Extended Description

On my PowerBook G4, compiling this program:

#include <stdio.h>

int main()
{
unsigned long int ctz_x = 0x0000f000;
unsigned long int ctz_c;

asm("{cntlz|cntlzw} %0,%1"
: "=r" (ctz_c)
: "r" (ctz_x & -ctz_x));

printf("ctz_c == %d\n", ctz_c);
return 0;
}

results in the use of the mnemonic "cntlz" instead of "cntlzw". This produces an error when trying to
assemble the program:

cntlzw_miscompile.s:25:Invalid mnemonic 'cntlz'

GCC outputs "cntlzw" instead.

-bw