Add option to emit Invariant position.

HansKristian-Work · Oct 12, 2021 · e74757f · e74757f
1 parent 447723b
commit e74757f
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Showing 9 changed files with 155 additions and 3 deletions.
diff --git a/dxil_converter.cpp b/dxil_converter.cpp
@@ -3111,6 +3111,8 @@ void Converter::Impl::emit_builtin_decoration(spv::Id id, DXIL::Semantic semanti
 		{
 			builder.addDecoration(id, spv::DecorationBuiltIn, spv::BuiltInPosition);
 			spirv_module.register_builtin_shader_output(id, spv::BuiltInPosition);
+			if (options.invariant_position)
+				builder.addDecoration(id, spv::DecorationInvariant);
 		}
 		break;
 
@@ -4989,6 +4991,10 @@ void Converter::Impl::set_option(const OptionBase &cap)
 		    static_cast<const OptionShaderRayTracingPrimitiveCulling &>(cap).supported;
 		break;
 
+	case Option::InvariantPosition:
+		options.invariant_position = static_cast<const OptionInvariantPosition &>(cap).enabled;
+		break;
+
 	default:
 		break;
 	}
@@ -5037,6 +5043,7 @@ bool Converter::recognizes_option(Option cap)
 	case Option::MinPrecisionNative16Bit:
 	case Option::ShaderI8Dot:
 	case Option::ShaderRayTracingPrimitiveCulling:
+	case Option::InvariantPosition:
 		return true;
 
 	default:

diff --git a/dxil_converter.hpp b/dxil_converter.hpp
@@ -208,7 +208,8 @@ enum class Option : uint32_t
 	DescriptorQA = 15,
 	MinPrecisionNative16Bit = 16,
 	ShaderI8Dot = 17,
-	ShaderRayTracingPrimitiveCulling = 18
+	ShaderRayTracingPrimitiveCulling = 18,
+	InvariantPosition = 19
 };
 
 enum class ResourceClass : uint32_t
@@ -413,6 +414,16 @@ struct OptionShaderRayTracingPrimitiveCulling : OptionBase
 	bool supported = false;
 };
 
+struct OptionInvariantPosition : OptionBase
+{
+	OptionInvariantPosition()
+		: OptionBase(Option::InvariantPosition)
+	{
+	}
+
+	bool enabled = false;
+};
+
 struct DescriptorTableEntry
 {
 	ResourceClass type;

diff --git a/dxil_spirv.cpp b/dxil_spirv.cpp
@@ -145,7 +145,8 @@ static void print_help()
 	     "\t[--root-descriptor <cbv/uav/srv> <space> <register>]\n"
 	     "\t[--descriptor-qa <set> <binding base> <shader hash>]\n"
 	     "\t[--min-precision-native-16bit]\n"
-	     "\t[--raw-llvm]\n");
+	     "\t[--raw-llvm]\n"
+	     "\t[--invariant-position]\n");
 }
 
 struct Arguments
@@ -172,6 +173,7 @@ struct Arguments
 	bool bindless_typed_buffer_offsets = false;
 	bool min_precision_native_16bit = false;
 	bool raw_llvm = false;
+	bool invariant_position = false;
 
 	unsigned ssbo_alignment = 1;
 
@@ -653,6 +655,7 @@ int main(int argc, char **argv)
 	});
 	cbs.add("--min-precision-native-16bit", [&](CLIParser &) { args.min_precision_native_16bit = true; });
 	cbs.add("--raw-llvm", [&](CLIParser &) { args.raw_llvm = true; });
+	cbs.add("--invariant-position", [&](CLIParser &) { args.invariant_position = true; });
 	cbs.error_handler = [] { print_help(); };
 	cbs.default_handler = [&](const char *arg) { args.input_path = arg; };
 	CLIParser cli_parser(std::move(cbs), argc - 1, argv + 1);
@@ -826,6 +829,12 @@ int main(int argc, char **argv)
 		dxil_spv_converter_add_option(converter, &minprec.base);
 	}
 
+	{
+		const dxil_spv_option_invariant_position invariant = { { DXIL_SPV_OPTION_INVARIANT_POSITION },
+		                                                       args.invariant_position ? DXIL_SPV_TRUE : DXIL_SPV_FALSE };
+		dxil_spv_converter_add_option(converter, &invariant.base);
+	}
+
 	dxil_spv_converter_add_option(converter, &args.offset_buffer_layout.base);
 
 	unsigned num_entry_points = 1;

diff --git a/dxil_spirv_c.cpp b/dxil_spirv_c.cpp
@@ -812,6 +812,15 @@ dxil_spv_result dxil_spv_converter_add_option(dxil_spv_converter converter, cons
 		break;
 	}
 
+	case DXIL_SPV_OPTION_INVARIANT_POSITION:
+	{
+		OptionInvariantPosition helper;
+		helper.enabled = bool(reinterpret_cast<const dxil_spv_option_invariant_position *>(option)->enabled);
+
+		converter->options.emplace_back(duplicate(helper));
+		break;
+	}
+
 	default:
 		return DXIL_SPV_ERROR_UNSUPPORTED_FEATURE;
 	}

diff --git a/dxil_spirv_c.h b/dxil_spirv_c.h
@@ -28,7 +28,7 @@ extern "C" {
 #endif
 
 #define DXIL_SPV_API_VERSION_MAJOR 2
-#define DXIL_SPV_API_VERSION_MINOR 12
+#define DXIL_SPV_API_VERSION_MINOR 13
 #define DXIL_SPV_API_VERSION_PATCH 0
 
 #define DXIL_SPV_DESCRIPTOR_QA_INTERFACE_VERSION 1
@@ -279,6 +279,7 @@ typedef enum dxil_spv_option
 	DXIL_SPV_OPTION_MIN_PRECISION_NATIVE_16BIT = 16,
 	DXIL_SPV_OPTION_SHADER_I8_DOT = 17,
 	DXIL_SPV_OPTION_SHADER_RAY_TRACING_PRIMITIVE_CULLING = 18,
+	DXIL_SPV_OPTION_INVARIANT_POSITION = 19,
 	DXIL_SPV_OPTION_INT_MAX = 0x7fffffff
 } dxil_spv_option;
 
@@ -422,6 +423,12 @@ typedef struct dxil_spv_option_shader_ray_tracing_primitive_culling
 	dxil_spv_bool supported;
 } dxil_spv_option_shader_ray_tracing_primitive_culling;
 
+typedef struct dxil_spv_option_invariant_position
+{
+	dxil_spv_option_base base;
+	dxil_spv_bool enabled;
+} dxil_spv_option_invariant_position;
+
 /* Gets the ABI version used to build this library. Used to detect API/ABI mismatches. */
 DXIL_SPV_PUBLIC_API void dxil_spv_get_version(unsigned *major, unsigned *minor, unsigned *patch);
 

diff --git a/opcodes/converter_impl.hpp b/opcodes/converter_impl.hpp
@@ -407,6 +407,7 @@ struct Converter::Impl
 		bool min_precision_prefer_native_16bit = false;
 		bool shader_i8_dot_enabled = false;
 		bool ray_tracing_primitive_culling_enabled = false;
+		bool invariant_position = false;
 	} options;
 
 	struct BindlessInfo

diff --git a/reference/shaders/stages/simple.invariant.vert b/reference/shaders/stages/simple.invariant.vert
diff --git a/shaders/stages/simple.invariant.vert b/shaders/stages/simple.invariant.vert
@@ -0,0 +1,4 @@
+float4 main(float4 a : A, float4 b : B, float4 c : C) : SV_Position
+{
+	return mad(a, b, c);
+}
diff --git a/test_shaders.py b/test_shaders.py
@@ -200,6 +200,8 @@ def cross_compile_dxil(shader, args, paths, is_asm):
         hlsl_cmd += ['--descriptor-qa', '10', '10', 'deadbeef']
     if '.native-fp16.' in shader:
         hlsl_cmd += ['--min-precision-native-16bit']
+    if '.invariant.' in shader:
+        hlsl_cmd += ['--invariant-position']
 
     subprocess.check_call(hlsl_cmd)
     if is_asm: