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TCG: Improve tb_phys_hash_func()

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Most of emulated CPU have instructions aligned on 16 or 32 bits, while
on others GCC tries to align the target jump location. This means that
1/2 or 3/4 of tb_phys_hash entries are never used.

Update the hash function tb_phys_hash_func() to ignore the two lowest
bits of the address. This brings a 6% speed-up when booting a MIPS
image.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2010-12-28 17:46:59 +01:00
parent 8aac08b10b
commit f96a38347a
1 changed files with 1 additions and 1 deletions
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2
exec-all.h
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@ -177,7 +177,7 @@ static inline unsigned int tb_jmp_cache_hash_func(target_ulong pc)
static inline unsigned int tb_phys_hash_func(tb_page_addr_t pc) static inline unsigned int tb_phys_hash_func(tb_page_addr_t pc)
{ {
return pc & (CODE_GEN_PHYS_HASH_SIZE - 1); return (pc >> 2) & (CODE_GEN_PHYS_HASH_SIZE - 1);
} }
TranslationBlock *tb_alloc(target_ulong pc); TranslationBlock *tb_alloc(target_ulong pc);