diff options
Diffstat (limited to 'gcc/postreload.c')
| -rw-r--r-- | gcc/postreload.c | 35 |
1 files changed, 15 insertions, 20 deletions
diff --git a/gcc/postreload.c b/gcc/postreload.c index 01e1f17ce04..cf165ec5f0f 100644 --- a/gcc/postreload.c +++ b/gcc/postreload.c @@ -815,22 +815,19 @@ reload_combine (void) rtx prev = prev_nonnote_insn (insn); rtx prev_set = prev ? single_set (prev) : NULL_RTX; unsigned int regno = REGNO (reg); - rtx const_reg = NULL_RTX; + rtx index_reg = NULL_RTX; rtx reg_sum = NULL_RTX; - /* Now, we need an index register. - We'll set index_reg to this index register, const_reg to the - register that is to be loaded with the constant - (denoted as REGZ in the substitution illustration above), - and reg_sum to the register-register that we want to use to - substitute uses of REG (typically in MEMs) with. - First check REG and BASE for being index registers; - we can use them even if they are not dead. */ + /* Now we need to set INDEX_REG to an index register (denoted as + REGZ in the illustration above) and REG_SUM to the expression + register+register that we want to use to substitute uses of REG + (typically in MEMs) with. First check REG and BASE for being + index registers; we can use them even if they are not dead. */ if (TEST_HARD_REG_BIT (reg_class_contents[INDEX_REG_CLASS], regno) || TEST_HARD_REG_BIT (reg_class_contents[INDEX_REG_CLASS], REGNO (base))) { - const_reg = reg; + index_reg = reg; reg_sum = plus; } else @@ -847,9 +844,7 @@ reload_combine (void) && reg_state[i].store_ruid <= reg_state[regno].use_ruid && hard_regno_nregs[i][GET_MODE (reg)] == 1) { - rtx index_reg = gen_rtx_REG (GET_MODE (reg), i); - - const_reg = index_reg; + index_reg = gen_rtx_REG (GET_MODE (reg), i); reg_sum = gen_rtx_PLUS (GET_MODE (reg), index_reg, base); break; } @@ -859,19 +854,19 @@ reload_combine (void) /* Check that PREV_SET is indeed (set (REGX) (CONST_INT)) and that (REGY), i.e. BASE, is not clobbered before the last use we'll create. */ - if (prev_set != 0 + if (reg_sum + && prev_set && CONST_INT_P (SET_SRC (prev_set)) && rtx_equal_p (SET_DEST (prev_set), reg) && reg_state[regno].use_index >= 0 && (reg_state[REGNO (base)].store_ruid - <= reg_state[regno].use_ruid) - && reg_sum != 0) + <= reg_state[regno].use_ruid)) { int i; - /* Change destination register and, if necessary, the - constant value in PREV, the constant loading instruction. */ - validate_change (prev, &SET_DEST (prev_set), const_reg, 1); + /* Change destination register and, if necessary, the constant + value in PREV, the constant loading instruction. */ + validate_change (prev, &SET_DEST (prev_set), index_reg, 1); if (reg_state[regno].offset != const0_rtx) validate_change (prev, &SET_SRC (prev_set), @@ -900,7 +895,7 @@ reload_combine (void) remove_reg_equal_equiv_notes (prev); reg_state[regno].use_index = RELOAD_COMBINE_MAX_USES; - reg_state[REGNO (const_reg)].store_ruid + reg_state[REGNO (index_reg)].store_ruid = reload_combine_ruid; continue; } |