diff options
Diffstat (limited to 'gcc-4.9/gcc/ree.c')
| -rw-r--r-- | gcc-4.9/gcc/ree.c | 131 |
1 files changed, 115 insertions, 16 deletions
diff --git a/gcc-4.9/gcc/ree.c b/gcc-4.9/gcc/ree.c index 435c16696..474c07089 100644 --- a/gcc-4.9/gcc/ree.c +++ b/gcc-4.9/gcc/ree.c @@ -261,6 +261,50 @@ typedef struct ext_cand static int max_insn_uid; +/* Update or remove REG_EQUAL or REG_EQUIV notes for INSN. */ + +static bool +update_reg_equal_equiv_notes (rtx insn, enum machine_mode new_mode, + enum machine_mode old_mode, enum rtx_code code) +{ + rtx *loc = ®_NOTES (insn); + while (*loc) + { + enum reg_note kind = REG_NOTE_KIND (*loc); + if (kind == REG_EQUAL || kind == REG_EQUIV) + { + rtx orig_src = XEXP (*loc, 0); + /* Update equivalency constants. Recall that RTL constants are + sign-extended. */ + if (GET_CODE (orig_src) == CONST_INT + && HOST_BITS_PER_WIDE_INT >= GET_MODE_BITSIZE (new_mode)) + { + if (INTVAL (orig_src) >= 0 || code == SIGN_EXTEND) + /* Nothing needed. */; + else + { + /* Zero-extend the negative constant by masking out the + bits outside the source mode. */ + rtx new_const_int + = gen_int_mode (INTVAL (orig_src) + & GET_MODE_MASK (old_mode), + new_mode); + if (!validate_change (insn, &XEXP (*loc, 0), + new_const_int, true)) + return false; + } + loc = &XEXP (*loc, 1); + } + /* Drop all other notes, they assume a wrong mode. */ + else if (!validate_change (insn, loc, XEXP (*loc, 1), true)) + return false; + } + else + loc = &XEXP (*loc, 1); + } + return true; +} + /* Given a insn (CURR_INSN), an extension candidate for removal (CAND) and a pointer to the SET rtx (ORIG_SET) that needs to be modified, this code modifies the SET rtx to a new SET rtx that extends the @@ -282,6 +326,7 @@ static bool combine_set_extension (ext_cand *cand, rtx curr_insn, rtx *orig_set) { rtx orig_src = SET_SRC (*orig_set); + enum machine_mode orig_mode = GET_MODE (SET_DEST (*orig_set)); rtx new_set; rtx cand_pat = PATTERN (cand->insn); @@ -318,9 +363,8 @@ combine_set_extension (ext_cand *cand, rtx curr_insn, rtx *orig_set) { /* Zero-extend the negative constant by masking out the bits outside the source mode. */ - enum machine_mode src_mode = GET_MODE (SET_DEST (*orig_set)); rtx new_const_int - = gen_int_mode (INTVAL (orig_src) & GET_MODE_MASK (src_mode), + = gen_int_mode (INTVAL (orig_src) & GET_MODE_MASK (orig_mode), GET_MODE (new_reg)); new_set = gen_rtx_SET (VOIDmode, new_reg, new_const_int); } @@ -359,7 +403,9 @@ combine_set_extension (ext_cand *cand, rtx curr_insn, rtx *orig_set) /* This change is a part of a group of changes. Hence, validate_change will not try to commit the change. */ - if (validate_change (curr_insn, orig_set, new_set, true)) + if (validate_change (curr_insn, orig_set, new_set, true) + && update_reg_equal_equiv_notes (curr_insn, cand->mode, orig_mode, + cand->code)) { if (dump_file) { @@ -409,7 +455,9 @@ transform_ifelse (ext_cand *cand, rtx def_insn) ifexpr = gen_rtx_IF_THEN_ELSE (cand->mode, cond, map_srcreg, map_srcreg2); new_set = gen_rtx_SET (VOIDmode, map_dstreg, ifexpr); - if (validate_change (def_insn, &PATTERN (def_insn), new_set, true)) + if (validate_change (def_insn, &PATTERN (def_insn), new_set, true) + && update_reg_equal_equiv_notes (def_insn, cand->mode, GET_MODE (dstreg), + cand->code)) { if (dump_file) { @@ -719,6 +767,17 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state) != REGNO (get_extended_src_reg (SET_SRC (PATTERN (cand->insn))))); if (copy_needed) { + /* Considering transformation of + (set (reg1) (expression)) + ... + (set (reg2) (any_extend (reg1))) + + into + + (set (reg2) (any_extend (expression))) + (set (reg1) (reg2)) + ... */ + /* In theory we could handle more than one reaching def, it just makes the code to update the insn stream more complex. */ if (state->defs_list.length () != 1) @@ -734,18 +793,6 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state) if (state->modified[INSN_UID (cand->insn)].kind != EXT_MODIFIED_NONE) return false; - /* Transformation of - (set (reg1) (expression)) - (set (reg2) (any_extend (reg1))) - into - (set (reg2) (any_extend (expression))) - (set (reg1) (reg2)) - is only valid for scalar integral modes, as it relies on the low - subreg of reg1 to have the value of (expression), which is not true - e.g. for vector modes. */ - if (!SCALAR_INT_MODE_P (GET_MODE (SET_DEST (PATTERN (cand->insn))))) - return false; - /* There's only one reaching def. */ rtx def_insn = state->defs_list[0]; @@ -954,6 +1001,7 @@ add_removable_extension (const_rtx expr, rtx insn, different extension. FIXME: this obviously can be improved. */ for (def = defs; def; def = def->next) if ((idx = def_map[INSN_UID (DF_REF_INSN (def->ref))]) + && idx != -1U && (cand = &(*insn_list)[idx - 1]) && cand->code != code) { @@ -965,6 +1013,57 @@ add_removable_extension (const_rtx expr, rtx insn, } return; } + /* For vector mode extensions, ensure that all uses of the + XEXP (src, 0) register are the same extension (both code + and to which mode), as unlike integral extensions lowpart + subreg of the sign/zero extended register are not equal + to the original register, so we have to change all uses or + none. */ + else if (VECTOR_MODE_P (GET_MODE (XEXP (src, 0)))) + { + if (idx == 0) + { + struct df_link *ref_chain, *ref_link; + + ref_chain = DF_REF_CHAIN (def->ref); + for (ref_link = ref_chain; ref_link; ref_link = ref_link->next) + { + if (ref_link->ref == NULL + || DF_REF_INSN_INFO (ref_link->ref) == NULL) + { + idx = -1U; + break; + } + rtx use_insn = DF_REF_INSN (ref_link->ref); + const_rtx use_set; + if (use_insn == insn || DEBUG_INSN_P (use_insn)) + continue; + if (!(use_set = single_set (use_insn)) + || !REG_P (SET_DEST (use_set)) + || GET_MODE (SET_DEST (use_set)) != GET_MODE (dest) + || GET_CODE (SET_SRC (use_set)) != code + || !rtx_equal_p (XEXP (SET_SRC (use_set), 0), + XEXP (src, 0))) + { + idx = -1U; + break; + } + } + if (idx == -1U) + def_map[INSN_UID (DF_REF_INSN (def->ref))] = idx; + } + if (idx == -1U) + { + if (dump_file) + { + fprintf (dump_file, "Cannot eliminate extension:\n"); + print_rtl_single (dump_file, insn); + fprintf (dump_file, + " because some vector uses aren't extension\n"); + } + return; + } + } /* Then add the candidate to the list and insert the reaching definitions into the definition map. */ |