From: "Kong, Lingling" <lingling.kong@intel.com>
To: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Cc: "Liu, Hongtao" <hongtao.liu@intel.com>, Uros Bizjak <ubizjak@gmail.com>
Subject: [PATCH] i386: fix ix86_hardreg_mov_ok with lra_in_progress
Date: Mon, 6 May 2024 07:39:39 +0000 [thread overview]
Message-ID: <DM4PR11MB5487F8160B8087A569EE5A45EC1C2@DM4PR11MB5487.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20240506071557.2072799-1-lingling.kong@intel.com>
Hi,
Originally eliminate_regs_in_insn will transform
(parallel [
(set (reg:QI 130)
(plus:QI (subreg:QI (reg:DI 19 frame) 0)
(const_int 96)))
(clobber (reg:CC 17 flag))]) {*addqi_1}
to
(set (reg:QI 130)
(subreg:QI (reg:DI 19 frame) 0)) {*movqi_internal}
when verify_changes.
But with No Flags add, it transforms
(set (reg:QI 5 di)
(plus:QI (subreg:QI (reg:DI 19 frame) 0)
(const_int 96))) {*addqi_1_nf}
to
(set (reg:QI 5 di)
(subreg:QI (reg:DI 19 frame) 0)) {*addqi_1_nf}.
there is no extra clobbers at the end, and its dest reg just is a hardreg. For ix86_hardreg_mov_ok, it returns false. So it fails to update insn and causes the ICE when transform to movqi_internal.
But actually it is ok and safe for ix86_hardreg_mov_ok when lra_in_progress.
And tested the spec2017, the performance was not affected.
Bootstrapped and regtested on x86_64-pc-linux-gnu. OK for trunk?
gcc/ChangeLog:
* config/i386/i386.cc (ix86_hardreg_mov_ok): Relax
hard reg mov restriction when lra in progress.
---
gcc/config/i386/i386.cc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index 4d6b2b98761..ca4348a18bf 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -20357,7 +20357,8 @@ ix86_hardreg_mov_ok (rtx dst, rtx src)
? standard_sse_constant_p (src, GET_MODE (dst))
: x86_64_immediate_operand (src, GET_MODE (dst)))
&& ix86_class_likely_spilled_p (REGNO_REG_CLASS (REGNO (dst)))
- && !reload_completed)
+ && !reload_completed
+ && !lra_in_progress)
return false;
return true;
}
--
2.31.1
next parent reply other threads:[~2024-05-06 7:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240506071557.2072799-1-lingling.kong@intel.com>
2024-05-06 7:39 ` Kong, Lingling [this message]
2024-05-08 2:08 ` Hongtao Liu
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