From: Bernd Schmidt Date: Fri, 16 Jul 2010 02:09:03 +0000 (+0000) Subject: re PR target/42235 (redundant memory move from parameter space to spill space) X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=71008de4b34ee7eafe17593528dca2dc26527a34;p=gcc.git re PR target/42235 (redundant memory move from parameter space to spill space) PR target/42235 * function.c (record_hard_reg_sets): New static function. (assign_parm_setup_reg): If an optab for extending exists and the generated code clobbbers no hard regs, emit the insn directly and create a REG_EQUIV note. From-SVN: r162240 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 268e2f37917..9e31ff0f762 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2010-07-16 Bernd Schmidt + + PR target/42235 + * function.c (record_hard_reg_sets): New static function. + (assign_parm_setup_reg): If an optab for extending exists and the + generated code clobbbers no hard regs, emit the insn directly and + create a REG_EQUIV note. + 2010-07-15 Nathan Froyd * c-decl.c (detect_field_duplicates): Use DECL_CHAIN insted of diff --git a/gcc/function.c b/gcc/function.c index a2b4814a582..74672c38249 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -2854,6 +2854,21 @@ assign_parm_setup_block (struct assign_parm_data_all *all, SET_DECL_RTL (parm, stack_parm); } +/* A subroutine of assign_parm_setup_reg, called through note_stores. + This collects sets and clobbers of hard registers in a HARD_REG_SET, + which is pointed to by DATA. */ +static void +record_hard_reg_sets (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) +{ + HARD_REG_SET *pset = (HARD_REG_SET *)data; + if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER) + { + int nregs = hard_regno_nregs[REGNO (x)][GET_MODE (x)]; + while (nregs-- > 0) + SET_HARD_REG_BIT (*pset, REGNO (x) + nregs); + } +} + /* A subroutine of assign_parms. Allocate a pseudo to hold the current parameter. Get it there. Perform all ABI specified conversions. */ @@ -2861,10 +2876,12 @@ static void assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, struct assign_parm_data_one *data) { - rtx parmreg; + rtx parmreg, validated_mem; + rtx equiv_stack_parm; enum machine_mode promoted_nominal_mode; int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm)); bool did_conversion = false; + bool need_conversion, moved; /* Store the parm in a pseudoregister during the function, but we may need to do it in a wider mode. Using 2 here makes the result @@ -2893,11 +2910,16 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, /* Copy the value into the register, thus bridging between assign_parm_find_data_types and expand_expr_real_1. */ - if (data->nominal_mode != data->passed_mode - || promoted_nominal_mode != data->promoted_mode) - { - int save_tree_used; + equiv_stack_parm = data->stack_parm; + validated_mem = validize_mem (data->entry_parm); + + need_conversion = (data->nominal_mode != data->passed_mode + || promoted_nominal_mode != data->promoted_mode); + moved = false; + + if (need_conversion) + { /* ENTRY_PARM has been converted to PROMOTED_MODE, its mode, by the caller. We now have to convert it to NOMINAL_MODE, if different. However, PARMREG may be in @@ -2913,13 +2935,70 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, In addition, the conversion may involve a call, which could clobber parameters which haven't been copied to pseudo - registers yet. Therefore, we must first copy the parm to - a pseudo reg here, and save the conversion until after all + registers yet. + + First, we try to emit an insn which performs the necessary + conversion. We verify that this insn does not clobber any + hard registers. */ + + enum insn_code icode; + rtx op0, op1; + + icode = can_extend_p (promoted_nominal_mode, data->passed_mode, + unsignedp); + + op0 = parmreg; + op1 = validated_mem; + if (icode != CODE_FOR_nothing + && insn_data[icode].operand[0].predicate (op0, promoted_nominal_mode) + && insn_data[icode].operand[1].predicate (op1, data->passed_mode)) + { + enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND; + rtx insn, insns; + HARD_REG_SET hardregs; + + start_sequence (); + insn = gen_extend_insn (op0, op1, promoted_nominal_mode, + data->passed_mode, unsignedp); + emit_insn (insn); + insns = get_insns (); + + moved = true; + CLEAR_HARD_REG_SET (hardregs); + for (insn = insns; insn && moved; insn = NEXT_INSN (insn)) + { + if (INSN_P (insn)) + note_stores (PATTERN (insn), record_hard_reg_sets, + &hardregs); + if (!hard_reg_set_empty_p (hardregs)) + moved = false; + } + + end_sequence (); + + if (moved) + { + emit_insn (insns); + equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg), + equiv_stack_parm); + } + } + } + + if (moved) + /* Nothing to do. */ + ; + else if (need_conversion) + { + /* We did not have an insn to convert directly, or the sequence + generated appeared unsafe. We must first copy the parm to a + pseudo reg, and save the conversion until after all parameters have been moved. */ + int save_tree_used; rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm)); - emit_move_insn (tempreg, validize_mem (data->entry_parm)); + emit_move_insn (tempreg, validated_mem); push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn); tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp); @@ -2949,7 +3028,7 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, did_conversion = true; } else - emit_move_insn (parmreg, validize_mem (data->entry_parm)); + emit_move_insn (parmreg, validated_mem); /* If we were passed a pointer but the actual value can safely live in a register, put it in one. */ @@ -3034,7 +3113,7 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, } else if ((set = single_set (linsn)) != 0 && SET_DEST (set) == parmreg) - set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm); + set_unique_reg_note (linsn, REG_EQUIV, equiv_stack_parm); } /* For pointer data type, suggest pointer register. */