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qemu-common.h: optimise muldiv64 if int128 is available

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Let compiler do the job to optimise the function.

Signed-off-by: Frediano Ziglio <frediano.ziglio@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
This commit is contained in:
Frediano Ziglio 2015-01-09 11:25:20 +00:00 committed by Paolo Bonzini
parent bee818872c
commit e1660dc57c
1 changed files with 7 additions and 0 deletions
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7
include/qemu-common.h
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@ -370,6 +370,12 @@ static inline uint8_t from_bcd(uint8_t val)
}
/* compute with 96 bit intermediate result: (a*b)/c */
#ifdef CONFIG_INT128
static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
{
return (__int128_t)a * b / c;
}
#else
static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
{
union {
@ -392,6 +398,7 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
res.l.low = (((rh % c) << 32) + (rl & 0xffffffff)) / c;
return res.ll;
}
#endif
/* Round number down to multiple */
#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))