From bea984814c6fcd056dc80c99805925eb19a591b9 Mon Sep 17 00:00:00 2001
From: liuhongt <hongtao.liu@intel.com>
Date: Mon, 4 Jan 2021 11:24:30 +0800
Subject: [PATCH] i386: Optimize pmovskb on zero_extend of subreg HI of pmovskb
 result [PR98461]

The following patch adds define_insn_and_split to optimize

       vpmovmskb       %xmm0, %eax
-       movzwl  %ax, %eax
        notl    %eax

and combine splitter to optimize

        pmovmskb        %xmm0, %eax
-       notl    %eax
-       movzwl  %ax, %eax
+       xorl    $65535, %eax

gcc/ChangeLog
	PR target/98461
	* config/i386/sse.md (*sse2_pmovskb_zexthisi): New
	define_insn_and_split for zero_extend of subreg HI of pmovskb
	result.
	(*sse2_pmovskb_zexthisi): Add new combine splitters for
	zero_extend of not of subreg HI of pmovskb result.

gcc/testsuite/ChangeLog
	* gcc.target/i386/sse2-pr98461-2.c: New test.
---
 gcc/config/i386/sse.md                        | 28 +++++++++++++++++++
 .../gcc.target/i386/sse2-pr98461-2.c          | 25 +++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/i386/sse2-pr98461-2.c

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 7bb6292138b..582bc07a00a 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -16099,6 +16099,34 @@
    (set_attr "prefix" "maybe_vex")
    (set_attr "mode" "SI")])
 
+(define_insn_and_split "*sse2_pmovskb_zexthisi"
+  [(set (match_operand:SI 0 "register_operand")
+	(zero_extend:SI
+	  (subreg:HI
+	    (unspec:SI
+	      [(match_operand:V16QI 1 "register_operand")]
+	      UNSPEC_MOVMSK) 0)))]
+  "TARGET_SSE2 && ix86_pre_reload_split ()"
+  "#"
+  "&& 1"
+  [(set (match_dup 0)
+	(unspec:SI [(match_dup 1)] UNSPEC_MOVMSK))])
+
+(define_split
+  [(set (match_operand:SI 0 "register_operand")
+	(zero_extend:SI
+	  (not:HI
+	    (subreg:HI
+	      (unspec:SI
+		[(match_operand:V16QI 1 "register_operand")]
+		UNSPEC_MOVMSK) 0))))]
+  "TARGET_SSE2"
+  [(set (match_dup 2)
+	(unspec:SI [(match_dup 1)] UNSPEC_MOVMSK))
+   (set (match_dup 0)
+	(xor:SI (match_dup 2) (const_int 65535)))]
+ "operands[2] = gen_reg_rtx (SImode);")
+
 (define_split
   [(set (match_operand:SI 0 "register_operand")
 	(unspec:SI
diff --git a/gcc/testsuite/gcc.target/i386/sse2-pr98461-2.c b/gcc/testsuite/gcc.target/i386/sse2-pr98461-2.c
new file mode 100644
index 00000000000..330272c69bc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/sse2-pr98461-2.c
@@ -0,0 +1,25 @@
+/* PR target/98461 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -msse2 -mno-sse3 -masm=att" } */
+/* { dg-final { scan-assembler-times "\tpmovmskb\t" 3 } } */
+/* { dg-final { scan-assembler-not "\tmovzwl" } } */
+/* { dg-final { scan-assembler-times "\tnotl" 1 } } *
+/* { dg-final { scan-assembler-times "\txorl" 1 } } */
+
+#include <immintrin.h>
+
+unsigned int movemask_not1(__m128i logical) {
+  unsigned short res = (unsigned short)(_mm_movemask_epi8(logical));
+  return ~res;
+}
+
+unsigned int movemask_not2(__m128i logical) {
+  unsigned short res = (unsigned short)(_mm_movemask_epi8(logical));
+  res = ~res;
+  return res;
+}
+
+unsigned int movemask_zero_extend(__m128i logical) {
+  unsigned int res = _mm_movemask_epi8(logical);
+  return res & 0xffff;
+}
-- 
2.30.2