Files
clang-p2996/compiler-rt/lib/builtins/arm/aeabi_dcmp.S
Victor Campos a59a8ae1a9 [compiler-rt][ARM] Add missing PACBTI support to assembly aeabi functions (#142400)
Some of the aeabi functions were missing PACBTI support. The lack of it
resulted in exceptions at runtime if the running environment had PAC
and/or BTI enabled.

This patch adds this support. This involves the addition of PACBTI
instructions, depending on whether each of these features is enabled,
plus the saving and restoring of the PAC code that resides in r12. Some
of the common code has been put in preprocessor macros to reduce
duplication, but not all, especially since some register saving and
restoring is very specific to each context.
2025-06-10 10:20:42 +01:00

66 lines
2.3 KiB
ArmAsm

//===-- aeabi_dcmp.S - EABI dcmp* implementation ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "../assembly.h"
// int __aeabi_dcmp{eq,lt,le,ge,gt}(double a, double b) {
// int result = __{eq,lt,le,ge,gt}df2(a, b);
// if (result {==,<,<=,>=,>} 0) {
// return 1;
// } else {
// return 0;
// }
// }
#if defined(COMPILER_RT_ARMHF_TARGET)
# define CONVERT_DCMP_ARGS_TO_DF2_ARGS \
VMOV_TO_DOUBLE(d0, r0, r1) \
VMOV_TO_DOUBLE(d1, r2, r3)
#else
# define CONVERT_DCMP_ARGS_TO_DF2_ARGS
#endif
#if defined(__ARM_FEATURE_PAC_DEFAULT)
# define PROLOGUE PACBTI_LANDING SEPARATOR \
push { r12, lr }
# define EPILOGUE pop { r12, lr } SEPARATOR \
bxaut r12, lr, sp
#elif defined(__ARM_FEATURE_BTI_DEFAULT)
# define PROLOGUE PACBTI_LANDING SEPARATOR \
push { r4, lr }
# define EPILOGUE pop { r4, pc }
#else
# define PROLOGUE push { r4, lr }
# define EPILOGUE pop { r4, pc }
#endif
#define DEFINE_AEABI_DCMP(cond) \
.syntax unified SEPARATOR \
.p2align 2 SEPARATOR \
DEFINE_COMPILERRT_FUNCTION(__aeabi_dcmp ## cond) \
PROLOGUE SEPARATOR \
CONVERT_DCMP_ARGS_TO_DF2_ARGS SEPARATOR \
bl SYMBOL_NAME(__ ## cond ## df2) SEPARATOR \
cmp r0, #0 SEPARATOR \
b ## cond 1f SEPARATOR \
movs r0, #0 SEPARATOR \
EPILOGUE SEPARATOR \
1: SEPARATOR \
movs r0, #1 SEPARATOR \
EPILOGUE SEPARATOR \
END_COMPILERRT_FUNCTION(__aeabi_dcmp ## cond)
DEFINE_AEABI_DCMP(eq)
DEFINE_AEABI_DCMP(lt)
DEFINE_AEABI_DCMP(le)
DEFINE_AEABI_DCMP(ge)
DEFINE_AEABI_DCMP(gt)
NO_EXEC_STACK_DIRECTIVE