Merge pull request #228 from KhronosGroup/various-fixes

Various bug fixes

main.cpp

@@ -417,11 +417,11 @@ struct VariableTypeRemap
 	string new_variable_type;
 };
 
-struct InterfaceVariableRename
-{
-	StorageClass storageClass;
-	uint32_t location;
-	string variable_name;
+struct InterfaceVariableRename
+{
+	StorageClass storageClass;
+	uint32_t location;
+	string variable_name;
 };
 
 struct CLIArguments
@@ -473,7 +473,7 @@ static void print_help()
 	                "[--flatten-multidimensional-arrays] "
 	                "[--remap-variable-type <variable_name> <new_variable_type>] "
 	                "[--rename-interface-variable <in|out> <location> <new_variable_name>] "
-					"\n");
+	                "\n");
 }
 
 static bool remap_generic(Compiler &compiler, const vector<Resource> &resources, const Remap &remap)
@@ -560,19 +560,20 @@ static PlsFormat pls_format(const char *str)
 		return PlsNone;
 }
 
-void rename_interface_variable(Compiler &compiler, const vector<Resource> &resources, const InterfaceVariableRename &rename)
-{
-	for (auto &v : resources)
-	{
-		if (!compiler.has_decoration(v.id, spv::DecorationLocation))
-			continue;
-
-		auto loc = compiler.get_decoration(v.id, spv::DecorationLocation);
-		if (loc != rename.location)
-			continue;
-
-		compiler.set_name(v.id, rename.variable_name);
-	}
+void rename_interface_variable(Compiler &compiler, const vector<Resource> &resources,
+                               const InterfaceVariableRename &rename)
+{
+	for (auto &v : resources)
+	{
+		if (!compiler.has_decoration(v.id, spv::DecorationLocation))
+			continue;
+
+		auto loc = compiler.get_decoration(v.id, spv::DecorationLocation);
+		if (loc != rename.location)
+			continue;
+
+		compiler.set_name(v.id, rename.variable_name);
+	}
 }
 
 int main(int argc, char *argv[])
@@ -796,7 +797,7 @@ int main(int argc, char *argv[])
 			continue;
 	}
 
-	for (auto &rename : args.interface_variable_renames) 
+	for (auto &rename : args.interface_variable_renames)
 	{
 		if (rename.storageClass == StorageClassInput)
 			rename_interface_variable(*compiler, res.stage_inputs, rename);

reference/shaders-hlsl/frag/unary-enclose.frag

@@ -0,0 +1,32 @@
+static float4 FragColor;
+static float4 vIn;
+static int4 vIn1;
+
+struct SPIRV_Cross_Input
+{
+    float4 vIn : TEXCOORD0;
+    nointerpolation int4 vIn1 : TEXCOORD1;
+};
+
+struct SPIRV_Cross_Output
+{
+    float4 FragColor : SV_Target0;
+};
+
+void frag_main()
+{
+    FragColor = -(-vIn);
+    int4 a = ~(~vIn1);
+    bool b = false;
+    b = !(!b);
+}
+
+SPIRV_Cross_Output main(SPIRV_Cross_Input stage_input)
+{
+    vIn = stage_input.vIn;
+    vIn1 = stage_input.vIn1;
+    frag_main();
+    SPIRV_Cross_Output stage_output;
+    stage_output.FragColor = FragColor;
+    return stage_output;
+}

reference/shaders-msl/frag/unary-enclose.frag

@@ -0,0 +1,26 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_in
+{
+    int4 vIn1 [[user(locn1)]];
+    float4 vIn [[user(locn0)]];
+};
+
+struct main0_out
+{
+    float4 FragColor [[color(0)]];
+};
+
+fragment main0_out main0(main0_in in [[stage_in]])
+{
+    main0_out out = {};
+    out.FragColor = -(-in.vIn);
+    int4 a = ~(~in.vIn1);
+    bool b = false;
+    b = !(!b);
+    return out;
+}
+

reference/shaders/asm/frag/hlsl-sample-cmp-level-zero-cube.asm.frag

@@ -0,0 +1,17 @@
+#version 450
+
+uniform samplerCubeShadow SPIRV_Cross_CombinedpointLightShadowMapshadowSamplerPCF;
+
+layout(location = 0) out float _entryPointOutput;
+
+float _main()
+{
+    vec4 _33 = vec4(vec3(0.100000001490116119384765625), 0.5);
+    return textureGrad(SPIRV_Cross_CombinedpointLightShadowMapshadowSamplerPCF, vec4(_33.xyz, _33.w), vec3(0.0), vec3(0.0));
+}
+
+void main()
+{
+    _entryPointOutput = _main();
+}
+

reference/shaders/frag/sample-parameter.frag

@@ -0,0 +1,13 @@
+#version 310 es
+#extension GL_OES_sample_variables : require
+precision mediump float;
+precision highp int;
+
+layout(location = 0) out vec2 FragColor;
+
+void main()
+{
+    FragColor = (gl_SamplePosition + vec2(float(gl_SampleMaskIn[0]))) + vec2(float(gl_SampleID));
+    gl_SampleMask[0] = 1;
+}
+

reference/shaders/frag/unary-enclose.frag

@@ -0,0 +1,16 @@
+#version 310 es
+precision mediump float;
+precision highp int;
+
+layout(location = 0) out vec4 FragColor;
+layout(location = 0) in vec4 vIn;
+layout(location = 1) flat in mediump ivec4 vIn1;
+
+void main()
+{
+    FragColor = -(-vIn);
+    mediump ivec4 a = ~(~vIn1);
+    bool b = false;
+    b = !(!b);
+}
+

reference/shaders/vert/ground.vert

@@ -78,7 +78,7 @@ vec2 warp_position()
         _117 = 0u;
     }
     uvec2 rounding = uvec2(_116, _117);
-    vec4 lower_upper_snapped = vec4((uPosition + rounding).xyxy & ~mask.xxyy);
+    vec4 lower_upper_snapped = vec4((uPosition + rounding).xyxy & (~mask).xxyy);
     return mix(lower_upper_snapped.xy, lower_upper_snapped.zw, vec2(fract_lod));
 }
 

reference/shaders/vert/ocean.vert

@@ -100,7 +100,7 @@ vec2 warp_position()
         _142 = 0u;
     }
     rounding.w = _142;
-    vec4 lower_upper_snapped = vec4((uPosition.xyxy + rounding) & ~mask.xxyy);
+    vec4 lower_upper_snapped = vec4((uPosition.xyxy + rounding) & (~mask).xxyy);
     return mix(lower_upper_snapped.xy, lower_upper_snapped.zw, vec2(fract_lod));
 }
 

reference/shaders/vulkan/frag/input-attachment-ms.vk.frag

@@ -1,14 +1,12 @@
-#version 310 es
-precision mediump float;
-precision highp int;
+#version 450
 
-layout(binding = 0) uniform mediump sampler2DMS uSubpass0;
-layout(binding = 1) uniform mediump sampler2DMS uSubpass1;
+layout(binding = 0) uniform sampler2DMS uSubpass0;
+layout(binding = 1) uniform sampler2DMS uSubpass1;
 
 layout(location = 0) out vec4 FragColor;
 
 void main()
 {
-    FragColor = texelFetch(uSubpass0, ivec2(gl_FragCoord.xy), 1) + texelFetch(uSubpass1, ivec2(gl_FragCoord.xy), 2);
+    FragColor = (texelFetch(uSubpass0, ivec2(gl_FragCoord.xy), 1) + texelFetch(uSubpass1, ivec2(gl_FragCoord.xy), 2)) + texelFetch(uSubpass0, ivec2(gl_FragCoord.xy), gl_SampleID);
 }
 

reference/shaders/vulkan/frag/input-attachment-ms.vk.frag.vk

@@ -1,14 +1,12 @@
-#version 310 es
-precision mediump float;
-precision highp int;
+#version 450
 
-layout(input_attachment_index = 0, set = 0, binding = 0) uniform mediump subpassInputMS uSubpass0;
-layout(input_attachment_index = 1, set = 0, binding = 1) uniform mediump subpassInputMS uSubpass1;
+layout(input_attachment_index = 0, set = 0, binding = 0) uniform subpassInputMS uSubpass0;
+layout(input_attachment_index = 1, set = 0, binding = 1) uniform subpassInputMS uSubpass1;
 
 layout(location = 0) out vec4 FragColor;
 
 void main()
 {
-    FragColor = subpassLoad(uSubpass0, 1) + subpassLoad(uSubpass1, 2);
+    FragColor = (subpassLoad(uSubpass0, 1) + subpassLoad(uSubpass1, 2)) + subpassLoad(uSubpass0, gl_SampleID);
 }
 

shaders-hlsl/frag/unary-enclose.frag

@@ -0,0 +1,15 @@
+#version 310 es
+precision mediump float;
+
+layout(location = 0) out vec4 FragColor;
+layout(location = 0) in vec4 vIn;
+layout(location = 1) flat in ivec4 vIn1;
+
+void main()
+{
+	FragColor = +(-(-vIn));
+	ivec4 a = ~(~vIn1);
+
+	bool b = false;
+	b = !!b;
+}

shaders-msl/frag/unary-enclose.frag

@@ -0,0 +1,15 @@
+#version 310 es
+precision mediump float;
+
+layout(location = 0) out vec4 FragColor;
+layout(location = 0) in vec4 vIn;
+layout(location = 1) flat in ivec4 vIn1;
+
+void main()
+{
+	FragColor = +(-(-vIn));
+	ivec4 a = ~(~vIn1);
+
+	bool b = false;
+	b = !!b;
+}

shaders/asm/frag/hlsl-sample-cmp-level-zero-cube.asm.frag

@@ -0,0 +1,58 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 1
+; Bound: 38
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %_entryPointOutput
+               OpExecutionMode %main OriginUpperLeft
+               OpSource HLSL 500
+               OpName %main "main"
+               OpName %_main_ "@main("
+               OpName %pointLightShadowMap "pointLightShadowMap"
+               OpName %shadowSamplerPCF "shadowSamplerPCF"
+               OpName %_entryPointOutput "@entryPointOutput"
+               OpDecorate %pointLightShadowMap DescriptorSet 0
+               OpDecorate %shadowSamplerPCF DescriptorSet 0
+               OpDecorate %_entryPointOutput Location 0
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+          %7 = OpTypeFunction %float
+         %10 = OpTypeImage %float Cube 0 0 0 1 Unknown
+%_ptr_UniformConstant_10 = OpTypePointer UniformConstant %10
+%pointLightShadowMap = OpVariable %_ptr_UniformConstant_10 UniformConstant
+         %14 = OpTypeSampler
+%_ptr_UniformConstant_14 = OpTypePointer UniformConstant %14
+%shadowSamplerPCF = OpVariable %_ptr_UniformConstant_14 UniformConstant
+         %18 = OpTypeImage %float Cube 1 0 0 1 Unknown
+         %19 = OpTypeSampledImage %18
+    %v3float = OpTypeVector %float 3
+  %float_0_1 = OpConstant %float 0.1
+         %23 = OpConstantComposite %v3float %float_0_1 %float_0_1 %float_0_1
+  %float_0_5 = OpConstant %float 0.5
+    %v4float = OpTypeVector %float 4
+    %float_0 = OpConstant %float 0
+%_ptr_Output_float = OpTypePointer Output %float
+%_entryPointOutput = OpVariable %_ptr_Output_float Output
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+         %37 = OpFunctionCall %float %_main_
+               OpStore %_entryPointOutput %37
+               OpReturn
+               OpFunctionEnd
+     %_main_ = OpFunction %float None %7
+          %9 = OpLabel
+         %13 = OpLoad %10 %pointLightShadowMap
+         %17 = OpLoad %14 %shadowSamplerPCF
+         %20 = OpSampledImage %19 %13 %17
+         %26 = OpCompositeExtract %float %23 0
+         %27 = OpCompositeExtract %float %23 1
+         %28 = OpCompositeExtract %float %23 2
+         %29 = OpCompositeConstruct %v4float %26 %27 %28 %float_0_5
+         %31 = OpCompositeExtract %float %29 3
+         %32 = OpImageSampleDrefExplicitLod %float %20 %29 %31 Lod %float_0
+               OpReturnValue %32
+               OpFunctionEnd

shaders/frag/sample-parameter.frag

@@ -0,0 +1,11 @@
+#version 310 es
+#extension GL_OES_sample_variables : require
+precision mediump float;
+
+layout(location = 0) out vec2 FragColor;
+
+void main()
+{
+	FragColor = gl_SamplePosition + vec2(gl_SampleMaskIn[0]) + float(gl_SampleID);
+	gl_SampleMask[0] = 1;
+}

shaders/frag/unary-enclose.frag

@@ -0,0 +1,15 @@
+#version 310 es
+precision mediump float;
+
+layout(location = 0) out vec4 FragColor;
+layout(location = 0) in vec4 vIn;
+layout(location = 1) flat in ivec4 vIn1;
+
+void main()
+{
+	FragColor = +(-(-vIn));
+	ivec4 a = ~(~vIn1);
+
+	bool b = false;
+	b = !!b;
+}

shaders/vulkan/frag/input-attachment-ms.vk.frag

@@ -1,11 +1,10 @@
-#version 310 es
-precision mediump float;
+#version 450
 
-layout(input_attachment_index = 0, set = 0, binding = 0) uniform mediump subpassInputMS uSubpass0;
-layout(input_attachment_index = 1, set = 0, binding = 1) uniform mediump subpassInputMS uSubpass1;
+layout(input_attachment_index = 0, set = 0, binding = 0) uniform subpassInputMS uSubpass0;
+layout(input_attachment_index = 1, set = 0, binding = 1) uniform subpassInputMS uSubpass1;
 layout(location = 0) out vec4 FragColor;
 
 void main()
 {
-    FragColor = subpassLoad(uSubpass0, 1) + subpassLoad(uSubpass1, 2);
+    FragColor = subpassLoad(uSubpass0, 1) + subpassLoad(uSubpass1, 2) + subpassLoad(uSubpass0, gl_SampleID);
 }

spirv_glsl.cpp

@@ -1812,6 +1812,16 @@ void CompilerGLSL::strip_enclosed_expression(string &expr)
 string CompilerGLSL::enclose_expression(const string &expr)
 {
 	bool need_parens = false;
+
+	// If the expression starts with a unary we need to enclose to deal with cases where we have back-to-back
+	// unary expressions.
+	if (!expr.empty())
+	{
+		auto c = expr.front();
+		if (c == '-' || c == '+' || c == '!' || c == '~')
+			need_parens = true;
+	}
+
 	uint32_t paren_count = 0;
 	for (auto c : expr)
 	{
@@ -1917,7 +1927,7 @@ string CompilerGLSL::to_expression(uint32_t id)
 		{
 			auto &dec = meta[var.self].decoration;
 			if (dec.builtin)
-				return builtin_to_glsl(dec.builtin_type);
+				return builtin_to_glsl(dec.builtin_type, var.storage);
 			else
 				return to_name(id);
 		}
@@ -2966,12 +2976,13 @@ string CompilerGLSL::to_function_name(uint32_t, const SPIRType &imgtype, bool is
 {
 	string fname;
 
-	// textureLod on sampler2DArrayShadow does not exist in GLSL for some reason.
+	// textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL for some reason.
 	// To emulate this, we will have to use textureGrad with a constant gradient of 0.
 	// The workaround will assert that the LOD is in fact constant 0, or we cannot emit correct code.
-	// This happens for HLSL SampleCmpLevelZero on Texture2DArray.
+	// This happens for HLSL SampleCmpLevelZero on Texture2DArray and TextureCube.
 	bool workaround_lod_array_shadow_as_grad = false;
-	if (imgtype.image.arrayed && imgtype.image.dim == Dim2D && imgtype.image.depth && lod)
+	if (((imgtype.image.arrayed && imgtype.image.dim == Dim2D) || imgtype.image.dim == DimCube) &&
+	    imgtype.image.depth && lod)
 	{
 		auto *constant_lod = maybe_get<SPIRConstant>(lod);
 		if (!constant_lod || constant_lod->scalar_f32() != 0.0f)
@@ -3037,12 +3048,13 @@ string CompilerGLSL::to_function_args(uint32_t img, const SPIRType &imgtype, boo
 	// Only enclose the UV expression if needed.
 	auto coord_expr = (*swizzle_expr == '\0') ? to_expression(coord) : (to_enclosed_expression(coord) + swizzle_expr);
 
-	// textureLod on sampler2DArrayShadow does not exist in GLSL for some reason.
+	// textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL for some reason.
 	// To emulate this, we will have to use textureGrad with a constant gradient of 0.
 	// The workaround will assert that the LOD is in fact constant 0, or we cannot emit correct code.
-	// This happens for HLSL SampleCmpLevelZero on Texture2DArray.
+	// This happens for HLSL SampleCmpLevelZero on Texture2DArray and TextureCube.
 	bool workaround_lod_array_shadow_as_grad =
-	    imgtype.image.arrayed && imgtype.image.dim == Dim2D && imgtype.image.depth && lod;
+	    ((imgtype.image.arrayed && imgtype.image.dim == Dim2D) || imgtype.image.dim == DimCube) &&
+	    imgtype.image.depth && lod;
 
 	if (dref)
 	{
@@ -3092,7 +3104,10 @@ string CompilerGLSL::to_function_args(uint32_t img, const SPIRType &imgtype, boo
 		{
 			// Implement textureGrad() instead. LOD == 0.0 is implemented as gradient of 0.0.
 			// Implementing this as plain texture() is not safe on some implementations.
-			farg_str += ", vec2(0.0), vec2(0.0)";
+			if (imgtype.image.dim == Dim2D)
+				farg_str += ", vec2(0.0), vec2(0.0)";
+			else if (imgtype.image.dim == DimCube)
+				farg_str += ", vec3(0.0), vec3(0.0)";
 		}
 		else
 		{
@@ -3443,7 +3458,7 @@ string CompilerGLSL::bitcast_glsl(const SPIRType &result_type, uint32_t argument
 		return join(op, "(", to_expression(argument), ")");
 }
 
-string CompilerGLSL::builtin_to_glsl(BuiltIn builtin)
+string CompilerGLSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
 {
 	switch (builtin)
 	{
@@ -3507,6 +3522,32 @@ string CompilerGLSL::builtin_to_glsl(BuiltIn builtin)
 		return "gl_GlobalInvocationID";
 	case BuiltInLocalInvocationIndex:
 		return "gl_LocalInvocationIndex";
+
+	case BuiltInSampleId:
+		if (options.es && options.version < 320)
+			require_extension("GL_OES_sample_variables");
+		if (!options.es && options.version < 400)
+			SPIRV_CROSS_THROW("gl_SampleID not supported before GLSL 400.");
+		return "gl_SampleID";
+
+	case BuiltInSampleMask:
+		if (options.es && options.version < 320)
+			require_extension("GL_OES_sample_variables");
+		if (!options.es && options.version < 400)
+			SPIRV_CROSS_THROW("gl_SampleMask/gl_SampleMaskIn not supported before GLSL 400.");
+
+		if (storage == StorageClassInput)
+			return "gl_SampleMaskIn";
+		else
+			return "gl_SampleMask";
+
+	case BuiltInSamplePosition:
+		if (options.es && options.version < 320)
+			require_extension("GL_OES_sample_variables");
+		if (!options.es && options.version < 400)
+			SPIRV_CROSS_THROW("gl_SamplePosition not supported before GLSL 400.");
+		return "gl_SamplePosition";
+
 	default:
 		return join("gl_BuiltIn_", convert_to_string(builtin));
 	}
@@ -3624,10 +3665,10 @@ string CompilerGLSL::access_chain_internal(uint32_t base, const uint32_t *indice
 				if (access_chain_is_arrayed)
 				{
 					expr += ".";
-					expr += builtin_to_glsl(builtin);
+					expr += builtin_to_glsl(builtin, type->storage);
 				}
 				else
-					expr = builtin_to_glsl(builtin);
+					expr = builtin_to_glsl(builtin, type->storage);
 			}
 			else
 			{

spirv_glsl.hpp

@@ -172,7 +172,7 @@ protected:
 	virtual void emit_sampled_image_op(uint32_t result_type, uint32_t result_id, uint32_t image_id, uint32_t samp_id);
 	virtual void emit_texture_op(const Instruction &i);
 	virtual std::string type_to_glsl(const SPIRType &type, uint32_t id = 0);
-	virtual std::string builtin_to_glsl(spv::BuiltIn builtin);
+	virtual std::string builtin_to_glsl(spv::BuiltIn builtin, spv::StorageClass storage);
 	virtual void emit_struct_member(const SPIRType &type, uint32_t member_type_id, uint32_t index,
 	                                const std::string &qualifier = "");
 	virtual std::string image_type_glsl(const SPIRType &type, uint32_t id = 0);

spirv_hlsl.cpp

@@ -326,7 +326,7 @@ void CompilerHLSL::emit_builtin_outputs_in_struct()
 		}
 
 		if (type && semantic)
-			statement(type, " ", builtin_to_glsl(builtin), " : ", semantic, ";");
+			statement(type, " ", builtin_to_glsl(builtin, StorageClassOutput), " : ", semantic, ";");
 	}
 }
 
@@ -375,7 +375,7 @@ void CompilerHLSL::emit_builtin_inputs_in_struct()
 		}
 
 		if (type && semantic)
-			statement(type, " ", builtin_to_glsl(builtin), " : ", semantic, ";");
+			statement(type, " ", builtin_to_glsl(builtin, StorageClassInput), " : ", semantic, ";");
 	}
 }
 
@@ -574,8 +574,12 @@ void CompilerHLSL::emit_builtin_variables()
 			break;
 		}
 
+		StorageClass storage = (active_input_builtins & (1ull << i)) != 0 ? StorageClassInput : StorageClassOutput;
+		// FIXME: SampleMask can be both in and out with sample builtin,
+		// need to distinguish that when we add support for that.
+
 		if (type)
-			statement("static ", type, " ", builtin_to_glsl(builtin), ";");
+			statement("static ", type, " ", builtin_to_glsl(builtin, storage), ";");
 	}
 }
 
@@ -909,7 +913,8 @@ void CompilerHLSL::emit_buffer_block(const SPIRVariable &var)
 
 	if (options.shader_model >= 51) // SM 5.1 uses ConstantBuffer<T> instead of cbuffer.
 	{
-		statement("ConstantBuffer<", struct_name, "> ", to_name(var.self), type_to_array_glsl(type), to_resource_binding(var), ";");
+		statement("ConstantBuffer<", struct_name, "> ", to_name(var.self), type_to_array_glsl(type),
+		          to_resource_binding(var), ";");
 	}
 	else
 	{
@@ -1065,7 +1070,7 @@ void CompilerHLSL::emit_hlsl_entry_point()
 		if (!(active_input_builtins & (1ull << i)))
 			continue;
 
-		auto builtin = builtin_to_glsl(static_cast<BuiltIn>(i));
+		auto builtin = builtin_to_glsl(static_cast<BuiltIn>(i), StorageClassInput);
 		switch (static_cast<BuiltIn>(i))
 		{
 		case BuiltInFragCoord:
@@ -1172,7 +1177,7 @@ void CompilerHLSL::emit_hlsl_entry_point()
 			if (i == BuiltInPointSize)
 				continue;
 
-			auto builtin = builtin_to_glsl(static_cast<BuiltIn>(i));
+			auto builtin = builtin_to_glsl(static_cast<BuiltIn>(i), StorageClassOutput);
 			statement("stage_output.", builtin, " = ", builtin, ";");
 		}
 

spirv_msl.cpp

@@ -591,7 +591,8 @@ string CompilerMSL::add_input_buffer_block_member(uint32_t mbr_type_id, string m
 	set_member_decoration(ib_type_id, ib_mbr_idx, DecorationLocation, k_unknown_location);
 
 	// Update the original variable reference to include the structure and index reference
-	string idx_var_name = builtin_to_glsl(p_va->per_instance ? BuiltInInstanceIndex : BuiltInVertexIndex);
+	string idx_var_name =
+	    builtin_to_glsl(p_va->per_instance ? BuiltInInstanceIndex : BuiltInVertexIndex, StorageClassInput);
 	return get_name(ib_var_id) + "[" + idx_var_name + "]." + mbr_name;
 }
 
@@ -2385,7 +2386,7 @@ string CompilerMSL::to_qualified_member_name(const SPIRType &type, uint32_t inde
 	// Don't qualify Builtin names because they are unique and are treated as such when building expressions
 	BuiltIn builtin;
 	if (is_member_builtin(type, index, &builtin))
-		return builtin_to_glsl(builtin);
+		return builtin_to_glsl(builtin, type.storage);
 
 	// Strip any underscore prefix from member name
 	string mbr_name = to_member_name(type, index);
@@ -2592,7 +2593,7 @@ string CompilerMSL::bitcast_glsl_op(const SPIRType &out_type, const SPIRType &in
 
 // Returns an MSL string identifying the name of a SPIR-V builtin.
 // Output builtins are qualified with the name of the stage out structure.
-string CompilerMSL::builtin_to_glsl(BuiltIn builtin)
+string CompilerMSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
 {
 	switch (builtin)
 	{
@@ -2613,12 +2614,12 @@ string CompilerMSL::builtin_to_glsl(BuiltIn builtin)
 	case BuiltInClipDistance:
 	case BuiltInLayer:
 		if (current_function && (current_function->self == entry_point))
-			return stage_out_var_name + "." + CompilerGLSL::builtin_to_glsl(builtin);
+			return stage_out_var_name + "." + CompilerGLSL::builtin_to_glsl(builtin, storage);
 		else
-			return CompilerGLSL::builtin_to_glsl(builtin);
+			return CompilerGLSL::builtin_to_glsl(builtin, storage);
 
 	default:
-		return CompilerGLSL::builtin_to_glsl(builtin);
+		return CompilerGLSL::builtin_to_glsl(builtin, storage);
 	}
 }
 
@@ -2744,7 +2745,10 @@ string CompilerMSL::built_in_func_arg(BuiltIn builtin, bool prefix_comma)
 	if (prefix_comma)
 		bi_arg += ", ";
 	bi_arg += builtin_type_decl(builtin);
-	bi_arg += " " + builtin_to_glsl(builtin);
+
+	assert(builtin == BuiltInVertexIndex || builtin == BuiltInInstanceIndex);
+	bi_arg += " " + builtin_to_glsl(builtin, StorageClassInput);
+
 	bi_arg += " [[" + builtin_qualifier(builtin) + "]]";
 	return bi_arg;
 }

spirv_msl.hpp

@@ -151,7 +151,7 @@ protected:
 	                        const std::string &qualifier = "") override;
 	std::string type_to_glsl(const SPIRType &type, uint32_t id = 0) override;
 	std::string image_type_glsl(const SPIRType &type, uint32_t id = 0) override;
-	std::string builtin_to_glsl(spv::BuiltIn builtin) override;
+	std::string builtin_to_glsl(spv::BuiltIn builtin, spv::StorageClass storage) override;
 	std::string constant_expression(const SPIRConstant &c) override;
 	size_t get_declared_struct_member_size(const SPIRType &struct_type, uint32_t index) const override;
 	std::string to_func_call_arg(uint32_t id) override;