From 4bff0a82874366a32d5931e1a21d5a071ec3b931 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 8 Aug 2023 14:19:47 +1000 Subject: [PATCH] host-utils: Add muldiv64_round_up MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This will be used for converting time intervals in different base units to host units, for the purpose of scheduling timers to emulate target timers. Timers typically must not fire before their requested expiry time but may fire some time afterward, so rounding up is the right way to implement these. Signed-off-by: Nicholas Piggin Reviewed-by: Richard Henderson [ clg: renamed __muldiv64() to muldiv64_rounding() ] Signed-off-by: Cédric Le Goater (cherry picked from commit 47de6c4c287079744ceb96f606b3c0457addf380) Signed-off-by: Michael Tokarev --- include/qemu/host-utils.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index 011618373e..ead97d354d 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -56,6 +56,11 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) return (__int128_t)a * b / c; } +static inline uint64_t muldiv64_round_up(uint64_t a, uint32_t b, uint32_t c) +{ + return ((__int128_t)a * b + c - 1) / c; +} + static inline uint64_t divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor) { @@ -83,7 +88,8 @@ void mulu64(uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b); uint64_t divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor); int64_t divs128(uint64_t *plow, int64_t *phigh, int64_t divisor); -static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) +static inline uint64_t muldiv64_rounding(uint64_t a, uint32_t b, uint32_t c, + bool round_up) { union { uint64_t ll; @@ -99,12 +105,25 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) u.ll = a; rl = (uint64_t)u.l.low * (uint64_t)b; + if (round_up) { + rl += c - 1; + } 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; } + +static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) +{ + return muldiv64_rounding(a, b, c, false); +} + +static inline uint64_t muldiv64_round_up(uint64_t a, uint32_t b, uint32_t c) +{ + return muldiv64_rounding(a, b, c, true); +} #endif /**