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llvm-project/compiler-rt/lib/builtins/arm/sync_fetch_and_umin_8.S

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ARM: implement __sync_fetch_and_* operations Since these are primarily useful for deeply embedded targets where code size is very important, they are each in a separate file making use of infrastructure in sync-ops.h. This allows a linker to include just the functions that are actually used. rdar://problem/14736665 llvm-svn: 202812
2014-03-04 18:10:17 +08:00
/*===-- sync_fetch_and_umin_8.S - ------------------------------------------===//
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
*===----------------------------------------------------------------------===//
*
* This file implements the __sync_fetch_and_umin_8 function for the ARM
* architecture.
*
*===----------------------------------------------------------------------===*/
#include "sync-ops.h"
[compiler-rt] Do not use ldrexd or strexd on v7M The ldrexd and strexd instructions are undefined for the ARMv7M architecture, so we cannot use them to implement the __sync_fetch_and_*_8 builtins. There is no other way to implement these without OS support, so this patch #ifdef's these functions out for M-class architectures. There are no tests as I cannot find any existing tests for these builtins. I used the __ARM_ARCH_PROFILE predefine because __ARM_FEATURE_LDREX is deprecated and not set by clang. llvm-svn: 218601
2014-09-29 18:23:20 +08:00
#if __ARM_ARCH_PROFILE != 'M'
ARM: implement __sync_fetch_and_* operations Since these are primarily useful for deeply embedded targets where code size is very important, they are each in a separate file making use of infrastructure in sync-ops.h. This allows a linker to include just the functions that are actually used. rdar://problem/14736665 llvm-svn: 202812
2014-03-04 18:10:17 +08:00
#define umin_8(rD_LO, rD_HI, rN_LO, rN_HI, rM_LO, rM_HI) MINMAX_8(rD_LO, rD_HI, rN_LO, rN_HI, rM_LO, rM_HI, lo)
SYNC_OP_8(umin_8)
[compiler-rt] Do not use ldrexd or strexd on v7M The ldrexd and strexd instructions are undefined for the ARMv7M architecture, so we cannot use them to implement the __sync_fetch_and_*_8 builtins. There is no other way to implement these without OS support, so this patch #ifdef's these functions out for M-class architectures. There are no tests as I cannot find any existing tests for these builtins. I used the __ARM_ARCH_PROFILE predefine because __ARM_FEATURE_LDREX is deprecated and not set by clang. llvm-svn: 218601
2014-09-29 18:23:20 +08:00
#endif
builtins: tag with noexecstack These routines do not require executable stacks. However, by default ELFish linkers may assume an executable stack on GNUish environments (and some non-GNU ones too!). The GNU extension to add a note to indicate a non-executable stack is honoured by these environments to mark the stack as non-executable (the compiler normally emits this directive on appropriate targets whenever possible). This allows normal builds from getting executable stacks due to linking to the compiler rt builtins. llvm-svn: 273500
2016-06-23 06:09:42 +08:00
NO_EXEC_STACK_DIRECTIVE