Add register Mips::GP to the list of reserved registers if target is bare-metal
to prevent it from being clobbered. mips uses $gp to access small data section.

This bug was originally reported by Carl Norum.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162340 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/MipsSubtarget.cpp b/lib/Target/Mips/MipsSubtarget.cpp
index 11ff809..ac83d83 100644
--- a/lib/Target/Mips/MipsSubtarget.cpp
+++ b/lib/Target/Mips/MipsSubtarget.cpp
@@ -25,7 +25,8 @@
 void MipsSubtarget::anchor() { }
 
 MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
-                             const std::string &FS, bool little) :
+                             const std::string &FS, bool little,
+                             Reloc::Model RM) :
   MipsGenSubtargetInfo(TT, CPU, FS),
   MipsArchVersion(Mips32), MipsABI(UnknownABI), IsLittle(little),
   IsSingleFloat(false), IsFP64bit(false), IsGP64bit(false), HasVFPU(false),
@@ -54,6 +55,9 @@
   // Is the target system Linux ?
   if (TT.find("linux") == std::string::npos)
     IsLinux = false;
+
+  // Set UseSmallSection.
+  UseSmallSection = !IsLinux && (RM == Reloc::Static);
 }
 
 bool