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Diffstat (limited to 'arch/h8300/include/asm/hash.h')
-rw-r--r-- | arch/h8300/include/asm/hash.h | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/arch/h8300/include/asm/hash.h b/arch/h8300/include/asm/hash.h deleted file mode 100644 index 2960b4c9e4ed..000000000000 --- a/arch/h8300/include/asm/hash.h +++ /dev/null @@ -1,54 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_HASH_H -#define _ASM_HASH_H - -/* - * The later H8SX models have a 32x32-bit multiply, but the H8/300H - * and H8S have only 16x16->32. Since it's tolerably compact, this is - * basically an inlined version of the __mulsi3 code. Since the inputs - * are not expected to be small, it's also simplfied by skipping the - * early-out checks. - * - * (Since neither CPU has any multi-bit shift instructions, a - * shift-and-add version is a non-starter.) - * - * TODO: come up with an arch-specific version of the hashing in fs/namei.c, - * since that is heavily dependent on rotates. Which, as mentioned, suck - * horribly on H8. - */ - -#if defined(CONFIG_CPU_H300H) || defined(CONFIG_CPU_H8S) - -#define HAVE_ARCH__HASH_32 1 - -/* - * Multiply by k = 0x61C88647. Fitting this into three registers requires - * one extra instruction, but reducing register pressure will probably - * make that back and then some. - * - * GCC asm note: %e1 is the high half of operand %1, while %f1 is the - * low half. So if %1 is er4, then %e1 is e4 and %f1 is r4. - * - * This has been designed to modify x in place, since that's the most - * common usage, but preserve k, since hash_64() makes two calls in - * quick succession. - */ -static inline u32 __attribute_const__ __hash_32(u32 x) -{ - u32 temp; - - asm( "mov.w %e1,%f0" - "\n mulxu.w %f2,%0" /* klow * xhigh */ - "\n mov.w %f0,%e1" /* The extra instruction */ - "\n mov.w %f1,%f0" - "\n mulxu.w %e2,%0" /* khigh * xlow */ - "\n add.w %e1,%f0" - "\n mulxu.w %f2,%1" /* klow * xlow */ - "\n add.w %f0,%e1" - : "=&r" (temp), "=r" (x) - : "%r" (GOLDEN_RATIO_32), "1" (x)); - return x; -} - -#endif -#endif /* _ASM_HASH_H */ |