[gcc r12-1436] i386: Split V2HImode *punpckwd to SSE instruction [PR101058]

[Uros Bizjak <uros@gcc.gnu.org>]

https://gcc.gnu.org/g:4986946f3b761dd4c3e0d79ca735c90e33f4bb83

commit r12-1436-g4986946f3b761dd4c3e0d79ca735c90e33f4bb83
Author: Uros Bizjak <ubizjak@gmail.com>
Date:   Mon Jun 14 20:56:18 2021 +0200

    i386: Split V2HImode *punpckwd to SSE instruction [PR101058]
    
    V2HImode *punpckwd should not be split to the insn that depends on
    TARGET_MMX_WITH_SSE, since the later is disabled on 32bit targets.
    
    Also return true early from ix86_vectorize_vec_perm_const when testing
    with V2HI mode.  *punpckwd can be used to implement all permutations.
    
    2021-06-14  Uroš Bizjak  <ubizjak@gmail.com>
    
    gcc/
            PR target/101058
            * config/i386/i386-expand.c (ix86_vectorize_vec_perm_const):
            Return true early when testing with V2HImode.
            * config/i386/mmx.md (*punpckwd): Split to sse2_pshuflw_1.
    
    gcc/testsuite/
    
            PR target/101058
            * gcc.target/i386/pr101058.c: New test.

Diff:
---
 gcc/config/i386/i386-expand.c            |  9 ++++++---
 gcc/config/i386/mmx.md                   | 13 +++++++------
 gcc/testsuite/gcc.target/i386/pr101058.c | 12 ++++++++++++
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 6e33f6f8196..dee3df2e3a0 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -20446,9 +20446,12 @@ ix86_vectorize_vec_perm_const (machine_mode vmode, rtx target, rtx op0,
 	return false;
       break;
     case E_V2HImode:
-	if (!TARGET_SSE2)
-	  return false;
-	break;
+      if (!TARGET_SSE2)
+	return false;
+      /* All implementable with *punpckwd.  */
+      if (d.testing_p)
+	return true;
+      break;
     case E_V2DImode:
     case E_V2DFmode:
       if (!TARGET_SSE)
diff --git a/gcc/config/i386/mmx.md b/gcc/config/i386/mmx.md
index f9e7d2786c6..1a9e7b024dd 100644
--- a/gcc/config/i386/mmx.md
+++ b/gcc/config/i386/mmx.md
@@ -3368,16 +3368,18 @@
 	  (vec_concat:V4HI
 	    (match_operand:V2HI 1 "register_operand" "0,Yw")
 	    (match_operand:V2HI 2 "register_operand" "x,Yw"))
-          (parallel [(match_operand 3 "const_0_to_3_operand")
-                     (match_operand 4 "const_0_to_3_operand")])))]
+	  (parallel [(match_operand 3 "const_0_to_3_operand")
+		     (match_operand 4 "const_0_to_3_operand")])))]
   "TARGET_SSE2"
   "#"
   "&& reload_completed"
   [(set (match_dup 5)
-        (vec_select:V4HI
+	(vec_select:V8HI
 	  (match_dup 5)
           (parallel [(match_dup 3) (match_dup 4)
-                     (const_int 0) (const_int 0)])))]
+                     (const_int 2) (const_int 3)
+                     (const_int 4) (const_int 5)
+                     (const_int 6) (const_int 7)])))]
 {
   rtx dest = lowpart_subreg (V8HImode, operands[0], V2HImode);
   rtx op1 = lowpart_subreg (V8HImode, operands[1], V2HImode);
@@ -3395,8 +3397,7 @@
 
   operands[3] = GEN_INT (sel0);
   operands[4] = GEN_INT (sel1);
-
-  operands[5] = lowpart_subreg (V4HImode, dest, V8HImode);
+  operands[5] = dest;
 }
   [(set_attr "isa" "noavx,avx")
    (set_attr "type" "sselog")
diff --git a/gcc/testsuite/gcc.target/i386/pr101058.c b/gcc/testsuite/gcc.target/i386/pr101058.c
new file mode 100644
index 00000000000..a2b251ce07d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr101058.c
@@ -0,0 +1,12 @@
+/* PR target/101058 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -msse2 -mno-mmx" } */
+
+short add90Hybrid_a_1;
+short *add90Hybrid_b, *add90Hybrid_c, *add90Hybrid_d;
+void add90Hybrid() {
+  for (int i; i < 200; i += 2) {
+    add90Hybrid_c[i] = add90Hybrid_b[i];
+    add90Hybrid_d[i] = add90Hybrid_a_1 - add90Hybrid_b[i + 1];
+  }
+}