support-single-floating-point-wasm.diff

diff --git a/llvm/include/llvm/MC/MCInst.h b/llvm/include/llvm/MC/MCInst.h
index 360dbda58fcb..50f847456c28 100644
--- a/llvm/include/llvm/MC/MCInst.h
+++ b/llvm/include/llvm/MC/MCInst.h
@@ -36,6 +36,7 @@ class MCOperand {
     kInvalid,     ///< Uninitialized.
     kRegister,    ///< Register operand.
     kImmediate,   ///< Immediate operand.
+    kSFPImmediate, ///< Single-floating-point immediate operand.
     kFPImmediate, ///< Floating-point immediate operand.
     kExpr,        ///< Relocatable immediate operand.
     kInst         ///< Sub-instruction operand.
@@ -45,6 +46,7 @@ class MCOperand {
   union {
     unsigned RegVal;
     int64_t ImmVal;
+    float SFPImmVal;
     double FPImmVal;
     const MCExpr *ExprVal;
     const MCInst *InstVal;
@@ -56,6 +58,7 @@ public:
   bool isValid() const { return Kind != kInvalid; }
   bool isReg() const { return Kind == kRegister; }
   bool isImm() const { return Kind == kImmediate; }
+  bool isSFPImm() const { return Kind == kSFPImmediate; }
   bool isFPImm() const { return Kind == kFPImmediate; }
   bool isExpr() const { return Kind == kExpr; }
   bool isInst() const { return Kind == kInst; }
@@ -82,6 +85,16 @@ public:
     ImmVal = Val;
   }
 
+  float getSFPImm() const {
+    assert(isSFPImm() && "This is not an SFP immediate");
+    return SFPImmVal;
+  }
+
+  void setSFPImm(float Val) {
+    assert(isSFPImm() && "This is not an SFP immediate");
+    SFPImmVal = Val;
+  }
+
   double getFPImm() const {
     assert(isFPImm() && "This is not an FP immediate");
     return FPImmVal;
@@ -126,6 +139,13 @@ public:
     return Op;
   }
 
+  static MCOperand createSFPImm(float Val) {
+    MCOperand Op;
+    Op.Kind = kSFPImmediate;
+    Op.SFPImmVal = Val;
+    return Op;
+  }
+
   static MCOperand createFPImm(double Val) {
     MCOperand Op;
     Op.Kind = kFPImmediate;
diff --git a/llvm/include/llvm/MC/MCInstBuilder.h b/llvm/include/llvm/MC/MCInstBuilder.h
index 0c8e01fdc412..f2986d6f2f5b 100644
--- a/llvm/include/llvm/MC/MCInstBuilder.h
+++ b/llvm/include/llvm/MC/MCInstBuilder.h
@@ -39,6 +39,12 @@ public:
     return *this;
   }
 
+  /// Add a new floating point immediate operand.
+  MCInstBuilder &addSFPImm(float Val) {
+    Inst.addOperand(MCOperand::createSFPImm(Val));
+    return *this;
+  }
+
   /// Add a new floating point immediate operand.
   MCInstBuilder &addFPImm(double Val) {
     Inst.addOperand(MCOperand::createFPImm(Val));
diff --git a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
index d0e9eb1fc9bc..41b2a29aaaf3 100644
--- a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
+++ b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
@@ -126,7 +126,7 @@ struct WebAssemblyOperand : public MCParsedAsmOperand {
   void addFPImmOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     if (Kind == Float)
-      Inst.addOperand(MCOperand::createFPImm(Flt.Val));
+      Inst.addOperand(MCOperand::createSFPImm(Flt.Val));
     else
       llvm_unreachable("Should be float immediate!");
   }
diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyInstPrinter.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyInstPrinter.cpp
index f60b5fcd14ec..4367fea5ce8d 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyInstPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyInstPrinter.cpp
@@ -240,9 +240,7 @@ void WebAssemblyInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
     const MCInstrDesc &Desc = MII.get(MI->getOpcode());
     const MCOperandInfo &Info = Desc.OpInfo[OpNo];
     if (Info.OperandType == WebAssembly::OPERAND_F32IMM) {
-      // TODO: MC converts all floating point immediate operands to double.
-      // This is fine for numeric values, but may cause NaNs to change bits.
-      O << ::toString(APFloat(float(Op.getFPImm())));
+      O << ::toString(APFloat(Op.getSFPImm()));
     } else {
       assert(Info.OperandType == WebAssembly::OPERAND_F64IMM);
       O << ::toString(APFloat(Op.getFPImm()));
diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
index 1a4c57e66d2f..4148a5432dcd 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
@@ -128,9 +128,7 @@ void WebAssemblyMCCodeEmitter::encodeInstruction(
     } else if (MO.isFPImm()) {
       const MCOperandInfo &Info = Desc.OpInfo[I];
       if (Info.OperandType == WebAssembly::OPERAND_F32IMM) {
-        // TODO: MC converts all floating point immediate operands to double.
-        // This is fine for numeric values, but may cause NaNs to change bits.
-        auto F = float(MO.getFPImm());
+        auto F = MO.getSFPImm();
         support::endian::write<float>(OS, F, support::little);
       } else {
         assert(Info.OperandType == WebAssembly::OPERAND_F64IMM);
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
index 07f183c0e1a1..a00323bc7bb9 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -275,11 +275,9 @@ void WebAssemblyMCInstLower::lower(const MachineInstr *MI,
       break;
     }
     case MachineOperand::MO_FPImmediate: {
-      // TODO: MC converts all floating point immediate operands to double.
-      // This is fine for numeric values, but may cause NaNs to change bits.
       const ConstantFP *Imm = MO.getFPImm();
       if (Imm->getType()->isFloatTy())
-        MCOp = MCOperand::createFPImm(Imm->getValueAPF().convertToFloat());
+        MCOp = MCOperand::createSFPImm(Imm->getValueAPF().convertToFloat());
       else if (Imm->getType()->isDoubleTy())
         MCOp = MCOperand::createFPImm(Imm->getValueAPF().convertToDouble());
       else