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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2012-09-27 18:29:58 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2012-09-27 18:29:58 +0000 |
| commit | c2081d1c19f71e1264e33e91425249fc8a4325f2 (patch) | |
| tree | 10a83310b512f5ba063a48ab5c5dbf4d49a6782c /llvm/lib/Transforms | |
| parent | eb9c0d0ed592736bfc6ed4ae4e6420c2140af1e3 (diff) | |
| download | bcm5719-llvm-c2081d1c19f71e1264e33e91425249fc8a4325f2.tar.gz bcm5719-llvm-c2081d1c19f71e1264e33e91425249fc8a4325f2.zip | |
Fix a integer overflow in SimplifyCFG's look up table formation logic.
If the width is very large it gets truncated from uint64_t to uint32_t when
passed to TD->fitsInLegalInteger. The truncated value can fit in a register.
This manifested in massive memory usage or crashes (PR13946).
llvm-svn: 164784
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 299c0596da3..065325b7c25 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -3414,6 +3414,10 @@ bool SwitchLookupTable::WouldFitInRegister(const TargetData *TD, return false; // FIXME: If the type is wider than it needs to be, e.g. i8 but all values // are <= 15, we could try to narrow the type. + + // Avoid overflow, fitsInLegalInteger uses unsigned int for the width. + if (TableSize >= UINT_MAX/IT->getBitWidth()) + return false; return TD->fitsInLegalInteger(TableSize * IT->getBitWidth()); } |
