ARM: support PIC on Windows on ARM

[oota-llvm.git] / lib / Target / ARM / ARMSubtarget.cpp

diff --git a/lib/Target/ARM/ARMSubtarget.cpp b/lib/Target/ARM/ARMSubtarget.cpp
index 0dec1c406a43a0f7afa4d71f4145753c91495c72..1c9dd4d49d6a6567bb24e46575deca6795857df4 100644 (file)
--- a/lib/Target/ARM/ARMSubtarget.cpp
+++ b/lib/Target/ARM/ARMSubtarget.cpp
@@ -21,12 +21,14 @@
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetOptions.h"
 
+using namespace llvm;
+
+#define DEBUG_TYPE "arm-subtarget"
+
 #define GET_SUBTARGETINFO_TARGET_DESC
 #define GET_SUBTARGETINFO_CTOR
 #include "ARMGenSubtargetInfo.inc"
 
-using namespace llvm;
-
 static cl::opt<bool>
 ReserveR9("arm-reserve-r9", cl::Hidden,
           cl::desc("Reserve R9, making it unavailable as GPR"));
@@ -212,6 +214,12 @@ void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
     }
   }
 
+  // FIXME: this is invalid for WindowsCE
+  if (isTargetWindows()) {
+    TargetABI = ARM_ABI_AAPCS;
+    NoARM = true;
+  }
+
   if (isAAPCS_ABI())
     stackAlignment = 8;
   if (isTargetNaCl())
@@ -236,7 +244,7 @@ void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
       //
       // ARMv6 may or may not support unaligned accesses depending on the
       // SCTLR.U bit, which is architecture-specific. We assume ARMv6
-      // Darwin targets support unaligned accesses, and others don't.
+      // Darwin and NetBSD targets support unaligned accesses, and others don't.
       //
       // ARMv7 always has SCTLR.U set to 1, but it has a new SCTLR.A bit
       // which raises an alignment fault on unaligned accesses. Linux
@@ -249,6 +257,11 @@ void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
           (hasV7Ops() && (isTargetLinux() || isTargetNaCl() ||
                           isTargetNetBSD())) ||
           (hasV6Ops() && (isTargetMachO() || isTargetNetBSD()));
+      // The one exception is cortex-m0, which despite being v6, does not
+      // support unaligned accesses. Rather than make the above boolean
+      // expression even more obtuse, just override the value here.
+      if (isThumb1Only() && isMClass())
+        AllowsUnalignedMem = false;
       break;
     case StrictAlign:
       AllowsUnalignedMem = false;