Get Triple::getARMCPUForArch() to use TargetParser

First ARMTargetParser FIXME, conservatively changing the way we parse CPUs
in the back-end. Still not perfect, with a lot of special cases, but moving
towards a more generic solution.

Moving all logic to the target parser made some unwritten assumptions
about architectures in Clang to break. I've added a lot of architectures
required by Clang, and default to CPUs that Clang believes it should
(and I agree).

I've also added a lot of unit tests, with the correct CPU for each
architecture, and Clang seems to be working correctly, too.

It also became clear that using "unsigned ID" as the argument for the get
methods makes it hard to know what ID, so I also changed the argument names
to match the enum type names.

llvm-svn: 237797

1 files changed, 33 insertions, 69 deletions

diff --git a/llvm/lib/Support/Triple.cpp b/llvm/lib/Support/Triple.cpp
index a88a82dee89..7f08ce0de47 100644
--- a/llvm/lib/Support/Triple.cpp
+++ b/llvm/lib/Support/Triple.cpp
@@ -12,6 +12,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetParser.h"
 #include <cstring>
 using namespace llvm;
 
@@ -1080,9 +1081,11 @@ const char *Triple::getARMCPUForArch(StringRef MArch) const {
   if (MArch.empty())
     MArch = getArchName();
 
+  // Some defaults are forced.
   switch (getOS()) {
   case llvm::Triple::FreeBSD:
   case llvm::Triple::NetBSD:
+    // FIXME: This doesn't work on BE/thumb variants.
     if (MArch == "armv6")
       return "arm1176jzf-s";
     break;
@@ -1093,77 +1096,38 @@ const char *Triple::getARMCPUForArch(StringRef MArch) const {
     break;
   }
 
-  // MArch is expected to be of the form (arm|thumb)?(eb)?(v.+)?(eb)?
-  // Only the (v.+) part is relevant for determining the CPU, as it determines
-  // the architecture version, so we first remove the surrounding parts.
-  // (ep9312|iwmmxt|xscale)(eb)? is also permitted, so we have to be a bit
-  // careful when removing the leading (arm|thumb)?(eb)? as we don't want to
-  // permit things like armep9312.
-  const char *result = nullptr;
-  size_t offset = StringRef::npos;
-  if (MArch.startswith("arm"))
-    offset = 3;
-  else if (MArch.startswith("thumb"))
-    offset = 5;
-  if (offset != StringRef::npos && MArch.substr(offset, 2) == "eb")
-    offset += 2;
-  else if (MArch.endswith("eb"))
-    MArch = MArch.substr(0, MArch.size() - 2);
-  if (offset != StringRef::npos && (offset == MArch.size() || MArch[offset] == 'v'))
-    MArch = MArch.substr(offset);
-
-  if (MArch == "") {
-    // If no specific architecture version is requested, return the minimum CPU
-    // required by the OS and environment.
-    switch (getOS()) {
-    case llvm::Triple::NetBSD:
-      switch (getEnvironment()) {
-      case llvm::Triple::GNUEABIHF:
-      case llvm::Triple::GNUEABI:
-      case llvm::Triple::EABIHF:
-      case llvm::Triple::EABI:
-        return "arm926ej-s";
-      default:
-        return "strongarm";
-      }
-    case llvm::Triple::NaCl:
-      return "cortex-a8";
+  MArch = ARMTargetParser::getCanonicalArchName(MArch);
+  if (MArch.empty())
+    return nullptr;
+
+  const char *CPU = ARMTargetParser::getDefaultCPU(MArch);
+  if (CPU)
+    return CPU;
+
+  // If no specific architecture version is requested, return the minimum CPU
+  // required by the OS and environment.
+  switch (getOS()) {
+  case llvm::Triple::NetBSD:
+    switch (getEnvironment()) {
+    case llvm::Triple::GNUEABIHF:
+    case llvm::Triple::GNUEABI:
+    case llvm::Triple::EABIHF:
+    case llvm::Triple::EABI:
+      return "arm926ej-s";
     default:
-      switch (getEnvironment()) {
-      case llvm::Triple::EABIHF:
-      case llvm::Triple::GNUEABIHF:
-        return "arm1176jzf-s";
-      default:
-        return "arm7tdmi";
-      }
+      return "strongarm";
+    }
+  case llvm::Triple::NaCl:
+    return "cortex-a8";
+  default:
+    switch (getEnvironment()) {
+    case llvm::Triple::EABIHF:
+    case llvm::Triple::GNUEABIHF:
+      return "arm1176jzf-s";
+    default:
+      return "arm7tdmi";
     }
-  } else {
-    result = llvm::StringSwitch<const char *>(MArch)
-      .Cases("v2", "v2a", "arm2")
-      .Case("v3", "arm6")
-      .Case("v3m", "arm7m")
-      .Case("v4", "strongarm")
-      .Case("v4t", "arm7tdmi")
-      .Cases("v5", "v5t", "arm10tdmi")
-      .Cases("v5e", "v5te", "arm1022e")
-      .Case("v5tej", "arm926ej-s")
-      .Case("v6", "arm1136jf-s")
-      .Case("v6j", "arm1136j-s")
-      .Cases("v6k", "v6z", "v6zk", "arm1176jzf-s")
-      .Case("v6t2", "arm1156t2-s")
-      .Cases("v6m", "v6-m", "v6sm", "v6s-m", "cortex-m0")
-      .Cases("v7", "v7a", "v7-a", "v7l", "v7-l", "cortex-a8")
-      .Cases("v7s", "v7-s", "swift")
-      .Cases("v7r", "v7-r", "cortex-r4")
-      .Cases("v7m", "v7-m", "cortex-m3")
-      .Cases("v7em", "v7e-m", "cortex-m4")
-      .Cases("v8", "v8a", "v8-a", "cortex-a53")
-      .Cases("v8.1a", "v8.1-a", "generic")
-      .Case("ep9312", "ep9312")
-      .Case("iwmmxt", "iwmmxt")
-      .Case("xscale", "xscale")
-      .Default(nullptr);
   }
 
-  return result;
+  llvm_unreachable("invalid arch name");
 }