Commit graph

2 commits

Author SHA1 Message Date
Heiko Carstens
e7583c5f8d s390/asm: Helper macros for flag output operand handling
Since gcc supports flag out operands for inline assemblies there is always
the question when this feature should be used and if it is worth all the
ifdefs that come with that.

In order to avoid that provide similar macros like x86 which can be used
for all inline assemblies which extract the condition code. Depending on
compiler features the generated code will either always contain an ipm+srl
instruction pair, which extracts the condition code, or alternatively let
the compiler handle this completely.

Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13 14:31:31 +01:00
Heiko Carstens
0b6de9aec2 s390/cmpxchg: Provide arch_try_cmpxchg()
Since gcc 14 flag output operands are supported also for s390.

Provide an arch_try_cmpxchg() implementation so that all existing
try_cmpxchg() variants provide slightly better code, if compiled
with gcc 14 or newer.

Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12 14:01:28 +01:00