diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineCasts.cpp')
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineCasts.cpp | 27 |
1 files changed, 0 insertions, 27 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index 8a2e8447ab..a6833b8825 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -953,33 +953,6 @@ Instruction *InstCombiner::visitSExt(SExtInst &CI) { return SelectInst::Create(Src, Constant::getAllOnesValue(CI.getType()), Constant::getNullValue(CI.getType())); - - // See if the value being truncated is already sign extended. If so, just - // eliminate the trunc/sext pair. - if (Operator::getOpcode(Src) == Instruction::Trunc) { - Value *Op = cast<User>(Src)->getOperand(0); - unsigned OpBits = Op->getType()->getScalarSizeInBits(); - unsigned MidBits = SrcTy->getScalarSizeInBits(); - unsigned DestBits = DestTy->getScalarSizeInBits(); - unsigned NumSignBits = ComputeNumSignBits(Op); - - if (OpBits == DestBits) { - // Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign - // bits, it is already ready. - if (NumSignBits > DestBits-MidBits) - return ReplaceInstUsesWith(CI, Op); - } else if (OpBits < DestBits) { - // Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign - // bits, just sext from i32. - if (NumSignBits > OpBits-MidBits) - return new SExtInst(Op, CI.getType(), "tmp"); - } else { - // Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign - // bits, just truncate to i32. - if (NumSignBits > OpBits-MidBits) - return new TruncInst(Op, CI.getType(), "tmp"); - } - } // Attempt to extend the entire input expression tree to the destination // type. Only do this if the dest type is a simple type, don't convert the |