Update fastmod.h

lemire · Jan 31, 2024 · 74063e0 · 74063e0
1 parent 3c1bc44
commit 74063e0
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/include/fastmod.h b/include/fastmod.h
@@ -40,6 +40,7 @@ FASTMOD_API uint64_t mul128_u32(uint64_t lowbits, uint32_t d) {
   return __umulh(lowbits, d);
 }
 FASTMOD_API uint64_t mul128_s32(uint64_t lowbits, int32_t d) {
+  // not equivalent to ((__int128_t)lowbits * d) >> 64
   return __mulh(lowbits, d);
 }