Re: [PATCH v2] AArch64: Improve immediate generation
On 24/10/2023 18:27, Wilco Dijkstra wrote:
v2: Use check-function-bodies in tests
Further improve immediate generation by adding support for 2-instruction
MOV/EOR bitmask immediates. This reduces the number of 3/4-instruction
immediates in SPECCPU2017 by ~2%.
Passes regress, OK for commit?
gcc/ChangeLog:
* config/aarch64/aarch64.cc (aarch64_internal_mov_immediate)
Add support for immediates using MOV/EOR bitmask.
gcc/testsuite:
* gcc.target/aarch64/imm_choice_comparison.c: Change tests.
* gcc.target/aarch64/moveor_imm.c: Add new test.
* gcc.target/aarch64/pr106583.c: Change tests.
---
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index
578a253d6e0e133e19592553fc873b3e73f9f218..ed5be2b64c9a767d74e9d78415da964c669001aa
100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -5748,6 +5748,26 @@ aarch64_internal_mov_immediate (rtx dest, rtx imm, bool
generate,
}
return 2;
}
+
+ /* Try 2 bitmask immediates which are xor'd together. */
+ for (i = 0; i < 64; i += 16)
+ {
+ val2 = (val >> i) & mask;
+ val2 |= val2 << 16;
+ val2 |= val2 << 32;
+ if (aarch64_bitmask_imm (val2) && aarch64_bitmask_imm (val ^ val2))
+ break;
+ }
+
+ if (i != 64)
+ {
+ if (generate)
+ {
+ emit_insn (gen_rtx_SET (dest, GEN_INT (val2)));
+ emit_insn (gen_xordi3 (dest, dest, GEN_INT (val ^ val2)));
+ }
+ return 2;
+ }
}
/* Try a bitmask plus 2 movk to generate the immediate in 3 instructions. */
diff --git a/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
b/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
index
ebc44d6dbc7287d907603d77d7b54496de177c4b..a1fc90ad73411ae8ed848fa321586afcb8d710aa
100644
--- a/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
+++ b/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
@@ -1,32 +1,64 @@
/* { dg-do compile } */
/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
/* Go from four moves to two. */
+/*
+** foo:
+** mov w[0-9]+, 2576980377
+** movkx[0-9]+, 0x, lsl 32
+** ...
+*/
+
int
foo (long long x)
{
- return x <= 0x1998;
+ return x <= 0x9998;
}
+/*
+** GT:
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
GT (unsigned int x)
{
return x > 0xfefe;
}
+/*
+** LE:
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
LE (unsigned int x)
{
return x <= 0xfefe;
}
+/*
+** GE:
+** mov w[0-9]+, 4278190079
+** ...
+*/
+
int
GE (long long x)
{
return x >= 0xff00;
}
+/*
+** LT:
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
LT (int x)
{
@@ -35,6 +67,13 @@ LT (int x)
/* Optimize the immediate in conditionals. */
+/*
+** check:
+** ...
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
check (int x, int y)
{
@@ -44,11 +83,15 @@ check (int x, int y)
return x;
}
+/*
+** tern:
+** ...
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
tern (int x)
{
return x >= 0xff00 ? 5 : -3;
}
-
-/* baz produces one movk instruction. */
-/* { dg-final { scan-assembler-times "movk" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/moveor_imm.c
b/gcc/testsuite/gcc.target/aarch64/moveor_imm.c
new file mode 100644
index
..1c0c3f3bf8c588f9661112a8b3f9a72c5ddff95c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/moveor_imm.c
@@ -0,0 +1,63 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+/*
+** f1:
+** movx0, -6148914691236517206
+** eor x0, x0, -9223372036854775807
+** ret
+*/
Some odd white space above.
Also, I think it would be better to write the tests as
** f1:
** ...
**
** ...
Then different prologue and epilogue options (such as BTI or pac-ret)
won't affect the tests.
+
+long f1 (void)
+{
+ return 0x2aab;
+}
+
+/*
+** f2:
+** mov x0, -1085102592571150096
+** eor x0, x0, -2305843009213693951
+** ret
+*/
+
+long f2 (void)
+{
+ return 0x10f0f0f0f0f0f0f1;
+}
+
+/*
+** f3:
+** mov x0, -3689348814741910324
+** eor x0, x0, -4611686018427387903
+** ret
+*/
+
+long f3 (void)
+{
+ return 0xccd;
+}
+
+/*
+** f4:
+** mov x0, -7378697629483820647
+** eor x0, x0, -9223372036854775807
+** ret
+*/
+
+long f4 (void)
+{
+ return 0x1998;
+}
+
+/*
+** f5:
+** mov x0, 3689348814741910323
+** eor x0, x0, 864691128656461824
+** ret
+*/
+
+long f5 (void)
+{
+ return 0x3f333f33;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/pr106583.c
b/gcc/testsuite/gcc.target/aarch64/pr106583.c
index
[PATCH v2] AArch64: Improve immediate generation
v2: Use check-function-bodies in tests
Further improve immediate generation by adding support for 2-instruction
MOV/EOR bitmask immediates. This reduces the number of 3/4-instruction
immediates in SPECCPU2017 by ~2%.
Passes regress, OK for commit?
gcc/ChangeLog:
* config/aarch64/aarch64.cc (aarch64_internal_mov_immediate)
Add support for immediates using MOV/EOR bitmask.
gcc/testsuite:
* gcc.target/aarch64/imm_choice_comparison.c: Change tests.
* gcc.target/aarch64/moveor_imm.c: Add new test.
* gcc.target/aarch64/pr106583.c: Change tests.
---
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index
578a253d6e0e133e19592553fc873b3e73f9f218..ed5be2b64c9a767d74e9d78415da964c669001aa
100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -5748,6 +5748,26 @@ aarch64_internal_mov_immediate (rtx dest, rtx imm, bool
generate,
}
return 2;
}
+
+ /* Try 2 bitmask immediates which are xor'd together. */
+ for (i = 0; i < 64; i += 16)
+ {
+ val2 = (val >> i) & mask;
+ val2 |= val2 << 16;
+ val2 |= val2 << 32;
+ if (aarch64_bitmask_imm (val2) && aarch64_bitmask_imm (val ^ val2))
+ break;
+ }
+
+ if (i != 64)
+ {
+ if (generate)
+ {
+ emit_insn (gen_rtx_SET (dest, GEN_INT (val2)));
+ emit_insn (gen_xordi3 (dest, dest, GEN_INT (val ^ val2)));
+ }
+ return 2;
+ }
}
/* Try a bitmask plus 2 movk to generate the immediate in 3 instructions. */
diff --git a/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
b/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
index
ebc44d6dbc7287d907603d77d7b54496de177c4b..a1fc90ad73411ae8ed848fa321586afcb8d710aa
100644
--- a/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
+++ b/gcc/testsuite/gcc.target/aarch64/imm_choice_comparison.c
@@ -1,32 +1,64 @@
/* { dg-do compile } */
/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
/* Go from four moves to two. */
+/*
+** foo:
+** mov w[0-9]+, 2576980377
+** movkx[0-9]+, 0x, lsl 32
+** ...
+*/
+
int
foo (long long x)
{
- return x <= 0x1998;
+ return x <= 0x9998;
}
+/*
+** GT:
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
GT (unsigned int x)
{
return x > 0xfefe;
}
+/*
+** LE:
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
LE (unsigned int x)
{
return x <= 0xfefe;
}
+/*
+** GE:
+** mov w[0-9]+, 4278190079
+** ...
+*/
+
int
GE (long long x)
{
return x >= 0xff00;
}
+/*
+** LT:
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
LT (int x)
{
@@ -35,6 +67,13 @@ LT (int x)
/* Optimize the immediate in conditionals. */
+/*
+** check:
+** ...
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
check (int x, int y)
{
@@ -44,11 +83,15 @@ check (int x, int y)
return x;
}
+/*
+** tern:
+** ...
+** mov w[0-9]+, -16777217
+** ...
+*/
+
int
tern (int x)
{
return x >= 0xff00 ? 5 : -3;
}
-
-/* baz produces one movk instruction. */
-/* { dg-final { scan-assembler-times "movk" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/moveor_imm.c
b/gcc/testsuite/gcc.target/aarch64/moveor_imm.c
new file mode 100644
index
..1c0c3f3bf8c588f9661112a8b3f9a72c5ddff95c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/moveor_imm.c
@@ -0,0 +1,63 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+/*
+** f1:
+** movx0, -6148914691236517206
+** eor x0, x0, -9223372036854775807
+** ret
+*/
+
+long f1 (void)
+{
+ return 0x2aab;
+}
+
+/*
+** f2:
+** mov x0, -1085102592571150096
+** eor x0, x0, -2305843009213693951
+** ret
+*/
+
+long f2 (void)
+{
+ return 0x10f0f0f0f0f0f0f1;
+}
+
+/*
+** f3:
+** mov x0, -3689348814741910324
+** eor x0, x0, -4611686018427387903
+** ret
+*/
+
+long f3 (void)
+{
+ return 0xccd;
+}
+
+/*
+** f4:
+** mov x0, -7378697629483820647
+** eor x0, x0, -9223372036854775807
+** ret
+*/
+
+long f4 (void)
+{
+ return 0x1998;
+}
+
+/*
+** f5:
+** mov x0, 3689348814741910323
+** eor x0, x0, 864691128656461824
+** ret
+*/
+
+long f5 (void)
+{
+ return 0x3f333f33;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/pr106583.c
b/gcc/testsuite/gcc.target/aarch64/pr106583.c
index
0f931580817d78dc1cc58f03b251bd21bec71f59..63df7395edf9491720e3601848e15aa773c51e6d
100644
--- a/gcc/testsuite/gcc.target/aarch64/pr106583.c
+++ b/gcc/testsuite/gcc.target/aarch64/pr106583.c
@@ -1,41 +1,94 @@
-/* { dg-do assemble } */
-/* { dg-options "-O2 --save-temps" } */
+/* { dg-do compile } */
+/* { dg-options "-O2" }
