Merging r217432:

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r217432 | tomatabacu | 2014-09-09 11:15:38 +0100 (Tue, 09 Sep 2014) | 12 lines

[mips] Add assembler support for .set push/pop directive.

Summary:
These directives are used to save the current assembler options (in the case of ".set push") and restore the previously saved options (in the case of ".set pop").

Contains work done by Matheus Almeida.

Reviewers: dsanders

Reviewed By: dsanders

Differential Revision: http://reviews.llvm.org/D4821
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@232082 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

@@ -13,6 +13,7 @@
 #include "MipsTargetStreamer.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
@@ -26,6 +27,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/TargetRegistry.h"
+#include <memory>
 
 using namespace llvm;
 
@@ -38,23 +40,35 @@ class MCInstrInfo;
 namespace {
 class MipsAssemblerOptions {
 public:
-  MipsAssemblerOptions() : ATReg(1), Reorder(true), Macro(true) {}
+  MipsAssemblerOptions(uint64_t Features_) : 
+    ATReg(1), Reorder(true), Macro(true), Features(Features_) {}
 
-  unsigned getATRegNum() { return ATReg; }
+  MipsAssemblerOptions(const MipsAssemblerOptions *Opts) {
+    ATReg = Opts->getATRegNum();
+    Reorder = Opts->isReorder();
+    Macro = Opts->isMacro();
+    Features = Opts->getFeatures();
+  }
+
+  unsigned getATRegNum() const { return ATReg; }
   bool setATReg(unsigned Reg);
 
-  bool isReorder() { return Reorder; }
+  bool isReorder() const { return Reorder; }
   void setReorder() { Reorder = true; }
   void setNoReorder() { Reorder = false; }
 
-  bool isMacro() { return Macro; }
+  bool isMacro() const { return Macro; }
   void setMacro() { Macro = true; }
   void setNoMacro() { Macro = false; }
 
+  uint64_t getFeatures() const { return Features; }
+  void setFeatures(uint64_t Features_) { Features = Features_; }
+
 private:
   unsigned ATReg;
   bool Reorder;
   bool Macro;
+  uint64_t Features;
 };
 }
 
@@ -67,7 +81,7 @@ class MipsAsmParser : public MCTargetAsmParser {
 
   MCSubtargetInfo &STI;
   MCAsmParser &Parser;
-  MipsAssemblerOptions Options;
+  SmallVector<std::unique_ptr<MipsAssemblerOptions>, 2> AssemblerOptions;
 
 #define GET_ASSEMBLER_HEADER
 #include "MipsGenAsmMatcher.inc"
@@ -157,6 +171,8 @@ class MipsAsmParser : public MCTargetAsmParser {
   bool parseSetNoReorderDirective();
   bool parseSetNoMips16Directive();
   bool parseSetFpDirective();
+  bool parseSetPopDirective();
+  bool parseSetPushDirective();
 
   bool parseSetAssignment();
 
@@ -205,6 +221,7 @@ class MipsAsmParser : public MCTargetAsmParser {
       setAvailableFeatures(
           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
     }
+    AssemblerOptions.back()->setFeatures(getAvailableFeatures());
   }
 
   void clearFeatureBits(uint64_t Feature, StringRef FeatureString) {
@@ -212,6 +229,7 @@ class MipsAsmParser : public MCTargetAsmParser {
       setAvailableFeatures(
           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
     }
+    AssemblerOptions.back()->setFeatures(getAvailableFeatures());
   }
 
 public:
@@ -228,6 +246,16 @@ public:
       : MCTargetAsmParser(), STI(sti), Parser(parser) {
     // Initialize the set of available features.
     setAvailableFeatures(ComputeAvailableFeatures(STI.getFeatureBits()));
+    
+    // Remember the initial assembler options. The user can not modify these.
+    MipsAssemblerOptions *TmpAOPtr = 
+      new MipsAssemblerOptions(getAvailableFeatures());
+    AssemblerOptions.push_back(std::unique_ptr<MipsAssemblerOptions>(TmpAOPtr));
+    
+    // Create an assembler options environment for the user to modify.
+    TmpAOPtr = new MipsAssemblerOptions(getAvailableFeatures());
+    AssemblerOptions.push_back(std::unique_ptr<MipsAssemblerOptions>(TmpAOPtr));
+    TmpAOPtr = nullptr;
 
     getTargetStreamer().updateABIInfo(*this);
 
@@ -961,7 +989,7 @@ bool MipsAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
                                                       "nop instruction");
   }
 
-  if (MCID.hasDelaySlot() && Options.isReorder()) {
+  if (MCID.hasDelaySlot() && AssemblerOptions.back()->isReorder()) {
     // If this instruction has a delay slot and .set reorder is active,
     // emit a NOP after it.
     Instructions.push_back(Inst);
@@ -1424,7 +1452,8 @@ bool MipsAsmParser::MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
 }
 
 void MipsAsmParser::WarnIfAssemblerTemporary(int RegIndex, SMLoc Loc) {
-  if ((RegIndex != 0) && ((int)Options.getATRegNum() == RegIndex)) {
+  if ((RegIndex != 0) && 
+      ((int)AssemblerOptions.back()->getATRegNum() == RegIndex)) {
     if (RegIndex == 1)
       Warning(Loc, "Used $at without \".set noat\"");
     else
@@ -1573,7 +1602,7 @@ bool MipsAssemblerOptions::setATReg(unsigned Reg) {
 }
 
 int MipsAsmParser::getATReg(SMLoc Loc) {
-  int AT = Options.getATRegNum();
+  int AT = AssemblerOptions.back()->getATRegNum();
   if (AT == 0)
     reportParseError(Loc,
                      "Pseudo instruction requires $at, which is not available");
@@ -2328,7 +2357,7 @@ bool MipsAsmParser::reportParseError(SMLoc Loc, Twine ErrorMsg) {
 bool MipsAsmParser::parseSetNoAtDirective() {
   // Line should look like: ".set noat".
   // set at reg to 0.
-  Options.setATReg(0);
+  AssemblerOptions.back()->setATReg(0);
   // eat noat
   Parser.Lex();
   // If this is not the end of the statement, report an error.
@@ -2346,7 +2375,7 @@ bool MipsAsmParser::parseSetAtDirective() {
   int AtRegNo;
   getParser().Lex();
   if (getLexer().is(AsmToken::EndOfStatement)) {
-    Options.setATReg(1);
+    AssemblerOptions.back()->setATReg(1);
     Parser.Lex(); // Consume the EndOfStatement.
     return false;
   } else if (getLexer().is(AsmToken::Equal)) {
@@ -2371,7 +2400,7 @@ bool MipsAsmParser::parseSetAtDirective() {
       return false;
     }
 
-    if (!Options.setATReg(AtRegNo)) {
+    if (!AssemblerOptions.back()->setATReg(AtRegNo)) {
       reportParseError("unexpected token in statement");
       return false;
     }
@@ -2396,7 +2425,7 @@ bool MipsAsmParser::parseSetReorderDirective() {
     reportParseError("unexpected token in statement");
     return false;
   }
-  Options.setReorder();
+  AssemblerOptions.back()->setReorder();
   getTargetStreamer().emitDirectiveSetReorder();
   Parser.Lex(); // Consume the EndOfStatement.
   return false;
@@ -2409,7 +2438,7 @@ bool MipsAsmParser::parseSetNoReorderDirective() {
     reportParseError("unexpected token in statement");
     return false;
   }
-  Options.setNoReorder();
+  AssemblerOptions.back()->setNoReorder();
   getTargetStreamer().emitDirectiveSetNoReorder();
   Parser.Lex(); // Consume the EndOfStatement.
   return false;
@@ -2422,7 +2451,7 @@ bool MipsAsmParser::parseSetMacroDirective() {
     reportParseError("unexpected token in statement");
     return false;
   }
-  Options.setMacro();
+  AssemblerOptions.back()->setMacro();
   Parser.Lex(); // Consume the EndOfStatement.
   return false;
 }
@@ -2434,11 +2463,11 @@ bool MipsAsmParser::parseSetNoMacroDirective() {
     reportParseError("`noreorder' must be set before `nomacro'");
     return false;
   }
-  if (Options.isReorder()) {
+  if (AssemblerOptions.back()->isReorder()) {
     reportParseError("`noreorder' must be set before `nomacro'");
     return false;
   }
-  Options.setNoMacro();
+  AssemblerOptions.back()->setNoMacro();
   Parser.Lex(); // Consume the EndOfStatement.
   return false;
 }
@@ -2481,6 +2510,39 @@ bool MipsAsmParser::parseSetFpDirective() {
   return false;
 }
 
+bool MipsAsmParser::parseSetPopDirective() {
+  SMLoc Loc = getLexer().getLoc();
+
+  Parser.Lex();
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return reportParseError("unexpected token, expected end of statement");
+
+  // Always keep an element on the options "stack" to prevent the user
+  // from changing the initial options. This is how we remember them.
+  if (AssemblerOptions.size() == 2)
+    return reportParseError(Loc, ".set pop with no .set push");
+
+  AssemblerOptions.pop_back();
+  setAvailableFeatures(AssemblerOptions.back()->getFeatures());
+
+  getTargetStreamer().emitDirectiveSetPop();
+  return false;
+}
+
+bool MipsAsmParser::parseSetPushDirective() {
+  Parser.Lex();
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return reportParseError("unexpected token, expected end of statement");
+
+  // Create a copy of the current assembler options environment and push it.
+  MipsAssemblerOptions *TmpAOPtr = 
+    new MipsAssemblerOptions(AssemblerOptions.back().get());
+  AssemblerOptions.push_back(std::unique_ptr<MipsAssemblerOptions>(TmpAOPtr));
+
+  getTargetStreamer().emitDirectiveSetPush();
+  return false;
+}
+
 bool MipsAsmParser::parseSetAssignment() {
   StringRef Name;
   const MCExpr *Value;
@@ -2551,7 +2613,7 @@ bool MipsAsmParser::eatComma(StringRef ErrorStr) {
 }
 
 bool MipsAsmParser::parseDirectiveCPLoad(SMLoc Loc) {
-  if (Options.isReorder())
+  if (AssemblerOptions.back()->isReorder())
     Warning(Loc, ".cpload in reorder section");
 
   // FIXME: Warn if cpload is used in Mips16 mode.
@@ -2664,6 +2726,10 @@ bool MipsAsmParser::parseDirectiveSet() {
     return parseSetAtDirective();
   } else if (Tok.getString() == "fp") {
     return parseSetFpDirective();
+  } else if (Tok.getString() == "pop") {
+    return parseSetPopDirective();
+  } else if (Tok.getString() == "push") {
+    return parseSetPushDirective();
   } else if (Tok.getString() == "reorder") {
     return parseSetReorderDirective();
   } else if (Tok.getString() == "noreorder") {

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

@@ -55,6 +55,8 @@ void MipsTargetStreamer::emitFMask(unsigned FPUBitmask, int FPUTopSavedRegOff) {
 void MipsTargetStreamer::emitDirectiveSetMips32R2() {}
 void MipsTargetStreamer::emitDirectiveSetMips64() {}
 void MipsTargetStreamer::emitDirectiveSetMips64R2() {}
+void MipsTargetStreamer::emitDirectiveSetPop() {}
+void MipsTargetStreamer::emitDirectiveSetPush() {}
 void MipsTargetStreamer::emitDirectiveSetDsp() {}
 void MipsTargetStreamer::emitDirectiveCpload(unsigned RegNo) {}
 void MipsTargetStreamer::emitDirectiveCpsetup(unsigned RegNo, int RegOrOffset,
@@ -171,6 +173,11 @@ void MipsTargetAsmStreamer::emitDirectiveSetDsp() {
   OS << "\t.set\tdsp\n";
   setCanHaveModuleDir(false);
 }
+
+void MipsTargetAsmStreamer::emitDirectiveSetPop() { OS << "\t.set\tpop\n"; }
+
+void MipsTargetAsmStreamer::emitDirectiveSetPush() { OS << "\t.set\tpush\n"; }
+
 // Print a 32 bit hex number with all numbers.
 static void printHex32(unsigned Value, raw_ostream &OS) {
   OS << "0x";

lib/Target/Mips/MipsTargetStreamer.h

@@ -49,6 +49,8 @@ public:
   virtual void emitDirectiveSetMips64();
   virtual void emitDirectiveSetMips64R2();
   virtual void emitDirectiveSetDsp();
+  virtual void emitDirectiveSetPop();
+  virtual void emitDirectiveSetPush();
 
   // PIC support
   virtual void emitDirectiveCpload(unsigned RegNo);
@@ -125,6 +127,8 @@ public:
   void emitDirectiveSetMips64() override;
   void emitDirectiveSetMips64R2() override;
   void emitDirectiveSetDsp() override;
+  void emitDirectiveSetPop() override;
+  void emitDirectiveSetPush() override;
 
   // PIC support
   virtual void emitDirectiveCpload(unsigned RegNo);

test/MC/Mips/set-push-pop-directives-bad.s

@@ -0,0 +1,14 @@
+# RUN: not llvm-mc %s -triple=mipsel-unknown-linux -mcpu=mips32r2 2>%t1
+# RUN:   FileCheck %s < %t1
+
+        .text
+        .set pop
+# CHECK: :[[@LINE-1]]:14: error: .set pop with no .set push
+        .set push
+        .set pop
+        .set pop
+# CHECK: :[[@LINE-1]]:14: error: .set pop with no .set push
+        .set push foo
+# CHECK: :[[@LINE-1]]:19: error: unexpected token, expected end of statement
+        .set pop bar
+# CHECK: :[[@LINE-1]]:18: error: unexpected token, expected end of statement

test/MC/Mips/set-push-pop-directives.s

@@ -0,0 +1,47 @@
+# RUN: llvm-mc %s -triple=mipsel-unknown-linux -mcpu=mips32r2 -mattr=+msa | \
+# RUN:   FileCheck %s
+# .set push creates a copy of the current environment.
+# .set pop restores the previous environment.
+# FIXME: Also test resetting of .set macro/nomacro option.
+
+    .text
+    # The first environment on the stack (with initial values).
+    lw       $1, 65536($1)
+    b        1336
+    addvi.b  $w15, $w13, 18
+    
+    # Create a new environment.
+    .set push
+    .set at=$ra           # Test the ATReg option.
+    lw       $1, 65536($1)
+    .set noreorder        # Test the Reorder option.
+    b        1336
+
+    # Switch back to the first environment.
+    .set pop
+    lw       $1, 65536($1)
+    b        1336
+    addvi.b  $w15, $w13, 18
+
+# CHECK:  lui      $1, 1
+# CHECK:  addu     $1, $1, $1
+# CHECK:  lw       $1, 0($1)
+# CHECK:  b        1336
+# CHECK:  nop
+# CHECK:  addvi.b  $w15, $w13, 18
+
+# CHECK:  .set push
+# CHECK:  lui      $ra, 1
+# CHECK:  addu     $ra, $ra, $1
+# CHECK:  lw       $1, 0($ra)
+# CHECK:  .set noreorder   
+# CHECK:  b        1336
+# CHECK-NOT:  nop
+
+# CHECK:  .set pop
+# CHECK:  lui      $1, 1
+# CHECK:  addu     $1, $1, $1
+# CHECK:  lw       $1, 0($1)
+# CHECK:  b        1336
+# CHECK:  nop
+# CHECK:  addvi.b  $w15, $w13, 18