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| author | Artur Pilipenko <apilipenko@azulsystems.com> | 2016-08-12 10:14:11 +0000 |
|---|---|---|
| committer | Artur Pilipenko <apilipenko@azulsystems.com> | 2016-08-12 10:14:11 +0000 |
| commit | 6669f253d582f3de896737001f8e67c84bab5b0e (patch) | |
| tree | 4f7a85e05a3cf73067c38b92b43fc0f4e518fa71 /llvm/lib/Analysis | |
| parent | 05e760ec4b53cac179dc5dfc4d3f76e1024a097e (diff) | |
| download | bcm5719-llvm-6669f253d582f3de896737001f8e67c84bab5b0e.tar.gz bcm5719-llvm-6669f253d582f3de896737001f8e67c84bab5b0e.zip | |
[LVI] Take range metadata into account while calculating icmp condition constraints
Take range metadata into account for conditions like this:
%length = load i32, i32* %length_ptr, !range !{i32 0, i32 2147483647}
%cmp = icmp ult i32 %a, %length
This is a common pattern for range checks where the length of the array is dynamically loaded.
Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D23267
llvm-svn: 278496
Diffstat (limited to 'llvm/lib/Analysis')
| -rw-r--r-- | llvm/lib/Analysis/LazyValueInfo.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp index c5c90271a08..8c090108c60 100644 --- a/llvm/lib/Analysis/LazyValueInfo.cpp +++ b/llvm/lib/Analysis/LazyValueInfo.cpp @@ -1211,6 +1211,9 @@ static LVILatticeVal getValueFromICmpCondition(Value *Val, ICmpInst *ICI, /*isFullSet=*/true); if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) RHSRange = ConstantRange(CI->getValue()); + else if (Instruction *I = dyn_cast<Instruction>(RHS)) + if (auto *Ranges = I->getMetadata(LLVMContext::MD_range)) + RHSRange = getConstantRangeFromMetadata(*Ranges); // If we're interested in the false dest, invert the condition CmpInst::Predicate Pred = |
