1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 12:43:36 +01:00

[ConstantRange] Add signed/unsigned unionWith()

This extends D59959 to unionWith(), allowing to specify that a
non-wrapping unsigned/signed range is preferred. This is somewhat
less useful than the intersect case, because union operations are
rarer. An example use would the the phi union computed in SCEV.

The implementation is mostly a straightforward use of getPreferredRange(),
but I also had to adjust some <=/< checks to make sure that no ranges with
lower==upper get constructed before they're passed to getPreferredRange(),
as these have additional constraints.

Differential Revision: https://reviews.llvm.org/D60377

llvm-svn: 357876
This commit is contained in:
Nikita Popov 2019-04-07 20:20:24 +00:00
parent 6b05308d50
commit 3d7ca4f4ba
3 changed files with 33 additions and 19 deletions

View File

@ -277,7 +277,8 @@ public:
/// elements of both sets, but may contain more. For example, [3, 9) union
/// [12,15) is [3, 15), which includes 9, 10, and 11, which were not included
/// in either set before.
ConstantRange unionWith(const ConstantRange &CR) const;
ConstantRange unionWith(const ConstantRange &CR,
PreferredRangeType Type = Smallest) const;
/// Return a new range representing the possible values resulting
/// from an application of the specified cast operator to this range. \p

View File

@ -593,23 +593,26 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR,
return getPreferredRange(*this, CR, Type);
}
ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
ConstantRange ConstantRange::unionWith(const ConstantRange &CR,
PreferredRangeType Type) const {
assert(getBitWidth() == CR.getBitWidth() &&
"ConstantRange types don't agree!");
if ( isFullSet() || CR.isEmptySet()) return *this;
if (CR.isFullSet() || isEmptySet()) return CR;
if (!isUpperWrapped() && CR.isUpperWrapped()) return CR.unionWith(*this);
if (!isUpperWrapped() && CR.isUpperWrapped())
return CR.unionWith(*this, Type);
if (!isUpperWrapped() && !CR.isUpperWrapped()) {
if (CR.Upper.ult(Lower) || Upper.ult(CR.Lower)) {
// If the two ranges are disjoint, find the smaller gap and bridge it.
APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
if (d1.ult(d2))
return ConstantRange(Lower, CR.Upper);
return ConstantRange(CR.Lower, Upper);
}
// L---U and L---U : this
// L---U L---U : CR
// result in one of
// L---------U
// -----U L-----
if (CR.Upper.ult(Lower) || Upper.ult(CR.Lower))
return getPreferredRange(
ConstantRange(Lower, CR.Upper), ConstantRange(CR.Lower, Upper), Type);
APInt L = CR.Lower.ult(Lower) ? CR.Lower : Lower;
APInt U = (CR.Upper - 1).ugt(Upper - 1) ? CR.Upper : Upper;
@ -633,22 +636,21 @@ ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
// ----U L---- : this
// L---U : CR
// <d1> <d2>
if (Upper.ule(CR.Lower) && CR.Upper.ule(Lower)) {
APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
if (d1.ult(d2))
return ConstantRange(Lower, CR.Upper);
return ConstantRange(CR.Lower, Upper);
}
// results in one of
// ----------U L----
// ----U L----------
if (Upper.ult(CR.Lower) && CR.Upper.ult(Lower))
return getPreferredRange(
ConstantRange(Lower, CR.Upper), ConstantRange(CR.Lower, Upper), Type);
// ----U L----- : this
// L----U : CR
if (Upper.ult(CR.Lower) && Lower.ult(CR.Upper))
if (Upper.ult(CR.Lower) && Lower.ule(CR.Upper))
return ConstantRange(CR.Lower, Upper);
// ------U L---- : this
// L-----U : CR
assert(CR.Lower.ult(Upper) && CR.Upper.ult(Lower) &&
assert(CR.Lower.ule(Upper) && CR.Upper.ult(Lower) &&
"ConstantRange::unionWith missed a case with one range wrapped");
return ConstantRange(Lower, CR.Upper);
}

View File

@ -501,6 +501,17 @@ TEST_F(ConstantRangeTest, IntersectWithExhaustive) {
});
}
TEST_F(ConstantRangeTest, UnionWithExhaustive) {
testBinarySetOperationExhaustive(
[](const ConstantRange &CR1, const ConstantRange &CR2,
ConstantRange::PreferredRangeType Type) {
return CR1.unionWith(CR2, Type);
},
[](const ConstantRange &CR1, const ConstantRange &CR2, const APInt &N) {
return CR1.contains(N) || CR2.contains(N);
});
}
TEST_F(ConstantRangeTest, UnionWith) {
EXPECT_EQ(Wrap.unionWith(One),
ConstantRange(APInt(16, 0xaaa), APInt(16, 0xb)));