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| author | Nuno Lopes <nunoplopes@sapo.pt> | 2012-07-23 20:33:29 +0000 |
|---|---|---|
| committer | Nuno Lopes <nunoplopes@sapo.pt> | 2012-07-23 20:33:29 +0000 |
| commit | b42729b53a061e2a3def61eb10e2a648cecd60ae (patch) | |
| tree | b85c046d83efb6af717a2259dae2ecacd80a765e /lib/Support | |
| parent | 5e31044e119c75899b91ca97eb4d8ba786afc01c (diff) | |
| download | llvm-b42729b53a061e2a3def61eb10e2a648cecd60ae.tar.gz llvm-b42729b53a061e2a3def61eb10e2a648cecd60ae.tar.bz2 llvm-b42729b53a061e2a3def61eb10e2a648cecd60ae.tar.xz | |
make ConstantRange::zeroExtend() optimal
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160643 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Support')
| -rw-r--r-- | lib/Support/ConstantRange.cpp | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp index a3f2297596..720ef36c46 100644 --- a/lib/Support/ConstantRange.cpp +++ b/lib/Support/ConstantRange.cpp @@ -427,9 +427,13 @@ ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const { unsigned SrcTySize = getBitWidth(); assert(SrcTySize < DstTySize && "Not a value extension"); - if (isFullSet() || isWrappedSet()) + if (isFullSet() || isWrappedSet()) { // Change into [0, 1 << src bit width) - return ConstantRange(APInt(DstTySize,0), APInt(DstTySize,1).shl(SrcTySize)); + APInt LowerExt(DstTySize, 0); + if (!Upper) // special case: [X, 0) -- not really wrapping around + LowerExt = Lower.zext(DstTySize); + return ConstantRange(LowerExt, APInt(DstTySize, 1).shl(SrcTySize)); + } return ConstantRange(Lower.zext(DstTySize), Upper.zext(DstTySize)); } |