riscv: Less inefficient gcc tishift helpers (and export their symbols)

The existing __lshrti3 was really inefficient, and the other two helpers
are also needed to compile some modules.

Add the missing versions, and export all of the symbols like arm64
already does.

This code is based on the assembly generated by libgcc builds.

This fixes a build break triggered by ubsan:

riscv64-unknown-linux-gnu-ld: lib/ubsan.o: in function `.L2':
ubsan.c:(.text.unlikely+0x38): undefined reference to `__ashlti3'
riscv64-unknown-linux-gnu-ld: ubsan.c:(.text.unlikely+0x42): undefined reference to `__ashrti3'

Signed-off-by: Olof Johansson <olof@lixom.net>
[paul.walmsley@sifive.com: use SYM_FUNC_{START,END} instead of
 ENTRY/ENDPROC; note libgcc origin]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

This commit is contained in:

Olof Johansson

2019-12-16 20:06:31 -08:00

committed by

Paul Walmsley

parent 95f4d9cced

commit fc585d4a5c

2 changed files with 61 additions and 18 deletions

									
										arch/riscv/include/asm/asm-prototypes.h
									
		+4
		
												View File
												
				@@ -5,4 +5,8 @@

				#include <linux/ftrace.h>

				#include <asm-generic/asm-prototypes.h>

				long long __lshrti3(long long a, int b);

				long long __ashrti3(long long a, int b);

				long long __ashlti3(long long a, int b);

				#endif /* _ASM_RISCV_PROTOTYPES_H */