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Minor efficiency tweak, suggested by Patrick Meredith
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13341 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -12,10 +12,10 @@
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// simplification happens.
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//
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// This pass combines things like:
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// %Y = add int 1, %X
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// %Z = add int 1, %Y
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// %Y = add int %X, 1
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// %Z = add int %Y, 1
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// into:
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// %Z = add int 2, %X
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// %Z = add int %X, 2
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//
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// This is a simple worklist driven algorithm.
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//
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@ -887,7 +887,7 @@ Instruction *InstCombiner::visitRem(BinaryOperator &I) {
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// if so, convert to a bitwise and.
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if (ConstantUInt *C = dyn_cast<ConstantUInt>(RHS))
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if (uint64_t Val = C->getValue()) // Don't break X % 0 (divide by zero)
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if (Log2(Val))
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if (!(Val & Val-1)) // Power of 2
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return BinaryOperator::create(Instruction::And, I.getOperand(0),
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ConstantUInt::get(I.getType(), Val-1));
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}
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