diff options
Diffstat (limited to 'gcc/postreload.c')
| -rw-r--r-- | gcc/postreload.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/gcc/postreload.c b/gcc/postreload.c index 886d024926c..5c189129445 100644 --- a/gcc/postreload.c +++ b/gcc/postreload.c @@ -1312,11 +1312,21 @@ reload_combine (void) is and then later disable any optimization that would cross it. */ if (LABEL_P (insn)) last_label_ruid = reload_combine_ruid; - else if (BARRIER_P (insn) - || (INSN_P (insn) && volatile_insn_p (PATTERN (insn)))) - for (r = 0; r < FIRST_PSEUDO_REGISTER; r++) - if (! fixed_regs[r]) + else if (BARRIER_P (insn)) + { + /* Crossing a barrier resets all the use information. */ + for (r = 0; r < FIRST_PSEUDO_REGISTER; r++) + if (! fixed_regs[r]) reg_state[r].use_index = RELOAD_COMBINE_MAX_USES; + } + else if (INSN_P (insn) && volatile_insn_p (PATTERN (insn))) + /* Optimizations across insns being marked as volatile must be + prevented. All the usage information is invalidated + here. */ + for (r = 0; r < FIRST_PSEUDO_REGISTER; r++) + if (! fixed_regs[r] + && reg_state[r].use_index != RELOAD_COMBINE_MAX_USES) + reg_state[r].use_index = -1; if (! NONDEBUG_INSN_P (insn)) continue; |