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| author | Xi Ruoyao <xry111@xry111.site> | 2024-05-14 06:24:18 +0200 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2024-05-14 06:24:18 +0200 |
| commit | 5125d033c8af733ee4d52e3e3c6ebf5784976e46 (patch) | |
| tree | a30781451050630b3d334e34dbc967e757135198 /arch/loongarch/include | |
| parent | LoongArch: Select ARCH_HAS_FAST_MULTIPLIER (diff) | |
| download | linux-5125d033c8af733ee4d52e3e3c6ebf5784976e46.tar.xz linux-5125d033c8af733ee4d52e3e3c6ebf5784976e46.zip | |
LoongArch: Select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
This allows compiling a full 128-bit product of two 64-bit integers as a
mul/mulh pair, instead of a nasty long sequence of 20+ instructions.
However, after selecting ARCH_SUPPORTS_INT128, when optimizing for size
the compiler generates calls to __ashlti3, __ashrti3, and __lshrti3 for
shifting __int128 values, causing a link failure:
loongarch64-unknown-linux-gnu-ld: kernel/sched/fair.o: in
function `mul_u64_u32_shr':
<PATH>/include/linux/math64.h:161:(.text+0x5e4): undefined
reference to `__lshrti3'
So provide the implementation of these functions if ARCH_SUPPORTS_INT128.
Closes: https://lore.kernel.org/loongarch/CAAhV-H5EZ=7OF7CSiYyZ8_+wWuenpo=K2WT8-6mAT4CvzUC_4g@mail.gmail.com/
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/include')
| -rw-r--r-- | arch/loongarch/include/asm/asm-prototypes.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/asm-prototypes.h b/arch/loongarch/include/asm/asm-prototypes.h index cf8e1a4e7c19..51f224bcfc65 100644 --- a/arch/loongarch/include/asm/asm-prototypes.h +++ b/arch/loongarch/include/asm/asm-prototypes.h @@ -6,3 +6,9 @@ #include <asm/page.h> #include <asm/ftrace.h> #include <asm-generic/asm-prototypes.h> + +#ifdef CONFIG_ARCH_SUPPORTS_INT128 +__int128_t __ashlti3(__int128_t a, int b); +__int128_t __ashrti3(__int128_t a, int b); +__int128_t __lshrti3(__int128_t a, int b); +#endif |