diff options
Diffstat (limited to 'gcc/gcse.c')
| -rw-r--r-- | gcc/gcse.c | 11 |
1 files changed, 9 insertions, 2 deletions
@@ -4054,7 +4054,9 @@ cprop_jump (bb, setcc, jump, from, src) /* First substitute in the INSN condition as the SET_SRC of the JUMP, then substitute that given values in this expanded JUMP. */ - if (setcc != NULL) + if (setcc != NULL + && !modified_between_p (from, setcc, jump) + && !modified_between_p (src, setcc, jump)) { rtx setcc_set = single_set (setcc); new_set = simplify_replace_rtx (SET_SRC (set), @@ -4068,7 +4070,7 @@ cprop_jump (bb, setcc, jump, from, src) /* If no simplification can be made, then try the next register. */ - if (rtx_equal_p (new, new_set)) + if (rtx_equal_p (new, new_set) || rtx_equal_p (new, SET_SRC (set))) return 0; /* If this is now a no-op delete it, otherwise this must be a valid insn. */ @@ -4076,6 +4078,11 @@ cprop_jump (bb, setcc, jump, from, src) delete_insn (jump); else { + /* Ensure the value computed inside the jump insn to be equivalent + to one computed by setcc. */ + if (setcc + && modified_in_p (new, setcc)) + return 0; if (! validate_change (jump, &SET_SRC (set), new, 0)) return 0; |