[gcc r15-1048] Adjust rtx_cost for MEM to enable more simplication
hongtao Liu
liuhongt@gcc.gnu.org
Thu Jun 6 00:36:44 GMT 2024
https://gcc.gnu.org/g:961dd0d635217c703a38c48903981e0d60962546
commit r15-1048-g961dd0d635217c703a38c48903981e0d60962546
Author: liuhongt <hongtao.liu@intel.com>
Date: Fri Apr 19 10:39:53 2024 +0800
Adjust rtx_cost for MEM to enable more simplication
For CONST_VECTOR_DUPLICATE_P in constant_pool, it is just broadcast or
variants in ix86_vector_duplicate_simode_const.
Adjust the cost to COSTS_N_INSNS (2) + speed which should be a little
bit larger than broadcast.
gcc/ChangeLog:
PR target/114428
* config/i386/i386.cc (ix86_rtx_costs): Adjust cost for
CONST_VECTOR_DUPLICATE_P in constant_pool.
* config/i386/i386-expand.cc (ix86_broadcast_from_constant):
Remove static.
* config/i386/i386-protos.h (ix86_broadcast_from_constant):
Declare.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr114428.c: New test.
Diff:
---
gcc/config/i386/i386-expand.cc | 2 +-
gcc/config/i386/i386-protos.h | 1 +
gcc/config/i386/i386.cc | 13 +++++++++++++
gcc/testsuite/gcc.target/i386/pr114428.c | 18 ++++++++++++++++++
4 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 215a998fc26..56d29c15f9a 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -588,7 +588,7 @@ ix86_expand_move (machine_mode mode, rtx operands[])
/* OP is a memref of CONST_VECTOR, return scalar constant mem
if CONST_VECTOR is a vec_duplicate, else return NULL. */
-static rtx
+rtx
ix86_broadcast_from_constant (machine_mode mode, rtx op)
{
int nunits = GET_MODE_NUNITS (mode);
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index dbc861fb1ea..90712769200 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -107,6 +107,7 @@ extern void ix86_expand_clear (rtx);
extern void ix86_expand_move (machine_mode, rtx[]);
extern void ix86_expand_vector_move (machine_mode, rtx[]);
extern void ix86_expand_vector_move_misalign (machine_mode, rtx[]);
+extern rtx ix86_broadcast_from_constant (machine_mode, rtx);
extern rtx ix86_fixup_binary_operands (enum rtx_code, machine_mode,
rtx[], bool = false);
extern void ix86_fixup_binary_operands_no_copy (enum rtx_code, machine_mode,
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 271da127a89..a9d62c84c52 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -22191,6 +22191,19 @@ ix86_rtx_costs (rtx x, machine_mode mode, int outer_code_i, int opno,
return true;
case MEM:
+ /* CONST_VECTOR_DUPLICATE_P in constant_pool is just broadcast.
+ or variants in ix86_vector_duplicate_simode_const. */
+
+ if (GET_MODE_SIZE (mode) >= 16
+ && VECTOR_MODE_P (mode)
+ && SYMBOL_REF_P (XEXP (x, 0))
+ && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))
+ && ix86_broadcast_from_constant (mode, x))
+ {
+ *total = COSTS_N_INSNS (2) + speed;
+ return true;
+ }
+
/* An insn that accesses memory is slightly more expensive
than one that does not. */
if (speed)
diff --git a/gcc/testsuite/gcc.target/i386/pr114428.c b/gcc/testsuite/gcc.target/i386/pr114428.c
new file mode 100644
index 00000000000..bbbc5a080f6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr114428.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-march=x86-64-v3 -mno-avx512f -O2" } */
+/* { dg-final { scan-assembler-not "vpsra[dw]" } } */
+
+void
+foo2 (char* __restrict a, short* b)
+{
+ for (int i = 0; i != 32; i++)
+ a[i] = b[i] >> (short)8;
+}
+
+void
+foo3 (char* __restrict a, short* b)
+{
+ for (int i = 0; i != 16; i++)
+ a[i] = b[i] >> (short)8;
+}
+
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