Tweaked.

1 files changed, 6 insertions, 5 deletions

diff --git a/stc/cstr.h b/stc/cstr.h
index b1f2c11d..42c0648f 100644
--- a/stc/cstr.h
+++ b/stc/cstr.h
@@ -398,13 +398,14 @@ STC_DEF void*
 c_memccpy(void* dst, const void* src, int c, size_t n) {

     enum {w = sizeof(uintptr_t)};

     #define _mc_z (~(uintptr_t)0/255)

-    const uint8_t* s = (const uint8_t *) src; uint8_t *d = (uint8_t *) dst, *e = d + n;

-    for (uintptr_t x; d + (w*2) <= e; s += w, d += w) {

-        memcpy(&x, s, w);

-        if (((x - _mc_z) & ~x & _mc_z*128) ^ (_mc_z*(uint8_t) c)) break; // hasvalue

+    const uint8_t* s = (const uint8_t *) src; 

+    uint8_t *d = (uint8_t *) dst, *end = d + n;

+    for (uintptr_t x; d + w <= end; s += w, d += w) {

+        memcpy(&x, s, w); /* check if x contains c: */

+        if (((x - _mc_z) & ~x & _mc_z*128) ^ (_mc_z*(uint8_t) c)) break;

         memcpy(d, &x, w);

     }

-    while (d < e) if ((*d++ = *s++) == (uint8_t) c) return d;

+    while (d < end) if ((*d++ = *s++) == (uint8_t) c) return d;

     return NULL;

 }