InstSimplify: Try to bring back the rest of r223583

This reverts r223624 with a small tweak, hopefully this will make stage3
equivalent.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223679 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2014-12-08 18:30:43 +00:00
parent 28eb431b8c
commit fca9c7b21c
2 changed files with 16 additions and 2 deletions

View File

@ -1448,8 +1448,8 @@ static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
Value *X, *Y;
ICmpInst::Predicate EqPred;
if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) &&
ICmpInst::isEquality(EqPred))
if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) ||
!ICmpInst::isEquality(EqPred))
return nullptr;
ICmpInst::Predicate UnsignedPred;
@ -1476,6 +1476,11 @@ static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
return UnsignedICmp;
}
// X < Y && Y == 0 --> false
if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_EQ &&
IsAnd)
return getFalse(UnsignedICmp->getType());
return nullptr;
}

View File

@ -166,6 +166,15 @@ define i1 @and_icmp1(i32 %x, i32 %y) {
; CHECK: %[[cmp:.*]] = icmp ult i32 %x, %y
; CHECK: ret i1 %[[cmp]]
define i1 @and_icmp2(i32 %x, i32 %y) {
%1 = icmp ult i32 %x, %y
%2 = icmp eq i32 %y, 0
%3 = and i1 %1, %2
ret i1 %3
}
; CHECK-LABEL: @and_icmp2(
; CHECK: ret i1 false
define i1 @or_icmp1(i32 %x, i32 %y) {
%1 = icmp ult i32 %x, %y
%2 = icmp ne i32 %y, 0