[ARM] Introduce subtarget features per ARM architecture.

This allows for accurate architecture targeting as well as removing
duplicate information (hardcoded feature strings) from MCTargetDesc.

llvm-svn: 253196

1 files changed, 5 insertions, 103 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp
index 7be092ac2ca..8c8c249addb 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp
@@ -24,6 +24,7 @@
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetParser.h"
 #include "llvm/Support/TargetRegistry.h"
 
 using namespace llvm;
@@ -134,110 +135,11 @@ std::string ARM_MC::ParseARMTriple(const Triple &TT, StringRef CPU) {
   bool isThumb =
       TT.getArch() == Triple::thumb || TT.getArch() == Triple::thumbeb;
 
-  bool NoCPU = CPU == "generic" || CPU.empty();
   std::string ARMArchFeature;
-  switch (TT.getSubArch()) {
-  default:
-    llvm_unreachable("invalid sub-architecture for ARM");
-  case Triple::ARMSubArch_v8:
-    if (NoCPU)
-      // v8a: FeatureDB, FeatureFPARMv8, FeatureNEON, FeatureDSP,
-      //      FeatureMP, FeatureHWDiv, FeatureHWDivARM, FeatureTrustZone,
-      //      FeatureT2XtPk, FeatureCrypto, FeatureCRC
-      ARMArchFeature = "+v8,+db,+fp-armv8,+neon,+dsp,+mp,+hwdiv,+hwdiv-arm,"
-                       "+trustzone,+t2xtpk,+crypto,+crc";
-    else
-      // Use CPU to figure out the exact features
-      ARMArchFeature = "+v8";
-    break;
-  case Triple::ARMSubArch_v8_1a:
-    if (NoCPU)
-      // v8.1a: FeatureDB, FeatureFPARMv8, FeatureNEON, FeatureDSP,
-      //      FeatureMP, FeatureHWDiv, FeatureHWDivARM, FeatureTrustZone,
-      //      FeatureT2XtPk, FeatureCrypto, FeatureCRC, FeatureV8_1a
-      ARMArchFeature = "+v8.1a,+db,+fp-armv8,+neon,+dsp,+mp,+hwdiv,+hwdiv-arm,"
-                       "+trustzone,+t2xtpk,+crypto,+crc";
-    else
-      // Use CPU to figure out the exact features
-      ARMArchFeature = "+v8.1a";
-    break;
-  case Triple::ARMSubArch_v7m:
-    isThumb = true;
-    if (NoCPU)
-      // v7m: FeatureNoARM, FeatureDB, FeatureHWDiv, FeatureMClass
-      ARMArchFeature = "+v7,+noarm,+db,+hwdiv,+mclass";
-    else
-      // Use CPU to figure out the exact features.
-      ARMArchFeature = "+v7";
-    break;
-  case Triple::ARMSubArch_v7em:
-    if (NoCPU)
-      // v7em: FeatureNoARM, FeatureDB, FeatureHWDiv, FeatureDSP,
-      //       FeatureT2XtPk, FeatureMClass
-      ARMArchFeature = "+v7,+noarm,+db,+hwdiv,+dsp,+t2xtpk,+mclass";
-    else
-      // Use CPU to figure out the exact features.
-      ARMArchFeature = "+v7";
-    break;
-  case Triple::ARMSubArch_v7s:
-    if (NoCPU)
-      // v7s: FeatureNEON, FeatureDB, FeatureDSP, FeatureHasRAS
-      //      Swift
-      ARMArchFeature = "+v7,+swift,+neon,+db,+dsp,+ras";
-    else
-      // Use CPU to figure out the exact features.
-      ARMArchFeature = "+v7";
-    break;
-  case Triple::ARMSubArch_v7k:
-    if (NoCPU)
-      // v7k: FeatureNEON, FeatureDB, FeatureDSP, FeatureHasRAS
-      //      A7
-      ARMArchFeature = "+v7,+a7,+neon,+db,+dsp,+ras";
-    else
-      // Use CPU to figure out the exact features.
-      ARMArchFeature = "+v7";
-    break;
-  case Triple::ARMSubArch_v7:
-    // v7 CPUs have lots of different feature sets. If no CPU is specified,
-    // then assume v7a (e.g. cortex-a8) feature set. Otherwise, return
-    // the "minimum" feature set and use CPU string to figure out the exact
-    // features.
-    if (NoCPU)
-      // v7a: FeatureNEON, FeatureDB, FeatureDSP, FeatureT2XtPk
-      ARMArchFeature = "+v7,+neon,+db,+dsp,+t2xtpk";
-    else
-      // Use CPU to figure out the exact features.
-      ARMArchFeature = "+v7";
-    break;
-  case Triple::ARMSubArch_v6t2:
-    ARMArchFeature = "+v6t2";
-    break;
-  case Triple::ARMSubArch_v6k:
-    ARMArchFeature = "+v6k";
-    break;
-  case Triple::ARMSubArch_v6m:
-    isThumb = true;
-    if (NoCPU)
-      // v6m: FeatureNoARM, FeatureMClass
-      ARMArchFeature = "+v6m,+noarm,+mclass";
-    else
-      ARMArchFeature = "+v6";
-    break;
-  case Triple::ARMSubArch_v6:
-    ARMArchFeature = "+v6";
-    break;
-  case Triple::ARMSubArch_v5te:
-    ARMArchFeature = "+v5te";
-    break;
-  case Triple::ARMSubArch_v5:
-    ARMArchFeature = "+v5t";
-    break;
-  case Triple::ARMSubArch_v4t:
-    ARMArchFeature = "+v4t";
-    break;
-  case Triple::NoSubArch:
-    break;
-  }
+
+  unsigned ArchID = ARM::parseArch(TT.getArchName());
+  if (ArchID != ARM::AK_INVALID &&  (CPU.empty() || CPU == "generic"))
+    ARMArchFeature = (ARMArchFeature + "+" + ARM::getArchName(ArchID)).str();
 
   if (isThumb) {
     if (ARMArchFeature.empty())