[PATCH] D98519: [M68k] Add support for Motorola literal syntax to AsmParser

[Ricky Taylor via Phabricator via llvm-commits]

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================
Comment at: llvm/include/llvm/MC/MCAsmInfo.h:449
+  // If true, use Motorola-style integers in Assembly (ex. $0ac).
+  bool UseMotorolaIntegers = false;
+
----------------
My apologies for intruding into a draft patch :) 

Firstly, I don't believe there is anything wrong with introducing a field in MCAsmInfo.h and setting it in the appropriate target inherited version of it. 

However, there seems to be previous precedent within MCAsmLexer.h to support a different class of Integers (`LexMasmIntegers`). So maybe the field could go directly into MCAsmLexer and could be set in AsmLexer/AsmParser as appropriate?



================
Comment at: llvm/include/llvm/MC/MCAsmInfo.h:449
+  // If true, use Motorola-style integers in Assembly (ex. $0ac).
+  bool UseMotorolaIntegers = false;
+
----------------
anirudhp wrote:
> My apologies for intruding into a draft patch :) 
> 
> Firstly, I don't believe there is anything wrong with introducing a field in MCAsmInfo.h and setting it in the appropriate target inherited version of it. 
> 
> However, there seems to be previous precedent within MCAsmLexer.h to support a different class of Integers (`LexMasmIntegers`). So maybe the field could go directly into MCAsmLexer and could be set in AsmLexer/AsmParser as appropriate?
> 
Hi, there's no problem there. I mostly uploaded this early since it's a dependency for one of my other patches. Feedback is always welcome. :)

I think I might've seen `LexMasmIntegers` when I was initially implementing this but having just followed it through the code again, I can't see how to make it the default (for example, I'd expect `clang -cc1as`/`llvm-mc`/etc to use Motorola-style integers by default for M68k but not anything else).

I'm lament to add specific logic to determine that default in all of the front-ends but it looks like that's what is done with `LexMasmIntegers`.

I'll open this up for review proper now anyway.


These look like $00A0cf for hex and  %001010101 for binary. They are used in Motorola assembly syntax.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98519

Files:
  llvm/include/llvm/MC/MCAsmInfo.h
  llvm/lib/MC/MCParser/AsmLexer.cpp


Index: llvm/lib/MC/MCParser/AsmLexer.cpp
===================================================================
--- llvm/lib/MC/MCParser/AsmLexer.cpp
+++ llvm/lib/MC/MCParser/AsmLexer.cpp
@@ -421,6 +421,32 @@
     return intToken(Result, Value);
   }
 
+  // Motorola hex integers: $[0-0a-fA-F]+
+  if (MAI.shouldUseMotorolaIntegers() && CurPtr[-1] == '$') {
+    const char *NumStart = CurPtr;
+    while (isHexDigit(CurPtr[0]))
+      ++CurPtr;
+
+    APInt Result(128, 0);
+    if (StringRef(NumStart, CurPtr - NumStart).getAsInteger(16, Result))
+      return ReturnError(TokStart, "invalid hexadecimal number");
+
+    return intToken(StringRef(TokStart, CurPtr - TokStart), Result);
+  }
+
+  // Motorola binary integers: %[01]+
+  if (MAI.shouldUseMotorolaIntegers() && CurPtr[-1] == '%') {
+    const char *NumStart = CurPtr;
+    while (*CurPtr == '0' || *CurPtr == '1')
+      ++CurPtr;
+
+    APInt Result(128, 0);
+    if (StringRef(NumStart, CurPtr - NumStart).getAsInteger(2, Result))
+      return ReturnError(TokStart, "invalid binary number");
+
+    return intToken(StringRef(TokStart, CurPtr - TokStart), Result);
+  }
+
   // Decimal integer: [1-9][0-9]*
   if (CurPtr[-1] != '0' || CurPtr[0] == '.') {
     unsigned Radix = doHexLookAhead(CurPtr, 10, LexMasmIntegers);
@@ -775,7 +801,13 @@
   case '}': return AsmToken(AsmToken::RCurly, StringRef(TokStart, 1));
   case '*': return AsmToken(AsmToken::Star, StringRef(TokStart, 1));
   case ',': return AsmToken(AsmToken::Comma, StringRef(TokStart, 1));
-  case '$': return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
+  case '$':
+    if (MAI.shouldUseMotorolaIntegers() && isDigit(CurPtr[1])) {
+      ++CurPtr;
+      return LexDigit();
+    }
+
+    return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
   case '@': return AsmToken(AsmToken::At, StringRef(TokStart, 1));
   case '\\': return AsmToken(AsmToken::BackSlash, StringRef(TokStart, 1));
   case '=':
@@ -810,6 +842,12 @@
     }
     return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
   case '%':
+    if (MAI.shouldUseMotorolaIntegers() &&
+        (CurPtr[1] == '0' || CurPtr[1] == '1')) {
+      ++CurPtr;
+      return LexDigit();
+    }
+
     if (MAI.hasMipsExpressions()) {
       AsmToken::TokenKind Operator;
       unsigned OperatorLength;
Index: llvm/include/llvm/MC/MCAsmInfo.h
===================================================================
--- llvm/include/llvm/MC/MCAsmInfo.h
+++ llvm/include/llvm/MC/MCAsmInfo.h
@@ -445,6 +445,9 @@
   // %hi(), and similar unary operators.
   bool HasMipsExpressions = false;
 
+  // If true, use Motorola-style integers in Assembly (ex. $0ac).
+  bool UseMotorolaIntegers = false;
+
   // If true, emit function descriptor symbol on AIX.
   bool NeedsFunctionDescriptors = false;
 
@@ -733,6 +736,7 @@
   void setRelaxELFRelocations(bool V) { RelaxELFRelocations = V; }
   bool hasMipsExpressions() const { return HasMipsExpressions; }
   bool needsFunctionDescriptors() const { return NeedsFunctionDescriptors; }
+  bool shouldUseMotorolaIntegers() const { return UseMotorolaIntegers; }
 };
 
 } // end namespace llvm


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