From 515c97c2301ac56f00f3acc443fc823e3153942e Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 11 Sep 2003 22:24:54 +0000 Subject: [PATCH] Simplify code Implement InstCombine/mul.ll:test9 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8488 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index eddde0caf17..47e53b56f39 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(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(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)); -- 2.34.1