Use integer CONST_VECTOR:
(const_vector:V2SI [
(const_int 1073741824 [0x40000000]) repeated x2
])
instead of
(const_vector:V2SF [
(const_int 1073741824 [0x40000000]) repeated x2
])
to load FP CONST_VECTOR converted from const_int:
(insn 25 24 27 2 (set (subreg:SI (reg/v:SF 144 [ d ]) 0)
(const_int 1073741824 [0x40000000])) "x.c":4:18 100 {*movsi_internal}
(nil))
...
(insn 90 88 91 2 (set (reg:V2SF 202 [ _15 ])
(vec_duplicate:V2SF (reg/v:SF 144 [ d ]))) "x.c":4:5 2137 {*vec_dupv2sf}
(expr_list:REG_DEAD (reg/v:SF 144 [ d ])
(nil)))
into GPR:
(insn 90 88 91 2 (set (subreg:DI (reg:V2SF 202 [ _15 ]) 0)
(const_int 4611686019501129728 [0x4000000040000000]))
"x.c":4:5 99 {*movdi_internal}
(expr_list:REG_DEAD (reg/v:SF 144 [ d ])
(nil)))
gcc/
PR target/125895
* config/i386/i386-features.cc (pass_x86_cse::x86_cse): Use
integer CONST_VECTOR to load FP CONST_VECTOR converted from
const_int.
gcc/testsuite/
PR target/125895
* gcc.target/i386/pr125895.c: New test.
--
H.J.
From 56c898dafd9311ce114a216a922a24261b017bff Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <[email protected]>
Date: Fri, 19 Jun 2026 16:31:26 +0800
Subject: [PATCH] x86_cse: Use integer CONST_VECTOR to load FP CONST_VECTOR
Use integer CONST_VECTOR:
(const_vector:V2SI [
(const_int 1073741824 [0x40000000]) repeated x2
])
instead of
(const_vector:V2SF [
(const_int 1073741824 [0x40000000]) repeated x2
])
to load FP CONST_VECTOR converted from const_int:
(insn 25 24 27 2 (set (subreg:SI (reg/v:SF 144 [ d ]) 0)
(const_int 1073741824 [0x40000000])) "x.c":4:18 100 {*movsi_internal}
(nil))
...
(insn 90 88 91 2 (set (reg:V2SF 202 [ _15 ])
(vec_duplicate:V2SF (reg/v:SF 144 [ d ]))) "x.c":4:5 2137 {*vec_dupv2sf}
(expr_list:REG_DEAD (reg/v:SF 144 [ d ])
(nil)))
into GPR:
(insn 90 88 91 2 (set (subreg:DI (reg:V2SF 202 [ _15 ]) 0)
(const_int 4611686019501129728 [0x4000000040000000])) "x.c":4:5 99 {*movdi_internal}
(expr_list:REG_DEAD (reg/v:SF 144 [ d ])
(nil)))
gcc/
PR target/125895
* config/i386/i386-features.cc (pass_x86_cse::x86_cse): Use
integer CONST_VECTOR to load FP CONST_VECTOR converted from
const_int.
gcc/testsuite/
PR target/125895
* gcc.target/i386/pr125895.c: New test.
Signed-off-by: H.J. Lu <[email protected]>
---
gcc/config/i386/i386-features.cc | 30 ++++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr125895.c | 10 ++++++++
2 files changed, 40 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/i386/pr125895.c
diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc
index d595f0bc2a3..37c68957cba 100644
--- a/gcc/config/i386/i386-features.cc
+++ b/gcc/config/i386/i386-features.cc
@@ -5040,6 +5040,36 @@ pass_x86_cse::x86_cse (void)
rtvec v = rtvec_alloc (nunits);
for (int j = 0; j < nunits ; j++)
RTVEC_ELT (v, j) = load->val;
+ if (CONST_INT_P (load->val)
+ && GET_MODE_CLASS (mode) != MODE_VECTOR_INT)
+ {
+ gcc_assert (load->size <= UNITS_PER_WORD);
+ machine_mode imode = GET_MODE_INNER (mode);
+ switch (imode)
+ {
+ case BFmode:
+ case HFmode:
+ imode = HImode;
+ break;
+
+ case SFmode:
+ imode = SImode;
+ break;
+
+ case DFmode:
+ imode = DImode;
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
+ class scalar_mode i_mode
+ = as_a <class scalar_mode> (imode);
+ mode = mode_for_vector (i_mode,
+ nunits).require ();
+ }
+
broadcast_source = gen_rtx_CONST_VECTOR (mode, v);
}
diff --git a/gcc/testsuite/gcc.target/i386/pr125895.c b/gcc/testsuite/gcc.target/i386/pr125895.c
new file mode 100644
index 00000000000..adc42955e24
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr125895.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=x86-64" } */
+
+__attribute__((__vector_size__(2 * sizeof(float)))) float b;
+void a(float d) {
+ double c;
+ b -= *(float *)__builtin_memcpy(&d, &c, 1);
+ __asm__("");
+ a(2);
+}
--
2.54.0
