diff options
Diffstat (limited to 'gcc/postreload.c')
| -rw-r--r-- | gcc/postreload.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/postreload.c b/gcc/postreload.c index 8abc90f83d9..3d4451c8a84 100644 --- a/gcc/postreload.c +++ b/gcc/postreload.c @@ -906,6 +906,42 @@ reload_combine (void) } } } + /* Look for (set (REGX) (CONST A)) + ... (MEM (PLUS (REGX) (const_int)))... + and convert it to + ... (MEM (CONST B))... . */ + if (set != NULL_RTX + && REG_P (SET_DEST (set)) + && (hard_regno_nregs[REGNO (SET_DEST (set))] + [GET_MODE (SET_DEST (set))] + == 1) + && CONSTANT_P (SET_SRC (set)) + && last_label_ruid < reg_state[REGNO (SET_DEST (set))].use_ruid + /* One use maximum - otherwise we'd de-cse. */ + && (reg_state[REGNO (SET_DEST (set))].use_index + == RELOAD_COMBINE_MAX_USES - 1)) + { + rtx reg = SET_DEST (set); + unsigned int regno = REGNO (reg); + rtx sum + = plus_constant (SET_SRC (set), INTVAL (reg_state[regno].offset)); + + if (GET_CODE (sum) == PLUS) + sum = gen_rtx_CONST (Pmode, sum); + i = RELOAD_COMBINE_MAX_USES - 1; + /* If we wanted to handle JUMP_INSNS, we'd have to fix up JUMP_LABEL. + (e.g. pr21728.c -Os). Doesn't seem worth the hassle. */ + if (!JUMP_P (reg_state[regno].reg_use[i].insn) + && validate_change (reg_state[regno].reg_use[i].insn, + reg_state[regno].reg_use[i].usep, sum, 0)) + { + /* Delete the reg set. */ + delete_insn (insn); + + reg_state[regno].use_index = RELOAD_COMBINE_MAX_USES; + continue; + } + } note_stores (PATTERN (insn), reload_combine_note_store, NULL); |