[mips][microMIPS] Mark symbols as microMIPS if necessary

Differential Revision: http://reviews.llvm.org/D6039


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221355 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCStreamer.h

@@ -346,8 +346,8 @@ public:
   /// @p Section.  This is required to update CurSection.
   ///
   /// This corresponds to assembler directives like .section, .text, etc.
-  void SwitchSection(const MCSection *Section,
-                     const MCExpr *Subsection = nullptr) {
+  virtual void SwitchSection(const MCSection *Section,
+                             const MCExpr *Subsection = nullptr) {
     assert(Section && "Cannot switch to a null section!");
     MCSectionSubPair curSection = SectionStack.back().first;
     SectionStack.back().second = curSection;

lib/Target/Mips/MCTargetDesc/MipsELFStreamer.cpp

@@ -8,7 +8,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "MipsELFStreamer.h"
+#include "MipsTargetStreamer.h"
+#include "llvm/MC/MCELF.h"
 #include "llvm/MC/MCInst.h"
+#include "llvm/Support/ELF.h"
+
 using namespace llvm;
 
 void MipsELFStreamer::EmitInstruction(const MCInst &Inst,
@@ -17,6 +21,8 @@ void MipsELFStreamer::EmitInstruction(const MCInst &Inst,
 
   MCContext &Context = getContext();
   const MCRegisterInfo *MCRegInfo = Context.getRegisterInfo();
+  MipsTargetELFStreamer *ELFTargetStreamer =
+      static_cast<MipsTargetELFStreamer *>(getTargetStreamer());
 
   for (unsigned OpIndex = 0; OpIndex < Inst.getNumOperands(); ++OpIndex) {
     const MCOperand &Op = Inst.getOperand(OpIndex);
@@ -27,6 +33,35 @@ void MipsELFStreamer::EmitInstruction(const MCInst &Inst,
     unsigned Reg = Op.getReg();
     RegInfoRecord->SetPhysRegUsed(Reg, MCRegInfo);
   }
+
+  if (ELFTargetStreamer->isMicroMipsEnabled()) {
+    for (auto Label : Labels) {
+      MCSymbolData &Data = getOrCreateSymbolData(Label);
+      // The "other" values are stored in the last 6 bits of the second byte.
+      // The traditional defines for STO values assume the full byte and thus
+      // the shift to pack it.
+      MCELF::setOther(Data, ELF::STO_MIPS_MICROMIPS >> 2);
+    }
+  }
+
+  Labels.clear();
+}
+
+void MipsELFStreamer::EmitLabel(MCSymbol *Symbol) {
+  MCELFStreamer::EmitLabel(Symbol);
+  Labels.push_back(Symbol);
+}
+
+void MipsELFStreamer::SwitchSection(const MCSection * Section,
+                                    const MCExpr *Subsection) {
+  MCELFStreamer::SwitchSection(Section, Subsection);
+  Labels.clear();
+}
+
+void MipsELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
+                                    const SMLoc &Loc) {
+  MCELFStreamer::EmitValueImpl(Value, Size, Loc);
+  Labels.clear();
 }
 
 void MipsELFStreamer::EmitMipsOptionRecords() {

lib/Target/Mips/MCTargetDesc/MipsELFStreamer.h

@@ -29,6 +29,8 @@ class MCSubtargetInfo;
 class MipsELFStreamer : public MCELFStreamer {
   SmallVector<std::unique_ptr<MipsOptionRecord>, 8> MipsOptionRecords;
   MipsRegInfoRecord *RegInfoRecord;
+  SmallVector<MCSymbol*, 4> Labels;
+
 
 public:
   MipsELFStreamer(MCContext &Context, MCAsmBackend &MAB, raw_ostream &OS,
@@ -46,6 +48,21 @@ public:
   /// usage for the translation unit.
   void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
 
+  /// Overriding this function allows us to record all labels that should be
+  /// marked as microMIPS. Based on this data marking is done in
+  /// EmitInstruction.
+  void EmitLabel(MCSymbol *Symbol) override;
+
+  /// Overriding this function allows us to dismiss all labels that are
+  /// candidates for marking as microMIPS when .section directive is processed.
+  void SwitchSection(const MCSection *Section,
+                     const MCExpr *Subsection = nullptr) override;
+
+  /// Overriding this function allows us to dismiss all labels that are
+  /// candidates for marking as microMIPS when .word directive is emitted.
+  void EmitValueImpl(const MCExpr *Value, unsigned Size,
+                     const SMLoc &Loc) override;
+
   /// Emits all the option records stored up until the point it's called.
   void EmitMipsOptionRecords();
 };

test/MC/Mips/micromips-label-test-sections.s

@@ -0,0 +1,35 @@
+# RUN: llvm-mc %s -triple=mipsel-unknown-linux -mcpu=mips32r2 \
+# RUN:   -mattr=+micromips -filetype=obj -o - | llvm-readobj -t | FileCheck %s
+  .text
+  .set micromips
+f:
+  nop
+g:
+  .section .text
+h:
+  nop
+
+# CHECK: Symbols [
+# CHECK:   Symbol {
+# CHECK:     Name: f
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 128
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: g
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: h
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 128
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK: ]
+

test/MC/Mips/micromips-label-test.s

@@ -0,0 +1,54 @@
+# RUN: llvm-mc %s -triple=mipsel-unknown-linux -mcpu=mips32r2 \
+# RUN:   -mattr=+micromips -filetype=obj -o - | llvm-readobj -t | FileCheck %s
+  .text
+  .set nomicromips
+f:
+  nop
+g:
+  .set micromips
+  nop
+h:
+  .word 0
+i:
+  nop
+j:
+  .set nomicromips
+  nop
+# CHECK: Symbols [
+# CHECK:   Symbol {
+# CHECK:     Name: f
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: g
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 128
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: h
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: i
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 128
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: j
+# CHECK:     Binding: Local
+# CHECK:     Type: None
+# CHECK:     Other: 0
+# CHECK:     Section: .text
+# CHECK:   }
+# CHECK: ]
+