From 297565aa22cfa80ab0f88c3569693aea0b6afb6d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 5 Feb 2022 16:23:45 +0100 Subject: lib/xor: make xor prototypes more friendly to compiler vectorization Modern compilers are perfectly capable of extracting parallelism from the XOR routines, provided that the prototypes reflect the nature of the input accurately, in particular, the fact that the input vectors are expected not to overlap. This is not documented explicitly, but is implied by the interchangeability of the various C routines, some of which use temporary variables while others don't: this means that these routines only behave identically for non-overlapping inputs. So let's decorate these input vectors with the __restrict modifier, which informs the compiler that there is no overlap. While at it, make the input-only vectors pointer-to-const as well. Tested-by: Nathan Chancellor Signed-off-by: Ard Biesheuvel Reviewed-by: Nick Desaulniers Link: https://github.com/ClangBuiltLinux/linux/issues/563 Signed-off-by: Herbert Xu --- arch/sparc/include/asm/xor_32.h | 21 ++++++++++++++------- arch/sparc/include/asm/xor_64.h | 42 +++++++++++++++++++++++++++-------------- 2 files changed, 42 insertions(+), 21 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/include/asm/xor_32.h b/arch/sparc/include/asm/xor_32.h index 3e5af37e4b9c..0351813cf3af 100644 --- a/arch/sparc/include/asm/xor_32.h +++ b/arch/sparc/include/asm/xor_32.h @@ -13,7 +13,8 @@ */ static void -sparc_2(unsigned long bytes, unsigned long *p1, unsigned long *p2) +sparc_2(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2) { int lines = bytes / (sizeof (long)) / 8; @@ -50,8 +51,9 @@ sparc_2(unsigned long bytes, unsigned long *p1, unsigned long *p2) } static void -sparc_3(unsigned long bytes, unsigned long *p1, unsigned long *p2, - unsigned long *p3) +sparc_3(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3) { int lines = bytes / (sizeof (long)) / 8; @@ -101,8 +103,10 @@ sparc_3(unsigned long bytes, unsigned long *p1, unsigned long *p2, } static void -sparc_4(unsigned long bytes, unsigned long *p1, unsigned long *p2, - unsigned long *p3, unsigned long *p4) +sparc_4(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3, + const unsigned long * __restrict p4) { int lines = bytes / (sizeof (long)) / 8; @@ -165,8 +169,11 @@ sparc_4(unsigned long bytes, unsigned long *p1, unsigned long *p2, } static void -sparc_5(unsigned long bytes, unsigned long *p1, unsigned long *p2, - unsigned long *p3, unsigned long *p4, unsigned long *p5) +sparc_5(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3, + const unsigned long * __restrict p4, + const unsigned long * __restrict p5) { int lines = bytes / (sizeof (long)) / 8; diff --git a/arch/sparc/include/asm/xor_64.h b/arch/sparc/include/asm/xor_64.h index 16169f3edcd5..caaddea8ad79 100644 --- a/arch/sparc/include/asm/xor_64.h +++ b/arch/sparc/include/asm/xor_64.h @@ -12,13 +12,20 @@ #include -void xor_vis_2(unsigned long, unsigned long *, unsigned long *); -void xor_vis_3(unsigned long, unsigned long *, unsigned long *, - unsigned long *); -void xor_vis_4(unsigned long, unsigned long *, unsigned long *, - unsigned long *, unsigned long *); -void xor_vis_5(unsigned long, unsigned long *, unsigned long *, - unsigned long *, unsigned long *, unsigned long *); +void xor_vis_2(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2); +void xor_vis_3(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3); +void xor_vis_4(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3, + const unsigned long * __restrict p4); +void xor_vis_5(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3, + const unsigned long * __restrict p4, + const unsigned long * __restrict p5); /* XXX Ugh, write cheetah versions... -DaveM */ @@ -30,13 +37,20 @@ static struct xor_block_template xor_block_VIS = { .do_5 = xor_vis_5, }; -void xor_niagara_2(unsigned long, unsigned long *, unsigned long *); -void xor_niagara_3(unsigned long, unsigned long *, unsigned long *, - unsigned long *); -void xor_niagara_4(unsigned long, unsigned long *, unsigned long *, - unsigned long *, unsigned long *); -void xor_niagara_5(unsigned long, unsigned long *, unsigned long *, - unsigned long *, unsigned long *, unsigned long *); +void xor_niagara_2(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2); +void xor_niagara_3(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3); +void xor_niagara_4(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3, + const unsigned long * __restrict p4); +void xor_niagara_5(unsigned long bytes, unsigned long * __restrict p1, + const unsigned long * __restrict p2, + const unsigned long * __restrict p3, + const unsigned long * __restrict p4, + const unsigned long * __restrict p5); static struct xor_block_template xor_block_niagara = { .name = "Niagara", -- cgit