From 112a2ba2763f14351de33501d2731dbdcab48658 Mon Sep 17 00:00:00 2001 From: Jordan Justen Date: Fri, 21 Oct 2016 16:50:50 +0100 Subject: [PATCH] i965/gen9: Allow sampling with hiz when supported For gen9+ this will indicate when we should allow hiz based sampling during rendering. Improves performance in : - Synmark's OglDeferred by 2.2% (n=20) - Synmark's OglShMapPcf by 0.44% (n=20) v2 by Ben: Add spec reference, and make it fix with some of the changes made on the previous patches Change the check from mt->aux_buf to mt->num_samples. The presence of an aux_buf isn't enough to determine there isn't a HiZ buffer to use. v3: It seems all depth surface end up with num_samples = 0 by default, so allow sampling from depth HiZ if num_samples <= 1. (Lionel) Allow sampling from HiZ only if all LOD are available from the HiZ buffer. (Lionel) Signed-off-by: Jordan Justen (v1) Signed-off-by: Ben Widawsky (v2) Signed-off-by: Lionel Landwerlin (v3) Reviewed-by: Topi Pohjolainen --- src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 29 ++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c index a44fce0..6c81ffb 100644 --- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c +++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c @@ -2022,7 +2022,34 @@ intel_miptree_sample_with_hiz(struct brw_context *brw, return false; } - return false; + if (!mt->hiz_buf) { + return false; + } + + /* It seems the hardware won't fallback to the depth buffer if some of the + * mipmap levels aren't available in the HiZ buffer. So we need all levels + * of the texture to be HiZ enabled. + */ + for (unsigned level = mt->first_level; level <= mt->last_level; ++level) { + if (!intel_miptree_level_has_hiz(mt, level)) + return false; + } + + /* If compressed multisampling is enabled, then we use it for the auxiliary + * buffer instead. + * + * From the BDW PRM (Volume 2d: Command Reference: Structures + * RENDER_SURFACE_STATE.AuxiliarySurfaceMode): + * + * "If this field is set to AUX_HIZ, Number of Multisamples must be + * MULTISAMPLECOUNT_1, and Surface Type cannot be SURFTYPE_3D. + * + * There is no such blurb for 1D textures, but there is sufficient evidence + * that this is broken on SKL+. + */ + return (mt->num_samples <= 1 && + mt->target != GL_TEXTURE_3D && + mt->target != GL_TEXTURE_1D /* gen9+ restriction */); } /** -- 2.7.4