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| author | Nick Lewycky <nicholas@mxc.ca> | 2007-03-18 22:58:46 +0000 |
|---|---|---|
| committer | Nick Lewycky <nicholas@mxc.ca> | 2007-03-18 22:58:46 +0000 |
| commit | 3f64b1ab1d580e17e90367ce3916061e9a11392e (patch) | |
| tree | c99ff39ebd6e2a36c05ff42e656d3d33ded781fc /lib/Transforms/Scalar/PredicateSimplifier.cpp | |
| parent | 318bf7963a0e34d5ce58460ac934f97e5f80f195 (diff) | |
| download | llvm-3f64b1ab1d580e17e90367ce3916061e9a11392e.tar.gz llvm-3f64b1ab1d580e17e90367ce3916061e9a11392e.tar.bz2 llvm-3f64b1ab1d580e17e90367ce3916061e9a11392e.tar.xz | |
Clean up this code and fix subtract miscompile.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35146 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar/PredicateSimplifier.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/PredicateSimplifier.cpp | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/lib/Transforms/Scalar/PredicateSimplifier.cpp b/lib/Transforms/Scalar/PredicateSimplifier.cpp index f6d8878265..072110642e 100644 --- a/lib/Transforms/Scalar/PredicateSimplifier.cpp +++ b/lib/Transforms/Scalar/PredicateSimplifier.cpp @@ -1543,13 +1543,26 @@ namespace { // "%x = mul i32 %y, 0" then %x EQ 0 Instruction::BinaryOps Opcode = BO->getOpcode(); + const Type *Ty = BO->getType(); + assert(!Ty->isFPOrFPVector() && "Float in work queue!"); + + Constant *Zero = Constant::getNullValue(Ty); + Constant *AllOnes = ConstantInt::getAllOnesValue(Ty); switch (Opcode) { default: break; case Instruction::Sub: + if (Op1 == Zero) { + add(BO, Op0, ICmpInst::ICMP_EQ, NewContext); + return; + } + break; + case Instruction::Or: + if (Op0 == AllOnes || Op1 == AllOnes) { + add(BO, AllOnes, ICmpInst::ICMP_EQ, NewContext); + return; + } // fall-through case Instruction::Add: - case Instruction::Or: { - Constant *Zero = Constant::getNullValue(BO->getType()); if (Op0 == Zero) { add(BO, Op1, ICmpInst::ICMP_EQ, NewContext); return; @@ -1557,9 +1570,8 @@ namespace { add(BO, Op0, ICmpInst::ICMP_EQ, NewContext); return; } - } break; - case Instruction::And: { - Constant *AllOnes = ConstantInt::getAllOnesValue(BO->getType()); + break; + case Instruction::And: if (Op0 == AllOnes) { add(BO, Op1, ICmpInst::ICMP_EQ, NewContext); return; @@ -1567,17 +1579,13 @@ namespace { add(BO, Op0, ICmpInst::ICMP_EQ, NewContext); return; } - } break; - case Instruction::Mul: { - Constant *Zero = Constant::getNullValue(BO->getType()); - if (Op0 == Zero) { - add(BO, Zero, ICmpInst::ICMP_EQ, NewContext); - return; - } else if (Op1 == Zero) { + // fall-through + case Instruction::Mul: + if (Op0 == Zero || Op1 == Zero) { add(BO, Zero, ICmpInst::ICMP_EQ, NewContext); return; } - } break; + break; } // "%x = add i32 %y, %z" and %x EQ %y then %z EQ 0 @@ -1585,9 +1593,6 @@ namespace { // 1. Repeat all of the above, with order of operands reversed. // "%x = udiv i32 %y, %z" and %x EQ %y then %z EQ 1 - const Type *Ty = BO->getType(); - assert(!Ty->isFPOrFPVector() && "Float in work queue!"); - Value *Known = Op0, *Unknown = Op1; if (Known != BO) std::swap(Known, Unknown); if (Known == BO) { @@ -1596,8 +1601,7 @@ namespace { case Instruction::Xor: case Instruction::Add: case Instruction::Sub: - add(Unknown, Constant::getNullValue(Ty), ICmpInst::ICMP_EQ, - NewContext); + add(Unknown, Zero, ICmpInst::ICMP_EQ, NewContext); break; case Instruction::UDiv: case Instruction::SDiv: |