[gcc r16-1694] x86: Also handle all 1s float vector constant

[H.J. Lu via Gcc-cvs]

https://gcc.gnu.org/g:77473a27bae04da99d6979d43e7bd0a8106f4557

commit r16-1694-g77473a27bae04da99d6979d43e7bd0a8106f4557
Author: H.J. Lu <hjl.to...@gmail.com>
Date:   Thu Jun 26 06:08:51 2025 +0800

    x86: Also handle all 1s float vector constant
    
    Since float vector constant
    
    (const_vector:V4SF [(const_double:SF -QNaN [-QNaN]) repeated x4])
    
    is an all 1s float vector constant, update the remove_redundant_vector
    pass to replace
    
    (insn 20 18 21 2 (set (reg:V4SF 124)
            (const_vector:V4SF [
                    (const_double:SF -QNaN [-QNaN]) repeated x4
                ])) "x.cc":26:5 2426 {movv4sf_internal}
         (nil))
    
    with
    
    (insn 49 2 5 2 (set (reg:V16QI 135)
            (const_vector:V16QI [
                    (const_int -1 [0xffffffffffffffff]) repeated x16
                ])) -1
         (nil))
    ...
    (insn 20 18 21 2 (set (reg:V4SF 124)
            (subreg:V4SF (reg:V16QI 135) 0)) "x.cc":26:5 2426 {movv4sf_internal}
         (nil))
    
    gcc/
    
            PR target/120819
            * config/i386/i386-features.cc (ix86_broadcast_inner): Also handle
            all 1s float vector constant.
    
    gcc/testsuite/
    
            PR target/120819
            * g++.target/i386/pr120819.C: New test.
    
    Signed-off-by: H.J. Lu <hjl.to...@gmail.com>

Diff:
---
 gcc/config/i386/i386-features.cc         |  6 ++++--
 gcc/testsuite/g++.target/i386/pr120819.C | 37 ++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc
index d942bf08b56f..fb4a9ec9903b 100644
--- a/gcc/config/i386/i386-features.cc
+++ b/gcc/config/i386/i386-features.cc
@@ -3532,8 +3532,10 @@ ix86_broadcast_inner (rtx op, machine_mode mode,
       *insn_p = nullptr;
       return const0_rtx;
     }
-  else if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT
-          && (op == constm1_rtx || op == CONSTM1_RTX (mode)))
+  else if ((GET_MODE_CLASS (mode) == MODE_VECTOR_INT
+           && (op == constm1_rtx || op == CONSTM1_RTX (mode)))
+           || (GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT
+               && float_vector_all_ones_operand (op, mode)))
     {
       *scalar_mode_p = QImode;
       *kind_p = X86_CSE_CONSTM1_VECTOR;
diff --git a/gcc/testsuite/g++.target/i386/pr120819.C 
b/gcc/testsuite/g++.target/i386/pr120819.C
new file mode 100644
index 000000000000..d0b05dfd0525
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/pr120819.C
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -march=znver2 -std=gnu++17 -w" } */
+
+typedef float a __attribute__ ((__vector_size__ (16)));
+typedef long long b __attribute__ ((__vector_size__ (16)));
+int c;
+a d, e, f;
+b g, h;
+struct i
+{
+  i (b j) : k (j) {}
+  i ();
+  b k;
+};
+i
+l (int j)
+{
+  g = (b)(__attribute__ ((__vector_size__ (4 * sizeof (1)))) int){ j, j, j,
+                                                                   j };
+  return g;
+}
+extern int m ();
+void
+n ()
+{
+  h = (__attribute__ ((
+      __vector_size__ (2 * sizeof (long long)))) long long){ c };
+  i o, p = l (2147483647 * 2 + 1);
+  f = __builtin_ia32_blendvps (a (p.k), d, e);
+  if (m ())
+    {
+      i q = l (2147483647 * 2 + 1);
+      a r = __builtin_ia32_blendvps (a (q.k), d, e);
+      o = b (r);
+      i s;
+    }
+}