[IR] Add AllowContract to FastMathFlags

-ffp-contract=fast does not currently work with LTO because it's passed as a
TargetOption to the backend rather than in the IR. This adds it to
FastMathFlags.

This is toward fixing PR25721

Differential Revision: https://reviews.llvm.org/D31164

llvm-svn: 298939

7 files changed, 17 insertions, 0 deletions

diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 752942fc9fc..49a8ce4bed0 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -548,6 +548,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(ninf);
   KEYWORD(nsz);
   KEYWORD(arcp);
+  KEYWORD(contract);
   KEYWORD(fast);
   KEYWORD(nuw);
   KEYWORD(nsw);
diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
index 7dae33480ed..3a794142172 100644
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -193,6 +193,10 @@ namespace llvm {
         case lltok::kw_ninf: FMF.setNoInfs();          Lex.Lex(); continue;
         case lltok::kw_nsz:  FMF.setNoSignedZeros();   Lex.Lex(); continue;
         case lltok::kw_arcp: FMF.setAllowReciprocal(); Lex.Lex(); continue;
+        case lltok::kw_contract:
+          FMF.setAllowContract(true);
+          Lex.Lex();
+          continue;
         default: return FMF;
         }
       return FMF;
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index 048aeee90b3..33f8e63daa0 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -98,6 +98,7 @@ enum Kind {
   kw_ninf,
   kw_nsz,
   kw_arcp,
+  kw_contract,
   kw_fast,
   kw_nuw,
   kw_nsw,
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 4bb0e9fb472..4198d8f7c10 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -971,6 +971,8 @@ static FastMathFlags getDecodedFastMathFlags(unsigned Val) {
     FMF.setNoSignedZeros();
   if (0 != (Val & FastMathFlags::AllowReciprocal))
     FMF.setAllowReciprocal();
+  if (0 != (Val & FastMathFlags::AllowContract))
+    FMF.setAllowContract(true);
   return FMF;
 }
 
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index b1200587e62..1bdb439086a 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1336,6 +1336,8 @@ static uint64_t getOptimizationFlags(const Value *V) {
       Flags |= FastMathFlags::NoSignedZeros;
     if (FPMO->hasAllowReciprocal())
       Flags |= FastMathFlags::AllowReciprocal;
+    if (FPMO->hasAllowContract())
+      Flags |= FastMathFlags::AllowContract;
   }
 
   return Flags;
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index ca00b1703cb..3afa3986052 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -1073,6 +1073,8 @@ static void WriteOptimizationInfo(raw_ostream &Out, const User *U) {
         Out << " nsz";
       if (FPO->hasAllowReciprocal())
         Out << " arcp";
+      if (FPO->hasAllowContract())
+        Out << " contract";
     }
   }
 
diff --git a/llvm/lib/IR/Instruction.cpp b/llvm/lib/IR/Instruction.cpp
index d2114dc24af..c26699eab4e 100644
--- a/llvm/lib/IR/Instruction.cpp
+++ b/llvm/lib/IR/Instruction.cpp
@@ -204,6 +204,11 @@ bool Instruction::hasAllowReciprocal() const {
   return cast<FPMathOperator>(this)->hasAllowReciprocal();
 }
 
+bool Instruction::hasAllowContract() const {
+  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
+  return cast<FPMathOperator>(this)->hasAllowContract();
+}
+
 FastMathFlags Instruction::getFastMathFlags() const {
   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
   return cast<FPMathOperator>(this)->getFastMathFlags();