This patch fixes a mode/rtx mismatch for ILP32 targets in:
mem = force_const_mem (ptr_mode, imm);
where imm can be Pmode rather than ptr_mode.
The patch uses convert_memory_address to convert the Pmode address
to ptr_mode before the call. However, immediate addresses can in
general contain unspecs, and convert_memory_address wasn't set up
to handle those.
The patch therefore adds some generic unspec handling to
convert_memory_address_addr_space_1. As the comment says, we can add
a target hook if this behaviour turns out to be wrong for some targets.
But I think what the patch does is a strict improvement over the status
quo: without it, we would try to force the unspec into a register,
but nevertheless wrap the result in a (const ...). That in turn
would be invalid rtl and seems bound to generate an ICE later.
I tested the explow.c part using -fstack-protector with local hacks
to force SYMBOL_FORCE_TO_MEM for UNSPEC_SALT_ADDR.
Fixes c-c++-common/torture/pr57945.c and various other tests.
Tested on aarch64-linux-gnu, aarch64_be-elf and x86_64-linux-gnu.
OK for the explow bits?
Richard
gcc/
PR target/97269
* explow.c (convert_memory_address_addr_space_1): Handle UNSPECs
nested in CONSTs.
* config/aarch64/aarch64.c (aarch64_expand_mov_immediate): Use
convert_memory_address to convert symbolic immediates to ptr_mode
before forcing them to memory.
---
gcc/config/aarch64/aarch64.c | 5 ++++-
gcc/explow.c | 20 ++++++++++++++++++++
2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index ed09fe0c6f8..d3ca6dc037e 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -5224,8 +5224,11 @@ aarch64_expand_mov_immediate (rtx dest, rtx imm)
switch (sty)
{
case SYMBOL_FORCE_TO_MEM:
+ if (int_mode != ptr_mode)
+ imm = convert_memory_address (ptr_mode, imm);
+
if (const_offset != 0
- && targetm.cannot_force_const_mem (int_mode, imm))
+ && targetm.cannot_force_const_mem (ptr_mode, imm))
{
gcc_assert (can_create_pseudo_p ());
base = aarch64_force_temporary (int_mode, dest, base);
diff --git a/gcc/explow.c b/gcc/explow.c
index 65f904a3d14..b8c9fbed03e 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -378,6 +378,26 @@ convert_memory_address_addr_space_1 (scalar_int_mode
to_mode ATTRIBUTE_UNUSED,
}
break;
+ case UNSPEC:
+ /* Assume that all UNSPECs in a constant address can be converted
+ operand-by-operand. We could add a target hook if some targets
+ require different behavior. */
+ if (in_const && GET_MODE (x) == from_mode)
+ {
+ unsigned int n = XVECLEN (x, 0);
+ rtvec v = gen_rtvec (n);
+ for (unsigned int i = 0; i < n; ++i)
+ {
+ rtx op = XVECEXP (x, 0, i);
+ if (GET_MODE (op) == from_mode)
+ op = convert_memory_address_addr_space_1 (to_mode, op, as,
+ in_const, no_emit);
+ RTVEC_ELT (v, i) = op;
+ }
+ return gen_rtx_UNSPEC (to_mode, v, XINT (x, 1));
+ }
+ break;
+
default:
break;
}
