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author | Chris Lattner <sabre@nondot.org> | 2003-09-11 22:24:54 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2003-09-11 22:24:54 +0000 |
commit | 515c97c2301ac56f00f3acc443fc823e3153942e (patch) | |
tree | d072792cc98381a28d69157d1c40d17c9e8c5f91 /lib | |
parent | 53dce0c43f25c64935ea5f26b19b04b0e533ef83 (diff) | |
download | external_llvm-515c97c2301ac56f00f3acc443fc823e3153942e.zip external_llvm-515c97c2301ac56f00f3acc443fc823e3153942e.tar.gz external_llvm-515c97c2301ac56f00f3acc443fc823e3153942e.tar.bz2 |
Simplify code
Implement InstCombine/mul.ll:test9
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8488 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index eddde0c..47e53b5 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -527,17 +527,14 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) { return BinaryOperator::create(Instruction::Mul, SI->getOperand(0), *CI << *ShOp); - const Type *Ty = CI->getType(); - int64_t Val = (int64_t)cast<ConstantInt>(CI)->getRawValue(); - switch (Val) { - case -1: // X * -1 -> -X + if (CI->isNullValue()) + return ReplaceInstUsesWith(I, Op1); // X * 0 == 0 + if (CI->equalsInt(1)) // X * 1 == X + return ReplaceInstUsesWith(I, Op0); + if (CI->isAllOnesValue()) // X * -1 == 0 - X return BinaryOperator::createNeg(Op0, I.getName()); - case 0: - return ReplaceInstUsesWith(I, Op1); // Eliminate 'mul double %X, 0' - case 1: - return ReplaceInstUsesWith(I, Op0); // Eliminate 'mul int %X, 1' - } + int64_t Val = (int64_t)cast<ConstantInt>(CI)->getRawValue(); if (uint64_t C = Log2(Val)) // Replace X*(2^C) with X << C return new ShiftInst(Instruction::Shl, Op0, ConstantUInt::get(Type::UByteTy, C)); |