Looks good,
Ethan
On Wed, Jan 18, 2012 at 11:30, Ben Pfaff <b...@nicira.com> wrote:
> I always assumed that macros would generate better code. I was wrong. The
> generated code was identical with inline functions, with GCC version 4.4.5.
>
> Signed-off-by: Ben Pfaff <b...@nicira.com>
> ---
> lib/hash.c | 12 ++++++------
> lib/hash.h | 50 ++++++++++++++++++++++++++++----------------------
> 2 files changed, 34 insertions(+), 28 deletions(-)
>
> diff --git a/lib/hash.c b/lib/hash.c
> index 61e17b2..b3d9156 100644
> --- a/lib/hash.c
> +++ b/lib/hash.c
> @@ -1,5 +1,5 @@
> /*
> - * Copyright (c) 2008, 2009, 2010 Nicira Networks.
> + * Copyright (c) 2008, 2009, 2010, 2012 Nicira Networks.
> *
> * Licensed under the Apache License, Version 2.0 (the "License");
> * you may not use this file except in compliance with the License.
> @@ -30,7 +30,7 @@ hash_words(const uint32_t *p, size_t n, uint32_t basis)
> a += p[0];
> b += p[1];
> c += p[2];
> - HASH_MIX(a, b, c);
> + hash_mix(&a, &b, &c);
> n -= 3;
> p += 3;
> }
> @@ -44,7 +44,7 @@ hash_words(const uint32_t *p, size_t n, uint32_t basis)
> /* fall through */
> case 1:
> a += p[0];
> - HASH_FINAL(a, b, c);
> + hash_final(&a, &b, &c);
> /* fall through */
> case 0:
> break;
> @@ -59,7 +59,7 @@ hash_3words(uint32_t a, uint32_t b, uint32_t c)
> a += 0xdeadbeef;
> b += 0xdeadbeef;
> c += 0xdeadbeef;
> - HASH_FINAL(a, b, c);
> + hash_final(&a, &b, &c);
> return c;
> }
>
> @@ -85,7 +85,7 @@ hash_bytes(const void *p_, size_t n, uint32_t basis)
> a += tmp[0];
> b += tmp[1];
> c += tmp[2];
> - HASH_MIX(a, b, c);
> + hash_mix(&a, &b, &c);
> n -= sizeof tmp;
> p += sizeof tmp;
> }
> @@ -96,7 +96,7 @@ hash_bytes(const void *p_, size_t n, uint32_t basis)
> a += tmp[0];
> b += tmp[1];
> c += tmp[2];
> - HASH_FINAL(a, b, c);
> + hash_final(&a, &b, &c);
> }
>
> return c;
> diff --git a/lib/hash.h b/lib/hash.h
> index 026eeda..05799b2 100644
> --- a/lib/hash.h
> +++ b/lib/hash.h
> @@ -1,5 +1,5 @@
> /*
> - * Copyright (c) 2008, 2009, 2010 Nicira Networks.
> + * Copyright (c) 2008, 2009, 2010, 2012 Nicira Networks.
> *
> * Licensed under the Apache License, Version 2.0 (the "License");
> * you may not use this file except in compliance with the License.
> @@ -29,28 +29,34 @@ extern "C" {
> /* This is the public domain lookup3 hash by Bob Jenkins from
> * http://burtleburtle.net/bob/c/lookup3.c, modified for style. */
>
> -#define HASH_ROT(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
> +static inline uint32_t
> +hash_rot(uint32_t x, int k)
> +{
> + return (x << k) | (x >> (32 - k));
> +}
>
> -#define HASH_MIX(a, b, c) \
> - do { \
> - a -= c; a ^= HASH_ROT(c, 4); c += b; \
> - b -= a; b ^= HASH_ROT(a, 6); a += c; \
> - c -= b; c ^= HASH_ROT(b, 8); b += a; \
> - a -= c; a ^= HASH_ROT(c, 16); c += b; \
> - b -= a; b ^= HASH_ROT(a, 19); a += c; \
> - c -= b; c ^= HASH_ROT(b, 4); b += a; \
> - } while (0)
> +static inline void
> +hash_mix(uint32_t *a, uint32_t *b, uint32_t *c)
> +{
> + *a -= *c; *a ^= hash_rot(*c, 4); *c += *b;
> + *b -= *a; *b ^= hash_rot(*a, 6); *a += *c;
> + *c -= *b; *c ^= hash_rot(*b, 8); *b += *a;
> + *a -= *c; *a ^= hash_rot(*c, 16); *c += *b;
> + *b -= *a; *b ^= hash_rot(*a, 19); *a += *c;
> + *c -= *b; *c ^= hash_rot(*b, 4); *b += *a;
> +}
>
> -#define HASH_FINAL(a, b, c) \
> - do { \
> - c ^= b; c -= HASH_ROT(b, 14); \
> - a ^= c; a -= HASH_ROT(c, 11); \
> - b ^= a; b -= HASH_ROT(a, 25); \
> - c ^= b; c -= HASH_ROT(b, 16); \
> - a ^= c; a -= HASH_ROT(c, 4); \
> - b ^= a; b -= HASH_ROT(a, 14); \
> - c ^= b; c -= HASH_ROT(b, 24); \
> - } while (0)
> +static inline void
> +hash_final(uint32_t *a, uint32_t *b, uint32_t *c)
> +{
> + *c ^= *b; *c -= hash_rot(*b, 14);
> + *a ^= *c; *a -= hash_rot(*c, 11);
> + *b ^= *a; *b -= hash_rot(*a, 25);
> + *c ^= *b; *c -= hash_rot(*b, 16);
> + *a ^= *c; *a -= hash_rot(*c, 4);
> + *b ^= *a; *b -= hash_rot(*a, 14);
> + *c ^= *b; *c -= hash_rot(*b, 24);
> +}
>
> uint32_t hash_words(const uint32_t *, size_t n_word, uint32_t basis);
> uint32_t hash_2words(uint32_t, uint32_t);
> @@ -87,7 +93,7 @@ static inline uint32_t hash_boolean(bool x, uint32_t basis)
> {
> const uint32_t P0 = 0xc2b73583; /* This is hash_int(1, 0). */
> const uint32_t P1 = 0xe90f1258; /* This is hash_int(2, 0). */
> - return (x ? P0 : P1) ^ HASH_ROT(basis, 1);
> + return (x ? P0 : P1) ^ hash_rot(basis, 1);
> }
>
> static inline uint32_t hash_double(double x, uint32_t basis)
> --
> 1.7.2.5
>
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> dev@openvswitch.org
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