diff options
Diffstat (limited to 'gcc/alias.c')
| -rw-r--r-- | gcc/alias.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/gcc/alias.c b/gcc/alias.c index 0943444185a..025da501a42 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -102,10 +102,14 @@ find_base_value (src) if (REGNO (src) < FIRST_PSEUDO_REGISTER && copying_arguments) return new_reg_base_value[REGNO (src)]; - /* If this REG is related to a known base value, return it. - This must happen after the arg register check above to avoid - circular set chains. */ - if (reg_base_value[REGNO (src)]) + /* If a pseudo has a known base value, return it. Do not do this + for hard regs since it can result in a circular dependency + chain for registers which have values at function entry. + + The test above is not sufficient because the scheduler may move + a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ + if (REGNO (src) >= FIRST_PSEUDO_REGISTER + && reg_base_value[REGNO (src)]) return reg_base_value[REGNO (src)]; return src; |