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Revert "[InstCombine][NFC] Factor out constant check" 

This reverts commit 9bdb918890.

This refactoring proved to not be useful.
This commit is contained in:
Max Kazantsev 2020-06-05 12:00:44 +07:00
parent 929edd8bd2
commit 80cb25cbd5
1 changed files with 3 additions and 9 deletions
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12
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
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@ -1432,13 +1432,6 @@ Instruction *InstCombiner::foldICmpWithZero(ICmpInst &Cmp) {
/// possible that code has been made unnecessary - do we canonicalize IR to
/// overflow/saturating intrinsics or not?).
Instruction *InstCombiner::foldICmpWithConstant(ICmpInst &Cmp) {
Value *Op0 = Cmp.getOperand(0), *Op1 = Cmp.getOperand(1);
ConstantInt *CI;
// Make sure that the RHS operand is a constant.
if (!match(Op1, m_ConstantInt(CI)))
return nullptr;
// Match the following pattern, which is a common idiom when writing
// overflow-safe integer arithmetic functions. The source performs an addition
// in wider type and explicitly checks for overflow using comparisons against
@ -1451,9 +1444,10 @@ Instruction *InstCombiner::foldICmpWithConstant(ICmpInst &Cmp) {
// sum = a + b
// if (sum+128 >u 255) ... -> llvm.sadd.with.overflow.i8
CmpInst::Predicate Pred = Cmp.getPredicate();
Value *Op0 = Cmp.getOperand(0), *Op1 = Cmp.getOperand(1);
Value *A, *B;
ConstantInt *CI2; // I = icmp ugt (add (add A, B), CI2), CI
if (Pred == ICmpInst::ICMP_UGT &&
ConstantInt *CI, *CI2; // I = icmp ugt (add (add A, B), CI2), CI
if (Pred == ICmpInst::ICMP_UGT && match(Op1, m_ConstantInt(CI)) &&
match(Op0, m_Add(m_Add(m_Value(A), m_Value(B)), m_ConstantInt(CI2))))
if (Instruction *Res = processUGT_ADDCST_ADD(Cmp, A, B, CI2, CI, *this))
return Res;