From: Eric Biggers <ebiggers@xxxxxxxxxx> crc32c_arch() is affected by https://github.com/llvm/llvm-project/issues/20571 where clang unnecessarily spills the inputs to "rm"-constrained operands to the stack. Replace "rm" with ASM_INPUT_RM which partially works around this by expanding to "r" when the compiler is clang. This results in better code generation with clang, though still not optimal. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- This applies to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=crc-next arch/x86/lib/crc32-glue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/crc32-glue.c b/arch/x86/lib/crc32-glue.c index 9c3f9c1b7bb9..4b4721176799 100644 --- a/arch/x86/lib/crc32-glue.c +++ b/arch/x86/lib/crc32-glue.c @@ -53,14 +53,14 @@ u32 crc32c_arch(u32 crc, const u8 *p, size_t len) return crc; } for (num_longs = len / sizeof(unsigned long); num_longs != 0; num_longs--, p += sizeof(unsigned long)) - asm(CRC32_INST : "+r" (crc) : "rm" (*(unsigned long *)p)); + asm(CRC32_INST : "+r" (crc) : ASM_INPUT_RM (*(unsigned long *)p)); for (len %= sizeof(unsigned long); len; len--, p++) - asm("crc32b %1, %0" : "+r" (crc) : "rm" (*p)); + asm("crc32b %1, %0" : "+r" (crc) : ASM_INPUT_RM (*p)); return crc; } EXPORT_SYMBOL(crc32c_arch); base-commit: 4ffd50862d41e5aaf2e749efa354afaa1317c309 -- 2.48.1
