Use ".arch_extension" ARM directive to specify the additional CPU features

This patch is in response to r223147 where the avaiable features are
computed based on ".cpu" directive. This will work clean for the standard
variants like cortex-a9. For custom variants which rely on standard cpu names
for assembly, the additional features of a CPU should be propagated. This can be
done via ".arch_extension" as long as the assembler supports it. The
implementation for krait along with unit test will be submitted in next patch.

llvm-svn: 230650

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 34dcd1e876c..2b655202c28 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -15,6 +15,7 @@
 
 #include "ARMArchName.h"
 #include "ARMFPUName.h"
+#include "ARMArchExtName.h"
 #include "ARMRegisterInfo.h"
 #include "ARMUnwindOpAsm.h"
 #include "llvm/ADT/StringExtras.h"
@@ -105,6 +106,19 @@ static unsigned GetArchDefaultCPUArch(unsigned ID) {
   return 0;
 }
 
+static const char *GetArchExtName(unsigned ID) {
+  switch (ID) {
+  default:
+    llvm_unreachable("Unknown ARCH Extension kind");
+    break;
+#define ARM_ARCHEXT_NAME(NAME, ID)                                             \
+  case ARM::ID:                                                                \
+    return NAME;
+#include "ARMArchExtName.def"
+  }
+  return nullptr;
+}
+
 namespace {
 
 class ARMELFStreamer;
@@ -134,6 +148,7 @@ class ARMTargetAsmStreamer : public ARMTargetStreamer {
   void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
                             StringRef StrinValue) override;
   void emitArch(unsigned Arch) override;
+  void emitArchExtension(unsigned ArchExt) override;
   void emitObjectArch(unsigned Arch) override;
   void emitFPU(unsigned FPU) override;
   void emitInst(uint32_t Inst, char Suffix = '\0') override;
@@ -249,6 +264,9 @@ void ARMTargetAsmStreamer::emitIntTextAttribute(unsigned Attribute,
 void ARMTargetAsmStreamer::emitArch(unsigned Arch) {
   OS << "\t.arch\t" << GetArchName(Arch) << "\n";
 }
+void ARMTargetAsmStreamer::emitArchExtension(unsigned ArchExt) {
+  OS << "\t.arch_extension\t" << GetArchExtName(ArchExt) << "\n";
+}
 void ARMTargetAsmStreamer::emitObjectArch(unsigned Arch) {
   OS << "\t.object_arch\t" << GetArchName(Arch) << '\n';
 }