From 919fbffef0755562cd3b686c838069c20bc7878f Mon Sep 17 00:00:00 2001
From: liuhongt <hongtao.liu@intel.com>
Date: Mon, 21 Mar 2022 20:54:30 +0800
Subject: [PATCH] Extend splitter pattern to reversed condition by swapping
then and else rtx. [PR target/104982]
Failed to match this instruction:
(set (reg/v:SI 88 [ z ])
(if_then_else:SI (eq (zero_extract:SI (reg:SI 92)
(const_int 1 [0x1])
(zero_extend:SI (subreg:QI (reg:SI 93) 0)))
(const_int 0 [0]))
(reg:SI 95)
(reg:SI 94)))
but it's equal to
(set (reg/v:SI 88 [ z ])
(if_then_else:SI (ne (zero_extract:SI (reg:SI 92)
(const_int 1 [0x1])
(zero_extend:SI (subreg:QI (reg:SI 93) 0)))
(const_int 0 [0]))
(reg:SI 94)
(reg:SI 95)))
which is the exact existing splitter.
The patch will fix below regressions:
On x86-64, r12-7687 caused:
FAIL: gcc.target/i386/bt-5.c scan-assembler-not sar[lq][ \t]
FAIL: gcc.target/i386/bt-5.c scan-assembler-times bt[lq][ \t] 7
gcc/ChangeLog:
PR target/104982
* config/i386/i386.md (*jcc_bt<mode>_mask): Extend the
following splitter to reversed condition.
---
gcc/config/i386/i386.md | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 02f298c28460..c74edd1aaef3 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -14182,12 +14182,12 @@
(define_split
[(set (match_operand:SWI248 0 "register_operand")
(if_then_else:SWI248
- (ne
- (zero_extract:SWI48
- (match_operand:SWI48 1 "register_operand")
- (const_int 1)
- (zero_extend:SI (match_operand:QI 2 "register_operand")))
- (const_int 0))
+ (match_operator 5 "bt_comparison_operator"
+ [(zero_extract:SWI48
+ (match_operand:SWI48 1 "register_operand")
+ (const_int 1)
+ (zero_extend:SI (match_operand:QI 2 "register_operand")))
+ (const_int 0)])
(match_operand:SWI248 3 "nonimmediate_operand")
(match_operand:SWI248 4 "nonimmediate_operand")))]
"TARGET_USE_BT && TARGET_CMOVE
@@ -14202,6 +14202,8 @@
(match_dup 3)
(match_dup 4)))]
{
+ if (GET_CODE (operands[5]) == EQ)
+ std::swap (operands[3], operands[4]);
operands[2] = lowpart_subreg (SImode, operands[2], QImode);
})
--
GitLab