Which are of course supported by clang.
Primary motivation is to eliminate problems like this (mtx lock):
0xffffffff80cb873b <+139>: xor %eax,%eax 0xffffffff80cb873d <+141>: lock cmpxchg %r14,0x18(%rbx) 0xffffffff80cb8743 <+147>: sete %cl 0xffffffff80cb8746 <+150>: test %cl,%cl 0xffffffff80cb8748 <+152>: je 0xffffffff80cb8798 <vfs_ref+232>
0xffffffff80caaa3b <+139>: xor %eax,%eax 0xffffffff80caaa3d <+141>: lock cmpxchg %r14,0x18(%rbx) 0xffffffff80caaa43 <+147>: jne 0xffffffff80caaa8e <vfs_ref+222>
Note that clang apparently now supports indicating the result in flags, meaning the hand-rolled routine can be patched to end up generating equivalent code. Howver, I don't think there is any good reason now to handroll said routines.
Note there is no equivalent for testandclear/readandclear so they are left be.
Also I did not alter load/store routines. In my opinion that part needs to be reworked to be type-friendly to passed arguments and goes beyond the scope of this patch.
The patch does not add routines which were not already present on amd64, but this can be changed later. The intent is to eventually remove all hand-rolled routines.
I provided powerpc64 people with a patch for their platform and asked that they test. Works for me on amd64 of course.
Kernel .text changed only a little bit:
text data bss dec hex filename 22234960 1778275 4505600 28518835 0x1b329b3 GENERIC-NODEBUG.patched/kernel 22340096 1778275 4505600 28623971 0x1b4c463 GENERIC-NODEBUG.stock/kernel