diff options
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/gcse.c | 26 |
2 files changed, 24 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b8c4d6f..9fb8927 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2003-02-23 Kazu Hirata <kazu@cs.umass.edu> + + * gcse.c (cprop_jump): Use the REG_EQUAL note if available. + 2003-02-23 Kaveh R. Ghazi <ghazi@caip.rutgers.edu> * doc/invoke.texi (ggc-min-expand, ggc-min-heapsize): Document @@ -4058,19 +4058,33 @@ cprop_jump (bb, setcc, jump, from, src) && !modified_between_p (src, setcc, jump)) { rtx setcc_set = single_set (setcc); + rtx note = find_reg_equal_equiv_note (setcc); + /* Use REG_EQUAL note if available. */ + rtx setcc_set_src = (note == 0) ? SET_SRC (setcc_set) : XEXP (note, 0); + new_set = simplify_replace_rtx (SET_SRC (set), SET_DEST (setcc_set), - SET_SRC (setcc_set)); + setcc_set_src); } else new_set = set; - new = simplify_replace_rtx (new_set, from, src); + /* If NEW_SET is simplified down to either a label or a no-op, we + don't have to replace FROM with SRC, but we still have to either + turn JUMP to an unconditional branch or remove the no-op. This + can happen if JUMP is simplified using the REG_EQUAL note in + SETCC. */ + if (GET_CODE (new_set) == LABEL_REF || new_set == pc_rtx) + new = new_set; + else + { + new = simplify_replace_rtx (new_set, from, src); - /* If no simplification can be made, then try the next - register. */ - if (rtx_equal_p (new, new_set) || rtx_equal_p (new, SET_SRC (set))) - return 0; + /* If no simplification can be made, then try the next + register. */ + 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. */ if (new == pc_rtx) |