com php-src: micro optimized initial hash size calculation: Zend/zend_hash.c

Commit: f59daf2104a8e08a49ab9e074e5dcd30fe5f0939 Author: Anatol Belski <ab@php.net> Wed, 22 Oct 2014 15:28:54 +0200 Parents: 1ea5982d074e3f1ec767f0f0fe79dd9c1860ef56 Branches: master Link: http://git.php.net/?p=php-src.git;a=commitdiff;h=f59daf2104a8e08a49ab9e074e5dcd30fe5f0939 Log: micro optimized initial hash size calculation most of the calls are with a size <= 8, so don't even bother any bitshifts. For the bigger sizes, use an intrinsic (should be extended with gcc ones though). Changed paths: M Zend/zend_hash.c Diff: diff --git a/Zend/zend_hash.c b/Zend/zend_hash.c index dfd63aa..d3423c8 100644 --- a/Zend/zend_hash.c +++ b/Zend/zend_hash.c @@ -99,7 +99,6 @@ static const uint32_t uninitialized_bucket = {INVALID_IDX}; ZEND_API void _zend_hash_init(HashTable *ht, uint32_t nSize, dtor_func_t pDestructor, zend_bool persistent ZEND_FILE_LINE_DC) { - uint32_t i = 3; SET_INCONSISTENT(HT_OK); @@ -107,10 +106,23 @@ ZEND_API void _zend_hash_init(HashTable *ht, uint32_t nSize, dtor_func_t pDestru /* prevent overflow */ ht->nTableSize = 0x80000000; } else { - while ((1U << i) < nSize) { - i++; + if (nSize > 8) { +#ifdef PHP_WIN32 + ht->nTableSize = 1U << __lzcnt(nSize); + if (ht->nTableSize < nSize) { + ht->nTableSize <<= 1; + } +#else + uint32_t i = 4; + + while ((1U << i) < nSize) { + i++; + } + ht->nTableSize = 1 << i; +#endif + } else { + ht->nTableSize = 8; } - ht->nTableSize = 1 << i; } ht->nTableMask = 0; /* 0 means that ht->arBuckets is uninitialized */