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| author | Diego Novillo <dnovillo@redhat.com> | 2006-07-18 17:27:57 +0000 |
|---|---|---|
| committer | Diego Novillo <dnovillo@gcc.gnu.org> | 2006-07-18 13:27:57 -0400 |
| commit | 548a6c6d0eaf08b916db237479647fa01d7e91a7 (patch) | |
| tree | 679bafddf7ab1d19e5ae8da990d4b134067ac67a | |
| parent | 492b73bda96d446cb62113559f1f705c1da365f3 (diff) | |
| download | gcc-548a6c6d0eaf08b916db237479647fa01d7e91a7.zip gcc-548a6c6d0eaf08b916db237479647fa01d7e91a7.tar.gz gcc-548a6c6d0eaf08b916db237479647fa01d7e91a7.tar.bz2 | |
re PR tree-optimization/28410 (Wrong aliasing with global var grouping during call clobbering)
PR 28410
* tree-ssa-operands.c (access_can_touch_variable): Update
comment.
Return true if ALIAS is .GLOBAL_VAR.
testsuite/ChangeLog
PR 28410
* gcc.dg/tree-ssa/pr28410.c: New test.
From-SVN: r115564
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr28410.c | 26 | ||||
| -rw-r--r-- | gcc/tree-ssa-operands.c | 10 |
4 files changed, 45 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index f64d3f2..435f325 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2006-07-18 Diego Novillo <dnovillo@redhat.com> + + PR 28410 + * tree-ssa-operands.c (access_can_touch_variable): Update + comment. + Return true if ALIAS is .GLOBAL_VAR. + 2006-07-18 David Daney <ddaney@avtrex.com> * gcc.c (display_help): Fix typo in help text. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 2025aad..505a2ad 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2006-07-18 Diego Novillo <dnovillo@redhat.com> + + PR 28410 + * gcc.dg/tree-ssa/pr28410.c: New test. + 2006-07-18 Lee Millward <lee.millward@gmail.com> PR c++/28258 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr28410.c b/gcc/testsuite/gcc.dg/tree-ssa/pr28410.c new file mode 100644 index 0000000..12f0633 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr28410.c @@ -0,0 +1,26 @@ +/* { dg-do run } */ +/* { dg-options "-O2 --param global-var-threshold=1" } */ + +extern void abort(void); +struct Bar { int p; }; +struct Foo { struct Bar *p; }; +struct Bar p0 = { 0 }; +struct Bar p1 = { 1 }; +void bar(struct Foo *f) +{ + f->p = &p0; +} +int foo(struct Foo *f) +{ + f->p->p = 1; + bar(f); + return f->p->p; +} +int main() +{ + struct Foo f; + f.p = &p1; + if (foo(&f) != 0) + abort (); + return 0; +} diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c index 3cd8c45..0563781 100644 --- a/gcc/tree-ssa-operands.c +++ b/gcc/tree-ssa-operands.c @@ -1037,9 +1037,7 @@ append_v_must_def (tree var) /* REF is a tree that contains the entire pointer dereference expression, if available, or NULL otherwise. ALIAS is the variable we are asking if REF can access. OFFSET and SIZE come from the - memory access expression that generated this virtual operand. - FOR_CLOBBER is true is this is adding a virtual operand for a call - clobber. */ + memory access expression that generated this virtual operand. */ static bool access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset, @@ -1049,6 +1047,12 @@ access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset, unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset; tree base = ref ? get_base_address (ref) : NULL; + /* If ALIAS is .GLOBAL_VAR then the memory reference REF must be + using a call-clobbered memory tag. By definition, call-clobbered + memory tags can always touch .GLOBAL_VAR. */ + if (alias == global_var) + return true; + /* If ALIAS is an SFT, it can't be touched if the offset and size of the access is not overlapping with the SFT offset and size. This is only true if we are accessing through a pointer |