[PATCH, i386]: Introduce signbit<mode>2 expander

[Uros Bizjak]

Based on the recent work that enabled vectorization of
__builtin_signbit on aarch64.

2019-05-21  Uroš Bizjak  <ubizjak@gmail.com>

    * config/i386/sse.md (VF1_AVX2): New mode iterator.
    (signbit<mode>2): New expander

testsuite/ChangeLog:

2019-05-21  Uroš Bizjak  <ubizjak@gmail.com>

    * gcc.target/i386/vect-signbitf.c: New test.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Committed to mainline SVN.

Uros.
-------------- next part --------------
Index: config/i386/sse.md
===================================================================
--- config/i386/sse.md	(revision 271467)
+++ config/i386/sse.md	(working copy)
@@ -279,6 +279,9 @@
 (define_mode_iterator VF1
   [(V16SF "TARGET_AVX512F") (V8SF "TARGET_AVX") V4SF])
 
+(define_mode_iterator VF1_AVX2
+  [(V16SF "TARGET_AVX512F") (V8SF "TARGET_AVX2") V4SF])
+
 ;; 128- and 256-bit SF vector modes
 (define_mode_iterator VF1_128_256
   [(V8SF "TARGET_AVX") V4SF])
@@ -3523,6 +3526,15 @@
   operands[4] = gen_reg_rtx (<MODE>mode);
 })
 
+(define_expand "signbit<mode>2"
+  [(set (match_operand:<sseintvecmode> 0 "register_operand")
+	(lshiftrt:<sseintvecmode>
+	  (subreg:<sseintvecmode>
+	    (match_operand:VF1_AVX2 1 "register_operand") 0)
+	  (match_dup 2)))]
+  "TARGET_SSE2"
+  "operands[2] = GEN_INT (GET_MODE_UNIT_BITSIZE (<MODE>mode)-1);")
+
 ;; Also define scalar versions.  These are used for abs, neg, and
 ;; conditional move.  Using subregs into vector modes causes register
 ;; allocation lossage.  These patterns do not allow memory operands
Index: testsuite/gcc.target/i386/vect-signbitf.c
===================================================================
--- testsuite/gcc.target/i386/vect-signbitf.c	(nonexistent)
+++ testsuite/gcc.target/i386/vect-signbitf.c	(working copy)
@@ -0,0 +1,30 @@
+/* { dg-do run { target sse2_runtime } } */
+/* { dg-options "-O2 -msse2 -ftree-vectorize -fdump-tree-vect-details -save-temps" } */
+
+extern void abort ();
+
+#define N 1024
+float a[N] = {0.0f, -0.0f, 1.0f, -1.0f,
+	      -2.0f, 3.0f, -5.0f, -8.0f,
+	      13.0f, 21.0f, -25.0f, 33.0f};
+int r[N];
+
+int
+main (void)
+{
+  int i;
+
+  for (i = 0; i < N; i++)
+    r[i] = __builtin_signbitf (a[i]);
+
+  /* check results:  */
+  for (i = 0; i < N; i++)
+    if (__builtin_signbit (a[i]) && !r[i])
+      abort ();
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
+/* { dg-final { scan-assembler-not "-2147483648" } } */
+/* { dg-final { scan-assembler "psrld" } } */