Commit 9bfe7553 authored Nov 07, 2017 by Jason A. Donenfeld Committed by Will Deacon Nov 13, 2017

arm64: Implement __lshrti3 library function



Commit fb872273 ("arm64: support __int128 on gcc 5+") added support
for the __int128 data type, but this breaks the build in some configurations
where GCC ends up emitting calls to the __lshrti3 helper in libgcc, which
results in a link error:

  kernel/sched/fair.o: In function `__calc_delta':
  fair.c:(.text+0xca0): undefined reference to `__lshrti3'
  kernel/time/timekeeping.o: In function `timekeeping_resume':
  timekeeping.c:(.text+0x3f60): undefined reference to `__lshrti3'
  make: *** [vmlinux] Error 1

Fix the build by providing an implementation of __lshrti3, like we do
already for __ashlti3 and __ashrti3.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

parent fb872273

arch/arm64/lib/tishift.S

+21 −0

Original line number	Diff line number	Diff line
		@@ -57,3 +57,24 @@ ENTRY(__ashrti3)
		mov x1, x2
		ret
		ENDPROC(__ashrti3)

		ENTRY(__lshrti3)
		cbz x2, 1f
		mov x3, #64
		sub x3, x3, x2
		cmp x3, #0
		b.le 2f
		lsr x0, x0, x2
		lsl x3, x1, x3
		lsr x2, x1, x2
		orr x0, x0, x3
		mov x1, x2
		1:
		ret
		2:
		neg w0, w3
		mov x2, #0
		lsr x0, x1, x0
		mov x1, x2
		ret
		ENDPROC(__lshrti3)