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-rw-r--r--llvm/docs/LangRef.rst8
-rw-r--r--llvm/include/llvm/IR/IRBuilder.h5
-rw-r--r--llvm/include/llvm/IR/Operator.h6
-rw-r--r--llvm/lib/Analysis/IVDescriptors.cpp3
-rw-r--r--llvm/lib/AsmParser/LLParser.cpp14
-rw-r--r--llvm/lib/Bitcode/Reader/BitcodeReader.cpp29
-rw-r--r--llvm/lib/Bitcode/Writer/BitcodeWriter.cpp5
-rw-r--r--llvm/test/Bitcode/compatibility.ll21
-rw-r--r--llvm/unittests/IR/InstructionsTest.cpp7
9 files changed, 85 insertions, 13 deletions
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index 87e1b971605..a38356aa27e 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -10067,7 +10067,7 @@ Syntax:
::
- <result> = phi <ty> [ <val0>, <label0>], ...
+ <result> = phi [fast-math-flags] <ty> [ <val0>, <label0>], ...
Overview:
"""""""""
@@ -10094,6 +10094,12 @@ deemed to occur on the edge from the corresponding predecessor block to
the current block (but after any definition of an '``invoke``'
instruction's return value on the same edge).
+The optional ``fast-math-flags`` marker indicates that the phi has one
+or more :ref:`fast-math-flags <fastmath>`. These are optimization hints
+to enable otherwise unsafe floating-point optimizations. Fast-math-flags
+are only valid for phis that return a floating-point scalar or vector
+type.
+
Semantics:
""""""""""
diff --git a/llvm/include/llvm/IR/IRBuilder.h b/llvm/include/llvm/IR/IRBuilder.h
index e5dcea1d4c0..c3918473eac 100644
--- a/llvm/include/llvm/IR/IRBuilder.h
+++ b/llvm/include/llvm/IR/IRBuilder.h
@@ -2231,7 +2231,10 @@ public:
PHINode *CreatePHI(Type *Ty, unsigned NumReservedValues,
const Twine &Name = "") {
- return Insert(PHINode::Create(Ty, NumReservedValues), Name);
+ PHINode *Phi = PHINode::Create(Ty, NumReservedValues);
+ if (isa<FPMathOperator>(Phi))
+ Phi = cast<PHINode>(setFPAttrs(Phi, nullptr /* MDNode* */, FMF));
+ return Insert(Phi, Name);
}
CallInst *CreateCall(FunctionType *FTy, Value *Callee,
diff --git a/llvm/include/llvm/IR/Operator.h b/llvm/include/llvm/IR/Operator.h
index 8199c65ca8a..608f33c3ed5 100644
--- a/llvm/include/llvm/IR/Operator.h
+++ b/llvm/include/llvm/IR/Operator.h
@@ -379,13 +379,17 @@ public:
return false;
switch (Opcode) {
+ // FIXME: To clean up and correct the semantics of fast-math-flags, FCmp
+ // should not be treated as a math op, but the other opcodes should.
+ // This would make things consistent with Select/PHI (FP value type
+ // determines whether they are math ops and, therefore, capable of
+ // having fast-math-flags).
case Instruction::FCmp:
return true;
// non math FP Operators (no FMF)
case Instruction::ExtractElement:
case Instruction::ShuffleVector:
case Instruction::InsertElement:
- case Instruction::PHI:
return false;
default:
return V->getType()->isFPOrFPVectorTy();
diff --git a/llvm/lib/Analysis/IVDescriptors.cpp b/llvm/lib/Analysis/IVDescriptors.cpp
index ce285f82f72..6fb600114bc 100644
--- a/llvm/lib/Analysis/IVDescriptors.cpp
+++ b/llvm/lib/Analysis/IVDescriptors.cpp
@@ -300,7 +300,8 @@ bool RecurrenceDescriptor::AddReductionVar(PHINode *Phi, RecurrenceKind Kind,
ReduxDesc = isRecurrenceInstr(Cur, Kind, ReduxDesc, HasFunNoNaNAttr);
if (!ReduxDesc.isRecurrence())
return false;
- if (isa<FPMathOperator>(ReduxDesc.getPatternInst()))
+ // FIXME: FMF is allowed on phi, but propagation is not handled correctly.
+ if (isa<FPMathOperator>(ReduxDesc.getPatternInst()) && !IsAPhi)
FMF &= ReduxDesc.getPatternInst()->getFastMathFlags();
}
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index eb66a7c82b5..5ea0b7d39c1 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -5802,7 +5802,19 @@ int LLParser::ParseInstruction(Instruction *&Inst, BasicBlock *BB,
case lltok::kw_extractelement: return ParseExtractElement(Inst, PFS);
case lltok::kw_insertelement: return ParseInsertElement(Inst, PFS);
case lltok::kw_shufflevector: return ParseShuffleVector(Inst, PFS);
- case lltok::kw_phi: return ParsePHI(Inst, PFS);
+ case lltok::kw_phi: {
+ FastMathFlags FMF = EatFastMathFlagsIfPresent();
+ int Res = ParsePHI(Inst, PFS);
+ if (Res != 0)
+ return Res;
+ if (FMF.any()) {
+ if (!Inst->getType()->isFPOrFPVectorTy())
+ return Error(Loc, "fast-math-flags specified for phi without "
+ "floating-point scalar or vector return type");
+ Inst->setFastMathFlags(FMF);
+ }
+ return 0;
+ }
case lltok::kw_landingpad: return ParseLandingPad(Inst, PFS);
// Call.
case lltok::kw_call: return ParseCall(Inst, PFS, CallInst::TCK_None);
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 89a5b7bdd5b..9c377552b4a 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4629,31 +4629,48 @@ Error BitcodeReader::parseFunctionBody(Function *F) {
InstructionList.push_back(I);
break;
case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
- if (Record.size() < 1 || ((Record.size()-1)&1))
+ if (Record.size() < 1)
return error("Invalid record");
+ // The first record specifies the type.
FullTy = getFullyStructuredTypeByID(Record[0]);
Type *Ty = flattenPointerTypes(FullTy);
if (!Ty)
return error("Invalid record");
- PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
+ // Phi arguments are pairs of records of [value, basic block].
+ // There is an optional final record for fast-math-flags if this phi has a
+ // floating-point type.
+ size_t NumArgs = (Record.size() - 1) / 2;
+ if ((Record.size() - 1) % 2 == 1 && !Ty->isFloatingPointTy())
+ return error("Invalid record");
+
+ PHINode *PN = PHINode::Create(Ty, NumArgs);
InstructionList.push_back(PN);
- for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
+ for (unsigned i = 0; i != NumArgs; i++) {
Value *V;
// With the new function encoding, it is possible that operands have
// negative IDs (for forward references). Use a signed VBR
// representation to keep the encoding small.
if (UseRelativeIDs)
- V = getValueSigned(Record, 1+i, NextValueNo, Ty);
+ V = getValueSigned(Record, i * 2 + 1, NextValueNo, Ty);
else
- V = getValue(Record, 1+i, NextValueNo, Ty);
- BasicBlock *BB = getBasicBlock(Record[2+i]);
+ V = getValue(Record, i * 2 + 1, NextValueNo, Ty);
+ BasicBlock *BB = getBasicBlock(Record[i * 2 + 2]);
if (!V || !BB)
return error("Invalid record");
PN->addIncoming(V, BB);
}
I = PN;
+
+ // If there are an even number of records, the final record must be FMF.
+ if (Record.size() % 2 == 0) {
+ assert(isa<FPMathOperator>(I) && "Unexpected phi type");
+ FastMathFlags FMF = getDecodedFastMathFlags(Record[Record.size() - 1]);
+ if (FMF.any())
+ I->setFastMathFlags(FMF);
+ }
+
break;
}
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 0eea6dc87ce..2818e843b50 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -2880,6 +2880,11 @@ void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
}
+
+ uint64_t Flags = getOptimizationFlags(&I);
+ if (Flags != 0)
+ Vals64.push_back(Flags);
+
// Emit a Vals64 vector and exit.
Stream.EmitRecord(Code, Vals64, AbbrevToUse);
Vals64.clear();
diff --git a/llvm/test/Bitcode/compatibility.ll b/llvm/test/Bitcode/compatibility.ll
index b17aeda8ebb..9e7f6ac9917 100644
--- a/llvm/test/Bitcode/compatibility.ll
+++ b/llvm/test/Bitcode/compatibility.ll
@@ -861,6 +861,27 @@ define void @fastmathflags_vector_select(<2 x i1> %cond, <2 x double> %op1, <2 x
ret void
}
+define void @fastmathflags_phi(i1 %cond, float %f1, float %f2, double %d1, double %d2, half %h1, half %h2) {
+entry:
+ br i1 %cond, label %L1, label %L2
+L1:
+ br label %exit
+L2:
+ br label %exit
+exit:
+ %p.nnan = phi nnan float [ %f1, %L1 ], [ %f2, %L2 ]
+ ; CHECK: %p.nnan = phi nnan float [ %f1, %L1 ], [ %f2, %L2 ]
+ %p.ninf = phi ninf double [ %d1, %L1 ], [ %d2, %L2 ]
+ ; CHECK: %p.ninf = phi ninf double [ %d1, %L1 ], [ %d2, %L2 ]
+ %p.contract = phi contract half [ %h1, %L1 ], [ %h2, %L2 ]
+ ; CHECK: %p.contract = phi contract half [ %h1, %L1 ], [ %h2, %L2 ]
+ %p.nsz.reassoc = phi reassoc nsz float [ %f1, %L1 ], [ %f2, %L2 ]
+ ; CHECK: %p.nsz.reassoc = phi reassoc nsz float [ %f1, %L1 ], [ %f2, %L2 ]
+ %p.fast = phi fast half [ %h2, %L1 ], [ %h1, %L2 ]
+ ; CHECK: %p.fast = phi fast half [ %h2, %L1 ], [ %h1, %L2 ]
+ ret void
+}
+
; Check various fast math flags and floating-point types on calls.
declare float @fmf1()
diff --git a/llvm/unittests/IR/InstructionsTest.cpp b/llvm/unittests/IR/InstructionsTest.cpp
index b2ea3844d33..afd579400ff 100644
--- a/llvm/unittests/IR/InstructionsTest.cpp
+++ b/llvm/unittests/IR/InstructionsTest.cpp
@@ -1034,13 +1034,16 @@ TEST(InstructionsTest, SkipDebug) {
EXPECT_EQ(nullptr, Term->getNextNonDebugInstruction());
}
-TEST(InstructionsTest, PhiIsNotFPMathOperator) {
+TEST(InstructionsTest, PhiMightNotBeFPMathOperator) {
LLVMContext Context;
IRBuilder<> Builder(Context);
MDBuilder MDHelper(Context);
- Instruction *I = Builder.CreatePHI(Builder.getDoubleTy(), 0);
+ Instruction *I = Builder.CreatePHI(Builder.getInt32Ty(), 0);
EXPECT_FALSE(isa<FPMathOperator>(I));
I->deleteValue();
+ Instruction *FP = Builder.CreatePHI(Builder.getDoubleTy(), 0);
+ EXPECT_TRUE(isa<FPMathOperator>(FP));
+ FP->deleteValue();
}
TEST(InstructionsTest, FNegInstruction) {
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