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| author | Denys Vlasenko | 2023-03-29 15:44:08 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2023-03-29 15:46:32 +0200 |
| commit | a59e5a7d08cb26ec029d00dd11e693765aca17be (patch) | |
| tree | 8b2dc901386a888d15ee8a70d148586022ae67e4 | |
| parent | bd76b75f72f717150b909e8c64edfda725cabe11 (diff) | |
| download | busybox-a59e5a7d08cb26ec029d00dd11e693765aca17be.zip busybox-a59e5a7d08cb26ec029d00dd11e693765aca17be.tar.gz | |
libbb/sha: do not read shaNI variable twice, and factor out its setting
My gcc inlines both calls, so instead of "-20 bytes" I get only this:
function old new delta
sha256_begin 84 83 -1
sha1_begin 114 111 -3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-4) Total: -4 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | libbb/hash_md5_sha.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/libbb/hash_md5_sha.c b/libbb/hash_md5_sha.c index bbe58c7..88baf51 100644 --- a/libbb/hash_md5_sha.c +++ b/libbb/hash_md5_sha.c @@ -23,6 +23,14 @@ static void cpuid(unsigned *eax, unsigned *ebx, unsigned *ecx, unsigned *edx) ); } static smallint shaNI; +static int get_shaNI(void) +{ + unsigned eax = 7, ebx = ebx, ecx = 0, edx = edx; + cpuid(&eax, &ebx, &ecx, &edx); + ebx = ((ebx >> 28) & 2) - 1; /* bit 29 -> 1 or -1 */ + shaNI = (int)ebx; + return (int)ebx; +} void FAST_FUNC sha1_process_block64_shaNI(sha1_ctx_t *ctx); void FAST_FUNC sha256_process_block64_shaNI(sha256_ctx_t *ctx); # if defined(__i386__) @@ -1175,12 +1183,10 @@ void FAST_FUNC sha1_begin(sha1_ctx_t *ctx) #if ENABLE_SHA1_HWACCEL # if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) { - if (!shaNI) { - unsigned eax = 7, ebx = ebx, ecx = 0, edx = edx; - cpuid(&eax, &ebx, &ecx, &edx); - shaNI = ((ebx >> 28) & 2) - 1; /* bit 29 -> 1 or -1 */ - } - if (shaNI > 0) + int ni = shaNI; + if (!ni) + ni = get_shaNI(); + if (ni > 0) ctx->process_block = sha1_process_block64_shaNI; } # endif @@ -1229,12 +1235,10 @@ void FAST_FUNC sha256_begin(sha256_ctx_t *ctx) #if ENABLE_SHA256_HWACCEL # if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) { - if (!shaNI) { - unsigned eax = 7, ebx = ebx, ecx = 0, edx = edx; - cpuid(&eax, &ebx, &ecx, &edx); - shaNI = ((ebx >> 28) & 2) - 1; /* bit 29 -> 1 or -1 */ - } - if (shaNI > 0) + int ni = shaNI; + if (!ni) + ni = get_shaNI(); + if (ni > 0) ctx->process_block = sha256_process_block64_shaNI; } # endif |