From cbc5796fc3f446dbc6da66d22de1ae2f8e9c0527 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 6 May 2017 21:31:49 +0200 Subject: [PATCH] avutil/softfloat: Fix overflow in av_div_sf() Signed-off-by: Michael Niedermayer (cherry picked from commit 277e397eb5964999bd76909f52d4bd3350289c22) Signed-off-by: Michael Niedermayer --- libavutil/softfloat.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/libavutil/softfloat.h b/libavutil/softfloat.h index fed3e77f87..daf91a5557 100644 --- a/libavutil/softfloat.h +++ b/libavutil/softfloat.h @@ -114,8 +114,15 @@ static inline av_const SoftFloat av_mul_sf(SoftFloat a, SoftFloat b){ * @return Will not be more denormalized than a. */ static inline av_const SoftFloat av_div_sf(SoftFloat a, SoftFloat b){ + int64_t temp = (int64_t)a.mant * (1<<(ONE_BITS+1)); + temp /= b.mant; a.exp -= b.exp; - a.mant = ((int64_t)a.mant<<(ONE_BITS+1)) / b.mant; + a.mant = temp; + while (a.mant != temp) { + temp /= 2; + a.exp--; + a.mant = temp; + } a = av_normalize1_sf(a); if (!a.mant || a.exp < MIN_EXP) return FLOAT_0;