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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 /flow.c | |
| 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>
Diffstat (limited to 'flow.c')
| -rw-r--r-- | flow.c | 11 |
1 files changed, 10 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; |