[PATCH] Extend ldexp{s, d}f3 to vscalefs{s, d} when TARGET_AVX512F and TARGET_SSE_MATH.

[liuhongt via Gcc-patches]

Hi:
  AVX512F supported vscalefs{s,d} which is the same as ldexp except the second 
operand should be floating point.
  Bootstrapped and regtested on x86_64-linux-gnu{-m32,}.

gcc/ChangeLog:

        PR target/98309
        * config/i386/i386.md (ldexp<mode>3): Extend to vscalefs[sd]
        when TARGET_AVX512F and TARGET_SSE_MATH.

gcc/testsuite/ChangeLog:

        PR target/98309
        * gcc.target/i386/pr98309-1.c: New test.
        * gcc.target/i386/pr98309-2.c: New test.
---
 gcc/config/i386/i386.md                   | 34 +++++++++++++++-----
 gcc/testsuite/gcc.target/i386/pr98309-1.c | 18 +++++++++++
 gcc/testsuite/gcc.target/i386/pr98309-2.c | 39 +++++++++++++++++++++++
 3 files changed, 83 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr98309-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr98309-2.c

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index bc1c30b77f4..56b09c566ed 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -17914,17 +17914,35 @@ (define_expand "ldexp<mode>3"
   [(use (match_operand:MODEF 0 "register_operand"))
    (use (match_operand:MODEF 1 "general_operand"))
    (use (match_operand:SI 2 "register_operand"))]
-  "TARGET_USE_FANCY_MATH_387
-   && (!(SSE_FLOAT_MODE_P (<MODE>mode) && TARGET_SSE_MATH)
-       || TARGET_MIX_SSE_I387)
+  "((TARGET_USE_FANCY_MATH_387
+     && (!(SSE_FLOAT_MODE_P (<MODE>mode) && TARGET_SSE_MATH)
+        || TARGET_MIX_SSE_I387))
+    || (TARGET_AVX512F && TARGET_SSE_MATH))
    && flag_unsafe_math_optimizations"
 {
-  rtx op0 = gen_reg_rtx (XFmode);
-  rtx op1 = gen_reg_rtx (XFmode);
+  /* Prefer avx512f version.  */
+  if (TARGET_AVX512F && TARGET_SSE_MATH)
+   {
+     rtx op2 = gen_reg_rtx (<MODE>mode);
+     emit_insn (gen_floatsi<mode>2 (op2, operands[2]));
+     operands[0] = lowpart_subreg (<ssevecmodef>mode, operands[0], <MODE>mode);
+     if (MEM_P (operands[1]))
+       operands[1] = force_reg (<MODE>mode, operands[1]);
+     operands[1] = lowpart_subreg (<ssevecmodef>mode, operands[1], <MODE>mode);
+     op2 = lowpart_subreg (<ssevecmodef>mode, op2, <MODE>mode);
+     emit_insn (gen_avx512f_vmscalef<ssevecmodelower> (operands[0],
+                                                      operands[1],
+                                                      op2));
+   }
+  else
+    {
+      rtx op0 = gen_reg_rtx (XFmode);
+      rtx op1 = gen_reg_rtx (XFmode);
 
-  emit_insn (gen_extend<mode>xf2 (op1, operands[1]));
-  emit_insn (gen_ldexpxf3 (op0, op1, operands[2]));
-  emit_insn (gen_truncxf<mode>2 (operands[0], op0));
+      emit_insn (gen_extend<mode>xf2 (op1, operands[1]));
+      emit_insn (gen_ldexpxf3 (op0, op1, operands[2]));
+      emit_insn (gen_truncxf<mode>2 (operands[0], op0));
+  }
   DONE;
 })
 
diff --git a/gcc/testsuite/gcc.target/i386/pr98309-1.c 
b/gcc/testsuite/gcc.target/i386/pr98309-1.c
new file mode 100644
index 00000000000..3a7afb58971
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr98309-1.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-mavx512f -O2 -mfpmath=sse -ffast-math" } */
+/* { dg-final { scan-assembler-times "vcvtsi2s\[sd\]" "2" } } */
+/* { dg-final { scan-assembler-times "vscalefs\[sd\]" "2" } } */
+
+double
+__attribute__((noipa))
+foo (double a, int b)
+{
+  return __builtin_ldexp (a, b);
+}
+
+float
+__attribute__((noipa))
+foo2 (float a, int b)
+{
+  return __builtin_ldexpf (a, b);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr98309-2.c 
b/gcc/testsuite/gcc.target/i386/pr98309-2.c
new file mode 100644
index 00000000000..ecfb9168b7d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr98309-2.c
@@ -0,0 +1,39 @@
+/* { dg-do run } */
+/* { dg-options "-mavx512f -O2 -mfpmath=sse -ffast-math" } */
+/* { dg-require-effective-target avx512f } */
+
+#define AVX512F
+#ifndef CHECK
+#define CHECK "avx512f-helper.h"
+#endif
+
+#include CHECK
+
+#include "pr98309-1.c"
+
+double
+__attribute__((noipa, target("fpmath=387")))
+foo_i387 (double a, int b)
+{
+  return __builtin_ldexp (a, b);
+}
+
+float
+__attribute__((noipa, target("fpmath=387")))
+foo2_i387 (float a, int b)
+{
+  return __builtin_ldexpf (a, b);
+}
+
+static void
+test_512 (void)
+{
+  float fa = 14.5;
+  double da = 44.5;
+  int fb = 12;
+  int db = 8;
+  if (foo_i387 (da, db) != foo (da, db))
+    abort ();
+  if (foo2_i387 (fa, fb) != foo2 (fa, fb))
+    abort ();
+}
-- 
2.27.0