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Revert r315992 because of a found miscompilation failure 

llvm-svn: 316164
This commit is contained in:
Nikolai Bozhenov 2017-10-19 15:36:18 +00:00
parent 1c09dfe2bc
commit 8dcab54cb4
2 changed files with 22 additions and 43 deletions
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45
llvm/lib/Analysis/ValueTracking.cpp
View File

@ -4083,14 +4083,6 @@ static SelectPatternResult matchMinMax(CmpInst::Predicate Pred,
Value *CmpLHS, Value *CmpRHS,
Value *TrueVal, Value *FalseVal,
Value *&LHS, Value *&RHS) {
assert(!ICmpInst::isEquality(Pred) && "Expected not equality predicate only!");
// First, check if select has inverse order of what we will check below:
if (CmpRHS == FalseVal) {
std::swap(TrueVal, FalseVal);
Pred = CmpInst::getInversePredicate(Pred);
}
// Assume success. If there's no match, callers should not use these anyway.
LHS = TrueVal;
RHS = FalseVal;
@ -4103,30 +4095,26 @@ static SelectPatternResult matchMinMax(CmpInst::Predicate Pred,
// (X <s C1) ? C1 : SMIN(X, C2) ==> SMAX(SMIN(X, C2), C1)
if (match(FalseVal, m_SMin(m_Specific(CmpLHS), m_APInt(C2))) &&
C1->slt(*C2) &&
(Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_SLE))
C1->slt(*C2) && Pred == CmpInst::ICMP_SLT)
return {SPF_SMAX, SPNB_NA, false};
// (X >s C1) ? C1 : SMAX(X, C2) ==> SMIN(SMAX(X, C2), C1)
if (match(FalseVal, m_SMax(m_Specific(CmpLHS), m_APInt(C2))) &&
C1->sgt(*C2) &&
(Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE))
C1->sgt(*C2) && Pred == CmpInst::ICMP_SGT)
return {SPF_SMIN, SPNB_NA, false};
// (X <u C1) ? C1 : UMIN(X, C2) ==> UMAX(UMIN(X, C2), C1)
if (match(FalseVal, m_UMin(m_Specific(CmpLHS), m_APInt(C2))) &&
C1->ult(*C2) &&
(Pred == CmpInst::ICMP_ULT || Pred == CmpInst::ICMP_ULE))
C1->ult(*C2) && Pred == CmpInst::ICMP_ULT)
return {SPF_UMAX, SPNB_NA, false};
// (X >u C1) ? C1 : UMAX(X, C2) ==> UMIN(UMAX(X, C2), C1)
if (match(FalseVal, m_UMax(m_Specific(CmpLHS), m_APInt(C2))) &&
C1->ugt(*C2) &&
(Pred == CmpInst::ICMP_UGT || Pred == CmpInst::ICMP_UGE))
C1->ugt(*C2) && Pred == CmpInst::ICMP_UGT)
return {SPF_UMIN, SPNB_NA, false};
}
if (!CmpInst::isSigned(Pred))
if (Pred != CmpInst::ICMP_SGT && Pred != CmpInst::ICMP_SLT)
return {SPF_UNKNOWN, SPNB_NA, false};
// Z = X -nsw Y
@ -4134,18 +4122,14 @@ static SelectPatternResult matchMinMax(CmpInst::Predicate Pred,
// (X <s Y) ? 0 : Z ==> (Z <s 0) ? 0 : Z ==> SMAX(Z, 0)
if (match(TrueVal, m_Zero()) &&
match(FalseVal, m_NSWSub(m_Specific(CmpLHS), m_Specific(CmpRHS))))
return {(Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE) ? SPF_SMIN
: SPF_SMAX,
SPNB_NA, false};
return {Pred == CmpInst::ICMP_SGT ? SPF_SMIN : SPF_SMAX, SPNB_NA, false};
// Z = X -nsw Y
// (X >s Y) ? Z : 0 ==> (Z >s 0) ? Z : 0 ==> SMAX(Z, 0)
// (X <s Y) ? Z : 0 ==> (Z <s 0) ? Z : 0 ==> SMIN(Z, 0)
if (match(FalseVal, m_Zero()) &&
match(TrueVal, m_NSWSub(m_Specific(CmpLHS), m_Specific(CmpRHS))))
return {(Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE) ? SPF_SMAX
: SPF_SMIN,
SPNB_NA, false};
return {Pred == CmpInst::ICMP_SGT ? SPF_SMAX : SPF_SMIN, SPNB_NA, false};
if (!match(CmpRHS, m_APInt(C1)))
return {SPF_UNKNOWN, SPNB_NA, false};
@ -4157,15 +4141,14 @@ static SelectPatternResult matchMinMax(CmpInst::Predicate Pred,
// Is the sign bit set?
// (X <s 0) ? X : MAXVAL ==> (X >u MAXVAL) ? X : MAXVAL ==> UMAX
// (X <s 0) ? MAXVAL : X ==> (X >u MAXVAL) ? MAXVAL : X ==> UMIN
if ((Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_SLE) && *C1 == 0 &&
C2->isMaxSignedValue())
if (Pred == CmpInst::ICMP_SLT && *C1 == 0 && C2->isMaxSignedValue())
return {CmpLHS == TrueVal ? SPF_UMAX : SPF_UMIN, SPNB_NA, false};
// Is the sign bit clear?
// (X >s -1) ? MINVAL : X ==> (X <u MINVAL) ? MINVAL : X ==> UMAX
// (X >s -1) ? X : MINVAL ==> (X <u MINVAL) ? X : MINVAL ==> UMIN
if ((Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE) &&
C1->isAllOnesValue() && C2->isMinSignedValue())
if (Pred == CmpInst::ICMP_SGT && C1->isAllOnesValue() &&
C2->isMinSignedValue())
return {CmpLHS == FalseVal ? SPF_UMAX : SPF_UMIN, SPNB_NA, false};
}
@ -4174,17 +4157,13 @@ static SelectPatternResult matchMinMax(CmpInst::Predicate Pred,
// (X <s C) ? ~X : ~C ==> (~X >s ~C) ? ~X : ~C ==> SMAX(~X, ~C)
if (match(TrueVal, m_Not(m_Specific(CmpLHS))) &&
match(FalseVal, m_APInt(C2)) && ~(*C1) == *C2)
return {(Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE) ? SPF_SMIN
: SPF_SMAX,
SPNB_NA, false};
return {Pred == CmpInst::ICMP_SGT ? SPF_SMIN : SPF_SMAX, SPNB_NA, false};
// (X >s C) ? ~C : ~X ==> (~X <s ~C) ? ~C : ~X ==> SMAX(~C, ~X)
// (X <s C) ? ~C : ~X ==> (~X >s ~C) ? ~C : ~X ==> SMIN(~C, ~X)
if (match(FalseVal, m_Not(m_Specific(CmpLHS))) &&
match(TrueVal, m_APInt(C2)) && ~(*C1) == *C2)
return {(Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE) ? SPF_SMAX
: SPF_SMIN,
SPNB_NA, false};
return {Pred == CmpInst::ICMP_SGT ? SPF_SMAX : SPF_SMIN, SPNB_NA, false};
return {SPF_UNKNOWN, SPNB_NA, false};
}

20
llvm/test/Transforms/InstCombine/minmax-fold.ll
View File

@ -404,8 +404,8 @@ define i32 @clamp_signed3(i32 %x) {
; CHECK-LABEL: @clamp_signed3(
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[X:%.*]], 255
; CHECK-NEXT: [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 255
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i32 [[MIN]], 15
; CHECK-NEXT: [[R:%.*]] = select i1 [[TMP1]], i32 [[MIN]], i32 15
; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 [[X]], 15
; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP1]], i32 [[MIN]], i32 15
; CHECK-NEXT: ret i32 [[R]]
;
%cmp2 = icmp slt i32 %x, 255
@ -421,8 +421,8 @@ define i32 @clamp_signed4(i32 %x) {
; CHECK-LABEL: @clamp_signed4(
; CHECK-NEXT: [[CMP2:%.*]] = icmp sgt i32 [[X:%.*]], 15
; CHECK-NEXT: [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 15
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i32 [[MAX]], 255
; CHECK-NEXT: [[R:%.*]] = select i1 [[TMP1]], i32 [[MAX]], i32 255
; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i32 [[X]], 255
; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP1]], i32 [[MAX]], i32 255
; CHECK-NEXT: ret i32 [[R]]
;
%cmp2 = icmp sgt i32 %x, 15
@ -472,8 +472,8 @@ define i32 @clamp_unsigned3(i32 %x) {
; CHECK-LABEL: @clamp_unsigned3(
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[X:%.*]], 255
; CHECK-NEXT: [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 255
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[MIN]], 15
; CHECK-NEXT: [[R:%.*]] = select i1 [[TMP1]], i32 [[MIN]], i32 15
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt i32 [[X]], 15
; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP1]], i32 [[MIN]], i32 15
; CHECK-NEXT: ret i32 [[R]]
;
%cmp2 = icmp ult i32 %x, 255
@ -489,8 +489,8 @@ define i32 @clamp_unsigned4(i32 %x) {
; CHECK-LABEL: @clamp_unsigned4(
; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i32 [[X:%.*]], 15
; CHECK-NEXT: [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 15
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 [[MAX]], 255
; CHECK-NEXT: [[R:%.*]] = select i1 [[TMP1]], i32 [[MAX]], i32 255
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[X]], 255
; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP1]], i32 [[MAX]], i32 255
; CHECK-NEXT: ret i32 [[R]]
;
%cmp2 = icmp ugt i32 %x, 15
@ -523,8 +523,8 @@ define i32 @clamp_check_for_no_infinite_loop2(i32 %i) {
; CHECK-LABEL: @clamp_check_for_no_infinite_loop2(
; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 [[I:%.*]], -255
; CHECK-NEXT: [[SEL1:%.*]] = select i1 [[CMP1]], i32 [[I]], i32 -255
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i32 [[SEL1]], 0
; CHECK-NEXT: [[RES:%.*]] = select i1 [[TMP1]], i32 [[SEL1]], i32 0
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[I]], 0
; CHECK-NEXT: [[RES:%.*]] = select i1 [[CMP2]], i32 [[SEL1]], i32 0
; CHECK-NEXT: ret i32 [[RES]]
;
%cmp1 = icmp sgt i32 %i, -255