[X86] Remove DATA32_PREFIX. Hack the printing for DATA16_PREFIX to print 'data32' in 16-bit mode. Hack the asm parser to convert 'data32' to 'data16' in 16-bit mode.

Improve the error messages to match GNU assembler.

This also allows us to remove the hack from the disassembler table building.

llvm-svn: 330531

6 files changed, 28 insertions, 19 deletions

diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 36aecb86347..b9d254e0e67 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -2385,6 +2385,20 @@ bool X86AsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
 
   if (Flags)
     PatchedName = Name;
+
+  // Hacks to handle 'data16' and 'data32'
+  if (PatchedName == "data16" && is16BitMode()) {
+    return Error(NameLoc, "redundant data16 prefix");
+  }
+  if (PatchedName == "data32") {
+    if (is32BitMode())
+      return Error(NameLoc, "redundant data32 prefix");
+    if (is64BitMode())
+      return Error(NameLoc, "'data32' is not supported in 64-bit mode");
+    // Hack to 'data16' for the table lookup.
+    PatchedName = "data16";
+  }
+
   Operands.push_back(X86Operand::CreateToken(PatchedName, NameLoc));
 
   // This does the actual operand parsing.  Don't parse any more if we have a
@@ -2419,7 +2433,7 @@ bool X86AsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
         (getLexer().is(AsmToken::LCurly) || getLexer().is(AsmToken::RCurly));
     if (getLexer().isNot(AsmToken::EndOfStatement) && !CurlyAsEndOfStatement)
       return TokError("unexpected token in argument list");
-   }
+  }
 
   // Consume the EndOfStatement or the prefix separator Slash
   if (getLexer().is(AsmToken::EndOfStatement) ||
diff --git a/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp b/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp
index dbc2570160e..8780e8b05c8 100644
--- a/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp
+++ b/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp
@@ -78,10 +78,8 @@ void X86ATTInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
   // 0x66 to be interpreted as "data16" by the asm printer.
   // Thus we add an adjustment here in order to print the "right" instruction.
   else if (MI->getOpcode() == X86::DATA16_PREFIX &&
-    (STI.getFeatureBits()[X86::Mode16Bit])) {
-    MCInst Data32MI(*MI);
-    Data32MI.setOpcode(X86::DATA32_PREFIX);
-    printInstruction(&Data32MI, OS);
+           STI.getFeatureBits()[X86::Mode16Bit]) {
+   OS << "\tdata32";
   }
   // Try to print any aliases first.
   else if (!printAliasInstr(MI, OS))
diff --git a/llvm/lib/Target/X86/InstPrinter/X86IntelInstPrinter.cpp b/llvm/lib/Target/X86/InstPrinter/X86IntelInstPrinter.cpp
index 0e069751821..57b5f777ccf 100644
--- a/llvm/lib/Target/X86/InstPrinter/X86IntelInstPrinter.cpp
+++ b/llvm/lib/Target/X86/InstPrinter/X86IntelInstPrinter.cpp
@@ -19,6 +19,7 @@
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCInstrDesc.h"
 #include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
@@ -52,7 +53,12 @@ void X86IntelInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
   if ((TSFlags & X86II::NOTRACK) || (Flags & X86::IP_HAS_NOTRACK))
     OS << "\tnotrack\t";
 
-  printInstruction(MI, OS);
+  // In 16-bit mode, print data16 as data32.
+  if (MI->getOpcode() == X86::DATA16_PREFIX &&
+      STI.getFeatureBits()[X86::Mode16Bit]) {
+    OS << "\tdata32";
+  } else
+    printInstruction(MI, OS);
 
   // Next always print the annotation.
   printAnnotation(OS, Annot);
diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
index 0990f210871..507746218ec 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.td
+++ b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -2063,12 +2063,7 @@ def REX64_PREFIX : I<0x48, RawFrm, (outs),  (ins), "rex64", []>,
                      Requires<[In64BitMode]>;
 
 // Data16 instruction prefix
-def DATA16_PREFIX : I<0x66, RawFrm, (outs),  (ins), "data16", []>,
-                     Requires<[Not16BitMode]>;
-
-// Data instruction prefix
-def DATA32_PREFIX : I<0x66, RawFrm, (outs),  (ins), "data32", []>,
-                     Requires<[In16BitMode]>;
+def DATA16_PREFIX : I<0x66, RawFrm, (outs),  (ins), "data16", []>;
 } // SchedRW
 
 // Repeat string operation instruction prefixes
diff --git a/llvm/test/MC/X86/data-prefix-fail.s b/llvm/test/MC/X86/data-prefix-fail.s
index 2b910cdc109..1d2b528a451 100644
--- a/llvm/test/MC/X86/data-prefix-fail.s
+++ b/llvm/test/MC/X86/data-prefix-fail.s
@@ -5,8 +5,8 @@
 // RUN: not llvm-mc -triple i386-unknown-unknown-code16 --show-encoding %s 2> %t.err | FileCheck --check-prefix=16 %s
 // RUN: FileCheck --check-prefix=ERR16 < %t.err %s
 
-// ERR64: error: instruction requires: 16-bit mode
-// ERR32: error: instruction requires: 16-bit mode
+// ERR64: error: 'data32' is not supported in 64-bit mode
+// ERR32: error: redundant data32 prefix
 // 16: data32
 // 16: encoding: [0x66]
 // 16: lgdtw 0
@@ -21,5 +21,5 @@ data32 lgdt 0
 // 32: encoding: [0x66]
 // 32: lgdtl 0
 // 32: encoding: [0x0f,0x01,0x15,0x00,0x00,0x00,0x00]
-// ERR16: error: instruction requires: Not 16-bit mode
+// ERR16: error: redundant data16 prefix
 data16 lgdt 0
diff --git a/llvm/utils/TableGen/X86DisassemblerTables.cpp b/llvm/utils/TableGen/X86DisassemblerTables.cpp
index 9c69abe1f3d..2b5cc127960 100644
--- a/llvm/utils/TableGen/X86DisassemblerTables.cpp
+++ b/llvm/utils/TableGen/X86DisassemblerTables.cpp
@@ -1088,10 +1088,6 @@ void DisassemblerTables::setTableFields(ModRMDecision     &decision,
                                            newInfo.name == "XCHG64ar"))
           continue; // special case for XCHG*ar and NOOP
 
-        if (previousInfo.name == "DATA16_PREFIX" &&
-            newInfo.name == "DATA32_PREFIX")
-          continue; // special case for data16 and data32
-
         if (outranks(previousInfo.insnContext, newInfo.insnContext))
           continue;