https://gcc.gnu.org/g:e79583cef924f5fb5de551bd61da7b5fdee5c690
commit r15-5802-ge79583cef924f5fb5de551bd61da7b5fdee5c690
Author: Vladimir N. Makarov <vmaka...@redhat.com>
Date: Fri Nov 29 14:58:47 2024 -0500
[PR117770][LRA]: Check hard regs corresponding insn operands for hard reg
clobbers
When LRA processes early clobbered hard regs explicitly present in the
insn description, it checks that the hard reg is also used as input.
If the hard reg is not an input also, it is marked as dying. For the
check LRA processed only input hard reg also explicitly present in the
insn description. For given PR, the hard reg is used as input as the
operand and is not present explicitly in the insn description and
therefore LRA marked the hard reg as dying. This results in wrong
allocation and wrong code. The patch solves the problem by processing
hard regs used as the insn operand.
gcc/ChangeLog:
PR rtl-optimization/117770
* lra-lives.cc: Include ira-int.h.
(process_bb_lives): Check hard regs corresponding insn operands
for dying hard wired reg clobbers.
Diff:
---
gcc/lra-lives.cc | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/gcc/lra-lives.cc b/gcc/lra-lives.cc
index 66c6577e5d60..49134ade713d 100644
--- a/gcc/lra-lives.cc
+++ b/gcc/lra-lives.cc
@@ -38,6 +38,7 @@ along with GCC; see the file COPYING3. If not see
#include "insn-config.h"
#include "regs.h"
#include "ira.h"
+#include "ira-int.h"
#include "recog.h"
#include "cfganal.h"
#include "sparseset.h"
@@ -990,6 +991,19 @@ process_bb_lives (basic_block bb, int &curr_point, bool
dead_insn_p)
for (reg2 = curr_static_id->hard_regs; reg2 != NULL; reg2 =
reg2->next)
if (reg2->type != OP_OUT && reg2->regno == reg->regno)
break;
+ if (reg2 != NULL)
+ continue;
+
+ HARD_REG_SET clobbered_regset;
+ CLEAR_HARD_REG_SET (clobbered_regset);
+ SET_HARD_REG_BIT (clobbered_regset, reg->regno);
+
+ for (reg2 = curr_id->regs; reg2 != NULL; reg2 = reg2->next)
+ if (reg2->type != OP_OUT && reg2->regno < FIRST_PSEUDO_REGISTER
+ && ira_hard_reg_set_intersection_p (reg2->regno,
+ reg2->biggest_mode,
+ clobbered_regset))
+ break;
if (reg2 == NULL)
make_hard_regno_dead (reg->regno);
}
