From 423d00c857ebc814ef6b5fc63f1d6c595cdc005d Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 28 Mar 2014 15:12:56 +0000 Subject: int128.h: Avoid undefined behaviours involving signed arithmetic Add casts when we're performing arithmetic on the .hi parts of an Int128, to avoid undefined behaviour. Signed-off-by: Peter Maydell Signed-off-by: Michael Tokarev --- include/qemu/int128.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/qemu/int128.h b/include/qemu/int128.h index 9ed47aafd3..f59703143a 100644 --- a/include/qemu/int128.h +++ b/include/qemu/int128.h @@ -53,7 +53,7 @@ static inline Int128 int128_rshift(Int128 a, int n) if (n >= 64) { return (Int128) { h, h >> 63 }; } else { - return (Int128) { (a.lo >> n) | (a.hi << (64 - n)), h }; + return (Int128) { (a.lo >> n) | ((uint64_t)a.hi << (64 - n)), h }; } } @@ -78,7 +78,7 @@ static inline Int128 int128_neg(Int128 a) static inline Int128 int128_sub(Int128 a, Int128 b) { - return (Int128){ a.lo - b.lo, a.hi - b.hi - (a.lo < b.lo) }; + return (Int128){ a.lo - b.lo, (uint64_t)a.hi - b.hi - (a.lo < b.lo) }; } static inline bool int128_nonneg(Int128 a) -- cgit v1.2.3-55-g7522