#endif
+
+#ifndef a_fetch_and
+#define a_fetch_and a_fetch_and
+static inline int a_fetch_and(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, old&v) != old);
+	return old;
+}
+#endif
+#ifndef a_fetch_or
+#define a_fetch_or a_fetch_or
+static inline int a_fetch_or(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, old|v) != old);
+	return old;
+}
+#endif
+
+#ifndef a_and
+#define a_and a_and
+static inline void a_and(volatile int *p, int v)
+{
+	a_fetch_and(p, v);
+}
+#endif
+
+#ifndef a_or
+#define a_or a_or
+static inline void a_or(volatile int *p, int v)
+{
+	a_fetch_or(p, v);
+}
+#endif
+
+#ifndef a_inc
+#define a_inc a_inc
+static inline void a_inc(volatile int *p)
+{
+	a_fetch_add(p, 1);
+}
+#endif
+
+#ifndef a_dec
+#define a_dec a_dec
+static inline void a_dec(volatile int *p)
+{
+	a_fetch_add(p, -1);
+}
+#endif
+
+#ifndef a_store
+#define a_store a_store
+static inline void a_store(volatile int *p, int v)
+{
+#ifdef a_barrier
+	a_barrier();
+	*p = v;
+	a_barrier();
+#else
+	a_swap(p, v);
+#endif
+}
+#endif
+
+#ifndef a_barrier
+#define a_barrier a_barrier
+static inline void a_barrier()
+{
+	volatile int tmp = 0;
+	a_cas(&tmp, 0, 0);
+}
+#endif
+
+#ifndef a_spin
+#define a_spin a_barrier
+#endif
+
+#ifndef a_and_64
+#define a_and_64 a_and_64
+static inline void a_and_64(volatile uint64_t *p, uint64_t v)
+{
+	union { uint64_t v; uint32_t r[2]; } u = { v };
+	if (u.r[0]+1) a_and((int *)p, u.r[0]);
+	if (u.r[1]+1) a_and((int *)p+1, u.r[1]);
+}
+#endif
+
+#ifndef a_or_64
+#define a_or_64 a_or_64
+static inline void a_or_64(volatile uint64_t *p, uint64_t v)
+{
+	union { uint64_t v; uint32_t r[2]; } u = { v };
+	if (u.r[0]) a_or((int *)p, u.r[0]);
+	if (u.r[1]) a_or((int *)p+1, u.r[1]);
+}
+#endif
+
+#ifndef a_cas_p
+typedef char a_cas_p_undefined_but_pointer_not_32bit[-sizeof(char) == 0xffffffff ? 1 : -1];
+#define a_cas_p a_cas_p
+static inline void *a_cas_p(volatile void *p, void *t, void *s)
+{
+	return (void *)a_cas((volatile int *)p, (int)t, (int)s);
+}
+#endif
+
+#ifndef a_or_l
+#define a_or_l a_or_l
+static inline void a_or_l(volatile void *p, long v)
+{
+	if (sizeof(long) == sizeof(int)) a_or(p, v);
+	else a_or_64(p, v);
+}
+#endif
+
+#ifndef a_crash
+#define a_crash a_crash
+static inline void a_crash()
+{
+	*(volatile char *)0=0;
+}
+#endif
+
+#ifndef a_ctz_32
+#define a_ctz_32 a_ctz_32
+static inline int a_ctz_32(uint32_t x)
+{
+#ifdef a_clz_32
+	return 31-a_clz_32(x&-x);
+#else
+	static const char debruijn32[32] = {
+		0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
+		31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
+	};
+	return debruijn32[(x&-x)*0x076be629 >> 27];
+#endif
+}
+#endif
+
+#ifndef a_ctz_64
+#define a_ctz_64 a_ctz_64
+static inline int a_ctz_64(uint64_t x)
+{
+	static const char debruijn64[64] = {
+		0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
+		62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
+		63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
+		51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
+	};
+	if (sizeof(long) < 8) {
+		uint32_t y = x;
+		if (!y) {
+			y = x>>32;
+			return 32 + a_ctz_32(y);
+		}
+		return a_ctz_32(y);
+	}
+	return debruijn64[(x&-x)*0x022fdd63cc95386dull >> 58];
+}
+#endif
+
+static inline int a_ctz_l(unsigned long x)
+{
+	return (sizeof(long) < 8) ? a_ctz_32(x) : a_ctz_64(x);
+}
+
+#ifndef a_clz_64
+#define a_clz_64 a_clz_64
+static inline int a_clz_64(uint64_t x)
+{
+#ifdef a_clz_32
+	if (x>>32)
+		return a_clz_32(x>>32);
+	return a_clz_32(x) + 32;
+#else
+	uint32_t y;
+	int r;
+	if (x>>32) y=x>>32, r=0; else y=x, r=32;
+	if (y>>16) y>>=16; else r |= 16;
+	if (y>>8) y>>=8; else r |= 8;
+	if (y>>4) y>>=4; else r |= 4;
+	if (y>>2) y>>=2; else r |= 2;
+	return r | !(y>>1);
+#endif
+}
+#endif
+
+#ifndef a_clz_32
+#define a_clz_32 a_clz_32
+static inline int a_clz_32(uint32_t x)
+{
+	x >>= 1;
+	x |= x >> 1;
+	x |= x >> 2;
+	x |= x >> 4;
+	x |= x >> 8;
+	x |= x >> 16;
+	x++;
+	return 31-a_ctz_32(x);
+}
+#endif
+
+#endif

musl/atomic_arch.h

@@ -0,0 +1,123 @@
+#define a_cas a_cas
+static inline int a_cas(volatile int *p, int t, int s)
+{
+	__asm__ __volatile__ (
+		"lock ; cmpxchg %3, %1"
+		: "=a"(t), "=m"(*p) : "a"(t), "r"(s) : "memory" );
+	return t;
+}
+
+#define a_cas_p a_cas_p
+static inline void *a_cas_p(volatile void *p, void *t, void *s)
+{
+	__asm__( "lock ; cmpxchg %3, %1"
+		: "=a"(t), "=m"(*(void *volatile *)p)
+		: "a"(t), "r"(s) : "memory" );
+	return t;
+}
+
+#define a_swap a_swap
+static inline int a_swap(volatile int *p, int v)
+{
+	__asm__ __volatile__(
+		"xchg %0, %1"
+		: "=r"(v), "=m"(*p) : "0"(v) : "memory" );
+	return v;
+}
+
+#define a_fetch_add a_fetch_add
+static inline int a_fetch_add(volatile int *p, int v)
+{
+	__asm__ __volatile__(
+		"lock ; xadd %0, %1"
+		: "=r"(v), "=m"(*p) : "0"(v) : "memory" );
+	return v;
+}
+
+#define a_and a_and
+static inline void a_and(volatile int *p, int v)
+{
+	__asm__ __volatile__(
+		"lock ; and %1, %0"
+		: "=m"(*p) : "r"(v) : "memory" );
+}
+
+#define a_or a_or
+static inline void a_or(volatile int *p, int v)
+{
+	__asm__ __volatile__(
+		"lock ; or %1, %0"
+		: "=m"(*p) : "r"(v) : "memory" );
+}
+
+#define a_and_64 a_and_64
+static inline void a_and_64(volatile uint64_t *p, uint64_t v)
+{
+	__asm__ __volatile(
+		"lock ; and %1, %0"
+		 : "=m"(*p) : "r"(v) : "memory" );
+}
+
+#define a_or_64 a_or_64
+static inline void a_or_64(volatile uint64_t *p, uint64_t v)
+{
+	__asm__ __volatile__(
+		"lock ; or %1, %0"
+		 : "=m"(*p) : "r"(v) : "memory" );
+}
+
+#define a_inc a_inc
+static inline void a_inc(volatile int *p)
+{
+	__asm__ __volatile__(
+		"lock ; incl %0"
+		: "=m"(*p) : "m"(*p) : "memory" );
+}
+
+#define a_dec a_dec
+static inline void a_dec(volatile int *p)
+{
+	__asm__ __volatile__(
+		"lock ; decl %0"
+		: "=m"(*p) : "m"(*p) : "memory" );
+}
+
+#define a_store a_store
+static inline void a_store(volatile int *p, int x)
+{
+	__asm__ __volatile__(
+		"mov %1, %0 ; lock ; orl $0,(%%rsp)"
+		: "=m"(*p) : "r"(x) : "memory" );
+}
+
+#define a_barrier a_barrier
+static inline void a_barrier()
+{
+	__asm__ __volatile__( "" : : : "memory" );
+}
+
+#define a_spin a_spin
+static inline void a_spin()
+{
+	__asm__ __volatile__( "pause" : : : "memory" );
+}
+
+#define a_crash a_crash
+static inline void a_crash()
+{
+	__asm__ __volatile__( "hlt" : : : "memory" );
+}
+
+#define a_ctz_64 a_ctz_64
+static inline int a_ctz_64(uint64_t x)
+{
+	__asm__( "bsf %1,%0" : "=r"(x) : "r"(x) );
+	return x;
+}
+
+#define a_clz_64 a_clz_64
+static inline int a_clz_64(uint64_t x)
+{
+	__asm__( "bsr %1,%0 ; xor $63,%0" : "=r"(x) : "r"(x) );
+	return x;
+}

musl/memcpy.s

@@ -0,0 +1,25 @@
+.global memcpy
+.global __memcpy_fwd
+.hidden __memcpy_fwd
+.type memcpy,@function
+memcpy:
+__memcpy_fwd:
+	mov %rdi,%rax
+	cmp $8,%rdx
+	jc 1f
+	test $7,%edi
+	jz 1f
+2:	movsb
+	dec %rdx
+	test $7,%edi
+	jnz 2b
+1:	mov %rdx,%rcx
+	shr $3,%rcx
+	rep
+	movsq
+	and $7,%edx
+	jz 1f
+2:	movsb
+	dec %edx
+	jnz 2b
+1:	ret

musl/memset.s

@@ -0,0 +1,72 @@
+.global memset
+.type memset,@function
+memset:
+	movzbq %sil,%rax
+	mov $0x101010101010101,%r8
+	imul %r8,%rax
+
+	cmp $126,%rdx
+	ja 2f
+
+	test %edx,%edx
+	jz 1f
+
+	mov %sil,(%rdi)
+	mov %sil,-1(%rdi,%rdx)
+	cmp $2,%edx
+	jbe 1f
+
+	mov %ax,1(%rdi)
+	mov %ax,(-1-2)(%rdi,%rdx)
+	cmp $6,%edx
+	jbe 1f
+
+	mov %eax,(1+2)(%rdi)
+	mov %eax,(-1-2-4)(%rdi,%rdx)
+	cmp $14,%edx
+	jbe 1f
+
+	mov %rax,(1+2+4)(%rdi)
+	mov %rax,(-1-2-4-8)(%rdi,%rdx)
+	cmp $30,%edx
+	jbe 1f
+
+	mov %rax,(1+2+4+8)(%rdi)
+	mov %rax,(1+2+4+8+8)(%rdi)
+	mov %rax,(-1-2-4-8-16)(%rdi,%rdx)
+	mov %rax,(-1-2-4-8-8)(%rdi,%rdx)
+	cmp $62,%edx
+	jbe 1f
+
+	mov %rax,(1+2+4+8+16)(%rdi)
+	mov %rax,(1+2+4+8+16+8)(%rdi)
+	mov %rax,(1+2+4+8+16+16)(%rdi)
+	mov %rax,(1+2+4+8+16+24)(%rdi)
+	mov %rax,(-1-2-4-8-16-32)(%rdi,%rdx)
+	mov %rax,(-1-2-4-8-16-24)(%rdi,%rdx)
+	mov %rax,(-1-2-4-8-16-16)(%rdi,%rdx)
+	mov %rax,(-1-2-4-8-16-8)(%rdi,%rdx)
+
+1:	mov %rdi,%rax
+	ret
+
+2:	test $15,%edi
+	mov %rdi,%r8
+	mov %rax,-8(%rdi,%rdx)
+	mov %rdx,%rcx
+	jnz 2f
+
+1:	shr $3,%rcx
+	rep
+	stosq
+	mov %r8,%rax
+	ret
+
+2:	xor %edx,%edx
+	sub %edi,%edx
+	and $15,%edx
+	mov %rax,(%rdi)
+	mov %rax,8(%rdi)
+	sub %rdx,%rcx
+	add %rdx,%rdi
+	jmp 1b

musl/qsort.c

@@ -0,0 +1,219 @@
+/* Copyright (C) 2011 by Lynn Ochs
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/* Minor changes by Rich Felker for integration in musl, 2011-04-27. */
+
+/* Smoothsort, an adaptive variant of Heapsort.  Memory usage: O(1).
+   Run time: Worst case O(n log n), close to O(n) in the mostly-sorted case. */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "atomic.h"
+#define ntz(x) a_ctz_l((x))
+
+typedef int (*cmpfun)(const void *, const void *, void *);
+
+static inline int pntz(size_t p[2]) {
+	int r = ntz(p[0] - 1);
+	if(r != 0 || (r = 8*sizeof(size_t) + ntz(p[1])) != 8*sizeof(size_t)) {
+		return r;
+	}
+	return 0;
+}
+
+static void cycle(size_t width, unsigned char* ar[], int n)
+{
+	unsigned char tmp[256];
+	size_t l;
+	int i;
+
+	if(n < 2) {
+		return;
+	}
+
+	ar[n] = tmp;
+	while(width) {
+		l = sizeof(tmp) < width ? sizeof(tmp) : width;
+		memcpy(ar[n], ar[0], l);
+		for(i = 0; i < n; i++) {
+			memcpy(ar[i], ar[i + 1], l);
+			ar[i] += l;
+		}
+		width -= l;
+	}
+    ar[n] = 0;
+}
+
+/* shl() and shr() need n > 0 */
+static inline void shl(size_t p[2], int n)
+{
+	if(n >= 8 * sizeof(size_t)) {
+		n -= 8 * sizeof(size_t);
+		p[1] = p[0];
+		p[0] = 0;
+	}
+	p[1] <<= n;
+	p[1] |= p[0] >> (sizeof(size_t) * 8 - n);
+	p[0] <<= n;
+}
+
+static inline void shr(size_t p[2], int n)
+{
+	if(n >= 8 * sizeof(size_t)) {
+		n -= 8 * sizeof(size_t);
+		p[0] = p[1];
+		p[1] = 0;
+	}
+	p[0] >>= n;
+	p[0] |= p[1] << (sizeof(size_t) * 8 - n);
+	p[1] >>= n;
+}
+
+static void sift(unsigned char *head, size_t width, cmpfun cmp, void *arg, int pshift, size_t lp[])
+{
+	unsigned char *rt, *lf;
+	unsigned char *ar[14 * sizeof(size_t) + 1];
+	int i = 1;
+
+	ar[0] = head;
+	while(pshift > 1) {
+		rt = head - width;
+		lf = head - width - lp[pshift - 2];
+
+		if(cmp(ar[0], lf, arg) >= 0 && cmp(ar[0], rt, arg) >= 0) {
+			break;
+		}
+		if(cmp(lf, rt, arg) >= 0) {
+			ar[i++] = lf;
+			head = lf;
+			pshift -= 1;
+		} else {
+			ar[i++] = rt;
+			head = rt;
+			pshift -= 2;
+		}
+	}
+	cycle(width, ar, i);
+}
+
+static void trinkle(unsigned char *head, size_t width, cmpfun cmp, void *arg, size_t pp[2], int pshift, int trusty, size_t lp[])
+{
+	unsigned char *stepson,
+	              *rt, *lf;
+	size_t p[2];
+	unsigned char *ar[14 * sizeof(size_t) + 1];
+	int i = 1;
+	int trail;
+
+	p[0] = pp[0];
+	p[1] = pp[1];
+
+	ar[0] = head;
+	while(p[0] != 1 || p[1] != 0) {
+		stepson = head - lp[pshift];
+		if(cmp(stepson, ar[0], arg) <= 0) {
+			break;
+		}
+		if(!trusty && pshift > 1) {
+			rt = head - width;
+			lf = head - width - lp[pshift - 2];
+			if(cmp(rt, stepson, arg) >= 0 || cmp(lf, stepson, arg) >= 0) {
+				break;
+			}
+		}
+
+		ar[i++] = stepson;
+		head = stepson;
+		trail = pntz(p);
+		shr(p, trail);
+		pshift += trail;
+		trusty = 0;
+	}
+	if(!trusty) {
+		cycle(width, ar, i);
+		sift(head, width, cmp, arg, pshift, lp);
+	}
+}
+
+void qsort_r(void *base, size_t nel, size_t width, cmpfun cmp, void *arg)
+{
+	size_t lp[12*sizeof(size_t)];
+	size_t i, size = width * nel;
+	unsigned char *head, *high;
+	size_t p[2] = {1, 0};
+	int pshift = 1;
+	int trail;
+
+	if (!size) return;
+
+	head = base;
+	high = head + size - width;
+
+	/* Precompute Leonardo numbers, scaled by element width */
+	for(lp[0]=lp[1]=width, i=2; (lp[i]=lp[i-2]+lp[i-1]+width) < size; i++);
+
+	while(head < high) {
+		if((p[0] & 3) == 3) {
+			sift(head, width, cmp, arg, pshift, lp);
+			shr(p, 2);
+			pshift += 2;
+		} else {
+			if(lp[pshift - 1] >= high - head) {
+				trinkle(head, width, cmp, arg, p, pshift, 0, lp);
+			} else {
+				sift(head, width, cmp, arg, pshift, lp);
+			}
+
+			if(pshift == 1) {
+				shl(p, 1);
+				pshift = 0;
+			} else {
+				shl(p, pshift - 1);
+				pshift = 1;
+			}
+		}
+
+		p[0] |= 1;
+		head += width;
+	}
+
+	trinkle(head, width, cmp, arg, p, pshift, 0, lp);
+
+	while(pshift != 1 || p[0] != 1 || p[1] != 0) {
+		if(pshift <= 1) {
+			trail = pntz(p);
+			shr(p, trail);
+			pshift += trail;
+		} else {
+			shl(p, 2);
+			pshift -= 2;
+			p[0] ^= 7;
+			shr(p, 1);
+			trinkle(head - lp[pshift] - width, width, cmp, arg, p, pshift + 1, 1, lp);
+			shl(p, 1);
+			p[0] |= 1;
+			trinkle(head - width, width, cmp, arg, p, pshift, 1, lp);
+		}
+		head -= width;
+	}
+}

musl/qsort_nr.c

@@ -0,0 +1,16 @@
+#include <stdlib.h>
+
+typedef int (*cmpfun)(const void *, const void *);
+typedef int (*cmpfun_r)(const void *, const void *, cmpfun);
+void qsort_r(void *base, size_t nel, size_t width, cmpfun_r cmp, cmpfun arg);
+
+
+static int wrapper_cmp(const void *v1, const void *v2, cmpfun cmp)
+{
+	return cmp(v1, v2);
+}
+
+void qsort(void *base, size_t nel, size_t width, cmpfun cmp)
+{
+	qsort_r(base, nel, width, wrapper_cmp, cmp);
+}

start.s

@@ -0,0 +1,7 @@
+extern run
+global _start
+_start:
+sub rsp,0x1000
+and rsp,~0xfff
+call run
+ud2