aarch64_operands_ok_for_ldpstp contained the code:
/* One of the memory accesses must be a mempair operand.
If it is not the first one, they need to be swapped by the
peephole. */
if (!aarch64_mem_pair_operand (mem_1, GET_MODE (mem_1))
&& !aarch64_mem_pair_operand (mem_2, GET_MODE (mem_2)))
return false;
But the requirement isn't just that one of the accesses must be a
valid mempair operand. It's that the lower access must be, since
that's the access that will be used for the instruction operand.
Tested on aarch64-linux-gnu & pushed. The patch applies cleanly
to GCC 12 and 13, so I'll backport there next week. GCC 11 will
need a bespoke fix if the problem shows up there, but I doubt it will.
Richard
gcc/
PR target/111411
* config/aarch64/aarch64.cc (aarch64_operands_ok_for_ldpstp): Require
the lower memory access to a mem-pair operand.
gcc/testsuite/
PR target/111411
* gcc.dg/rtl/aarch64/pr111411.c: New test.
---
gcc/config/aarch64/aarch64.cc | 8 ++-
gcc/testsuite/gcc.dg/rtl/aarch64/pr111411.c | 57 +++++++++++++++++++++
2 files changed, 60 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/rtl/aarch64/pr111411.c
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 0962fc4f56e..7bb1161f943 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -26503,11 +26503,9 @@ aarch64_operands_ok_for_ldpstp (rtx *operands, bool
load,
gcc_assert (known_eq (GET_MODE_SIZE (GET_MODE (mem_1)),
GET_MODE_SIZE (GET_MODE (mem_2))));
- /* One of the memory accesses must be a mempair operand.
- If it is not the first one, they need to be swapped by the
- peephole. */
- if (!aarch64_mem_pair_operand (mem_1, GET_MODE (mem_1))
- && !aarch64_mem_pair_operand (mem_2, GET_MODE (mem_2)))
+ /* The lower memory access must be a mem-pair operand. */
+ rtx lower_mem = reversed ? mem_2 : mem_1;
+ if (!aarch64_mem_pair_operand (lower_mem, GET_MODE (lower_mem)))
return false;
if (REG_P (reg_1) && FP_REGNUM_P (REGNO (reg_1)))
diff --git a/gcc/testsuite/gcc.dg/rtl/aarch64/pr111411.c
b/gcc/testsuite/gcc.dg/rtl/aarch64/pr111411.c
new file mode 100644
index 00000000000..ad07e9c6c89
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/rtl/aarch64/pr111411.c
@@ -0,0 +1,57 @@
+/* { dg-do compile { target aarch64*-*-* } } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-options "-O -fdisable-rtl-postreload -fpeephole2 -fno-schedule-fusion"
} */
+
+extern int data[];
+
+void __RTL (startwith ("ira")) foo (void *ptr)
+{
+ (function "foo"
+ (param "ptr"
+ (DECL_RTL (reg/v:DI <0> [ ptr ]))
+ (DECL_RTL_INCOMING (reg/v:DI x0 [ ptr ]))
+ ) ;; param "ptr"
+ (insn-chain
+ (block 2
+ (edge-from entry (flags "FALLTHRU"))
+ (cnote 3 [bb 2] NOTE_INSN_BASIC_BLOCK)
+ (insn 4 (set (reg:DI <0>) (reg:DI x0)))
+ (insn 5 (set (reg:DI <1>)
+ (plus:DI (reg:DI <0>) (const_int 768))))
+ (insn 6 (set (mem:SI (plus:DI (reg:DI <0>)
+ (const_int 508)) [1 &data+508 S4 A4])
+ (const_int 0)))
+ (insn 7 (set (mem:SI (plus:DI (reg:DI <1>)
+ (const_int -256)) [1 &data+512 S4 A4])
+ (const_int 0)))
+ (edge-to exit (flags "FALLTHRU"))
+ ) ;; block 2
+ ) ;; insn-chain
+ ) ;; function
+}
+
+void __RTL (startwith ("ira")) bar (void *ptr)
+{
+ (function "bar"
+ (param "ptr"
+ (DECL_RTL (reg/v:DI <0> [ ptr ]))
+ (DECL_RTL_INCOMING (reg/v:DI x0 [ ptr ]))
+ ) ;; param "ptr"
+ (insn-chain
+ (block 2
+ (edge-from entry (flags "FALLTHRU"))
+ (cnote 3 [bb 2] NOTE_INSN_BASIC_BLOCK)
+ (insn 4 (set (reg:DI <0>) (reg:DI x0)))
+ (insn 5 (set (reg:DI <1>)
+ (plus:DI (reg:DI <0>) (const_int 768))))
+ (insn 6 (set (mem:SI (plus:DI (reg:DI <1>)
+ (const_int -256)) [1 &data+512 S4 A4])
+ (const_int 0)))
+ (insn 7 (set (mem:SI (plus:DI (reg:DI <0>)
+ (const_int 508)) [1 &data+508 S4 A4])
+ (const_int 0)))
+ (edge-to exit (flags "FALLTHRU"))
+ ) ;; block 2
+ ) ;; insn-chain
+ ) ;; function
+}
--
2.25.1
