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Implement InstCombine/sub.ll:test15: X % -Y === X % Y
Also, remove X % -1 = 0, because it's not true for unsigneds, and the signed case is superceeded by this new handling. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14637 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -844,11 +844,18 @@ Instruction *InstCombiner::visitDiv(BinaryOperator &I) {
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Instruction *InstCombiner::visitRem(BinaryOperator &I) {
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if (I.getType()->isSigned())
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if (Value *RHSNeg = dyn_castNegVal(I.getOperand(1)))
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if (RHSNeg != I.getOperand(1)) { // Avoid problems with MININT
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// X % -Y -> X % Y
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AddUsesToWorkList(I);
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I.setOperand(1, RHSNeg);
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return &I;
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}
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if (ConstantInt *RHS = dyn_cast<ConstantInt>(I.getOperand(1))) {
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if (RHS->equalsInt(1)) // X % 1 == 0
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return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
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if (RHS->isAllOnesValue()) // X % -1 == 0
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return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
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// Check to see if this is an unsigned remainder with an exact power of 2,
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// if so, convert to a bitwise and.
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