At 07 Jul 2006 10:32:28 -0700, Ian Lance Taylor wrote: > > Simon Kagstrom <simon.kagstrom@xxxxxx> writes: > > > So, I used the -fno-delayed-branch instruction when compiling, which > > is documented as > > [...] > > This looks like a bug to me. You may want to open a bug report; see > http://gcc.gnu.org/bugs.html > > I suspect the bug is that -fdelayed-branch is failing to pass -O0 to > the assembler. Try compiling with -Wa,-O0. Unfortunately there was no difference with -Wa,-O0. It does however look like the use of Linux-style syscalls break the -fno-delayed-branch behavior. I have code like #define _syscall1(type,name,atype,a) \ type name(atype a) \ { \ register unsigned long __a0 asm("$4") = (unsigned long) a; \ register unsigned long __v0 asm("$2"); \ \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ "li\t$2, %2\t\t\t# " #name "\n\t" \ "syscall\n\t" \ ".set\treorder" \ : "=&r" (__v0) \ : "r" (__a0), "i" (__NR_##name) \ ); \ \ return (type) __v0; \ } #define __NR_exit 0 static inline _syscall1(void,exit , int, code ); and with the call of exit(...), the delay slots are filled with instructions. If I just define a plain function and call that, -fno-delayed-branch seems to behave correctly. Anyway, I've submitted a bug report at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28325 Thanks for the input! // Simon
