From fc7070025d1a6668ff6cb4391f84771a7662def7 Mon Sep 17 00:00:00 2001
From: Wilco Dijkstra <wilco.dijkstra@arm.com>
Date: Wed, 13 Sep 2023 13:21:50 +0100
Subject: [PATCH] AArch64: Improve immediate expansion [PR105928]
Support immediate expansion of immediates which can be created from 2 MOVKs
and a shifted ORR or BIC instruction. Change aarch64_split_dimode_const_store
to apply if we save one instruction.
This reduces the number of 4-instruction immediates in SPECINT/FP by 5%.
gcc/ChangeLog:
PR target/105928
* config/aarch64/aarch64.cc (aarch64_internal_mov_immediate)
Add support for immediates using shifted ORR/BIC.
(aarch64_split_dimode_const_store): Apply if we save one instruction.
* config/aarch64/aarch64.md (<LOGICAL:optab>_<SHIFT:optab><mode>3):
Make pattern global.
gcc/testsuite:
PR target/105928
* gcc.target/aarch64/pr105928.c: Add new test.
* gcc.target/aarch64/vect-cse-codegen.c: Fix test.
---
gcc/config/aarch64/aarch64.cc | 43 ++++++++++++++-----
gcc/config/aarch64/aarch64.md | 2 +-
gcc/testsuite/gcc.target/aarch64/pr105928.c | 43 +++++++++++++++++++
.../gcc.target/aarch64/vect-cse-codegen.c | 3 +-
4 files changed, 77 insertions(+), 14 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/aarch64/pr105928.c
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 7bb1161f9430..219c4ee6d4cd 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -5640,7 +5640,7 @@ aarch64_internal_mov_immediate (rtx dest, rtx imm, bool generate,
machine_mode mode)
{
int i;
- unsigned HOST_WIDE_INT val, val2, mask;
+ unsigned HOST_WIDE_INT val, val2, val3, mask;
int one_match, zero_match;
int num_insns;
@@ -5722,6 +5722,35 @@ aarch64_internal_mov_immediate (rtx dest, rtx imm, bool generate,
}
return 3;
}
+
+ /* Try shifting and inserting the bottom 32-bits into the top bits. */
+ val2 = val & 0xffffffff;
+ val3 = 0xffffffff;
+ val3 = val2 | (val3 << 32);
+ for (i = 17; i < 48; i++)
+ if ((val2 | (val2 << i)) == val)
+ {
+ if (generate)
+ {
+ emit_insn (gen_rtx_SET (dest, GEN_INT (val2 & 0xffff)));
+ emit_insn (gen_insv_immdi (dest, GEN_INT (16),
+ GEN_INT (val2 >> 16)));
+ emit_insn (gen_ior_ashldi3 (dest, dest, GEN_INT (i), dest));
+ }
+ return 3;
+ }
+ else if ((val3 & ~(val3 << i)) == val)
+ {
+ if (generate)
+ {
+ emit_insn (gen_rtx_SET (dest, GEN_INT (val3 | 0xffff0000)));
+ emit_insn (gen_insv_immdi (dest, GEN_INT (16),
+ GEN_INT (val2 >> 16)));
+ emit_insn (gen_and_one_cmpl_ashldi3 (dest, dest, GEN_INT (i),
+ dest));
+ }
+ return 3;
+ }
}
/* Generate 2-4 instructions, skipping 16 bits of all zeroes or ones which
@@ -25540,8 +25569,6 @@ aarch64_split_dimode_const_store (rtx dst, rtx src)
rtx lo = gen_lowpart (SImode, src);
rtx hi = gen_highpart_mode (SImode, DImode, src);
- bool size_p = optimize_function_for_size_p (cfun);
-
if (!rtx_equal_p (lo, hi))
return false;
@@ -25560,14 +25587,8 @@ aarch64_split_dimode_const_store (rtx dst, rtx src)
MOV w1, 49370
MOVK w1, 0x140, lsl 16
STP w1, w1, [x0]
- So we want to perform this only when we save two instructions
- or more. When optimizing for size, however, accept any code size
- savings we can. */
- if (size_p && orig_cost <= lo_cost)
- return false;
-
- if (!size_p
- && (orig_cost <= lo_cost + 1))
+ So we want to perform this when we save at least one instruction. */
+ if (orig_cost <= lo_cost)
return false;
rtx mem_lo = adjust_address (dst, SImode, 0);
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 6f7827bd8c93..60133b541e92 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -4637,7 +4637,7 @@
[(set_attr "type" "logics_shift_imm")]
)
-(define_insn "*<LOGICAL:optab>_<SHIFT:optab><mode>3"
+(define_insn "<LOGICAL:optab>_<SHIFT:optab><mode>3"
[(set (match_operand:GPI 0 "register_operand" "=r")
(LOGICAL:GPI (SHIFT:GPI
(match_operand:GPI 1 "register_operand" "r")
diff --git a/gcc/testsuite/gcc.target/aarch64/pr105928.c b/gcc/testsuite/gcc.target/aarch64/pr105928.c
new file mode 100644
index 000000000000..9aff892670e4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr105928.c
@@ -0,0 +1,43 @@
+/* { dg-do assemble } */
+/* { dg-options "-O2 --save-temps" } */
+
+long long f1 (void)
+{
+ return 0x80402010080400;
+}
+
+long long f2 (void)
+{
+ return 0x1234567812345678;
+}
+
+long long f3 (void)
+{
+ return 0x4567800012345678;
+}
+
+long long f4 (void)
+{
+ return 0x3ecccccd3ecccccd;
+}
+
+long long f5 (void)
+{
+ return 0x38e38e38e38e38e;
+}
+
+long long f6 (void)
+{
+ return 0x1745d1745d1745d;
+}
+
+void f7 (long long *p)
+{
+ *p = 0x1234567812345678;
+}
+
+/* { dg-final { scan-assembler-times {\tmovk\t} 7 } } */
+/* { dg-final { scan-assembler-times {\tmov\t} 7 } } */
+/* { dg-final { scan-assembler-times {\tbic\t} 2 } } */
+/* { dg-final { scan-assembler-times {\torr\t} 4 } } */
+/* { dg-final { scan-assembler-times {\tstp\t} 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/vect-cse-codegen.c b/gcc/testsuite/gcc.target/aarch64/vect-cse-codegen.c
index d025e989a1e6..2b8e64313bb4 100644
--- a/gcc/testsuite/gcc.target/aarch64/vect-cse-codegen.c
+++ b/gcc/testsuite/gcc.target/aarch64/vect-cse-codegen.c
@@ -72,8 +72,7 @@ test3 (uint32_t a, uint32x4_t b, uint32x4_t* rt)
** ushr v[0-9]+.16b, v[0-9]+.16b, 7
** mov x[0-9]+, 16512
** movk x[0-9]+, 0x1020, lsl 16
-** movk x[0-9]+, 0x408, lsl 32
-** movk x[0-9]+, 0x102, lsl 48
+** orr x[0-9]+, x[0-9]+, x[0-9]+, lsl 28
** fmov d[0-9]+, x[0-9]+
** pmull v[0-9]+.1q, v[0-9]+.1d, v[0-9]+.1d
** dup v[0-9]+.2d, v[0-9]+.d\[0\]
--
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