Reduce GNU Make latency 17% for cosmo

fgets() is now 4x faster which makes Make 2% faster. Landlock Make now
has a builtin $(uniq ...) function that uses critbit trees rather than
functional programming. Since uniq is the most important function this
optimization makes our cold start latency 15% faster.

.gitignore

@@ -11,3 +11,5 @@ __pycache__
 /TAGS
 /bx_enh_dbg.ini
 /tool/emacs/*.elc
+/perf.data
+/perf.data.old

build/functions.mk

@@ -12,5 +12,9 @@
 
 tail = $(wordlist 2,$(words $1),$1)
 reverse = $(if $1,$(call reverse,$(call tail,$1)) $(firstword $1))
-uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))
 uniqr = $(if $1,$(call uniqr,$(filter-out $(firstword $1),$1)) $(firstword $1))
+
+# polyfill uniq native (landlock make 1.4)
+ifneq ($(call uniq,c b c a),c b a)
+uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))
+endif

libc/stdio/fgets_unlocked.c

@@ -16,8 +16,12 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/macros.internal.h"
 #include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
 
 /**
  * Reads line from stream.
@@ -33,20 +37,33 @@
  *     zero characters have been read
  */
 char *fgets_unlocked(char *s, int size, FILE *f) {
-  int c;
-  char *p;
+  int c, n;
+  char *p, *b, *t;
   p = s;
   if (size > 0) {
     while (--size > 0) {
-      if ((c = fgetc_unlocked(f)) == -1) {
-        if (ferror_unlocked(f) == EINTR) {
-          continue;
-        } else {
-          break;
+      if (!IsTiny() && f->beg < f->end) {
+        b = f->buf + f->beg;
+        n = MIN(f->end - f->beg, size);
+        if ((t = memchr(b, '\n', n))) {
+          n = t + 1 - b;
         }
+        memcpy(p, b, n);
+        f->beg += n;
+        size -= n - 1;
+        p += n;
+        if (t) break;
+      } else {
+        if ((c = fgetc_unlocked(f)) == -1) {
+          if (ferror_unlocked(f) == EINTR) {
+            continue;
+          } else {
+            break;
+          }
+        }
+        *p++ = c & 255;
+        if (c == '\n') break;
       }
-      *p++ = c & 255;
-      if (c == '\n') break;
     }
     *p = '\0';
   }

test/libc/stdio/fgets_test.c

@@ -19,6 +19,7 @@
 #include "libc/mem/mem.h"
 #include "libc/runtime/gc.internal.h"
 #include "libc/stdio/stdio.h"
+#include "libc/testlib/ezbench.h"
 #include "libc/testlib/hyperion.h"
 #include "libc/testlib/testlib.h"
 
@@ -31,3 +32,19 @@ TEST(fgets, test) {
   ASSERT_STREQ("John Keats\n", fgets(buf, sizeof(buf), f));
   fclose(f);
 }
+
+void Benchmark(void) {
+  FILE *f;
+  char *line;
+  char buf[512];
+  f = fmemopen(gc(strdup(kHyperion)), kHyperionSize, "r+");
+  for (;;) {
+    line = fgets(buf, sizeof(buf), f);
+    if (!line) break;
+  }
+  fclose(f);
+}
+
+BENCH(fgets, bench) {
+  EZBENCH2("fgets", donothing, Benchmark());
+}

third_party/make/commands.c

@@ -520,6 +520,7 @@ fatal_error_signal (int sig)
   if (sig == SIGTERM || sig == SIGINT
     || sig == SIGHUP
     || sig == SIGQUIT
+    || sig == SIGPIPE
     )
     {
       struct child *c;

third_party/make/expand.c

@@ -441,7 +441,8 @@ expand_argument (const char *str, const char *end)
 
   r = allocated_variable_expand (tmp);
 
-  free (alloc);
+  if (alloc)
+    free (alloc);
 
   return r;
 }

third_party/make/function.c

@@ -23,6 +23,9 @@ this program.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "third_party/make/job.h"
 #include "third_party/make/os.h"
 #include "third_party/make/commands.h"
+#include "libc/mem/critbit0.h"
+#include "libc/log/rop.h"
+#include "libc/runtime/runtime.h"
 #include "third_party/make/debug.h"
 
 struct function_table_entry
@@ -1160,6 +1163,45 @@ func_sort (char *o, char **argv, const char *funcname UNUSED)
   return o;
 }
 
+/*
+  chop argv[0] into words, and remove duplicates.
+ */
+static char *
+func_uniq (char *o, char **argv, const char *funcname UNUSED)
+{
+  char *p;
+  size_t len;
+  int mutated;
+  bool once = false;
+  const char *s = argv[0];
+  struct critbit0 t = {0};
+
+  while ((p = find_next_token (&s, &len)))
+    {
+      ++s;
+      p[len] = 0;
+      RETURN_ON_ERROR ((mutated = critbit0_insert (&t, p)));
+      if (mutated)
+        {
+          if (once)
+            o = variable_buffer_output (o, " ", 1);
+          else
+            once = true;
+          o = variable_buffer_output (o, p, len);
+        }
+    }
+
+  critbit0_clear (&t);
+
+  return o;
+
+OnError:
+  critbit0_clear (&t);
+  OSS (error, NILF, "%s: function failed: %s",
+       "uniq", strerror (errno));
+  exit (1);
+}
+
 /*
   $(if condition,true-part[,false-part])
 
@@ -2137,6 +2179,7 @@ static struct function_table_entry function_table_init[] =
   FT_ENTRY ("value",         0,  1,  1,  func_value),
   FT_ENTRY ("eval",          0,  1,  1,  func_eval),
   FT_ENTRY ("file",          1,  2,  1,  func_file),
+  FT_ENTRY ("uniq",          0,  1,  1,  func_uniq),
 #ifdef EXPERIMENTAL
   FT_ENTRY ("eq",            2,  2,  1,  func_eq),
   FT_ENTRY ("not",           0,  1,  1,  func_not),