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[LVI][CVP] Add support for saturating add/sub 

Adds support for the uadd.sat family of intrinsics in LVI, based on
ConstantRange methods from D60946.

Differential Revision: https://reviews.llvm.org/D62447

llvm-svn: 361703
This commit is contained in:
Nikita Popov 2019-05-25 16:44:14 +00:00
parent 34d5a74b03
commit 6bb5041e94
2 changed files with 40 additions and 4 deletions
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36
llvm/lib/Analysis/LazyValueInfo.cpp
View File

@ -432,6 +432,8 @@ namespace {
BasicBlock *BB);
bool solveBlockValueOverflowIntrinsic(
ValueLatticeElement &BBLV, WithOverflowInst *WO, BasicBlock *BB);
bool solveBlockValueIntrinsic(ValueLatticeElement &BBLV, IntrinsicInst *II,
BasicBlock *BB);
void intersectAssumeOrGuardBlockValueConstantRange(Value *Val,
ValueLatticeElement &BBLV,
Instruction *BBI);
@ -649,6 +651,9 @@ bool LazyValueInfoImpl::solveBlockValueImpl(ValueLatticeElement &Res,
if (auto *WO = dyn_cast<WithOverflowInst>(EVI->getAggregateOperand()))
if (EVI->getNumIndices() == 1 && *EVI->idx_begin() == 0)
return solveBlockValueOverflowIntrinsic(Res, WO, BB);
if (auto *II = dyn_cast<IntrinsicInst>(BBI))
return solveBlockValueIntrinsic(Res, II, BB);
}
LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()
@ -1112,6 +1117,37 @@ bool LazyValueInfoImpl::solveBlockValueOverflowIntrinsic(
});
}
bool LazyValueInfoImpl::solveBlockValueIntrinsic(
ValueLatticeElement &BBLV, IntrinsicInst *II, BasicBlock *BB) {
switch (II->getIntrinsicID()) {
case Intrinsic::uadd_sat:
return solveBlockValueBinaryOpImpl(BBLV, II, BB,
[](const ConstantRange &CR1, const ConstantRange &CR2) {
return CR1.uadd_sat(CR2);
});
case Intrinsic::usub_sat:
return solveBlockValueBinaryOpImpl(BBLV, II, BB,
[](const ConstantRange &CR1, const ConstantRange &CR2) {
return CR1.usub_sat(CR2);
});
case Intrinsic::sadd_sat:
return solveBlockValueBinaryOpImpl(BBLV, II, BB,
[](const ConstantRange &CR1, const ConstantRange &CR2) {
return CR1.sadd_sat(CR2);
});
case Intrinsic::ssub_sat:
return solveBlockValueBinaryOpImpl(BBLV, II, BB,
[](const ConstantRange &CR1, const ConstantRange &CR2) {
return CR1.ssub_sat(CR2);
});
default:
LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()
<< "' - overdefined (unknown intrinsic).\n");
BBLV = ValueLatticeElement::getOverdefined();
return true;
}
}
static ValueLatticeElement getValueFromICmpCondition(Value *Val, ICmpInst *ICI,
bool isTrueDest) {
Value *LHS = ICI->getOperand(0);

8
llvm/test/Transforms/CorrelatedValuePropagation/basic.ll
View File

@ -995,7 +995,7 @@ define i1 @uadd_sat_unknown(i32 %a) {
; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i32 [[VAL]], 100
; CHECK-NEXT: br i1 undef, label [[EXIT1:%.*]], label [[EXIT2:%.*]]
; CHECK: exit1:
; CHECK-NEXT: ret i1 [[CMP1]]
; CHECK-NEXT: ret i1 true
; CHECK: exit2:
; CHECK-NEXT: ret i1 [[CMP2]]
;
@ -1018,7 +1018,7 @@ define i1 @usub_sat_unknown(i32 %a) {
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[VAL]], -101
; CHECK-NEXT: br i1 undef, label [[EXIT1:%.*]], label [[EXIT2:%.*]]
; CHECK: exit1:
; CHECK-NEXT: ret i1 [[CMP1]]
; CHECK-NEXT: ret i1 true
; CHECK: exit2:
; CHECK-NEXT: ret i1 [[CMP2]]
;
@ -1041,7 +1041,7 @@ define i1 @sadd_sat_unknown(i32 %a) {
; CHECK-NEXT: [[CMP2:%.*]] = icmp sgt i32 [[VAL]], -2147483548
; CHECK-NEXT: br i1 undef, label [[EXIT1:%.*]], label [[EXIT2:%.*]]
; CHECK: exit1:
; CHECK-NEXT: ret i1 [[CMP1]]
; CHECK-NEXT: ret i1 true
; CHECK: exit2:
; CHECK-NEXT: ret i1 [[CMP2]]
;
@ -1064,7 +1064,7 @@ define i1 @ssub_sat_unknown(i32 %a) {
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[VAL]], 2147483547
; CHECK-NEXT: br i1 undef, label [[EXIT1:%.*]], label [[EXIT2:%.*]]
; CHECK: exit1:
; CHECK-NEXT: ret i1 [[CMP1]]
; CHECK-NEXT: ret i1 true
; CHECK: exit2:
; CHECK-NEXT: ret i1 [[CMP2]]
;