TeamHeptaMirrors/gcc
1
0
Fork 1
mirror of https://github.com/gcc-mirror/gcc.git synced 2026-05-06 06:49:09 +02:00
Code Issues Packages Projects Releases Wiki Activity

[PR124041, PR124439, LRA]: Check hard_regno_mode_ok for hard reg subreg to satisfy reg constraint

Browse Source 
Patch for PR124041 resulted in wrong code generation and in new
PR124439 as the patch prevented equivalence substitution when
equivalence initialization insn was removed.

This patch implements another fix for PR124041 and this fixes
PR124439.

gcc/ChangeLog:

	PR rtl-optimization/124041
	PR rtl-optimization/124439
	* lra-constraints.cc (process_alt_operands): Check hard reg subreg
	mode by hard_regno_mode_ok.
	(curr_insn_transform): Always subsitute equivalence for hard reg
	subreg.
This commit is contained in:
Vladimir N. Makarov
2026-03-18 15:12:00 -04:00
parent 1c73a21caf
commit 5a16651495
1 changed files with 8 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
gcc/lra-constraints.cc
View File

@@ -2741,7 +2741,14 @@ process_alt_operands (int only_alternative)
winreg = true;
if (REG_P (op))
{
rtx orig_op = *curr_id->operand_loc[nop];
if (GET_CODE (orig_op) == SUBREG && HARD_REGISTER_P (op)
&& !targetm.hard_regno_mode_ok (REGNO (op),
GET_MODE(orig_op)))
break;
tree decl;
if (hard_regno[nop] >= 0
&& in_hard_reg_set_p (this_alternative_set,
mode, hard_regno[nop])
@@ -4402,23 +4409,12 @@ curr_insn_transform (bool check_only_p)
continue;
old = op = *curr_id->operand_loc[i];
machine_mode outer_mode = GET_MODE (old);
bool subreg_p = false;
if (GET_CODE (old) == SUBREG)
{
old = SUBREG_REG (old);
subreg_p = true;
}
old = SUBREG_REG (old);
subst = get_equiv_with_elimination (old, curr_insn);
original_subreg_reg_mode[i] = VOIDmode;
equiv_substition_p[i] = false;
/* If we are about to replace a register inside a subreg, check if
the target can handle that. */
if (subreg_p && REG_P (subst) && HARD_REGISTER_P (subst)
&& !targetm.hard_regno_mode_ok (REGNO (subst), outer_mode))
continue;
if (subst != old
/* We don't want to change an out operand by constant or invariant
which will require additional reloads, e.g. by putting a constant