[ARM] Using cp15 while mtp =auto and arch is arm_arch6k and support thumb2

We follow GCC mtp=auto when arch is arm_arch6k and support thumb2

Reference: https://reviews.llvm.org/D114116

Author: Zhenhang1213

clang/lib/Driver/ToolChains/Arch/ARM.cpp

@@ -208,8 +208,9 @@ bool arm::useAAPCSForMachO(const llvm::Triple &T) {
 bool arm::isHardTPSupported(const llvm::Triple &Triple) {
   int Ver = getARMSubArchVersionNumber(Triple);
   llvm::ARM::ArchKind AK = llvm::ARM::parseArch(Triple.getArchName());
-  return Triple.isARM() || AK == llvm::ARM::ArchKind::ARMV6T2 ||
-         (Ver >= 7 && AK != llvm::ARM::ArchKind::ARMV8MBaseline);
+  return AK == llvm::ARM::ArchKind::ARMV6K ||
+         AK == llvm::ARM::ArchKind::ARMV6KZ ||
+         (Ver >= 7 && !isARMMProfile(Triple));
 }
 
 // Select mode for reading thread pointer (-mtp=soft/cp15).

clang/test/Driver/arm-thread-pointer.c

@@ -14,17 +14,19 @@
 // RUN: FileCheck -check-prefix=ARMv7_THREAD_POINTER-TPIDRPRW %s
 // ARMv7_THREAD_POINTER-TPIDRPRW: "-target-feature" "+read-tp-tpidrprw"
 
-// RUN: %clang --target=armv6t2-linux -mtp=cp15 -### -S %s 2>&1 | \
-// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER-HARD %s
-// RUN: %clang --target=thumbv6t2-linux -mtp=cp15 -### -S %s 2>&1 | \
-// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER-HARD %s
 // RUN: %clang --target=armv6k-linux -mtp=cp15 -### -S %s 2>&1 | \
 // RUN: FileCheck -check-prefix=ARM_THREAD_POINTER-HARD %s
+// ARM_THREAD_POINTER-HARD: "-target-feature" "+read-tp-tpidruro"
+
+// RUN: %clang --target=thumbv6t2-linux -mtp=cp15 -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER_NO_HARD %s
+// RUN: %clang --target=armv6t2-linux -mtp=cp15 -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER_NO_HARD %s
 // RUN: %clang --target=armv6-linux -mtp=cp15 -### -S %s 2>&1 | \
-// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER-HARD %s
+// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER_NO_HARD %s
 // RUN: %clang --target=armv5t-linux -mtp=cp15 -### -S %s 2>&1 | \
-// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER-HARD %s
-// ARM_THREAD_POINTER-HARD: "-target-feature" "+read-tp-tpidruro"
+// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER_NO_HARD %s
+// ARM_THREAD_POINTER_NO_HARD-NOT: "-target-feature" "+read-tp-tpidruro"
 
 // RUN: %clang --target=armv5t-linux -mtp=cp15 -x assembler -### %s 2>&1 | \
 // RUN: FileCheck -check-prefix=ARMv5_THREAD_POINTER_ASSEMBLER %s
@@ -47,3 +49,22 @@
 // RUN: %clang --target=armv7-linux -mtp=auto -### -S %s 2>&1 | \
 // RUN: FileCheck -check-prefix=ARMv7_THREAD_POINTER_Auto %s
 // ARMv7_THREAD_POINTER_Auto: "-target-feature" "+read-tp-tpidruro"
+
+// RUN: %clang --target=armv5t-linux -mtp=auto -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARMv5t_THREAD_POINTER_Auto %s
+// ARMv5t_THREAD_POINTER_Auto-NOT: "-target-feature" "+read-tp-tpidruro"
+
+// RUN: %clang --target=armv6k-linux -mtp=auto -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARMv6k_THREAD_POINTER_Auto %s
+// ARMv6k_THREAD_POINTER_Auto: "-target-feature" "+read-tp-tpidruro"
+
+// RUN: %clang --target=armv6-linux -mtp=auto -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARMv6_THREAD_POINTER_Auto %s
+// ARMv6_THREAD_POINTER_Auto-NOT: "-target-feature" "+read-tp-tpidruro"
+
+// RUN: %clang --target=armv6kz-linux -mtp=auto -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARMv6kz_THREAD_POINTER_Auto %s
+// ARMv6kz_THREAD_POINTER_Auto: "-target-feature" "+read-tp-tpidruro"
+// RUN: %clang --target=armv6kz-linux -mtp=cp15 -### -S %s 2>&1 | \
+// RUN: FileCheck -check-prefix=ARMv6kz_THREAD_POINTER_Cp15 %s
+// ARMv6kz_THREAD_POINTER_Cp15: "-target-feature" "+read-tp-tpidruro"