ARM backend contribution from Apple.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33353 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 52 insertions, 0 deletions

diff --git a/lib/Target/ARM/ARMSubtarget.cpp b/lib/Target/ARM/ARMSubtarget.cpp
new file mode 100644
index 0000000000..35bb9accc3
--- /dev/null
+++ b/lib/Target/ARM/ARMSubtarget.cpp
@@ -0,0 +1,52 @@
+//===-- ARMSubtarget.cpp - ARM Subtarget Information ------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Evan Cheng and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the ARM specific subclass of TargetSubtarget.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARMSubtarget.h"
+#include "ARMGenSubtarget.inc"
+#include "llvm/Module.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+// FIXME: this is temporary.
+static cl::opt<bool> Thumb("enable-thumb",
+                           cl::desc("Switch to thumb mode in ARM backend"));
+
+ARMSubtarget::ARMSubtarget(const Module &M, const std::string &FS)
+  : ARMArchVersion(V4T), HasVFP2(false), IsDarwin(false),
+    UseThumbBacktraces(false), IsR9Reserved(false), stackAlignment(8) {
+
+  // Determine default and user specified characteristics
+  std::string CPU = "generic";
+
+  // Parse features string.
+  ParseSubtargetFeatures(FS, CPU);
+
+  IsThumb = Thumb;
+  
+  // Set the boolean corresponding to the current target triple, or the default
+  // if one cannot be determined, to true.
+  const std::string& TT = M.getTargetTriple();
+  if (TT.length() > 5) {
+    IsDarwin = TT.find("-darwin") != std::string::npos;
+  } else if (TT.empty()) {
+#if defined(__APPLE__)
+    IsDarwin = true;
+#endif
+  }
+
+  if (IsDarwin) {
+    UseThumbBacktraces = true;
+    IsR9Reserved = true;
+    stackAlignment = 4;
+  } 
+}