diff --git a/gcc/ree.cc b/gcc/ree.cc index fc04249fa84..2025a7c43da 100644 --- a/gcc/ree.cc +++ b/gcc/ree.cc @@ -514,7 +514,8 @@ get_uses (rtx_insn *insn, rtx reg) if (REGNO (DF_REF_REG (def)) == REGNO (reg)) break; - gcc_assert (def != NULL); + if (def == NULL) + return NULL; ref_chain = DF_REF_CHAIN (def); @@ -750,6 +751,120 @@ get_extended_src_reg (rtx src) return src; } +/* Return TRUE if target mode is equal to source mode of zero_extend + or sign_extend otherwise false. */ + +static bool +abi_target_promote_function_mode (machine_mode mode) +{ + int unsignedp; + machine_mode tgt_mode = + targetm.calls.promote_function_mode (NULL_TREE, mode, &unsignedp, + NULL_TREE, 1); + + if (tgt_mode == mode) + return true; + else + return false; +} + +/* Return TRUE if the candidate insn is zero extend and regno is + an return registers. */ + +static bool +abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno) +{ + rtx set = single_set (insn); + + if (GET_CODE (SET_SRC (set)) != ZERO_EXTEND) + return false; + + if (FUNCTION_VALUE_REGNO_P (regno)) + return true; + + return false; +} + +/* Return TRUE if reg source operand of zero_extend is argument registers + and not return registers and source and destination operand are same + and mode of source and destination operand are not same. */ + +static bool +abi_extension_candidate_p (rtx_insn *insn) +{ + rtx set = single_set (insn); + + if (GET_CODE (SET_SRC (set)) != ZERO_EXTEND) + return false; + + machine_mode ext_dst_mode = GET_MODE (SET_DEST (set)); + rtx orig_src = XEXP (SET_SRC (set),0); + + bool copy_needed + = (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0))); + + if (!copy_needed && ext_dst_mode != GET_MODE (orig_src) + && FUNCTION_ARG_REGNO_P (REGNO (orig_src)) + && !abi_extension_candidate_return_reg_p (insn, REGNO (orig_src))) + return true; + + return false; +} + +/* Return TRUE if the candidate insn is zero extend and regno is + an argument registers. */ + +static bool +abi_extension_candidate_argno_p (rtx_code code, int regno) +{ + if (code != ZERO_EXTEND) + return false; + + if (FUNCTION_ARG_REGNO_P (regno)) + return true; + + return false; +} + +/* Return TRUE if the candidate insn doesn't have defs and have + * uses without RTX_BIN_ARITH/RTX_COMM_ARITH/RTX_UNARY rtx class. */ + +static bool +abi_handle_regs_without_defs_p (rtx_insn *insn) +{ + if (side_effects_p (PATTERN (insn))) + return false; + + struct df_link *uses + = get_uses (insn, SET_DEST (PATTERN (insn))); + + if (!uses) + return false; + + for (df_link *use = uses; use; use = use->next) + { + if (!use->ref) + return false; + + if (BLOCK_FOR_INSN (insn) + != BLOCK_FOR_INSN (DF_REF_INSN (use->ref))) + return false; + + rtx_insn *use_insn = DF_REF_INSN (use->ref); + + if (GET_CODE (PATTERN (use_insn)) == SET) + { + rtx_code code = GET_CODE (SET_SRC (PATTERN (use_insn))); + + if (GET_RTX_CLASS (code) == RTX_BIN_ARITH + || GET_RTX_CLASS (code) == RTX_COMM_ARITH + || GET_RTX_CLASS (code) == RTX_UNARY) + return false; + } + } + return true; +} + /* This function goes through all reaching defs of the source of the candidate for elimination (CAND) and tries to combine the extension with the definition instruction. The changes @@ -770,6 +885,11 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state) state->defs_list.truncate (0); state->copies_list.truncate (0); + rtx orig_src = XEXP (SET_SRC (cand->expr),0); + + if (abi_extension_candidate_p (cand->insn) + && (!get_defs (cand->insn, orig_src, NULL))) + return abi_handle_regs_without_defs_p (cand->insn); outcome = make_defs_and_copies_lists (cand->insn, set_pat, state); @@ -1036,6 +1156,15 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state) } } + rtx insn_set = single_set (cand->insn); + + machine_mode mode = (GET_MODE (XEXP (SET_SRC (insn_set), 0))); + + bool promote_p = abi_target_promote_function_mode (mode); + + if (promote_p) + return true; + if (merge_successful) { /* Commit the changes here if possible @@ -1112,26 +1241,34 @@ add_removable_extension (const_rtx expr, rtx_insn *insn, rtx reg = XEXP (src, 0); struct df_link *defs, *def; ext_cand *cand; + defs = get_defs (insn, reg, NULL); /* Zero-extension of an undefined value is partly defined (it's completely undefined for sign-extension, though). So if there exists a path from the entry to this zero-extension that leaves this register uninitialized, removing the extension could change the behavior of correct programs. So first, check it is not the case. */ - if (code == ZERO_EXTEND && !bitmap_bit_p (init_regs, REGNO (reg))) + if (!defs && abi_extension_candidate_argno_p (code, REGNO (reg))) { - if (dump_file) - { - fprintf (dump_file, "Cannot eliminate extension:\n"); - print_rtl_single (dump_file, insn); - fprintf (dump_file, " because it can operate on uninitialized" - " data\n"); - } + ext_cand e = {expr, code, mode, insn}; + insn_list->safe_push (e); return; } + if ((code == ZERO_EXTEND + && !bitmap_bit_p (init_regs, REGNO (reg)))) + { + if (dump_file) + { + fprintf (dump_file, "Cannot eliminate extension:\n"); + print_rtl_single (dump_file, insn); + fprintf (dump_file, " because it can operate on uninitialized" + " data\n"); + } + return; + } + /* Second, make sure we can get all the reaching definitions. */ - defs = get_defs (insn, reg, NULL); if (!defs) { if (dump_file) @@ -1321,7 +1458,8 @@ find_and_remove_re (void) && (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0)))) { reinsn_copy_list.safe_push (curr_cand->insn); - reinsn_copy_list.safe_push (state.defs_list[0]); + if (state.defs_list.length() != 0) + reinsn_copy_list.safe_push (state.defs_list[0]); } reinsn_del_list.safe_push (curr_cand->insn); state.modified[INSN_UID (curr_cand->insn)].deleted = 1; @@ -1342,24 +1480,27 @@ find_and_remove_re (void) Remember that the memory reference will be changed to refer to the destination of the extention. So we're actually emitting a copy from the new destination to the old destination. */ - for (unsigned int i = 0; i < reinsn_copy_list.length (); i += 2) - { - rtx_insn *curr_insn = reinsn_copy_list[i]; - rtx_insn *def_insn = reinsn_copy_list[i + 1]; - - /* Use the mode of the destination of the defining insn - for the mode of the copy. This is necessary if the - defining insn was used to eliminate a second extension - that was wider than the first. */ - rtx sub_rtx = *get_sub_rtx (def_insn); - rtx set = single_set (curr_insn); - rtx new_dst = gen_rtx_REG (GET_MODE (SET_DEST (sub_rtx)), - REGNO (XEXP (SET_SRC (set), 0))); - rtx new_src = gen_rtx_REG (GET_MODE (SET_DEST (sub_rtx)), - REGNO (SET_DEST (set))); - rtx new_set = gen_rtx_SET (new_dst, new_src); - emit_insn_after (new_set, def_insn); - } + for (unsigned int i = 0; i < reinsn_copy_list.length (); i += 2) + { + rtx_insn *curr_insn = reinsn_copy_list[i]; + + if ((i+1) < reinsn_copy_list.length()) + { + rtx_insn *def_insn = reinsn_copy_list[i + 1]; + /* Use the mode of the destination of the defining insn + for the mode of the copy. This is necessary if the + defining insn was used to eliminate a second extension + that was wider than the first. */ + rtx sub_rtx = *get_sub_rtx (def_insn); + rtx set = single_set (curr_insn); + rtx new_dst = gen_rtx_REG (GET_MODE (SET_DEST (sub_rtx)), + REGNO (XEXP (SET_SRC (set), 0))); + rtx new_src = gen_rtx_REG (GET_MODE (SET_DEST (sub_rtx)), + REGNO (SET_DEST (set))); + rtx new_set = gen_rtx_SET (new_dst, new_src); + emit_insn_after (new_set, def_insn); + } + } /* Delete all useless extensions here in one sweep. */ FOR_EACH_VEC_ELT (reinsn_del_list, i, curr_insn) diff --git a/gcc/testsuite/g++.target/powerpc/zext-elim-3.C b/gcc/testsuite/g++.target/powerpc/zext-elim-3.C new file mode 100644 index 00000000000..5a050df06ff --- /dev/null +++ b/gcc/testsuite/g++.target/powerpc/zext-elim-3.C @@ -0,0 +1,13 @@ +/* { dg-options "-mcpu=power9 -O2" } */ + +void *memset(void *b, int c, unsigned long len) +{ + unsigned long i; + + for (i = 0; i < len; i++) + ((unsigned char *)b)[i] = c; + + return b; +} + +/* { dg-final { scan-assembler-not "\mrlwinm\M" } } */