[ARM] Fix MachO CPU Subtype inference in llvm::createARMAsmBackend()

[vsk]

Summary

This patch makes the Darwin ARM backend take advantage of TargetParser.

Previously, Darwin relied on a StringSwitch to convert architecture names to MachO CPU Subtypes. This was brittle and prone to bugs. Using TargetParser makes triple parsing more consistent across LLVM, and eliminates frontend <-> Darwin backend misunderstandings.

This patch also teaches TargetParser about ARMV7K for the first time.

[rengolin]

With the two comments, LGTM. Thanks!

lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

752 ↗

(On Diff #31993)

the king of all nitpicks: too many spaces. :)

test/CodeGen/ARM/MachO-subtypes.ll

56 ↗

(On Diff #31993)

Do you guys really use xscale? If not, I'd remove it from here.

Support for those deprecated arches is deprecated, and here only for legacy reasons. :)

[vsk]

• Removed extra spaces.
• Dropped the xscale subtype from the patch.

[vsk]

Thanks Renato, the two changes you wanted are up. Could you commit this for me?

llvm/trunk/include/llvm/Support/TargetParser.h

enum ArchKind {
     AK_ARMV5,
     AK_ARMV5E,
     AK_ARMV6J,
     AK_ARMV6HL,
     AK_ARMV7,
     AK_ARMV7L,
     AK_ARMV7HL,
     AK_ARMV7S,
+    AK_ARMV7K,
     AK_LAST
   };
 
   // Arch extension modifiers for CPUs.
   enum ArchExtKind : unsigned {
     AEK_INVALID  = 0x0,
     AEK_NONE     = 0x1,
     AEK_CRC      = 0x2,

llvm/trunk/lib/Support/TargetParser.cpp

struct {
   { "armv6z",    ARM::AK_ARMV6Z,   "6Z",      "v6z",   ARMBuildAttrs::CPUArch::v6KZ },
   { "armv6zk",   ARM::AK_ARMV6ZK,  "6ZK",     "v6zk",  ARMBuildAttrs::CPUArch::v6KZ },
   { "armv6-m",   ARM::AK_ARMV6M,   "6-M",     "v6m",   ARMBuildAttrs::CPUArch::v6_M },
   { "armv6s-m",  ARM::AK_ARMV6SM,  "6S-M",    "v6sm",  ARMBuildAttrs::CPUArch::v6S_M },
   { "armv7-a",   ARM::AK_ARMV7A,   "7-A",     "v7",    ARMBuildAttrs::CPUArch::v7 },
   { "armv7-r",   ARM::AK_ARMV7R,   "7-R",     "v7r",   ARMBuildAttrs::CPUArch::v7 },
   { "armv7-m",   ARM::AK_ARMV7M,   "7-M",     "v7m",   ARMBuildAttrs::CPUArch::v7 },
   { "armv7e-m",  ARM::AK_ARMV7EM,  "7E-M",    "v7em",  ARMBuildAttrs::CPUArch::v7E_M },
+  { "armv7k",    ARM::AK_ARMV7K,   "7-K",     "v7k",   ARMBuildAttrs::CPUArch::v7 },
   { "armv8-a",   ARM::AK_ARMV8A,   "8-A",     "v8",    ARMBuildAttrs::CPUArch::v8 },
   { "armv8.1-a", ARM::AK_ARMV8_1A, "8.1-A",   "v8.1a", ARMBuildAttrs::CPUArch::v8 },
   // Non-standard Arch names.
   { "iwmmxt",    ARM::AK_IWMMXT,   "iwmmxt",  "",      ARMBuildAttrs::CPUArch::v5TE },
   { "iwmmxt2",   ARM::AK_IWMMXT2,  "iwmmxt2", "",      ARMBuildAttrs::CPUArch::v5TE },
   { "xscale",    ARM::AK_XSCALE,   "xscale",  "",      ARMBuildAttrs::CPUArch::v5TE },
   { "armv5",     ARM::AK_ARMV5,    "5T",      "v5",    ARMBuildAttrs::CPUArch::v5T },
   { "armv5e",    ARM::AK_ARMV5E,   "5TE",     "v5e",   ARMBuildAttrs::CPUArch::v5TE },
unsigned ARMTargetParser::parseArchVersion(StringRef Arch) {
   case ARM::AK_ARMV7:
   case ARM::AK_ARMV7A:
   case ARM::AK_ARMV7R:
   case ARM::AK_ARMV7M:
   case ARM::AK_ARMV7L:
   case ARM::AK_ARMV7HL:
   case ARM::AK_ARMV7S:
   case ARM::AK_ARMV7EM:
+  case ARM::AK_ARMV7K:
     return 7;
   case ARM::AK_ARMV8A:
   case ARM::AK_ARMV8_1A:
     return 8;
   }
   return 0;
 }

llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MachO.h"
+#include "llvm/Support/TargetParser.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
 namespace {
 class ARMELFObjectWriter : public MCELFObjectTargetWriter {
 public:
   ARMELFObjectWriter(uint8_t OSABI)
       : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI, ELF::EM_ARM,
void ARMAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
   // the fixup value. The Value has been "split up" into the appropriate
   // bitfields above.
   for (unsigned i = 0; i != NumBytes; ++i) {
     unsigned Idx = IsLittleEndian ? i : (FullSizeBytes - 1 - i);
     Data[Offset + Idx] |= uint8_t((Value >> (i * 8)) & 0xff);
   }
 }
 
+static MachO::CPUSubTypeARM getMachOSubTypeFromArch(StringRef Arch) {
+  unsigned AK = ARMTargetParser::parseArch(Arch);
+  switch (AK) {
+  default:
+    return MachO::CPU_SUBTYPE_ARM_V7;
+  case ARM::AK_ARMV4T:
+    return MachO::CPU_SUBTYPE_ARM_V4T;
+  case ARM::AK_ARMV6:
+  case ARM::AK_ARMV6K:
+    return MachO::CPU_SUBTYPE_ARM_V6;
+  case ARM::AK_ARMV5:
+    return MachO::CPU_SUBTYPE_ARM_V5;
+  case ARM::AK_ARMV5T:
+  case ARM::AK_ARMV5E:
+  case ARM::AK_ARMV5TE:
+  case ARM::AK_ARMV5TEJ:
+    return MachO::CPU_SUBTYPE_ARM_V5TEJ;
+  case ARM::AK_ARMV7:
+    return MachO::CPU_SUBTYPE_ARM_V7;
+  case ARM::AK_ARMV7S:
+    return MachO::CPU_SUBTYPE_ARM_V7S;
+  case ARM::AK_ARMV7K:
+    return MachO::CPU_SUBTYPE_ARM_V7K;
+  case ARM::AK_ARMV6M:
+  case ARM::AK_ARMV6SM:
+    return MachO::CPU_SUBTYPE_ARM_V6M;
+  case ARM::AK_ARMV7M:
+    return MachO::CPU_SUBTYPE_ARM_V7M;
+  case ARM::AK_ARMV7EM:
+    return MachO::CPU_SUBTYPE_ARM_V7EM;
+  }
+}
+
 MCAsmBackend *llvm::createARMAsmBackend(const Target &T,
                                         const MCRegisterInfo &MRI,
                                         const Triple &TheTriple, StringRef CPU,
                                         bool isLittle) {
   switch (TheTriple.getObjectFormat()) {
   default:
     llvm_unreachable("unsupported object format");
   case Triple::MachO: {
-    MachO::CPUSubTypeARM CS =
-        StringSwitch<MachO::CPUSubTypeARM>(TheTriple.getArchName())
-            .Cases("armv4t", "thumbv4t", MachO::CPU_SUBTYPE_ARM_V4T)
-            .Cases("armv5e", "thumbv5e", MachO::CPU_SUBTYPE_ARM_V5TEJ)
-            .Cases("armv6", "thumbv6", MachO::CPU_SUBTYPE_ARM_V6)
-            .Cases("armv6m", "thumbv6m", MachO::CPU_SUBTYPE_ARM_V6M)
-            .Cases("armv7em", "thumbv7em", MachO::CPU_SUBTYPE_ARM_V7EM)
-            .Cases("armv7k", "thumbv7k", MachO::CPU_SUBTYPE_ARM_V7K)
-            .Cases("armv7m", "thumbv7m", MachO::CPU_SUBTYPE_ARM_V7M)
-            .Cases("armv7s", "thumbv7s", MachO::CPU_SUBTYPE_ARM_V7S)
-            .Default(MachO::CPU_SUBTYPE_ARM_V7);
-
+    MachO::CPUSubTypeARM CS = getMachOSubTypeFromArch(TheTriple.getArchName());
     return new ARMAsmBackendDarwin(T, TheTriple, CS);
   }
   case Triple::COFF:
     assert(TheTriple.isOSWindows() && "non-Windows ARM COFF is not supported");
     return new ARMAsmBackendWinCOFF(T, TheTriple);
   case Triple::ELF:
     assert(TheTriple.isOSBinFormatELF() && "using ELF for non-ELF target");
     uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());

llvm/trunk/test/CodeGen/ARM/MachO-subtypes.ll

+; Check that MachO ARM CPU Subtypes are respected
+
+; RUN: llc -mtriple=armv4t-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V4T
+
+; RUN: llc -mtriple=armv5-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V5
+; RUN: llc -mtriple=armv5e-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V5
+; RUN: llc -mtriple=armv5t-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V5
+; RUN: llc -mtriple=armv5te-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V5
+; RUN: llc -mtriple=armv5tej-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V5
+
+; RUN: llc -mtriple=armv6-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V6
+; RUN: llc -mtriple=armv6k-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V6
+; RUN: llc -mtriple=thumbv6-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V6
+; RUN: llc -mtriple=thumbv6k-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V6
+
+; RUN: llc -mtriple=armv6m-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V6M
+; RUN: llc -mtriple=thumbv6m-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V6M
+
+; RUN: llc -mtriple=armv7-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7
+; RUN: llc -mtriple=thumbv7-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7
+
+; RUN: llc -mtriple=thumbv7em-apple-darwin -mcpu=cortex-m4 -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7EM
+; RUN: llc -mtriple=thumbv7em-apple-darwin -mcpu=cortex-m7 -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7EM
+
+; RUN: llc -mtriple=armv7k-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7K
+; RUN: llc -mtriple=thumbv7k-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7K
+
+; RUN: llc -mtriple=thumbv7m-apple-darwin -mcpu=sc300 -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7M
+; RUN: llc -mtriple=thumbv7m-apple-darwin -mcpu=cortex-m3 -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7M
+
+; RUN: llc -mtriple=armv7s-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7S
+; RUN: llc -mtriple=thumbv7s-apple-darwin -filetype=obj -o - < %s \
+; RUN: | llvm-readobj -file-headers | FileCheck %s --check-prefix=CHECK-V7S
+
+define void @_test() {
+  ret void
+}
+
+; CHECK-V4T:   CpuSubType: CPU_SUBTYPE_ARM_V4T (0x5)
+; CHECK-V5:   CpuSubType: CPU_SUBTYPE_ARM_V5 (0x7)
+; CHECK-V6:   CpuSubType: CPU_SUBTYPE_ARM_V6 (0x6)
+; CHECK-V6M:   CpuSubType: CPU_SUBTYPE_ARM_V6M (0xE)
+; CHECK-V7:   CpuSubType: CPU_SUBTYPE_ARM_V7 (0x9)
+; CHECK-V7EM:   CpuSubType: CPU_SUBTYPE_ARM_V7EM (0x10)
+; CHECK-V7K:   CpuSubType: CPU_SUBTYPE_ARM_V7K (0xC)
+; CHECK-V7M:   CpuSubType: CPU_SUBTYPE_ARM_V7M (0xF)
+; CHECK-V7S:   CpuSubType: CPU_SUBTYPE_ARM_V7S (0xB)