[ARM] Remove ThumbTargetMachines. (NFC)

Summary:
Thumb code generation is controlled by ARMSubtarget and the concrete
ThumbLETargetMachine and ThumbBETargetMachine are not needed.

Eric Christopher suggested removing the unneeded target machines in
https://reviews.llvm.org/D33287.

I think it still makes sense to keep separate TargetMachines for big and
little endian as we probably do not want to have different endianess for
difference functions in a single compilation unit. The MIPS backend has
two separate TargetMachines for big and little endian as well. 

Reviewers: echristo, rengolin, kristof.beyls, t.p.northover

Reviewed By: echristo

Subscribers: aemerson, javed.absar, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D33318

llvm-svn: 303733

1 files changed, 4 insertions, 58 deletions

diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.h b/llvm/lib/Target/ARM/ARMTargetMachine.h
index f0ca9427d9f..e5eb27114c7 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.h
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.h
@@ -62,23 +62,9 @@ public:
   }
 };
 
-/// ARM target machine.
+/// ARM/Thumb little endian target machine.
 ///
-class ARMTargetMachine : public ARMBaseTargetMachine {
-  virtual void anchor();
-
-public:
-   ARMTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
-                    StringRef FS, const TargetOptions &Options,
-                    Optional<Reloc::Model> RM, CodeModel::Model CM,
-                    CodeGenOpt::Level OL, bool isLittle);
-};
-
-/// ARM little endian target machine.
-///
-class ARMLETargetMachine : public ARMTargetMachine {
-  void anchor() override;
-
+class ARMLETargetMachine : public ARMBaseTargetMachine {
 public:
   ARMLETargetMachine(const Target &T, const Triple &TT, StringRef CPU,
                      StringRef FS, const TargetOptions &Options,
@@ -86,11 +72,9 @@ public:
                      CodeGenOpt::Level OL);
 };
 
-/// ARM big endian target machine.
+/// ARM/Thumb big endian target machine.
 ///
-class ARMBETargetMachine : public ARMTargetMachine {
-  void anchor() override;
-
+class ARMBETargetMachine : public ARMBaseTargetMachine {
 public:
   ARMBETargetMachine(const Target &T, const Triple &TT, StringRef CPU,
                      StringRef FS, const TargetOptions &Options,
@@ -98,44 +82,6 @@ public:
                      CodeGenOpt::Level OL);
 };
 
-/// Thumb target machine.
-/// Due to the way architectures are handled, this represents both
-///   Thumb-1 and Thumb-2.
-///
-class ThumbTargetMachine : public ARMBaseTargetMachine {
-  virtual void anchor();
-
-public:
-  ThumbTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
-                     StringRef FS, const TargetOptions &Options,
-                     Optional<Reloc::Model> RM, CodeModel::Model CM,
-                     CodeGenOpt::Level OL, bool isLittle);
-};
-
-/// Thumb little endian target machine.
-///
-class ThumbLETargetMachine : public ThumbTargetMachine {
-  void anchor() override;
-
-public:
-  ThumbLETargetMachine(const Target &T, const Triple &TT, StringRef CPU,
-                       StringRef FS, const TargetOptions &Options,
-                       Optional<Reloc::Model> RM, CodeModel::Model CM,
-                       CodeGenOpt::Level OL);
-};
-
-/// Thumb big endian target machine.
-///
-class ThumbBETargetMachine : public ThumbTargetMachine {
-  void anchor() override;
-
-public:
-  ThumbBETargetMachine(const Target &T, const Triple &TT, StringRef CPU,
-                       StringRef FS, const TargetOptions &Options,
-                       Optional<Reloc::Model> RM, CodeModel::Model CM,
-                       CodeGenOpt::Level OL);
-};
-
 } // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_ARM_ARMTARGETMACHINE_H