Merge pull request #1309 from KhronosGroup/fix-1305

Expose query if a resource was used as a comparison/depth resource

CMakeLists.txt

@@ -323,7 +323,7 @@ if (SPIRV_CROSS_STATIC)
 endif()
 
 set(spirv-cross-abi-major 0)
-set(spirv-cross-abi-minor 29)
+set(spirv-cross-abi-minor 30)
 set(spirv-cross-abi-patch 0)
 
 if (SPIRV_CROSS_SHARED)

main.cpp

@@ -277,6 +277,8 @@ static void print_resources(const Compiler &compiler, const char *tag, const Sma
 			fprintf(stderr, " (Set : %u)", compiler.get_decoration(res.id, DecorationDescriptorSet));
 		if (mask.get(DecorationBinding))
 			fprintf(stderr, " (Binding : %u)", compiler.get_decoration(res.id, DecorationBinding));
+		if (static_cast<const CompilerGLSL &>(compiler).variable_is_depth_or_compare(res.id))
+			fprintf(stderr, " (comparison)");
 		if (mask.get(DecorationInputAttachmentIndex))
 			fprintf(stderr, " (Attachment : %u)", compiler.get_decoration(res.id, DecorationInputAttachmentIndex));
 		if (mask.get(DecorationNonReadable))
@@ -1056,14 +1058,6 @@ static string compile_iteration(const CLIArguments &args, std::vector<uint32_t>
 		}
 	}
 
-	if (args.dump_resources)
-	{
-		print_resources(*compiler, res);
-		print_push_constant_resources(*compiler, res.push_constant_buffers);
-		print_spec_constants(*compiler);
-		print_capabilities_and_extensions(*compiler);
-	}
-
 	if (combined_image_samplers)
 	{
 		compiler->build_combined_image_samplers();
@@ -1095,7 +1089,17 @@ static string compile_iteration(const CLIArguments &args, std::vector<uint32_t>
 			static_cast<CompilerHLSL *>(compiler.get())->add_vertex_attribute_remap(remap);
 	}
 
-	return compiler->compile();
+	auto ret = compiler->compile();
+
+	if (args.dump_resources)
+	{
+		print_resources(*compiler, res);
+		print_push_constant_resources(*compiler, res.push_constant_buffers);
+		print_spec_constants(*compiler);
+		print_capabilities_and_extensions(*compiler);
+	}
+
+	return ret;
 }
 
 static int main_inner(int argc, char *argv[])

spirv_cross_c.cpp

@@ -711,6 +711,23 @@ spvc_result spvc_compiler_flatten_buffer_block(spvc_compiler compiler, spvc_vari
 #endif
 }
 
+spvc_bool spvc_compiler_variable_is_depth_or_compare(spvc_compiler compiler, spvc_variable_id id)
+{
+#if SPIRV_CROSS_C_API_GLSL
+	if (compiler->backend == SPVC_BACKEND_NONE)
+	{
+		compiler->context->report_error("Cross-compilation related option used on NONE backend which only supports reflection.");
+		return SPVC_ERROR_INVALID_ARGUMENT;
+	}
+
+	return static_cast<CompilerGLSL *>(compiler->compiler.get())->variable_is_depth_or_compare(id) ? SPVC_TRUE : SPVC_FALSE;
+#else
+	(void)id;
+	compiler->context->report_error("Cross-compilation related option used on NONE backend which only supports reflection.");
+	return SPVC_FALSE;
+#endif
+}
+
 spvc_result spvc_compiler_hlsl_set_root_constants_layout(spvc_compiler compiler,
                                                          const spvc_hlsl_root_constants *constant_info,
                                                          size_t count)

spirv_cross_c.h

@@ -33,7 +33,7 @@ extern "C" {
 /* Bumped if ABI or API breaks backwards compatibility. */
 #define SPVC_C_API_VERSION_MAJOR 0
 /* Bumped if APIs or enumerations are added in a backwards compatible way. */
-#define SPVC_C_API_VERSION_MINOR 29
+#define SPVC_C_API_VERSION_MINOR 30
 /* Bumped if internal implementation details change. */
 #define SPVC_C_API_VERSION_PATCH 0
 
@@ -642,6 +642,8 @@ SPVC_PUBLIC_API spvc_result spvc_compiler_add_header_line(spvc_compiler compiler
 SPVC_PUBLIC_API spvc_result spvc_compiler_require_extension(spvc_compiler compiler, const char *ext);
 SPVC_PUBLIC_API spvc_result spvc_compiler_flatten_buffer_block(spvc_compiler compiler, spvc_variable_id id);
 
+SPVC_PUBLIC_API spvc_bool spvc_compiler_variable_is_depth_or_compare(spvc_compiler compiler, spvc_variable_id id);
+
 /*
  * HLSL specifics.
  * Maps to C++ API.

spirv_glsl.cpp

@@ -2543,7 +2543,7 @@ void CompilerGLSL::fixup_image_load_store_access()
 
 	ir.for_each_typed_id<SPIRVariable>([&](uint32_t var, const SPIRVariable &) {
 		auto &vartype = expression_type(var);
-		if (vartype.basetype == SPIRType::Image)
+		if (vartype.basetype == SPIRType::Image && vartype.image.sampled == 2)
 		{
 			// Very old glslangValidator and HLSL compilers do not emit required qualifiers here.
 			// Solve this by making the image access as restricted as possible and loosen up if we need to.
@@ -13702,3 +13702,8 @@ void CompilerGLSL::emit_inout_fragment_outputs_copy_to_subpass_inputs()
 		});
 	}
 }
+
+bool CompilerGLSL::variable_is_depth_or_compare(VariableID id) const
+{
+	return image_is_comparison(get<SPIRType>(get<SPIRVariable>(id).basetype), id);
+}

spirv_glsl.hpp

@@ -228,6 +228,14 @@ public:
 	// The name of the uniform array will be the same as the interface block name.
 	void flatten_buffer_block(VariableID id);
 
+	// After compilation, query if a variable ID was used as a depth resource.
+	// This is meaningful for MSL since descriptor types depend on this knowledge.
+	// Cases which return true:
+	// - Images which are declared with depth = 1 image type.
+	// - Samplers which are statically used at least once with Dref opcodes.
+	// - Images which are statically used at least once with Dref opcodes.
+	bool variable_is_depth_or_compare(VariableID id) const;
+
 protected:
 	void reset();
 	void emit_function(SPIRFunction &func, const Bitset &return_flags);