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| author | Peter Maydell <peter.maydell@linaro.org> | 2015-08-19 16:20:20 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2015-08-19 16:29:53 +0100 |
| commit | 49caffe0cc95a9d0dc344e3328be8197f3536cf8 (patch) | |
| tree | 6d78d17355987bd24ae1ae09bd50e4cb9eef777c /include/qemu | |
| parent | 03557b9abaee78e9d1ef5cd236d32a7b3e75e6f8 (diff) | |
| download | qemu-49caffe0cc95a9d0dc344e3328be8197f3536cf8.zip qemu-49caffe0cc95a9d0dc344e3328be8197f3536cf8.tar.gz qemu-49caffe0cc95a9d0dc344e3328be8197f3536cf8.tar.bz2 | |
qemu-common.h: Move muldiv64() to host-utils.h
Move the muldiv64() function from qemu-common.h to host-utils.h.
This puts it together with all the other arithmetic functions
where we provide a version with __int128_t and a fallback
without, and allows headers which need muldiv64() to avoid
including qemu-common.h.
We don't include host-utils from qemu-common.h, to avoid dragging
more things into qemu-common.h than it already has; in practice
everywhere that needs muldiv64() can get it via qemu/timer.h.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Diffstat (limited to 'include/qemu')
| -rw-r--r-- | include/qemu/host-utils.h | 29 | ||||
| -rw-r--r-- | include/qemu/timer.h | 1 |
2 files changed, 30 insertions, 0 deletions
diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index d4f21c9..c27d3dc 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -45,6 +45,12 @@ static inline void muls64(uint64_t *plow, uint64_t *phigh, *phigh = r >> 64; } +/* compute with 96 bit intermediate result: (a*b)/c */ +static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) +{ + return (__int128_t)a * b / c; +} + static inline int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor) { if (divisor == 0) { @@ -75,6 +81,29 @@ void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b); void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b); int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor); int divs128(int64_t *plow, int64_t *phigh, int64_t divisor); + +static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) +{ + union { + uint64_t ll; + struct { +#ifdef HOST_WORDS_BIGENDIAN + uint32_t high, low; +#else + uint32_t low, high; +#endif + } l; + } u, res; + uint64_t rl, rh; + + u.ll = a; + rl = (uint64_t)u.l.low * (uint64_t)b; + rh = (uint64_t)u.l.high * (uint64_t)b; + rh += (rl >> 32); + res.l.high = rh / c; + res.l.low = (((rh % c) << 32) + (rl & 0xffffffff)) / c; + return res.ll; +} #endif /** diff --git a/include/qemu/timer.h b/include/qemu/timer.h index 5923d60..9939246 100644 --- a/include/qemu/timer.h +++ b/include/qemu/timer.h @@ -4,6 +4,7 @@ #include "qemu/typedefs.h" #include "qemu-common.h" #include "qemu/notify.h" +#include "qemu/host-utils.h" #define NANOSECONDS_PER_SECOND 1000000000LL |