From c813f5e3436b5ba40b105cdaaaa7b1184baabde7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Mon, 17 May 2021 12:48:03 +0300 Subject: [PATCH] aarch64: hevc_idct: Fix overflows in idct_dc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is marginally slower, but correct for all input values. The previous implementation failed with certain input seeds, e.g. "checkasm --test=hevc_idct 98". Signed-off-by: Martin Storsjö (cherry picked from commit f27e3ccf06ee19935d160164ca4a02f28cfc2a27) --- libavcodec/aarch64/hevcdsp_idct_neon.S | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/libavcodec/aarch64/hevcdsp_idct_neon.S b/libavcodec/aarch64/hevcdsp_idct_neon.S index 28c11e632c..0869431294 100644 --- a/libavcodec/aarch64/hevcdsp_idct_neon.S +++ b/libavcodec/aarch64/hevcdsp_idct_neon.S @@ -573,14 +573,13 @@ idct_16x16 10 // void ff_hevc_idct_NxN_dc_DEPTH_neon(int16_t *coeffs) .macro idct_dc size, bitdepth function ff_hevc_idct_\size\()x\size\()_dc_\bitdepth\()_neon, export=1 - movi v1.8h, #((1 << (14 - \bitdepth))+1) ld1r {v4.8h}, [x0] - add v4.8h, v4.8h, v1.8h - sshr v0.8h, v4.8h, #(15 - \bitdepth) - sshr v1.8h, v4.8h, #(15 - \bitdepth) + srshr v4.8h, v4.8h, #1 + srshr v0.8h, v4.8h, #(14 - \bitdepth) + srshr v1.8h, v4.8h, #(14 - \bitdepth) .if \size > 4 - sshr v2.8h, v4.8h, #(15 - \bitdepth) - sshr v3.8h, v4.8h, #(15 - \bitdepth) + srshr v2.8h, v4.8h, #(14 - \bitdepth) + srshr v3.8h, v4.8h, #(14 - \bitdepth) .if \size > 16 /* dc 32x32 */ mov x2, #4 1: