Hi, Using this simple test program: int main (int argc, char *argv[]) { int i; int test[8];
__builtin_prefetch (test, 1); for (i = 0; i < 8; i++) { test[i] = i; } return 0; } And compiling using gcc -S test.c, the generated .s file includes the following assembly code: .LCFI1: movl %edi, -52(%rbp) movq %rsi, -64(%rbp) leaq -48(%rbp), %rax prefetchw (%rax) movl $0, -4(%rbp) jmp .L2 .L3: prefetchw is a 3Dnow! instruction, not available on EMT64. -- GCC emits 3DNow!-specific instruction for __builtin_prefetch https://launchpad.net/bugs/66702 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs