Andrew Pinski writes:
> The split for movv8di is not ready to handle the case where the setting
> register overlaps with the address of the memory that is being load.
> Fixing the split than just making the output constraint as an early clobber
> for this alternative. The split would first need to figure out which register
> is overlapping with the address and then only emit that move last.
I was curious how strained that detection would be in practice, and in
the end it didn't seem too bad. I pushed the following variant after
testing on aarch64-linux-gnu.
Thanks,
Richard
The LS64 movv8di pattern didn't handle loads that overlapped with
the address register (unless the overlap happened to be in the
last subload).
gcc/
PR target/113550
* config/aarch64/aarch64-simd.md: In the movv8di splitter, check
whether each split instruction is a load that clobbers the source
address. Emit that instruction last if so.
gcc/testsuite/
PR target/113550
* gcc.target/aarch64/pr113550.c: New test.
---
gcc/config/aarch64/aarch64-simd.md | 18 ++--
gcc/testsuite/gcc.target/aarch64/pr113550.c | 48 +
2 files changed, 62 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/aarch64/pr113550.c
diff --git a/gcc/config/aarch64/aarch64-simd.md
b/gcc/config/aarch64/aarch64-simd.md
index 48f0741e7d0..f036f6ce997 100644
--- a/gcc/config/aarch64/aarch64-simd.md
+++ b/gcc/config/aarch64/aarch64-simd.md
@@ -8221,11 +8221,21 @@ (define_split
|| (memory_operand (operands[0], V8DImode)
&& register_operand (operands[1], V8DImode)))
{
+ std::pair last_pair = {};
for (int offset = 0; offset < 64; offset += 16)
- emit_move_insn (simplify_gen_subreg (TImode, operands[0],
-V8DImode, offset),
- simplify_gen_subreg (TImode, operands[1],
-V8DImode, offset));
+{
+ std::pair pair = {
+ simplify_gen_subreg (TImode, operands[0], V8DImode, offset),
+ simplify_gen_subreg (TImode, operands[1], V8DImode, offset)
+ };
+ if (register_operand (pair.first, TImode)
+ && reg_overlap_mentioned_p (pair.first, pair.second))
+ last_pair = pair;
+ else
+ emit_move_insn (pair.first, pair.second);
+}
+ if (last_pair.first)
+ emit_move_insn (last_pair.first, last_pair.second);
DONE;
}
else
diff --git a/gcc/testsuite/gcc.target/aarch64/pr113550.c
b/gcc/testsuite/gcc.target/aarch64/pr113550.c
new file mode 100644
index 000..0ff3c7b5c00
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr113550.c
@@ -0,0 +1,48 @@
+/* { dg-options "-O" } */
+/* { dg-do run } */
+
+#pragma GCC push_options
+#pragma GCC target "+ls64"
+#pragma GCC aarch64 "arm_acle.h"
+#pragma GCC pop_options
+
+#define DEF_FUNCTION(NAME, ARGS) \
+ __attribute__((noipa)) \
+ __arm_data512_t \
+ NAME ARGS\
+ {\
+return *ptr; \
+ }
+
+DEF_FUNCTION (f0, (__arm_data512_t *ptr))
+DEF_FUNCTION (f1, (int x0, __arm_data512_t *ptr))
+DEF_FUNCTION (f2, (int x0, int x1, __arm_data512_t *ptr))
+DEF_FUNCTION (f3, (int x0, int x1, int x2, __arm_data512_t *ptr))
+DEF_FUNCTION (f4, (int x0, int x1, int x2, int x3, __arm_data512_t *ptr))
+DEF_FUNCTION (f5, (int x0, int x1, int x2, int x3, int x4,
+ __arm_data512_t *ptr))
+DEF_FUNCTION (f6, (int x0, int x1, int x2, int x3, int x4, int x5,
+ __arm_data512_t *ptr))
+DEF_FUNCTION (f7, (int x0, int x1, int x2, int x3, int x4, int x5, int x6,
+ __arm_data512_t *ptr))
+
+int
+main (void)
+{
+ __arm_data512_t x = { 0, 10, 20, 30, 40, 50, 60, 70 };
+ __arm_data512_t res[8] =
+ {
+f0 (),
+f1 (0, ),
+f2 (0, 1, ),
+f3 (0, 1, 2, ),
+f4 (0, 1, 2, 3, ),
+f5 (0, 1, 2, 3, 4, ),
+f6 (0, 1, 2, 3, 4, 5, ),
+f7 (0, 1, 2, 3, 4, 5, 6, )
+ };
+ for (int i = 0; i < 8; ++i)
+if (__builtin_memcmp (, [i], sizeof (x)) != 0)
+ __builtin_abort ();
+ return 0;
+}
--
2.25.1
