[mips] [IAS] Add support for the .set softfloat/hardfloat directives.

[tomatabacu]

Summary

These directives are used to set the current value of the SoftFloat feature.

[dsanders]

LGTM

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

#include "MipsGenAsmMatcher.inc"
   bool parseSetNoDspDirective();
   bool parseSetReorderDirective();
   bool parseSetNoReorderDirective();
   bool parseSetMips16Directive();
   bool parseSetNoMips16Directive();
   bool parseSetFpDirective();
   bool parseSetPopDirective();
   bool parseSetPushDirective();
+  bool parseSetSoftFloatDirective();
+  bool parseSetHardFloatDirective();
 
   bool parseSetAssignment();
 
   bool parseDataDirective(unsigned Size, SMLoc L);
   bool parseDirectiveGpWord();
   bool parseDirectiveGpDWord();
   bool parseDirectiveModule();
   bool parseDirectiveModuleFP();
bool MipsAsmParser::parseSetPushDirective() {
   // Create a copy of the current assembler options environment and push it.
   AssemblerOptions.push_back(
               make_unique<MipsAssemblerOptions>(AssemblerOptions.back().get()));
 
   getTargetStreamer().emitDirectiveSetPush();
   return false;
 }
 
+bool MipsAsmParser::parseSetSoftFloatDirective() {
+  MCAsmParser &Parser = getParser();
+  Parser.Lex();
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return reportParseError("unexpected token, expected end of statement");
+
+  setFeatureBits(Mips::FeatureSoftFloat, "soft-float");
+  getTargetStreamer().emitDirectiveSetSoftFloat();
+  return false;
+}
+
+bool MipsAsmParser::parseSetHardFloatDirective() {
+  MCAsmParser &Parser = getParser();
+  Parser.Lex();
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return reportParseError("unexpected token, expected end of statement");
+
+  clearFeatureBits(Mips::FeatureSoftFloat, "soft-float");
+  getTargetStreamer().emitDirectiveSetHardFloat();
+  return false;
+}
+
 bool MipsAsmParser::parseSetAssignment() {
   StringRef Name;
   const MCExpr *Value;
   MCAsmParser &Parser = getParser();
 
   if (Parser.parseIdentifier(Name))
     reportParseError("expected identifier after .set");
 
bool MipsAsmParser::parseDirectiveSet() {
   } else if (Tok.getString() == "dsp") {
     return parseSetFeature(Mips::FeatureDSP);
   } else if (Tok.getString() == "nodsp") {
     return parseSetNoDspDirective();
   } else if (Tok.getString() == "msa") {
     return parseSetMsaDirective();
   } else if (Tok.getString() == "nomsa") {
     return parseSetNoMsaDirective();
+  } else if (Tok.getString() == "softfloat") {
+    return parseSetSoftFloatDirective();
+  } else if (Tok.getString() == "hardfloat") {
+    return parseSetHardFloatDirective();
   } else {
     // It is just an identifier, look for an assignment.
     parseSetAssignment();
     return false;
   }
 
   return true;
 }

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

 void MipsTargetStreamer::emitDirectiveSetMips32R6() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetMips64() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetMips64R2() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetMips64R3() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetMips64R5() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetMips64R6() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetPop() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetPush() { forbidModuleDirective(); }
+void MipsTargetStreamer::emitDirectiveSetSoftFloat() {
+  forbidModuleDirective();
+}
+void MipsTargetStreamer::emitDirectiveSetHardFloat() {
+  forbidModuleDirective();
+}
 void MipsTargetStreamer::emitDirectiveSetDsp() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveSetNoDsp() { forbidModuleDirective(); }
 void MipsTargetStreamer::emitDirectiveCpLoad(unsigned RegNo) {}
 void MipsTargetStreamer::emitDirectiveCpsetup(unsigned RegNo, int RegOrOffset,
                                               const MCSymbol &Sym, bool IsReg) {
 }
 void MipsTargetStreamer::emitDirectiveModuleOddSPReg(bool Enabled,
                                                      bool IsO32ABI) {
void MipsTargetAsmStreamer::emitDirectiveSetPop() {
   MipsTargetStreamer::emitDirectiveSetPop();
 }
 
 void MipsTargetAsmStreamer::emitDirectiveSetPush() {
  OS << "\t.set\tpush\n";
  MipsTargetStreamer::emitDirectiveSetPush();
 }
 
+void MipsTargetAsmStreamer::emitDirectiveSetSoftFloat() {
+  OS << "\t.set\tsoftfloat\n";
+  MipsTargetStreamer::emitDirectiveSetSoftFloat();
+}
+
+void MipsTargetAsmStreamer::emitDirectiveSetHardFloat() {
+  OS << "\t.set\thardfloat\n";
+  MipsTargetStreamer::emitDirectiveSetHardFloat();
+}
+
 // Print a 32 bit hex number with all numbers.
 static void printHex32(unsigned Value, raw_ostream &OS) {
   OS << "0x";
   for (int i = 7; i >= 0; i--)
     OS.write_hex((Value & (0xF << (i * 4))) >> (i * 4));
 }
 
 void MipsTargetAsmStreamer::emitMask(unsigned CPUBitmask,

lib/Target/Mips/MipsTargetStreamer.h

public:
   virtual void emitDirectiveSetMips64R2();
   virtual void emitDirectiveSetMips64R3();
   virtual void emitDirectiveSetMips64R5();
   virtual void emitDirectiveSetMips64R6();
   virtual void emitDirectiveSetDsp();
   virtual void emitDirectiveSetNoDsp();
   virtual void emitDirectiveSetPop();
   virtual void emitDirectiveSetPush();
+  virtual void emitDirectiveSetSoftFloat();
+  virtual void emitDirectiveSetHardFloat();
 
   // PIC support
   virtual void emitDirectiveCpLoad(unsigned RegNo);
   virtual void emitDirectiveCpsetup(unsigned RegNo, int RegOrOffset,
                                     const MCSymbol &Sym, bool IsReg);
 
   /// Emit a '.module fp=value' directive using the given values.
   /// Updates the .MIPS.abiflags section
public:
   void emitDirectiveSetMips64R2() override;
   void emitDirectiveSetMips64R3() override;
   void emitDirectiveSetMips64R5() override;
   void emitDirectiveSetMips64R6() override;
   void emitDirectiveSetDsp() override;
   void emitDirectiveSetNoDsp() override;
   void emitDirectiveSetPop() override;
   void emitDirectiveSetPush() override;
+  void emitDirectiveSetSoftFloat() override;
+  void emitDirectiveSetHardFloat() override;
 
   // PIC support
   void emitDirectiveCpLoad(unsigned RegNo) override;
   void emitDirectiveCpsetup(unsigned RegNo, int RegOrOffset,
                             const MCSymbol &Sym, bool IsReg) override;
 
   // ABI Flags
   void emitDirectiveModuleFP(MipsABIFlagsSection::FpABIKind Value,

test/MC/Mips/set-softfloat-hardfloat-bad.s

+# RUN: not llvm-mc %s -triple=mips-unknown-linux -mcpu=mips32 -mattr=+soft-float 2>%t1
+# RUN: FileCheck %s < %t1
+
+  .set hardfloat
+  add.s $f2, $f2, $f2
+  # CHECK-NOT: :[[@LINE-1]]:3: error: instruction requires a CPU feature not currently enabled
+  sub.s $f2, $f2, $f2
+  # CHECK-NOT: :[[@LINE-1]]:3: error: instruction requires a CPU feature not currently enabled
+
+  .set softfloat
+  add.s $f2, $f2, $f2
+  # CHECK: :[[@LINE-1]]:3: error: instruction requires a CPU feature not currently enabled
+  sub.s $f2, $f2, $f2
+  # CHECK: :[[@LINE-1]]:3: error: instruction requires a CPU feature not currently enabled

test/MC/Mips/set-softfloat-hardfloat.s

+# RUN: llvm-mc %s -triple=mips-unknown-linux -mcpu=mips32r2 -mattr=+soft-float | \
+# RUN:   FileCheck %s
+
+  .set hardfloat
+  add.s $f2, $f2, $f2
+  sub.s $f2, $f2, $f2
+  .set softfloat
+
+# CHECK: .set hardfloat
+# CHECK: add.s $f2, $f2, $f2
+# CHECK: sub.s $f2, $f2, $f2
+# CHECK: .set softfloat