commit 20187778363471b0a9be67e5672830b3632bc781
author Martin Storsjo <martin@martin.st> Sun Dec 30 21:06:32 2018 +0000
committer Martin Storsjo <martin@martin.st> Sun Dec 30 21:06:32 2018 +0000
tree 65903e928cab7fe7b6c99d55f38de755c55b4ca3
parent 0a5d5b1377b1c5716829dcc53a9b11c9db7abb7f

[AArch64] Implement the .arch_extension directive

Differential Revision: https://reviews.llvm.org/D56131

llvm-svn: 350169

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

diff --git a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
index 384b474..d2f78af 100644
--- a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -165,6 +165,7 @@
                       OperandVector &Operands);
 
   bool parseDirectiveArch(SMLoc L);
+  bool parseDirectiveArchExtension(SMLoc L);
   bool parseDirectiveCPU(SMLoc L);
   bool parseDirectiveInst(SMLoc L);
 
@@ -5033,6 +5034,8 @@
     parseDirectiveCFINegateRAState();
   else if (IDVal == ".cfi_b_key_frame")
     parseDirectiveCFIBKeyFrame();
+  else if (IDVal == ".arch_extension")
+    parseDirectiveArchExtension(Loc);
   else if (IsMachO) {
     if (IDVal == MCLOHDirectiveName())
       parseDirectiveLOH(IDVal, Loc);
@@ -5153,6 +5156,50 @@
   return false;
 }
 
+/// parseDirectiveArchExtension
+///   ::= .arch_extension [no]feature
+bool AArch64AsmParser::parseDirectiveArchExtension(SMLoc L) {
+  MCAsmParser &Parser = getParser();
+
+  if (getLexer().isNot(AsmToken::Identifier))
+    return Error(getLexer().getLoc(), "expected architecture extension name");
+
+  const AsmToken &Tok = Parser.getTok();
+  StringRef Name = Tok.getString();
+  SMLoc ExtLoc = Tok.getLoc();
+  Lex();
+
+  if (parseToken(AsmToken::EndOfStatement,
+                 "unexpected token in '.arch_extension' directive"))
+    return true;
+
+  bool EnableFeature = true;
+  if (Name.startswith_lower("no")) {
+    EnableFeature = false;
+    Name = Name.substr(2);
+  }
+
+  MCSubtargetInfo &STI = copySTI();
+  FeatureBitset Features = STI.getFeatureBits();
+  for (const auto &Extension : ExtensionMap) {
+    if (Extension.Name != Name)
+      continue;
+
+    if (Extension.Features.none())
+      return Error(ExtLoc, "unsupported architectural extension: " + Name);
+
+    FeatureBitset ToggleFeatures = EnableFeature
+                                       ? (~Features & Extension.Features)
+                                       : (Features & Extension.Features);
+    uint64_t Features =
+        ComputeAvailableFeatures(STI.ToggleFeature(ToggleFeatures));
+    setAvailableFeatures(Features);
+    return false;
+  }
+
+  return Error(ExtLoc, "unknown architectural extension: " + Name);
+}
+
 static SMLoc incrementLoc(SMLoc L, int Offset) {
   return SMLoc::getFromPointer(L.getPointer() + Offset);
 }