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[ARM] mtp = auto using hard point while arch supports thumb2 and hardtp #130027

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Merged
merged 1 commit into from
Mar 10, 2025
Merged

[ARM] mtp = auto using hard point while arch supports thumb2 and hardtp #130027

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24 changes: 21 additions & 3 deletions clang/lib/Driver/ToolChains/Arch/ARM.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -202,13 +202,25 @@ bool arm::useAAPCSForMachO(const llvm::Triple &T) {
T.getOS() == llvm::Triple::UnknownOS || isARMMProfile(T);
}

// We follow GCC and support when the backend has support for the MRC/MCR
// Check whether the architecture backend has support for the MRC/MCR
// instructions that are used to set the hard thread pointer ("CP15 C13
// Thread id").
// This is not identical to ability to use the instruction, as the ARMV6K
// variants can only use it in Arm mode since they don't support Thumb2
// encoding.
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 ||
return AK == llvm::ARM::ArchKind::ARMV6K ||
AK == llvm::ARM::ArchKind::ARMV6KZ ||
(Ver >= 7 && !isARMMProfile(Triple));
}

// Checks whether the architecture is capable of supporting the Thumb2 encoding
static bool supportsThumb2Encoding(const llvm::Triple &Triple) {
int Ver = arm::getARMSubArchVersionNumber(Triple);
llvm::ARM::ArchKind AK = llvm::ARM::parseArch(Triple.getArchName());
return AK == llvm::ARM::ArchKind::ARMV6T2 ||
(Ver >= 7 && AK != llvm::ARM::ArchKind::ARMV8MBaseline);
}

Expand Down Expand Up @@ -240,7 +252,13 @@ arm::ReadTPMode arm::getReadTPMode(const Driver &D, const ArgList &Args,
D.Diag(diag::err_drv_invalid_mtp) << A->getAsString(Args);
return ReadTPMode::Invalid;
}
return (isHardTPSupported(Triple) ? ReadTPMode::TPIDRURO : ReadTPMode::Soft);
// In auto mode we enable HW mode only if both the hardware supports it and
// the thumb2 encoding. For example ARMV6T2 supports thumb2, but not hardware.
// ARMV6K has HW suport, but not thumb2. Otherwise we could enable it for
// ARMV6K in thumb mode.
bool autoUseHWTPMode =
isHardTPSupported(Triple) && supportsThumb2Encoding(Triple);
return autoUseHWTPMode ? ReadTPMode::TPIDRURO : ReadTPMode::Soft;
}

void arm::setArchNameInTriple(const Driver &D, const ArgList &Args,
Expand Down
60 changes: 52 additions & 8 deletions clang/test/Driver/arm-thread-pointer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -14,18 +14,26 @@
// 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
// RUN: %clang --target=armv6-linux -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER-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: %clang --target=armv6k-linux -mtp=auto -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER_AUTO %s
// ARM_THREAD_POINTER_AUTO-NOT: "-target-feature" "+read-tp-tpidruro"

// RUN: %clang --target=thumbv6k-apple-darwin -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=THUMBv6_THREAD_POINTER_NO_AUTO %s
// THUMBv6_THREAD_POINTER_NO_AUTO-NOT: "-target-feature" "+read-tp-tpidruro"

// RUN: not %clang --target=thumbv6k-apple-darwin -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=THUMBv6_THREAD_POINTER_NO_HARD %s
// THUMBv6_THREAD_POINTER_NO_HARD: unsupported option '-mtp=' for target 'thumbv6k-apple-darwin'

// RUN: not %clang --target=thumbv6t2-linux -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARM_THREAD_POINTER_NO_HARD %s
// ARM_THREAD_POINTER_NO_HARD: hardware TLS register is not supported for the armv6t2 sub-architecture

// RUN: %clang --target=armv5t-linux -mtp=cp15 -x assembler -### %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv5_THREAD_POINTER_ASSEMBLER %s
// ARMv5_THREAD_POINTER_ASSEMBLER-NOT: hardware TLS register is not supported for the armv5 sub-architecture
Expand All @@ -47,3 +55,39 @@
// 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=armv7-linux -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv7_THREAD_POINTER_HARD %s
// ARMv7_THREAD_POINTER_HARD: "-target-feature" "+read-tp-tpidruro"

// RUN: %clang --target=armv7m-linux -mtp=auto -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv7m_THREAD_POINTER_Auto %s
// ARMv7m_THREAD_POINTER_Auto-NOT: "-target-feature" "+read-tp-tpidruro"

// RUN: not %clang --target=armv7m-linux -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv7m_THREAD_POINTER_HARD %s
// ARMv7m_THREAD_POINTER_HARD: hardware TLS register is not supported for the thumbv7m sub-architecture

// 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=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv6k_THREAD_POINTER_Auto %s
// ARMv6k_THREAD_POINTER_Auto: "-target-feature" "+read-tp-tpidruro"

// RUN: not %clang --target=armv6t2-linux -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv6t2_THREAD_POINTER_HARD %s
// ARMv6t2_THREAD_POINTER_HARD: hardware TLS register is not supported for the armv6t2 sub-architecture

// RUN: %clang --target=armv6t2-linux -mtp=auto -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMV6t2_THREAD_POINTER_AUTO %s
// ARMV6t2_THREAD_POINTER_AUTO-NOT: "-target-feature" "+read-tp-tpidruro"

// RUN: %clang --target=armv6kz-linux -mtp=cp15 -### -S %s 2>&1 | \
// RUN: FileCheck -check-prefix=ARMv6kz_THREAD_POINTER_HARD %s
// ARMv6kz_THREAD_POINTER_HARD: "-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-NOT: "-target-feature" "+read-tp-tpidruro"