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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2017-02-26 10:38:15 +0100 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2017-05-12 03:47:41 +0200 |
| commit | cd7015c026dc512f9fcc78f38bbb99f57623e329 (patch) | |
| tree | 0a8ebce131475716dd73c2c05f66db53b32c1c3d | |
| parent | e35efe330c6ae7d154197c29b127560d569016d0 (diff) | |
| download | sparse-dev-cd7015c026dc512f9fcc78f38bbb99f57623e329.tar.gz | |
fix missing reload
In dominates() there is the following comment:
"We don't think two explicitly different symbols ever alias"
but the corresponding test only check if the storage in the
potentialy dominating instruction is a symbol and if so returns 0
meaning that it can't dominate.
But that's without taking in account that a pointer can point
to this symbol and thus that a store via this symbol can dominate
a store via a pointer.
Fix this by changing the test more in accordance to the comment:
return 0 only if the 2 concerned location correspond to 2 *distinct*
symbols (and thus do not return 0 if one of the location is not a symbol).
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | flow.c | 11 | ||||
| -rw-r--r-- | validation/alias-distinct.c | 17 | ||||
| -rw-r--r-- | validation/alias-mixed.c | 30 | ||||
| -rw-r--r-- | validation/alias-same.c | 17 |
4 files changed, 74 insertions, 1 deletions
@@ -314,6 +314,15 @@ static inline int same_memop(struct instruction *a, struct instruction *b) return a->offset == b->offset && a->size == b->size; } +static inline int distinct_symbols(pseudo_t a, pseudo_t b) +{ + if (a->type != PSEUDO_SYM) + return 0; + if (b->type != PSEUDO_SYM) + return 0; + return a->sym != b->sym; +} + /* * Return 1 if "dom" dominates the access to "pseudo" * in "insn". @@ -332,7 +341,7 @@ int dominates(pseudo_t pseudo, struct instruction *insn, struct instruction *dom if (local) return 0; /* We don't think two explicitly different symbols ever alias */ - if (dom->src->type == PSEUDO_SYM) + if (distinct_symbols(insn->src, dom->src)) return 0; /* We could try to do some alias analysis here */ return -1; diff --git a/validation/alias-distinct.c b/validation/alias-distinct.c new file mode 100644 index 00000000..42937b24 --- /dev/null +++ b/validation/alias-distinct.c @@ -0,0 +1,17 @@ +extern int g; +extern int h; + +static int foo(void) +{ + g = 1; + h = 2; + return g == 1; +} + +/* + * check-name: alias distinct symbols + * check-command: test-linearize $file + * check-output-ignore + * + * check-output-contains: ret\\..* *\\$1 + */ diff --git a/validation/alias-mixed.c b/validation/alias-mixed.c new file mode 100644 index 00000000..42930477 --- /dev/null +++ b/validation/alias-mixed.c @@ -0,0 +1,30 @@ +extern int g; + + +static int foo(int *p) +{ + *p = 1; + g = 2; + return *p == 1; +} + +static int bar(int *p) +{ + g = 1; + *p = 2; + return g == 1; +} + +static test(void) +{ + foo(&g); + bar(&g); +} + +/* + * check-name: alias symbol/pointer + * check-command: test-linearize $file + * check-output-ignore + * + * check-output-excludes: ret\\..* *\\$1 + */ diff --git a/validation/alias-same.c b/validation/alias-same.c new file mode 100644 index 00000000..55cf4244 --- /dev/null +++ b/validation/alias-same.c @@ -0,0 +1,17 @@ +extern int g; + + +static int foo(void) +{ + g = 1; + g = 2; + return g != 1; +} + +/* + * check-name: alias same symbols + * check-command: test-linearize $file + * check-output-ignore + * + * check-output-contains: ret\\..* *\\$1 + */ |