[mips] Make mips64 the default CPU for the mips64 architecture

Summary:
This is consistent with the integrated assembler.
All mips64 codegen tests previously passed -mcpu. Removed -mcpu from
blez_bgez.ll and const-mult.ll to cover the default case.

Ideally, the two implementations of selectMipsCPU() will be merged but it's
proven difficult to find a home for the function that doesn't cause link errors.
For now, we'll hoist the common functionality into a function and mark it with
FIXME's.

Reviewers: jacksprat, matheusalmeida

Reviewed By: matheusalmeida

Differential Revision: http://llvm-reviews.chandlerc.com/D2830

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201782 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 2 deletions

diff --git a/lib/Target/Mips/MipsSubtarget.cpp b/lib/Target/Mips/MipsSubtarget.cpp
index a715b6285c..a5d910e3e5 100644
--- a/lib/Target/Mips/MipsSubtarget.cpp
+++ b/lib/Target/Mips/MipsSubtarget.cpp
@@ -59,6 +59,20 @@ Mips16ConstantIslands(
   cl::desc("MIPS: mips16 constant islands enable."),
   cl::init(true));
 
+/// Select the Mips CPU for the given triple and cpu name.
+/// FIXME: Merge with the copy in MipsMCTargetDesc.cpp
+static inline StringRef selectMipsCPU(StringRef TT, StringRef CPU) {
+  if (CPU.empty()) {
+    Triple TheTriple(TT);
+    if (TheTriple.getArch() == Triple::mips ||
+        TheTriple.getArch() == Triple::mipsel)
+      CPU = "mips32";
+    else
+      CPU = "mips64";
+  }
+  return CPU;
+}
+
 void MipsSubtarget::anchor() { }
 
 MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
@@ -75,8 +89,7 @@ MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
   RM(_RM), OverrideMode(NoOverride), TM(_TM), TargetTriple(TT)
 {
   std::string CPUName = CPU;
-  if (CPUName.empty())
-    CPUName = "mips32";
+  CPUName = selectMipsCPU(TT, CPUName);
 
   // Parse features string.
   ParseSubtargetFeatures(CPUName, FS);