[ConstantRange] Add getNonEmpty() constructor
ConstantRanges have an annoying special case: If upper and lower are
the same, it can be either an empty or a full set. When constructing
constant ranges nearly always a full set is intended, but this still
requires an explicit check in many places.
This revision adds a getNonEmpty() constructor that disambiguates this
case: If upper and lower are the same, a full set is created.
Differential Revision: https://reviews.llvm.org/D60947
llvm-svn: 358854
diff --git a/llvm/include/llvm/IR/ConstantRange.h b/llvm/include/llvm/IR/ConstantRange.h
index ec57e08..6dbe405 100644
--- a/llvm/include/llvm/IR/ConstantRange.h
+++ b/llvm/include/llvm/IR/ConstantRange.h
@@ -79,6 +79,14 @@
return ConstantRange(BitWidth, true);
}
+ /// Create non-empty constant range with the given bounds. If Lower and
+ /// Upper are the same, a full range is returned.
+ static ConstantRange getNonEmpty(APInt Lower, APInt Upper) {
+ if (Lower == Upper)
+ return getFull(Lower.getBitWidth());
+ return ConstantRange(std::move(Lower), std::move(Upper));
+ }
+
/// Initialize a range based on a known bits constraint. The IsSigned flag
/// indicates whether the constant range should not wrap in the signed or
/// unsigned domain.
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 01b4019..1f69bc8 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -5808,12 +5808,8 @@
Descending ? std::move(StartUpper) : std::move(MovedBoundary);
NewUpper += 1;
- // If we end up with full range, return a proper full range.
- if (NewLower == NewUpper)
- return ConstantRange::getFull(BitWidth);
-
// No overflow detected, return [StartLower, StartUpper + Offset + 1) range.
- return ConstantRange(std::move(NewLower), std::move(NewUpper));
+ return ConstantRange::getNonEmpty(std::move(NewLower), std::move(NewUpper));
}
ConstantRange ScalarEvolution::getRangeForAffineAR(const SCEV *Start,
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 9c7b0fa..3b08a2d 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5726,8 +5726,7 @@
else if (auto *SI = dyn_cast<SelectInst>(V))
setLimitsForSelectPattern(*SI, Lower, Upper);
- ConstantRange CR = Lower != Upper ? ConstantRange(Lower, Upper)
- : ConstantRange::getFull(BitWidth);
+ ConstantRange CR = ConstantRange::getNonEmpty(Lower, Upper);
if (auto *I = dyn_cast<Instruction>(V))
if (auto *Range = IIQ.getMetadata(I, LLVMContext::MD_range))
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 87b66fa..7bd14e6 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -101,18 +101,10 @@
return getEmpty(W);
return ConstantRange(APInt::getSignedMinValue(W), std::move(SMax));
}
- case CmpInst::ICMP_ULE: {
- APInt UMax(CR.getUnsignedMax());
- if (UMax.isMaxValue())
- return getFull(W);
- return ConstantRange(APInt::getMinValue(W), std::move(UMax) + 1);
- }
- case CmpInst::ICMP_SLE: {
- APInt SMax(CR.getSignedMax());
- if (SMax.isMaxSignedValue())
- return getFull(W);
- return ConstantRange(APInt::getSignedMinValue(W), std::move(SMax) + 1);
- }
+ case CmpInst::ICMP_ULE:
+ return getNonEmpty(APInt::getMinValue(W), CR.getUnsignedMax() + 1);
+ case CmpInst::ICMP_SLE:
+ return getNonEmpty(APInt::getSignedMinValue(W), CR.getSignedMax() + 1);
case CmpInst::ICMP_UGT: {
APInt UMin(CR.getUnsignedMin());
if (UMin.isMaxValue())
@@ -125,18 +117,10 @@
return getEmpty(W);
return ConstantRange(std::move(SMin) + 1, APInt::getSignedMinValue(W));
}
- case CmpInst::ICMP_UGE: {
- APInt UMin(CR.getUnsignedMin());
- if (UMin.isMinValue())
- return getFull(W);
- return ConstantRange(std::move(UMin), APInt::getNullValue(W));
- }
- case CmpInst::ICMP_SGE: {
- APInt SMin(CR.getSignedMin());
- if (SMin.isMinSignedValue())
- return getFull(W);
- return ConstantRange(std::move(SMin), APInt::getSignedMinValue(W));
- }
+ case CmpInst::ICMP_UGE:
+ return getNonEmpty(CR.getUnsignedMin(), APInt::getNullValue(W));
+ case CmpInst::ICMP_SGE:
+ return getNonEmpty(CR.getSignedMin(), APInt::getSignedMinValue(W));
}
}
@@ -948,9 +932,7 @@
return getEmpty();
APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin());
APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1;
- if (NewU == NewL)
- return getFull();
- return ConstantRange(std::move(NewL), std::move(NewU));
+ return getNonEmpty(std::move(NewL), std::move(NewU));
}
ConstantRange
@@ -961,9 +943,7 @@
return getEmpty();
APInt NewL = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin());
APInt NewU = APIntOps::umax(getUnsignedMax(), Other.getUnsignedMax()) + 1;
- if (NewU == NewL)
- return getFull();
- return ConstantRange(std::move(NewL), std::move(NewU));
+ return getNonEmpty(std::move(NewL), std::move(NewU));
}
ConstantRange
@@ -974,9 +954,7 @@
return getEmpty();
APInt NewL = APIntOps::smin(getSignedMin(), Other.getSignedMin());
APInt NewU = APIntOps::smin(getSignedMax(), Other.getSignedMax()) + 1;
- if (NewU == NewL)
- return getFull();
- return ConstantRange(std::move(NewL), std::move(NewU));
+ return getNonEmpty(std::move(NewL), std::move(NewU));
}
ConstantRange
@@ -987,9 +965,7 @@
return getEmpty();
APInt NewL = APIntOps::umin(getUnsignedMin(), Other.getUnsignedMin());
APInt NewU = APIntOps::umin(getUnsignedMax(), Other.getUnsignedMax()) + 1;
- if (NewU == NewL)
- return getFull();
- return ConstantRange(std::move(NewL), std::move(NewU));
+ return getNonEmpty(std::move(NewL), std::move(NewU));
}
ConstantRange
@@ -1012,13 +988,7 @@
}
APInt Upper = getUnsignedMax().udiv(RHS_umin) + 1;
-
- // If the LHS is Full and the RHS is a wrapped interval containing 1 then
- // this could occur.
- if (Lower == Upper)
- return getFull();
-
- return ConstantRange(std::move(Lower), std::move(Upper));
+ return getNonEmpty(std::move(Lower), std::move(Upper));
}
ConstantRange
@@ -1029,9 +999,7 @@
// TODO: replace this with something less conservative
APInt umin = APIntOps::umin(Other.getUnsignedMax(), getUnsignedMax());
- if (umin.isAllOnesValue())
- return getFull();
- return ConstantRange(APInt::getNullValue(getBitWidth()), std::move(umin) + 1);
+ return getNonEmpty(APInt::getNullValue(getBitWidth()), std::move(umin) + 1);
}
ConstantRange
@@ -1042,9 +1010,7 @@
// TODO: replace this with something less conservative
APInt umax = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin());
- if (umax.isNullValue())
- return getFull();
- return ConstantRange(std::move(umax), APInt::getNullValue(getBitWidth()));
+ return getNonEmpty(std::move(umax), APInt::getNullValue(getBitWidth()));
}
ConstantRange
@@ -1079,10 +1045,7 @@
APInt max = getUnsignedMax().lshr(Other.getUnsignedMin()) + 1;
APInt min = getUnsignedMin().lshr(Other.getUnsignedMax());
- if (min == max)
- return getFull();
-
- return ConstantRange(std::move(min), std::move(max));
+ return getNonEmpty(std::move(min), std::move(max));
}
ConstantRange
@@ -1133,10 +1096,7 @@
min = NegMin;
max = PosMax;
}
- if (min == max)
- return getFull();
-
- return ConstantRange(std::move(min), std::move(max));
+ return getNonEmpty(std::move(min), std::move(max));
}
ConstantRange ConstantRange::inverse() const {