diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/sched.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/gcc/sched.c b/gcc/sched.c index 7f9c831f662..ac0b7a576fd 100644 --- a/gcc/sched.c +++ b/gcc/sched.c @@ -1940,11 +1940,16 @@ sched_analyze_2 (x, insn) rtx u; /* Traditional and volatile asm instructions must be considered to use - and clobber all hard registers and all of memory. So must - TRAP_IF and UNSPEC_VOLATILE operations. */ + and clobber all hard registers, all pseudo-registers and all of + memory. So must TRAP_IF and UNSPEC_VOLATILE operations. + + Consider for instance a volatile asm that changes the fpu rounding + mode. An insn should not be moved across this even if it only uses + pseudo-regs because it might give an incorrectly rounded result. */ if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) { - for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + int max_reg = max_reg_num (); + for (i = 0; i < max_reg; i++) { for (u = reg_last_uses[i]; u; u = XEXP (u, 1)) add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); |