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.

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 7bb6292138bcf8b2a9b0ad8e8a49645eff34da82..582bc07a00aa22af308022a16e14c33d79b146ee 100644 (file)
--- 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 (file)
index 0000000..330272c
--- /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;
+}