The problem here is DSE was not taking into account the address space
which meant if you had two addresses say `fs:0` and `gs:0` (on x86_64),
DSE would think they were the same and remove the first store.
This fixes that issue by adding a check for the address space too.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR rtl-optimization/102733
gcc/ChangeLog:
* dse.cc (store_info): Add addrspace field.
(record_store): Record the address space
and check to make sure they are the same.
gcc/testsuite/ChangeLog:
* gcc.target/i386/addr-space-6.c: New test.
---
gcc/dse.cc | 9 ++++++++-
gcc/testsuite/gcc.target/i386/addr-space-6.c | 21 ++++++++++++++++++++
2 files changed, 29 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/i386/addr-space-6.c
diff --git a/gcc/dse.cc b/gcc/dse.cc
index 802b949cfb2..8b07be17674 100644
--- a/gcc/dse.cc
+++ b/gcc/dse.cc
@@ -251,6 +251,9 @@ public:
and known (rather than -1). */
poly_int64 width;
+ /* The address space that the memory reference uses. */
+ unsigned char addrspace;
+
union
{
/* A bitmask as wide as the number of bytes in the word that
@@ -1524,6 +1527,7 @@ record_store (rtx body, bb_info_t bb_info)
ptr = active_local_stores;
last = NULL;
redundant_reason = NULL;
+ unsigned char addrspace = MEM_ADDR_SPACE (mem);
mem = canon_rtx (mem);
if (group_id < 0)
@@ -1548,7 +1552,9 @@ record_store (rtx body, bb_info_t bb_info)
while (!s_info->is_set)
s_info = s_info->next;
- if (s_info->group_id == group_id && s_info->cse_base == base)
+ if (s_info->group_id == group_id
+ && s_info->cse_base == base
+ && s_info->addrspace == addrspace)
{
HOST_WIDE_INT i;
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1688,6 +1694,7 @@ record_store (rtx body, bb_info_t bb_info)
store_info->rhs = rhs;
store_info->const_rhs = const_rhs;
store_info->redundant_reason = redundant_reason;
+ store_info->addrspace = addrspace;
/* If this is a clobber, we return 0. We will only be able to
delete this insn if there is only one store USED store, but we
diff --git a/gcc/testsuite/gcc.target/i386/addr-space-6.c
b/gcc/testsuite/gcc.target/i386/addr-space-6.c
new file mode 100644
index 00000000000..82eca4d7e0c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/addr-space-6.c
@@ -0,0 +1,21 @@
+/* PR rtl-optimization/102733 */
+/* { dg-do compile } */
+/* { dg-options "-O1" } */
+
+/* DSE was removing a store to fs:0 (correctly)
+ and gs:0 (incorrectly) as DSE didn't take into
+ account the address space was different. */
+
+void test_null_store (void)
+{
+ int __seg_fs *fs = (int __seg_fs *)0;
+ *fs = 1;
+
+ int __seg_gs *gs = (int __seg_gs *)0;
+ *gs = 2;
+ *fs = 3;
+}
+
+/* { dg-final { scan-assembler-times "movl\t" 2 } } */
+/* { dg-final { scan-assembler "gs:" } } */
+/* { dg-final { scan-assembler "fs:" } } */
--
2.31.1
