This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Fix PR70526
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Tue, 5 Apr 2016 13:47:17 +0200 (CEST)
- Subject: [PATCH] Fix PR70526
- Authentication-results: sourceware.org; auth=none
SRA uses bogus alias sets for access replacements if a alias-punning
MEM_REF is based on a decl. The following patch fixes this.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
The testcase is a GCC 6 regression but the issue is older.
Richard.
2016-04-05 Richard Biener <rguenther@suse.de>
PR tree-optimization/70526
* tree-sra.c (build_ref_for_offset): Use prev_base to
extract the alias pointer type.
* g++.dg/torture/pr70526.C: New testcase.
Index: gcc/tree-sra.c
===================================================================
*** gcc/tree-sra.c (revision 234736)
--- gcc/tree-sra.c (working copy)
*************** build_ref_for_offset (location_t loc, tr
*** 1673,1679 ****
}
else
{
! off = build_int_cst (reference_alias_ptr_type (base),
base_offset + offset / BITS_PER_UNIT);
base = build_fold_addr_expr (unshare_expr (base));
}
--- 1673,1679 ----
}
else
{
! off = build_int_cst (reference_alias_ptr_type (prev_base),
base_offset + offset / BITS_PER_UNIT);
base = build_fold_addr_expr (unshare_expr (base));
}
Index: gcc/testsuite/g++.dg/torture/pr70526.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr70526.C (revision 0)
--- gcc/testsuite/g++.dg/torture/pr70526.C (working copy)
***************
*** 0 ****
--- 1,35 ----
+ // { dg-do run }
+
+ typedef unsigned uint32_t;
+
+ template<typename T>
+ struct AlignedStorage2
+ {
+ char mBytes[sizeof(T)];
+
+ const T* addr() const { return reinterpret_cast<const T*>(mBytes); }
+ T* addr() { return reinterpret_cast<T*>(mBytes); }
+ };
+
+ struct Register {
+ uint32_t reg_;
+ };
+
+ class TypedOrValueRegister
+ {
+ AlignedStorage2<Register> typed;
+ __attribute__((noinline)) Register& dataTyped() { return *typed.addr(); }
+ public:
+ TypedOrValueRegister(Register reg)
+ {
+ dataTyped() = reg;
+ }
+ Register typedReg() const { return *typed.addr(); }
+ };
+
+ int main() {
+ Register reg = { 10u };
+ if (TypedOrValueRegister(reg).typedReg().reg_ != 10)
+ __builtin_abort();
+ return 0;
+ }