From eb9d2755b20f9874b5cf77d77d7b5692628d93ea Mon Sep 17 00:00:00 2001 From: Nuno Lopes Date: Mon, 23 Jul 2012 20:33:29 +0000 Subject: make ConstantRange::zeroExtend() optimal llvm-svn: 160643 --- llvm/lib/Support/ConstantRange.cpp | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Support/ConstantRange.cpp') diff --git a/llvm/lib/Support/ConstantRange.cpp b/llvm/lib/Support/ConstantRange.cpp index a3f22975963..720ef36c464 100644 --- a/llvm/lib/Support/ConstantRange.cpp +++ b/llvm/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)); } -- cgit v1.2.3