ms inline asm: Don't add x86 segment registers to the clobber list.

Clang tries to check the clobber list but doesn't list segment registers in its
x86 register list. This fixes PR20343.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213303 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCTargetAsmParser.h b/include/llvm/MC/MCTargetAsmParser.h
index 384cc1b880cad1a6153fbb524608f81688f8b5f5..9a5881b14b44c3f704b8f3782fa5529058a93b01 100644 (file)
--- a/include/llvm/MC/MCTargetAsmParser.h
+++ b/include/llvm/MC/MCTargetAsmParser.h
@@ -164,6 +164,9 @@ public:
                                        unsigned &ErrorInfo,
                                        bool MatchingInlineAsm) = 0;
 
+  /// Allows targets to let registers opt out of clobber lists.
+  virtual bool OmitRegisterFromClobberLists(unsigned RegNo) { return false; }
+
   /// Allow a target to add special case operand matching for things that
   /// tblgen doesn't/can't handle effectively. For example, literal
   /// immediates on ARM. TableGen expects a token operand, but the parser

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 62ab4a567a12f922d1b53ec01f9deb8b3fc5aa08..ed1d704c1d67ceaa30af200a6e0ed8fba91d2a5e 100644 (file)
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -4510,7 +4510,8 @@ bool AsmParser::parseMSInlineAsm(
         continue;
 
       // Register operand.
-      if (Operand.isReg() && !Operand.needAddressOf()) {
+      if (Operand.isReg() && !Operand.needAddressOf() &&
+          !getTargetParser().OmitRegisterFromClobberLists(Operand.getReg())) {
         unsigned NumDefs = Desc.getNumDefs();
         // Clobber.
         if (NumDefs && Operand.getMCOperandNum() < NumDefs)

diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index f0765ed50d71befce6005eb6f481b2efd5c427ac..a259c96320322ebf79806f044824f349a753cc71 100644 (file)
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -696,6 +696,8 @@ private:
                                unsigned &ErrorInfo,
                                bool MatchingInlineAsm) override;
 
+  virtual bool OmitRegisterFromClobberLists(unsigned RegNo) override;
+
   /// doSrcDstMatch - Returns true if operands are matching in their
   /// word size (%si and %di, %esi and %edi, etc.). Order depends on
   /// the parsing mode (Intel vs. AT&T).
@@ -2520,6 +2522,9 @@ bool X86AsmParser::MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
   return true;
 }
 
+bool X86AsmParser::OmitRegisterFromClobberLists(unsigned RegNo) {
+  return X86MCRegisterClasses[X86::SEGMENT_REGRegClassID].contains(RegNo);
+}
 
 bool X86AsmParser::ParseDirective(AsmToken DirectiveID) {
   StringRef IDVal = DirectiveID.getIdentifier();