enhance vmcore to know that udiv's can be exact, and add a trivial
instcombine xform to exercise this.
Nothing forms exact udivs yet though. This is progress on PR8862
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124992 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 8ef4634..6d71c9e 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -2304,7 +2304,7 @@
if (EatIfPresent(lltok::kw_nuw))
NUW = true;
}
- } else if (Opc == Instruction::SDiv) {
+ } else if (Opc == Instruction::SDiv || Opc == Instruction::UDiv) {
if (EatIfPresent(lltok::kw_exact))
Exact = true;
}
@@ -2347,7 +2347,7 @@
unsigned Flags = 0;
if (NUW) Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
if (NSW) Flags |= OverflowingBinaryOperator::NoSignedWrap;
- if (Exact) Flags |= SDivOperator::IsExact;
+ if (Exact) Flags |= PossiblyExactOperator::IsExact;
Constant *C = ConstantExpr::get(Opc, Val0, Val1, Flags);
ID.ConstantVal = C;
ID.Kind = ValID::t_Constant;
@@ -3032,7 +3032,8 @@
case lltok::kw_fsub:
case lltok::kw_fmul: return ParseArithmetic(Inst, PFS, KeywordVal, 2);
- case lltok::kw_sdiv: {
+ case lltok::kw_sdiv:
+ case lltok::kw_udiv: {
bool Exact = false;
if (EatIfPresent(lltok::kw_exact))
Exact = true;
@@ -3043,7 +3044,6 @@
return Result;
}
- case lltok::kw_udiv:
case lltok::kw_urem:
case lltok::kw_srem: return ParseArithmetic(Inst, PFS, KeywordVal, 1);
case lltok::kw_fdiv:
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index adcad74..a744d83 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1090,8 +1090,9 @@
Flags |= OverflowingBinaryOperator::NoSignedWrap;
if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
- } else if (Opc == Instruction::SDiv) {
- if (Record[3] & (1 << bitc::SDIV_EXACT))
+ } else if (Opc == Instruction::SDiv ||
+ Opc == Instruction::UDiv) {
+ if (Record[3] & (1 << bitc::PEO_EXACT))
Flags |= SDivOperator::IsExact;
}
}
@@ -1905,8 +1906,9 @@
cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
- } else if (Opc == Instruction::SDiv) {
- if (Record[OpNum] & (1 << bitc::SDIV_EXACT))
+ } else if (Opc == Instruction::SDiv ||
+ Opc == Instruction::UDiv) {
+ if (Record[OpNum] & (1 << bitc::PEO_EXACT))
cast<BinaryOperator>(I)->setIsExact(true);
}
}
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 702a611..f8ef8c6 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -470,9 +470,10 @@
Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
if (OBO->hasNoUnsignedWrap())
Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
- } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
- if (Div->isExact())
- Flags |= 1 << bitc::SDIV_EXACT;
+ } else if (const PossiblyExactOperator *PEO =
+ dyn_cast<PossiblyExactOperator>(V)) {
+ if (PEO->isExact())
+ Flags |= 1 << bitc::PEO_EXACT;
}
return Flags;
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 035ee72..559788b 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -135,8 +135,8 @@
BO->getOpcode() == Instruction::SDiv)) {
Value *Op0BO = BO->getOperand(0), *Op1BO = BO->getOperand(1);
- // If the division is exact, X % Y is zero.
- if (SDivOperator *SDiv = dyn_cast<SDivOperator>(BO))
+ // If the division is exact, X % Y is zero, so we end up with X or -X.
+ if (PossiblyExactOperator *SDiv = dyn_cast<PossiblyExactOperator>(BO))
if (SDiv->isExact()) {
if (Op1BO == Op1C)
return ReplaceInstUsesWith(I, Op0BO);
diff --git a/lib/VMCore/AsmWriter.cpp b/lib/VMCore/AsmWriter.cpp
index 1a11d9c..5b56cb5 100644
--- a/lib/VMCore/AsmWriter.cpp
+++ b/lib/VMCore/AsmWriter.cpp
@@ -831,7 +831,8 @@
Out << " nuw";
if (OBO->hasNoSignedWrap())
Out << " nsw";
- } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(U)) {
+ } else if (const PossiblyExactOperator *Div =
+ dyn_cast<PossiblyExactOperator>(U)) {
if (Div->isExact())
Out << " exact";
} else if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 62117b2..d2359e5 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -683,7 +683,12 @@
Constant* ConstantExpr::getExactSDiv(Constant* C1, Constant* C2) {
return getTy(C1->getType(), Instruction::SDiv, C1, C2,
- SDivOperator::IsExact);
+ PossiblyExactOperator::IsExact);
+}
+
+Constant* ConstantExpr::getExactUDiv(Constant* C1, Constant* C2) {
+ return getTy(C1->getType(), Instruction::UDiv, C1, C2,
+ PossiblyExactOperator::IsExact);
}
// Utility function for determining if a ConstantExpr is a CastOp or not. This
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 6b561f3..d129028 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -1822,7 +1822,7 @@
}
void BinaryOperator::setIsExact(bool b) {
- cast<SDivOperator>(this)->setIsExact(b);
+ cast<PossiblyExactOperator>(this)->setIsExact(b);
}
bool BinaryOperator::hasNoUnsignedWrap() const {
@@ -1834,7 +1834,7 @@
}
bool BinaryOperator::isExact() const {
- return cast<SDivOperator>(this)->isExact();
+ return cast<PossiblyExactOperator>(this)->isExact();
}
//===----------------------------------------------------------------------===//