Added inst-combine for 'MIN(MIN(A, 97), 23)' and 'MAX(MAX(A, 23), 97)'

This removes TODO added in r208849 [http://reviews.llvm.org/D3629]

MIN(MIN(A, 97), 23) -> MIN(A, 23)
MAX(MAX(A, 23), 97) -> MAX(A, 97)

Differential Revision: http://reviews.llvm.org/D3785



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209110 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dinesh Dwivedi
2014-05-19 07:08:32 +00:00
parent cb596baadd
commit 306cd28e21
2 changed files with 65 additions and 5 deletions

View File

@@ -651,24 +651,32 @@ Instruction *InstCombiner::FoldSPFofSPF(Instruction *Inner,
return ReplaceInstUsesWith(Outer, C);
}
// MIN(MIN(A, 23), 97) -> MIN(A, 23)
// MAX(MAX(A, 97), 23) -> MAX(A, 97)
if (SPF1 == SPF2) {
if (ConstantInt *CB = dyn_cast<ConstantInt>(B)) {
if (ConstantInt *CC = dyn_cast<ConstantInt>(C)) {
APInt ACB = CB->getValue();
APInt ACC = CC->getValue();
// MIN(MIN(A, 23), 97) -> MIN(A, 23)
// MAX(MAX(A, 97), 23) -> MAX(A, 97)
if ((SPF1 == SPF_UMIN && ACB.ule(ACC)) ||
(SPF1 == SPF_SMIN && ACB.sle(ACC)) ||
(SPF1 == SPF_UMAX && ACB.uge(ACC)) ||
(SPF1 == SPF_SMAX && ACB.sge(ACC)))
return ReplaceInstUsesWith(Outer, Inner);
// MIN(MIN(A, 97), 23) -> MIN(A, 23)
// MAX(MAX(A, 23), 97) -> MAX(A, 97)
if ((SPF1 == SPF_UMIN && ACB.ugt(ACC)) ||
(SPF1 == SPF_SMIN && ACB.sgt(ACC)) ||
(SPF1 == SPF_UMAX && ACB.ult(ACC)) ||
(SPF1 == SPF_SMAX && ACB.slt(ACC))) {
Outer.replaceUsesOfWith(Inner, A);
return &Outer;
}
}
}
}
// TODO: MIN(MIN(A, 97), 23) -> MIN(A, 23)
// TODO: MAX(MAX(A, 23), 97) -> MAX(A, 97)
return nullptr;
}