This patch implements .set mips32r2 directive and sets appropriate feature bits. It also introduces helper functions that are used to set and clear feature bits as necessary. This directive is a counterpart of -mips32r2 command line options with the exception that it does not influence elf header flags. The usage example is gives in test file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202807 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

@@ -257,6 +257,20 @@ class MipsAsmParser : public MCTargetAsmParser {
   // Example: INSERT.B $w0[n], $1 => 16 > n >= 0
   bool validateMSAIndex(int Val, int RegKind);
 
+  void setFeatureBits(unsigned Feature, StringRef FeatureString) {
+    if (!(STI.getFeatureBits() & Feature)) {
+      setAvailableFeatures(ComputeAvailableFeatures(
+                           STI.ToggleFeature(FeatureString)));
+    }
+  }
+
+  void clearFeatureBits(unsigned Feature, StringRef FeatureString) {
+    if (STI.getFeatureBits() & Feature) {
+     setAvailableFeatures(ComputeAvailableFeatures(
+                           STI.ToggleFeature(FeatureString)));
+    }
+  }
+
 public:
   MipsAsmParser(MCSubtargetInfo &sti, MCAsmParser &parser,
                 const MCInstrInfo &MII)
@@ -2439,6 +2453,13 @@ bool MipsAsmParser::parseDirectiveSet() {
     getTargetStreamer().emitDirectiveSetMicroMips();
     Parser.eatToEndOfStatement();
     return false;
+  } else if (Tok.getString() == "mips32r2") {
+    Parser.Lex(); // Eat token.
+    if (getLexer().isNot(AsmToken::EndOfStatement))
+      return reportParseError("unexpected token in .set directive");
+    setFeatureBits(Mips::FeatureMips32r2,"mips32r2");
+    getTargetStreamer().emitDirectiveSetMips32R2();
+    return false;
   } else {
     // It is just an identifier, look for an assignment.
     parseSetAssignment();

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

@@ -97,6 +97,10 @@ void MipsTargetAsmStreamer::emitFrame(unsigned StackReg, unsigned StackSize,
      << StringRef(MipsInstPrinter::getRegisterName(ReturnReg)).lower() << '\n';
 }
 
+void MipsTargetAsmStreamer::emitDirectiveSetMips32R2() {
+  OS << "\t.set\tmips32r2\n";
+}
+
 // Print a 32 bit hex number with all numbers.
 static void printHex32(unsigned Value, raw_ostream &OS) {
   OS << "0x";
@@ -302,3 +306,7 @@ void MipsTargetELFStreamer::emitFMask(unsigned FPUBitmask,
                                       int FPUTopSavedRegOff) {
   // FIXME: implement.
 }
+
+void MipsTargetELFStreamer::emitDirectiveSetMips32R2() {
+  // No action required for ELF output.
+}

lib/Target/Mips/MipsTargetStreamer.h

@@ -39,6 +39,8 @@ public:
                          unsigned ReturnReg) = 0;
   virtual void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff) = 0;
   virtual void emitFMask(unsigned FPUBitmask, int FPUTopSavedRegOff) = 0;
+
+  virtual void emitDirectiveSetMips32R2() = 0;
 };
 
 // This part is for ascii assembly output
@@ -67,6 +69,8 @@ public:
                          unsigned ReturnReg);
   virtual void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff);
   virtual void emitFMask(unsigned FPUBitmask, int FPUTopSavedRegOff);
+
+  virtual void emitDirectiveSetMips32R2();
 };
 
 // This part is for ELF object output
@@ -102,6 +106,8 @@ public:
                          unsigned ReturnReg);
   virtual void emitMask(unsigned CPUBitmask, int CPUTopSavedRegOff);
   virtual void emitFMask(unsigned FPUBitmask, int FPUTopSavedRegOff);
+
+  virtual void emitDirectiveSetMips32R2();
 };
 }
 #endif

test/MC/Mips/mips_directives.s

@@ -1,4 +1,4 @@
-# RUN: llvm-mc -show-encoding -triple mips-unknown-unknown %s | FileCheck %s
+# RUN: llvm-mc -show-encoding -mcpu=mips32 -triple mips-unknown-unknown %s | FileCheck %s
 #
 # CHECK:  .text
 # CHECK:  $BB0_2:
@@ -49,3 +49,12 @@ $BB0_4:
 # CHECK:                               #   fixup A - offset: 0, value: ($tmp7)@ABS_HI, kind: fixup_Mips_HI16
     abs.s  f6,FPU_MASK
     lui $1, %hi($tmp7)
+
+# CHECK:    .set mips32r2
+# CHECK:    ldxc1   $f0, $zero($5)     # encoding: [0x4c,0xa0,0x00,0x01]
+# CHECK:    luxc1   $f0, $6($5)        # encoding: [0x4c,0xa6,0x00,0x05]
+# CHECK:    lwxc1   $f6, $2($5)        # encoding: [0x4c,0xa2,0x01,0x80]
+     .set mips32r2
+    ldxc1   $f0, $zero($5)
+    luxc1   $f0, $6($5)
+    lwxc1   $f6, $2($5)