Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp =================================================================== --- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -785,7 +785,9 @@ // This transform is performance neutral if we can elide at least one xor from // the set of three operands, since we'll be tacking on an xor at the very // end. - if (IsFreeOrProfitableToInvert(A, NotA, ElidesXor) && + if (SelectPatternResult::isMinOrMax(SPF1) && + SelectPatternResult::isMinOrMax(SPF2) && + IsFreeOrProfitableToInvert(A, NotA, ElidesXor) && IsFreeOrProfitableToInvert(B, NotB, ElidesXor) && IsFreeOrProfitableToInvert(C, NotC, ElidesXor) && ElidesXor) { if (!NotA) Index: llvm/trunk/test/Transforms/InstCombine/max-of-nots.ll =================================================================== --- llvm/trunk/test/Transforms/InstCombine/max-of-nots.ll +++ llvm/trunk/test/Transforms/InstCombine/max-of-nots.ll @@ -90,6 +90,28 @@ ret i32 %smax96 } + ; negative test case (i.e. can not simplify) : ABS(MIN(NOT x,y)) +define i32 @abs_of_min_of_not(i32 %x, i32 %y) { +; CHECK-LABEL: @abs_of_min_of_not( +; CHECK-NEXT: xor +; CHECK-NEXT: add +; CHECK-NEXT: icmp sge +; CHECK-NEXT: select +; CHECK-NEXT: icmp sgt +; CHECK-NEXT: sub +; CHECK-NEXT: select +; CHECK-NEXT: ret + + %xord = xor i32 %x, -1 + %yadd = add i32 %y, 2 + %cond.i = icmp sge i32 %yadd, %xord + %min = select i1 %cond.i, i32 %xord, i32 %yadd + %cmp2 = icmp sgt i32 %min, -1 + %sub = sub i32 0, %min + %abs = select i1 %cmp2, i32 %min, i32 %sub + ret i32 %abs +} + define <2 x i32> @max_of_nots_vec(<2 x i32> %x, <2 x i32> %y) { ; CHECK-LABEL: @max_of_nots_vec( ; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt <2 x i32> %y, zeroinitializer