[AArch64] Add native CPU detection for Neoverse N1

[jgreenhalgh]

Summary

Hi,

As subject line, map the ID value 0xd0c to "neoverse-n1". This reflects the value used by the GCC support https://gcc.gnu.org/git/?p=gcc.git;a=blobdiff;f=gcc/config/aarch64/aarch64-cores.def;h=b0c7d2f23ace1e3c3a89f4e3ab10c9ad08f56b22;hp=7c4bd52049e5ae33241acce37414da91abaa989c;hb=9ed6834deacecd0e0671793e1440aa728939b93f;hpb=229d576cde53ac4396583da3642ca969cca413d1

I've got no commit access over here, so would appreciate this being committed on my behalf if it is OK.

Thanks,
James

[SjoerdMeijer]

Hi James, looks like a very straightforward fix to me, so will commit it right away on your behalf.

llvm/lib/Support/Host.cpp

207

if this CPU ID would have been defined where the rest of the core is defined, we might not forget it all the time...

llvm/lib/Support/Host.cpp

for (unsigned I = 0, E = Lines.size(); I != E; ++I)
             .Case("0xd02", "cortex-a34")
             .Case("0xd04", "cortex-a35")
             .Case("0xd03", "cortex-a53")
             .Case("0xd07", "cortex-a57")
             .Case("0xd08", "cortex-a72")
             .Case("0xd09", "cortex-a73")
             .Case("0xd0a", "cortex-a75")
             .Case("0xd0b", "cortex-a76")
+            .Case("0xd0c", "neoverse-n1")
             .Default("generic");
   }
 
   if (Implementer == "0x42" || Implementer == "0x43") { // Broadcom | Cavium.
     for (unsigned I = 0, E = Lines.size(); I != E; ++I) {
       if (Lines[I].startswith("CPU part")) {
         return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
           .Case("0x516", "thunderx2t99")

llvm/unittests/Support/Host.cpp

EXPECT_EQ(sys::detail::getHostCPUNameForARM("CPU implementer : 0x51\n"
                                               "CPU part        : 0x06f"),
             "krait");
 }
 
 TEST(getLinuxHostCPUName, AArch64) {
   EXPECT_EQ(sys::detail::getHostCPUNameForARM("CPU implementer : 0x41\n"
                                               "CPU part        : 0xd03"),
             "cortex-a53");
+
+  EXPECT_EQ(sys::detail::getHostCPUNameForARM("CPU implementer : 0x41\n"
+                                              "CPU part        : 0xd0c"),
+            "neoverse-n1");
   // Verify that both CPU implementer and CPU part are checked:
   EXPECT_EQ(sys::detail::getHostCPUNameForARM("CPU implementer : 0x40\n"
                                               "CPU part        : 0xd03"),
             "generic");
   EXPECT_EQ(sys::detail::getHostCPUNameForARM("CPU implementer : 0x51\n"
                                               "CPU part        : 0x201"),
             "kryo");
   EXPECT_EQ(sys::detail::getHostCPUNameForARM("CPU implementer : 0x51\n"