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| author | Heiko Carstens <hca@linux.ibm.com> | 2023-04-25 13:42:11 +0200 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2023-05-15 14:12:14 +0200 |
| commit | fbac266f095de92b93e7c91c71cdca432c2c9275 (patch) | |
| tree | 75c1f682e65031c03532b880eab1cab559afba82 /arch/s390/lib/Makefile | |
| parent | 1f2597cd3686955a4d64e01909dbfe625a2a35a1 (diff) | |
| download | linux-next-fbac266f095de92b93e7c91c71cdca432c2c9275.tar.gz | |
s390: select ARCH_SUPPORTS_INT128
s390 has instructions to support 128 bit arithmetics, e.g. a 64 bit
multiply instruction with a 128 bit result. Also 128 bit integer
artithmetics are already used in s390 specific architecture code (see
e.g. read_persistent_clock64()).
Therefore select ARCH_SUPPORTS_INT128.
However limit this to clang for now, since gcc generates inefficient code,
which may lead to stack overflows, when compiling
lib/crypto/curve25519-hacl64.c which depends on ARCH_SUPPORTS_INT128. The
gcc generated functions have 6kb stack frames, compared to only 1kb of the
code generated with clang.
If the kernel is compiled with -Os library calls for __ashlti3(),
__ashrti3(), and __lshrti3() may be generated. Similar to arm64
and riscv provide assembler implementations for these functions.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'arch/s390/lib/Makefile')
| -rw-r--r-- | arch/s390/lib/Makefile | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile index 580d2e3265cb..7c50eca85ca4 100644 --- a/arch/s390/lib/Makefile +++ b/arch/s390/lib/Makefile @@ -3,7 +3,7 @@ # Makefile for s390-specific library files.. # -lib-y += delay.o string.o uaccess.o find.o spinlock.o +lib-y += delay.o string.o uaccess.o find.o spinlock.o tishift.o obj-y += mem.o xor.o lib-$(CONFIG_KPROBES) += probes.o lib-$(CONFIG_UPROBES) += probes.o |