commit 3346582bca29a077d24362f3dbea45f96d693904
author Eli Friedman <eli.friedman@gmail.com> Fri Jul 08 23:31:17 2011 +0000
committer Eli Friedman <eli.friedman@gmail.com> Fri Jul 08 23:31:17 2011 +0000
tree 0398f3187f1a8e0ebcf732a78bd8bd57e373a522
parent 07398b5d48c92bea7de6032e46ab5d39a204fb15

Change -mno-mmx to be more compatible with gcc.  Specifically, -mno-mmx should not imply -mno-sse.

Note that because we don't usually touch the MMX registers anyway, all -mno-mmx needs to do is tweak the x86-32 calling convention a little for vectors that look like MMX vectors, and prevent the definition of __MMX__.

clang doesn't actually stop the user from using MMX inline asm operands or MMX builtins in -mno-mmx mode; as a QOI issue, it would be nice to diagnose, but I doubt it really matters much.

<rdar://problem/9694837>

llvm-svn: 134770

clang/lib/CodeGen/TargetInfo.cpp

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 8736d59..28afda1 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -374,6 +374,7 @@
 
   bool IsDarwinVectorABI;
   bool IsSmallStructInRegABI;
+  bool IsMMXDisabled;
 
   static bool isRegisterSize(unsigned Size) {
     return (Size == 8 || Size == 16 || Size == 32 || Size == 64);
@@ -403,14 +404,15 @@
   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
                                  CodeGenFunction &CGF) const;
 
-  X86_32ABIInfo(CodeGen::CodeGenTypes &CGT, bool d, bool p)
-    : ABIInfo(CGT), IsDarwinVectorABI(d), IsSmallStructInRegABI(p) {}
+  X86_32ABIInfo(CodeGen::CodeGenTypes &CGT, bool d, bool p, bool m)
+    : ABIInfo(CGT), IsDarwinVectorABI(d), IsSmallStructInRegABI(p),
+      IsMMXDisabled(m) {}
 };
 
 class X86_32TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
-  X86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, bool d, bool p)
-    :TargetCodeGenInfo(new X86_32ABIInfo(CGT, d, p)) {}
+  X86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, bool d, bool p, bool m)
+    :TargetCodeGenInfo(new X86_32ABIInfo(CGT, d, p, m)) {}
 
   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
                            CodeGen::CodeGenModule &CGM) const;
@@ -701,6 +703,9 @@
 
     const llvm::Type *IRType = CGT.ConvertTypeRecursive(Ty);
     if (UseX86_MMXType(IRType)) {
+      if (IsMMXDisabled)
+        return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
+                                                            64));
       ABIArgInfo AAI = ABIArgInfo::getDirect(IRType);
       AAI.setCoerceToType(llvm::Type::getX86_MMXTy(getVMContext()));
       return AAI;
@@ -3006,10 +3011,12 @@
   case llvm::Triple::msp430:
     return *(TheTargetCodeGenInfo = new MSP430TargetCodeGenInfo(Types));
 
-  case llvm::Triple::x86:
+  case llvm::Triple::x86: {
+    bool DisableMMX = strcmp(getContext().Target.getABI(), "no-mmx") == 0;
+
     if (Triple.isOSDarwin())
       return *(TheTargetCodeGenInfo =
-               new X86_32TargetCodeGenInfo(Types, true, true));
+               new X86_32TargetCodeGenInfo(Types, true, true, DisableMMX));
 
     switch (Triple.getOS()) {
     case llvm::Triple::Cygwin:
@@ -3020,12 +3027,13 @@
     case llvm::Triple::OpenBSD:
     case llvm::Triple::NetBSD:
       return *(TheTargetCodeGenInfo =
-               new X86_32TargetCodeGenInfo(Types, false, true));
+               new X86_32TargetCodeGenInfo(Types, false, true, DisableMMX));
 
     default:
       return *(TheTargetCodeGenInfo =
-               new X86_32TargetCodeGenInfo(Types, false, false));
+               new X86_32TargetCodeGenInfo(Types, false, false, DisableMMX));
     }
+  }
 
   case llvm::Triple::x86_64:
     switch (Triple.getOS()) {