[mips] .word and .dword are not the same as .4byte and .8byte

[dsanders]

Summary

.word and .dword emit naturally aligned data whereas .4byte and .8byte
emit unaligned data.

[vmedic]

LGTM

[Eugene.Zelenko]

Looks like patch was not committed.

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

 ///  ::= .word [ expression (, expression)* ]
 bool MipsAsmParser::parseDataDirective(unsigned Size, SMLoc L) {
   if (getLexer().isNot(AsmToken::EndOfStatement)) {
     for (;;) {
       const MCExpr *Value;
       if (getParser().parseExpression(Value))
         return true;
 
-      getParser().getStreamer().EmitValue(Value, Size);
+      getTargetStreamer().emitAlignedDataDirective(Value, Size);
 
       if (getLexer().is(AsmToken::EndOfStatement))
         break;
 
       // FIXME: Improve diagnostic.
       if (getLexer().isNot(AsmToken::Comma))
         return Error(L, "unexpected token in directive");
       Parser.Lex();

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormattedStream.h"
 
 using namespace llvm;
 
 MipsTargetStreamer::MipsTargetStreamer(MCStreamer &S)
     : MCTargetStreamer(S), canHaveModuleDirective(true) {}
+
+void MipsTargetStreamer::emitAlignedDataDirective(const MCExpr *Value,
+                                                  unsigned Size) {}
+
 void MipsTargetStreamer::emitDirectiveSetMicroMips() {}
 void MipsTargetStreamer::emitDirectiveSetNoMicroMips() {}
 void MipsTargetStreamer::emitDirectiveSetMips16() {}
 void MipsTargetStreamer::emitDirectiveSetNoMips16() {}
 void MipsTargetStreamer::emitDirectiveSetReorder() {}
 void MipsTargetStreamer::emitDirectiveSetNoReorder() {}
 void MipsTargetStreamer::emitDirectiveSetMacro() {}
 void MipsTargetStreamer::emitDirectiveSetNoMacro() {}
void MipsTargetStreamer::emitDirectiveModuleOddSPReg(bool Enabled,
   if (!Enabled && !IsO32ABI)
     report_fatal_error("+nooddspreg is only valid for O32");
 }
 
 MipsTargetAsmStreamer::MipsTargetAsmStreamer(MCStreamer &S,
                                              formatted_raw_ostream &OS)
     : MipsTargetStreamer(S), OS(OS) {}
 
+void MipsTargetAsmStreamer::emitAlignedDataDirective(const MCExpr *Value,
+                                                     unsigned Size) {
+  switch (Size) {
+  case 4:
+    OS << "\t.word\t";
+    break;
+  case 8:
+    OS << "\t.dword\t";
+    break;
+  default:
+    llvm_unreachable("Unexpected alignment");
+  }
+
+  Value->print(OS);
+  OS << "\n";
+}
+
 void MipsTargetAsmStreamer::emitDirectiveSetMicroMips() {
   OS << "\t.set\tmicromips\n";
   setCanHaveModuleDir(false);
 }
 
 void MipsTargetAsmStreamer::emitDirectiveSetNoMicroMips() {
   OS << "\t.set\tnomicromips\n";
   setCanHaveModuleDir(false);
void MipsTargetELFStreamer::emitAssignment(MCSymbol *Symbol,
   // the shift to pack it.
   MCELF::setOther(SymbolData, ELF::STO_MIPS_MICROMIPS >> 2);
 }
 
 MCELFStreamer &MipsTargetELFStreamer::getStreamer() {
   return static_cast<MCELFStreamer &>(Streamer);
 }
 
+void MipsTargetELFStreamer::emitAlignedDataDirective(const MCExpr *Value,
+                                                     unsigned Size) {
+  getStreamer().EmitValueToAlignment(Size, 0, 1, 0);
+  getStreamer().EmitValue(Value, Size);
+}
+
 void MipsTargetELFStreamer::emitDirectiveSetMicroMips() {
   MicroMipsEnabled = true;
 
   MCAssembler &MCA = getStreamer().getAssembler();
   unsigned Flags = MCA.getELFHeaderEFlags();
   Flags |= ELF::EF_MIPS_MICROMIPS;
   MCA.setELFHeaderEFlags(Flags);
 }

lib/Target/Mips/MipsTargetStreamer.h

 
 namespace llvm {
 
 struct MipsABIFlagsSection;
 
 class MipsTargetStreamer : public MCTargetStreamer {
 public:
   MipsTargetStreamer(MCStreamer &S);
+
+  virtual void emitAlignedDataDirective(const MCExpr *Value, unsigned Size);
+
   virtual void emitDirectiveSetMicroMips();
   virtual void emitDirectiveSetNoMicroMips();
   virtual void emitDirectiveSetMips16();
   virtual void emitDirectiveSetNoMips16();
 
   virtual void emitDirectiveSetReorder();
   virtual void emitDirectiveSetNoReorder();
   virtual void emitDirectiveSetMacro();

 };
 
 // This part is for ascii assembly output
 class MipsTargetAsmStreamer : public MipsTargetStreamer {
   formatted_raw_ostream &OS;
 
 public:
   MipsTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS);
+
+  void emitAlignedDataDirective(const MCExpr *Value, unsigned Size) override;
+
   void emitDirectiveSetMicroMips() override;
   void emitDirectiveSetNoMicroMips() override;
   void emitDirectiveSetMips16() override;
   void emitDirectiveSetNoMips16() override;
 
   void emitDirectiveSetReorder() override;
   void emitDirectiveSetNoReorder() override;
   void emitDirectiveSetMacro() override;
public:
   bool isMicroMipsEnabled() const { return MicroMipsEnabled; }
   MCELFStreamer &getStreamer();
   MipsTargetELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
 
   void emitLabel(MCSymbol *Symbol) override;
   void emitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
   void finish() override;
 
+  void emitAlignedDataDirective(const MCExpr *Value, unsigned Size) override;
+
   void emitDirectiveSetMicroMips() override;
   void emitDirectiveSetNoMicroMips() override;
   void emitDirectiveSetMips16() override;
   void emitDirectiveSetNoMips16() override;
 
   void emitDirectiveSetReorder() override;
   void emitDirectiveSetNoReorder() override;
   void emitDirectiveSetMacro() override;

test/MC/Mips/aligned_data.s

+# Test that the .text and .data sections are padded to the AddressAlignment
+# before finishing the ELF
+
+# RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 | FileCheck %s -check-prefix=CHECK-ASM
+#
+# RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 -filetype=obj -o - | \
+# RUN:   llvm-readobj -sections -section-data - | \
+# RUN:     FileCheck %s -check-prefix=CHECK-OBJ
+
+# CHECK-ASM:    .text
+# CHECK-ASM:    .byte 1
+# CHECK-ASM:    .word 2
+# CHECK-ASM:    .word 3
+# CHECK-ASM:    .data
+# CHECK-ASM:    .byte 1
+# CHECK-ASM:    .byte 2
+# CHECK-ASM:    .word 3
+# CHECK-ASM:    .word 4
+
+# CHECK-OBJ:       Section {
+# CHECK-OBJ-LABEL:   Name: .text
+# CHECK-OBJ:         AddressAlignment: 16
+# CHECK-OBJ:         SectionData (
+# CHECK-OBJ:           0000: 01000000 00000002 00000003 00000000  |................|
+# CHECK-OBJ:           0010: 00000000 00000004 00000000 00000005  |................|
+# CHECK-OBJ:         )
+# CHECK-OBJ-LABEL: }
+# CHECK-OBJ:       Section {
+# CHECK-OBJ-LABEL:   Name: .data
+# CHECK-OBJ:         AddressAlignment: 16
+# CHECK-OBJ:         SectionData (
+# CHECK-OBJ:           0000: 01020000 00000003 00000004 00000000  |................|
+# CHECK-OBJ:           0010: 00000000 00000005 00000000 00000006  |................|
+# CHECK-OBJ:         )
+# CHECK-OBJ-LABEL: }
+
+        .text
+        .byte  1
+        .word  2
+        .word  3
+        .dword 4
+        .dword 5
+
+        .data
+        .byte  1
+        .byte  2
+        .word  3
+        .word  4
+        .dword 5
+        .dword 6

test/MC/Mips/mips-data-directives.s

 # RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 | \
 # RUN:   FileCheck %s -check-prefix=CHECK-ASM
 #
 # RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 -filetype=obj -o - | \
 # RUN:   llvm-readobj -sections -section-data -section-relocations - | \
 # RUN:     FileCheck %s -check-prefix=CHECK-OBJ
 
-# CHECK-ASM: .4byte 3735929054
-# CHECK-ASM: .8byte -2401050962867405073
-# CHECK-ASM: .4byte label
-# CHECK-ASM: .8byte label
+# CHECK-ASM: .word  3735929054
+# CHECK-ASM: .dword -2401050962867405073
+# CHECK-ASM: .word  label
+# CHECK-ASM: .dword label
 
 # Checking if the data and reloations were correctly emitted
 # CHECK-OBJ:  Section {
 # CHECK-OBJ:    Name: .data (66)
 # CHECK-OBJ:    SectionData (
-# CHECK-OBJ:      0000: DEADC0DE DEADC0DE DEADBEEF 00000000
-# CHECK-OBJ:      0010: 00000000 00000000
+# CHECK-OBJ:      0000: DEADC0DE 00000000 DEADC0DE DEADBEEF
+# CHECK-OBJ:      0010: 00000000 00000000 00000000 00000000
 # CHECK-OBJ:    )
 # CHECK-OBJ:  }
 
 # CHECK-OBJ:  Section {
 # CHECK-OBJ:    Name: .rel.data (62)
 # CHECK-OBJ:    Relocations [
-# CHECK-OBJ:      0xC R_MIPS_32 .data 0x0
-# CHECK-OBJ:      0x10 R_MIPS_64 .data 0x0
+# CHECK-OBJ:      0x10 R_MIPS_32 .data 0x0
+# CHECK-OBJ:      0x18 R_MIPS_64 .data 0x0
 # CHECK-OBJ:    ]
 # CHECK-OBJ:  }
 
 .data
 label:
         .word 0xdeadc0de
         .dword 0xdeadc0dedeadbeef
 
         .word label
         .dword label

test/MC/Mips/mips_directives.s

# CHECK-NOT: nop
     .set    nomacro
     .set    noat
 $JTI0_0:
     .gpword    ($BB0_2)
 
     .word 0x77fffffc
 # CHECK: $JTI0_0:
 # CHECK: .gpword ($BB0_2)
-# CHECK:     .4byte    2013265916
+# CHECK:     .word    2013265916
     .set  at=$12
     .set macro
 # CHECK:   .set reorder
 # CHECK:   b 1332               # encoding: [0x10,0x00,0x01,0x4d]
 # CHECK:   nop                  # encoding: [0x00,0x00,0x00,0x00]
 # CHECK:   j 1328               # encoding: [0x08,0x00,0x01,0x4c]
 # CHECK:   nop                  # encoding: [0x00,0x00,0x00,0x00]
 # CHECK:   jal 1328             # encoding: [0x0c,0x00,0x01,0x4c]