On Fri, Feb 10, 2017 at 05:04:48PM -0800, Jason Ekstrand wrote: > On Fri, Feb 10, 2017 at 4:47 PM, Nanley Chery <nanleych...@gmail.com> wrote: > > > On Fri, Feb 10, 2017 at 03:21:38PM -0800, Jason Ekstrand wrote: > > > On Fri, Feb 10, 2017 at 2:55 PM, Nanley Chery <nanleych...@gmail.com> > > wrote: > > > > > > > On Fri, Feb 10, 2017 at 11:02:19AM -0800, Jason Ekstrand wrote: > > > > > It's a bit hard to measure because it almost gets lost in the noise, > > > > > but this seemed to help Dota 2 by a percent or two on my Broadwell > > > > > GT3e desktop. > > > > > > > > > > Reviewed-by: Lionel Landwerlin <lionel.g.landwer...@intel.com> > > > > > --- > > > > > src/intel/vulkan/genX_pipeline.c | 171 > > ++++++++++++++++++++++++++++++ > > > > +-------- > > > > > 1 file changed, 137 insertions(+), 34 deletions(-) > > > > > > > > > > diff --git a/src/intel/vulkan/genX_pipeline.c > > b/src/intel/vulkan/genX_ > > > > pipeline.c > > > > > index 71b9e30..d2af8b9 100644 > > > > > --- a/src/intel/vulkan/genX_pipeline.c > > > > > +++ b/src/intel/vulkan/genX_pipeline.c > > > > > @@ -638,6 +638,133 @@ static const uint32_t vk_to_gen_stencil_op[] = > > { > > > > > [VK_STENCIL_OP_DECREMENT_AND_WRAP] = STENCILOP_DECR, > > > > > }; > > > > > > > > > > +static bool > > > > > +may_write_stencil_face(const VkStencilOpState *face, > > > > > + VkCompareOp depthCompareOp) > > > > > +{ > > > > > > > > This function triggers some false negatives. One example is > > > > > > > > face->compareOp == VK_COMPARE_OP_GREATER && > > > > face->depthFailOp == VK_STENCIL_OP_KEEP && > > > > face->passOp == VK_STENCIL_OP_KEEP && > > > > face->failOp == VK_STENCIL_OP_INVERT && > > > > depthCompareOp == don't care; > > > > > > > > This function returns false even though a stencil write occurs if the > > > > stencil test results in a fail. > > > > > > > > The possible input combinations that affect writing to stencil can be > > > > divided up into 10 sets. > > > > > > > > s = stencil compare op > > > > d = depth compare op > > > > df = depth fail op > > > > sf = stencil fail op > > > > sp = stencil pass op > > > > > > > > s.Always | !s.Always > > > > d.Never | !d.Never | s.Never | > > > > | d.Always | | | > > > > !keep | | | | > > > > | | | | > > > > ------------|----------|------ > > |--------------|-------------- > > > > | | | | > > > > keep df.Keep | sp.Keep | | sf.Keep | > > > > | | | | > > > > | | | | > > > > > > > > We know that stencil won't be written if the function inputs land us in > > > > 3 of these sets (denoted by the *.Keep's above). I think this function > > > > would be easier to understand if it determined if we fell in one of the > > > > 3 instead of the 7. How about something like this: > > > > > > > > static bool > > > > wont_write_stencil_face(const VkStencilOpState *face, > > > > VkCompareOp depthCompareOp) > > > > { > > > > if (face->compareOp == VK_COMPARE_OP_NEVER && > > > > face->failOp == VK_STENCIL_OP_KEEP) > > > > return true; > > > > > > > > if (face->compareOp == VK_COMPARE_OP_ALWAYS) { > > > > if (depthCompareOp == VK_COMPARE_OP_NEVER && > > > > face->depthFailOp == VK_STENCIL_OP_KEEP) > > > > return true; > > > > if (depthCompareOp == VK_COMPARE_OP_ALWAYS && > > > > face->passOp == VK_STENCIL_OP_KEEP) > > > > return true; > > > > } > > > > > > > > > > This covers a lot fewer cases. For instance, if all of the stencil ops > > are > > > VK_STENCIL_OP_KEEP but compareOp == VK_COMPARE_OP_GREATER, your function > > > will claim that it writes stencil even though it clearly doesn't. > > > > > > > You're right, there are more than 3/10 cases in which we know we won't > > be writing to the stencil face. Here's another attempt at an > > easier-to-understand function: > > > > This function gets it wrong in the following case: > > compareOp == VK_COMPARE_OP_GREATER > failOp == VK_STENCIL_OP_KEEP > passOp == VK_STENCIL_OP_REPLACE > depthFailOp == VK_STENCIL_OP_REPLACE > > In this case, st_may_fail == true but sfo_not_keep == false so it returns > false. However, it can clearly still write stencil if the stencil test > passes. >
I didn't see this reply. Yes, there's a bug in this function. -Nanley > --Jason > > > > static bool > > may_write_stencil_face(const VkStencilOpState *face, > > VkCompareOp depthCompareOp) > > { > > const bool spo_not_keep = face->passOp != VK_STENCIL_OP_KEEP; > > const bool sfo_not_keep = face->failOp != VK_STENCIL_OP_KEEP; > > const bool dfo_not_keep = face->depthFailOp != VK_STENCIL_OP_KEEP; > > > > const bool dt_may_fail = depthCompareOp != VK_COMPARE_OP_ALWAYS; > > const bool st_may_fail = face->compareOp != VK_COMPARE_OP_ALWAYS; > > > > if (st_may_fail) { > > /* If the stencil test may fail, but the fail op is not keep, we > > might be > > * writing to the stencil face. > > */ > > if (sfo_not_keep) > > return true; > > } else { > > /* If the stencil test will pass, but the pass op is not keep, we > > might > > * be writing to the stencil face. > > */ > > if (spo_not_keep) > > return true; > > > > /* If the stencil test will pass, and the depth test may fail, but > > the > > * depth fail op is not keep, we might be writing to the stencil > > face. > > */ > > if (dt_may_fail && dfo_not_keep) > > return true; > > } > > > > return false; > > } > > > > -Nanley > > > > > > > > > return false; > > > > } > > > > > > > > -Nanley > > > > > > > > > + /* If compareOp is ALWAYS then the stencil test will never fail > > and > > > > we can > > > > > + * ignore failOp. If it's not ALWAYS and failOp is not KEEP, we > > may > > > > write > > > > > + * stencil. > > > > > + */ > > > > > + if (face->compareOp != VK_COMPARE_OP_ALWAYS && > > > > > + face->failOp != VK_STENCIL_OP_KEEP) > > > > > + return true; > > > > > + > > > > > + > > > > > + /* If the compareOp is NEVER then the stencil test will never > > pass > > > > and the > > > > > + * passOp and depthFailOp don't matter. If compareOp isn't > > NEVER, > > > > then we > > > > > + * need to take them into account. > > > > > + */ > > > > > + if (face->compareOp != VK_COMPARE_OP_NEVER) { > > > > > + /* If depthOp is NEVER then passOp doesn't matter. */ > > > > > + if (depthCompareOp != VK_COMPARE_OP_NEVER && > > > > > + face->passOp != VK_STENCIL_OP_KEEP) > > > > > + return true; > > > > > + > > > > > + /* If depthOp is ALWAYS then depthFailOp doesn't matter. */ > > > > > + if (depthCompareOp != VK_COMPARE_OP_ALWAYS && > > > > > + face->depthFailOp != VK_STENCIL_OP_KEEP) > > > > > + return true; > > > > > + } > > > > > + > > > > > + return false; > > > > > +} > > > > > + > > > > > +/* Intel hardware is fairly sensitive to whether or not > > depth/stencil > > > > writes > > > > > + * are enabled. In the presence of discards, it's fairly easy to > > get > > > > into the > > > > > + * non-promoted case which means a fairly big performance hit. From > > > > the Iron > > > > > + * Lake PRM, Vol 2, pt. 1, section 8.4.3.2, "Early Depth Test > > Cases": > > > > > + * > > > > > + * "Non-promoted depth (N) is active whenever the depth test can > > be > > > > done > > > > > + * early but it cannot determine whether or not to write source > > > > depth to > > > > > + * the depth buffer, therefore the depth write must be performed > > > > post pixel > > > > > + * shader. This includes cases where the pixel shader can kill > > > > pixels, > > > > > + * including via sampler chroma key, as well as cases where the > > > > alpha test > > > > > + * function is enabled, which kills pixels based on a > > programmable > > > > alpha > > > > > + * test. In this case, even if the depth test fails, the pixel > > > > cannot be > > > > > + * killed if a stencil write is indicated. Whether or not the > > > > stencil write > > > > > + * happens depends on whether or not the pixel is killed later. > > In > > > > these > > > > > + * cases if stencil test fails and stencil writes are off, the > > > > pixels can > > > > > + * also be killed early. If stencil writes are enabled, the > > pixels > > > > must be > > > > > + * treated as Computed depth (described above)." > > > > > + * > > > > > + * The same thing as mentioned in the stencil case can happen in the > > > > depth > > > > > + * case as well if it thinks it writes depth but, thanks to the > > depth > > > > test > > > > > + * being GL_EQUAL, the write doesn't actually matter. A little > > extra > > > > work > > > > > + * up-front to try and disable depth and stencil writes can make a > > big > > > > > + * difference. > > > > > + * > > > > > + * Unfortunately, the way depth and stencil testing is specified, > > there > > > > are > > > > > + * many case where, regardless of depth/stencil writes being > > enabled, > > > > nothing > > > > > + * actually gets written due to some other bit of state being set. > > This > > > > > + * function attempts to "sanitize" the depth stencil state and > > disable > > > > writes > > > > > + * and sometimes even testing whenever possible. > > > > > + */ > > > > > +static void > > > > > +sanitize_ds_state(VkPipelineDepthStencilStateCreateInfo *state, > > > > > + bool *stencilWriteEnable, > > > > > + VkImageAspectFlags ds_aspects) > > > > > +{ > > > > > + *stencilWriteEnable = state->stencilTestEnable; > > > > > + > > > > > + /* If the depth test is disabled, we won't be writing anything. > > */ > > > > > + if (!state->depthTestEnable) > > > > > + state->depthWriteEnable = false; > > > > > + > > > > > + /* The Vulkan spec requires that if either depth or stencil is > > not > > > > present, > > > > > + * the pipeline is to act as if the test silently passes. > > > > > + */ > > > > > + if (!(ds_aspects & VK_IMAGE_ASPECT_DEPTH_BIT)) { > > > > > + state->depthWriteEnable = false; > > > > > + state->depthCompareOp = VK_COMPARE_OP_ALWAYS; > > > > > + } > > > > > + > > > > > + if (!(ds_aspects & VK_IMAGE_ASPECT_STENCIL_BIT)) { > > > > > + *stencilWriteEnable = false; > > > > > + state->front.compareOp = VK_COMPARE_OP_ALWAYS; > > > > > + state->back.compareOp = VK_COMPARE_OP_ALWAYS; > > > > > + } > > > > > + > > > > > + /* If the stencil test is enabled and always fails, then we will > > > > never get > > > > > + * to the depth test so we can just disable the depth test > > entirely. > > > > > + */ > > > > > + if (state->stencilTestEnable && > > > > > + state->front.compareOp == VK_COMPARE_OP_NEVER && > > > > > + state->back.compareOp == VK_COMPARE_OP_NEVER) { > > > > > + state->depthTestEnable = false; > > > > > + state->depthWriteEnable = false; > > > > > + } > > > > > + > > > > > + /* If depthCompareOp is EQUAL then the value we would be writing > > to > > > > the > > > > > + * depth buffer is the same as the value that's already there so > > > > there's no > > > > > + * point in writing it. > > > > > + */ > > > > > + if (state->depthCompareOp == VK_COMPARE_OP_EQUAL) > > > > > + state->depthWriteEnable = false; > > > > > + > > > > > + /* If the stencil ops are such that we don't actually ever > > modify the > > > > > + * stencil buffer, we should disable writes. > > > > > + */ > > > > > + if (!may_write_stencil_face(&state->front, > > state->depthCompareOp) && > > > > > + !may_write_stencil_face(&state->back, > > state->depthCompareOp)) > > > > > + *stencilWriteEnable = false; > > > > > + > > > > > + /* If the depth test always passes and we never write out depth, > > > > that's the > > > > > + * same as if the depth test is disabled entirely. > > > > > + */ > > > > > + if (state->depthCompareOp == VK_COMPARE_OP_ALWAYS && > > > > > + !state->depthWriteEnable) > > > > > + state->depthTestEnable = false; > > > > > + > > > > > + /* If the stencil test always passes and we never write out > > stencil, > > > > that's > > > > > + * the same as if the stencil test is disabled entirely. > > > > > + */ > > > > > + if (state->front.compareOp == VK_COMPARE_OP_ALWAYS && > > > > > + state->back.compareOp == VK_COMPARE_OP_ALWAYS && > > > > > + !*stencilWriteEnable) > > > > > + state->stencilTestEnable = false; > > > > > +} > > > > > + > > > > > static void > > > > > emit_ds_state(struct anv_pipeline *pipeline, > > > > > const VkPipelineDepthStencilStateCreateInfo > > *pCreateInfo, > > > > > @@ -663,12 +790,20 @@ emit_ds_state(struct anv_pipeline *pipeline, > > > > > return; > > > > > } > > > > > > > > > > + VkImageAspectFlags ds_aspects = 0; > > > > > + if (subpass->depth_stencil_attachment != VK_ATTACHMENT_UNUSED) { > > > > > + VkFormat depth_stencil_format = > > > > > + pass->attachments[subpass->depth_stencil_attachment]. > > format; > > > > > + ds_aspects = vk_format_aspects(depth_stencil_format); > > > > > + } > > > > > + > > > > > VkPipelineDepthStencilStateCreateInfo info = *pCreateInfo; > > > > > + sanitize_ds_state(&info, &pipeline->writes_stencil, ds_aspects); > > > > > + pipeline->writes_depth = info.depthWriteEnable; > > > > > + pipeline->depth_test_enable = info.depthTestEnable; > > > > > > > > > > /* VkBool32 depthBoundsTestEnable; // optional > > (depth_bounds_test) */ > > > > > > > > > > - pipeline->writes_stencil = info.stencilTestEnable; > > > > > - > > > > > #if GEN_GEN <= 7 > > > > > struct GENX(DEPTH_STENCIL_STATE) depth_stencil = { > > > > > #else > > > > > @@ -690,38 +825,6 @@ emit_ds_state(struct anv_pipeline *pipeline, > > > > > .BackfaceStencilTestFunction = vk_to_gen_compare_op[info. > > > > back.compareOp], > > > > > }; > > > > > > > > > > - VkImageAspectFlags aspects = 0; > > > > > - if (subpass->depth_stencil_attachment != VK_ATTACHMENT_UNUSED) { > > > > > - VkFormat depth_stencil_format = > > > > > - pass->attachments[subpass->depth_stencil_attachment]. > > format; > > > > > - aspects = vk_format_aspects(depth_stencil_format); > > > > > - } > > > > > - > > > > > - /* The Vulkan spec requires that if either depth or stencil is > > not > > > > present, > > > > > - * the pipeline is to act as if the test silently passes. > > > > > - */ > > > > > - if (!(aspects & VK_IMAGE_ASPECT_DEPTH_BIT)) { > > > > > - depth_stencil.DepthBufferWriteEnable = false; > > > > > - depth_stencil.DepthTestFunction = PREFILTEROPALWAYS; > > > > > - } > > > > > - > > > > > - if (!(aspects & VK_IMAGE_ASPECT_STENCIL_BIT)) { > > > > > - pipeline->writes_stencil = false; > > > > > - depth_stencil.StencilTestFunction = PREFILTEROPALWAYS; > > > > > - depth_stencil.BackfaceStencilTestFunction = > > PREFILTEROPALWAYS; > > > > > - } > > > > > - > > > > > - /* From the Broadwell PRM: > > > > > - * > > > > > - * "If Depth_Test_Enable = 1 AND Depth_Test_func = EQUAL, the > > > > > - * Depth_Write_Enable must be set to 0." > > > > > - */ > > > > > - if (info.depthTestEnable && info.depthCompareOp == > > > > VK_COMPARE_OP_EQUAL) > > > > > - depth_stencil.DepthBufferWriteEnable = false; > > > > > - > > > > > - pipeline->writes_depth = depth_stencil.DepthBufferWriteEnable; > > > > > - pipeline->depth_test_enable = depth_stencil.DepthTestEnable; > > > > > - > > > > > #if GEN_GEN <= 7 > > > > > GENX(DEPTH_STENCIL_STATE_pack)(NULL, depth_stencil_dw, > > > > &depth_stencil); > > > > > #else > > > > > -- > > > > > 2.5.0.400.gff86faf > > > > > > > > > > _______________________________________________ > > > > > mesa-dev mailing list > > > > > mesa-dev@lists.freedesktop.org > > > > > https://lists.freedesktop.org/mailman/listinfo/mesa-dev > > > > > > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev