day 7

day0.h

@@ -12,27 +12,36 @@ 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]) {
-    ch *s = file;
+    m = (typeof(m)){ };
-    num result = 0;
+    m.s = file;
+    m.result.n = 0;
 
 #if DBG
     print("\n");
 #endif
 
 do {
-    s++;
+    m.s++;
-} while (s != &file[file_len]);
+} while (m.s != &file[file_len]);
 
-    return result;
+    return m.result.n;
 }
 
 static
 num do_part2(size_t file_len, ch file[file_len]) {
-    num result = 0;
+    return 0;
-    return result;
 }
 
 #define RUN_TEST1 1

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);
+}

lib.h

@@ -9,14 +9,6 @@
 
 #define STDOUT_FILENO 1
 
-__attribute__((always_inline))
-void *memchr(const void *s, int 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;
-}
-
 static
 void write(uint64_t fileno, void *buffer, size_t len) {
     uint64_t a,d;
@@ -45,6 +37,36 @@ 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);
@@ -72,6 +94,7 @@ void print_many_char(size_t len, char chars[len]) {
 }
 
 #define print(string) print_many_char(sizeof(string)-1, string)
+#define pnl() print("\n")
 
 static
 void printd(unsigned long v) {