Apply SPIRV-Cross workarounds for Metal bugs

2 workarounds introduced:
 - Fragments with side effects will now execute following Vulkan
 - Depth/Stencil write postponed to post fragment execution when
   input attachment and depth/stencil attachment reference the
   same resource

MoltenVK/MoltenVK/GPUObjects/MVKPipeline.h

@@ -456,6 +456,7 @@ class MVKGraphicsPipeline : public MVKPipeline {
  bool _isRasterizingColor = false;
  bool _sampleLocationsEnable = false;
  bool _isTessellationPipeline = false;
+ bool _input_attachment_is_ds_attachment = false;
 };
 
 

MoltenVK/MoltenVK/GPUObjects/MVKPipeline.mm

@@ -507,6 +507,16 @@
  _outputControlPointCount = reflectData.numControlPoints;
  mvkSetOrClear(&_tessInfo, _isTessellationPipeline ? pCreateInfo->pTessellationState : nullptr);
 
+ // Handles depth attachment being used as input attachment. However, it does not solve the issue when
+ // the pipeline is created without render pass (dynamic rendering) since we won't be able to know
+ // which resources will be used when rendering. Needs to be done before we do shaders
+ // Potential solution would be to generate 2 pipelines, one with the workaround for the Metal issue
+ // and one without it, and decide at bind time once we know the resources which one to use.
+ if (pCreateInfo->renderPass) {
+ MVKRenderSubpass* subpass = ((MVKRenderPass*)pCreateInfo->renderPass)->getSubpass(pCreateInfo->subpass);
+ _input_attachment_is_ds_attachment = subpass->isInputAttachmentDepthStencilAttachment();
+ }
+
  // Render pipeline state. Do this as early as possible, to fail fast if pipeline requires a fail on cache-miss.
  initMTLRenderPipelineState(pCreateInfo, reflectData, pPipelineFB, pVertexSS, pVertexFB, pTessCtlSS, pTessCtlFB, pTessEvalSS, pTessEvalFB, pFragmentSS, pFragmentFB);
  if ( !_hasValidMTLPipelineStates ) { return; }
@@ -1332,6 +1342,8 @@ static MTLVertexFormat mvkAdjustFormatVectorToSize(MTLVertexFormat format, uint3
  shaderConfig.options.mslOptions.capture_output_to_buffer = false;
  shaderConfig.options.mslOptions.fixed_subgroup_size = mvkIsAnyFlagEnabled(pFragmentSS->flags, VK_PIPELINE_SHADER_STAGE_CREATE_ALLOW_VARYING_SUBGROUP_SIZE_BIT_EXT) ? 0 : mtlFeats.maxSubgroupSize;
  shaderConfig.options.mslOptions.check_discarded_frag_stores = true;
+ shaderConfig.options.mslOptions.force_fragment_with_side_effects_execution = true;
+ shaderConfig.options.mslOptions.input_attachment_is_ds_attachment = _input_attachment_is_ds_attachment;
  if (mtlFeats.needsSampleDrefLodArrayWorkaround) {
  shaderConfig.options.mslOptions.sample_dref_lod_array_as_grad = true;
  }
@@ -2580,6 +2592,8 @@ void serialize(Archive & archive, CompilerMSL::Options& opt) {
  opt.force_sample_rate_shading,
  opt.manual_helper_invocation_updates,
  opt.check_discarded_frag_stores,
+ opt.force_fragment_with_side_effects_execution,
+ opt.input_attachment_is_ds_attachment,
  opt.sample_dref_lod_array_as_grad,
  opt.replace_recursive_inputs,
  opt.agx_manual_cube_grad_fixup);

MoltenVK/MoltenVK/GPUObjects/MVKRenderPass.h

@@ -67,10 +67,10 @@ class MVKRenderSubpass : public MVKBaseObject {
  bool isColorAttachmentAlsoInputAttachment(uint32_t colorAttIdx);
 
  /** Returns whether or not the depth attachment is being used. */
- bool isDepthAttachmentUsed() { return _depthAttachment.attachment != VK_ATTACHMENT_UNUSED; }
+ bool isDepthAttachmentUsed() const { return _depthAttachment.attachment != VK_ATTACHMENT_UNUSED; }
 
  /** Returns whether or not the stencil attachment is being used. */
- bool isStencilAttachmentUsed() { return _stencilAttachment.attachment != VK_ATTACHMENT_UNUSED; }
+ bool isStencilAttachmentUsed() const { return _stencilAttachment.attachment != VK_ATTACHMENT_UNUSED; }
 
  /** Return the depth attachment format. */
  VkFormat getDepthFormat();
@@ -90,6 +90,9 @@ class MVKRenderSubpass : public MVKBaseObject {
  /** Returns whether or not this is a multiview subpass. */
  bool isMultiview() const { return _pipelineRenderingCreateInfo.viewMask != 0; }
 
+ /** Returns whether or not the depth stencil is being used as input attachment */
+ bool isInputAttachmentDepthStencilAttachment() const;
+
  /** Returns the multiview view mask. */
  uint32_t getViewMask() const { return _pipelineRenderingCreateInfo.viewMask; }
 

MoltenVK/MoltenVK/GPUObjects/MVKRenderPass.mm

@@ -94,6 +94,22 @@
  return VK_SAMPLE_COUNT_1_BIT;
 }
 
+bool MVKRenderSubpass::isInputAttachmentDepthStencilAttachment() const {
+ bool is_depth_attachment_used = isDepthAttachmentUsed();
+ bool is_stencil_attachment_used = isStencilAttachmentUsed();
+ if (!is_depth_attachment_used && !is_stencil_attachment_used) return false;
+
+ for (uint32_t i = 0u; i < _inputAttachments.size(); ++i) {
+ bool is_depth_input = is_depth_attachment_used && (_inputAttachments[i].attachment == _depthAttachment.attachment) &&
+ (_inputAttachments[i].aspectMask & _depthAttachment.aspectMask);
+ bool is_stencil_input = is_stencil_attachment_used && (_inputAttachments[i].attachment == _stencilAttachment.attachment) &&
+ (_inputAttachments[i].aspectMask & _stencilAttachment.aspectMask);
+ if (is_depth_input || is_stencil_input)
+ return true;
+ }
+ return false;
+}
+
 // Get the portion of the view mask that will be rendered in the specified Metal render pass.
 uint32_t MVKRenderSubpass::getViewMaskGroupForMetalPass(uint32_t passIdx) {
  if (!_pipelineRenderingCreateInfo.viewMask) { return 0; }