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-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp35
1 files changed, 16 insertions, 19 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index d3155e13c4d..a2f7fa3c19a 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -1971,15 +1971,6 @@ Instruction *InstCombiner::foldICmpUDivConstant(ICmpInst &Cmp,
Instruction *InstCombiner::foldICmpDivConstant(ICmpInst &Cmp,
BinaryOperator *Div,
const APInt *C) {
- // FIXME: These checks restrict all folds under here to scalar types.
- ConstantInt *RHS = dyn_cast<ConstantInt>(Cmp.getOperand(1));
- if (!RHS)
- return nullptr;
-
- ConstantInt *DivRHS = dyn_cast<ConstantInt>(Div->getOperand(1));
- if (!DivRHS)
- return nullptr;
-
// Fold: icmp pred ([us]div X, C2), C -> range test
// Fold this div into the comparison, producing a range check.
// Determine, based on the divide type, what the range is being
@@ -2002,16 +1993,22 @@ Instruction *InstCombiner::foldICmpDivConstant(ICmpInst &Cmp,
if (!Cmp.isEquality() && DivIsSigned != Cmp.isSigned())
return nullptr;
- // FIXME: These 3 checks can be asserts.
- if (*C2 == 0)
- return nullptr; // The ProdOV computation fails on divide by zero.
- if (DivIsSigned && C2->isAllOnesValue())
- return nullptr; // The overflow computation also screws up here
- if (*C2 == 1) {
- // This eliminates some funny cases with INT_MIN.
- Cmp.setOperand(0, Div->getOperand(0)); // X/1 == X.
- return &Cmp;
- }
+ // These constant divides should already be folded in InstSimplify.
+ assert(*C2 != 0 && "The ProdOV computation fails on divide by zero.");
+ assert(*C2 != 1 && "Funny cases with INT_MIN will fail.");
+
+ // This constant divide should already be folded in InstCombine.
+ assert(!(DivIsSigned && C2->isAllOnesValue()) &&
+ "The overflow computation will fail.");
+
+ // FIXME: These checks restrict all folds under here to scalar types.
+ ConstantInt *RHS = dyn_cast<ConstantInt>(Cmp.getOperand(1));
+ if (!RHS)
+ return nullptr;
+
+ ConstantInt *DivRHS = dyn_cast<ConstantInt>(Div->getOperand(1));
+ if (!DivRHS)
+ return nullptr;
// Compute Prod = CI * DivRHS. We are essentially solving an equation
// of form X/C2=C. We solve for X by multiplying C2 (DivRHS) and
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