Add support for forcefully zero-initialized variables.

Useful to better support certain platforms which require all variables
to be initialized to something.

3 files changed, 183 insertions, 0 deletions

diff --git a/shaders-hlsl-no-opt/asm/frag/phi.zero-initialize.asm.frag b/shaders-hlsl-no-opt/asm/frag/phi.zero-initialize.asm.frag
new file mode 100644
index 00000000..3696660d
--- /dev/null
+++ b/shaders-hlsl-no-opt/asm/frag/phi.zero-initialize.asm.frag
@@ -0,0 +1,69 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 8
+; Bound: 40
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %vColor %FragColor
+               OpExecutionMode %main OriginUpperLeft
+               OpSource GLSL 450
+               OpName %main "main"
+               OpName %vColor "vColor"
+               OpName %uninit_function_int "uninit_function_int"
+               OpName %FragColor "FragColor"
+               OpName %uninit_int "uninit_int"
+               OpName %uninit_vector "uninit_vector"
+               OpName %uninit_matrix "uninit_matrix"
+               OpName %Foo "Foo"
+               OpMemberName %Foo 0 "a"
+               OpName %uninit_foo "uninit_foo"
+               OpDecorate %vColor Location 0
+               OpDecorate %FragColor Location 0
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%_ptr_Input_v4float = OpTypePointer Input %v4float
+     %vColor = OpVariable %_ptr_Input_v4float Input
+       %uint = OpTypeInt 32 0
+     %uint_0 = OpConstant %uint 0
+%_ptr_Input_float = OpTypePointer Input %float
+   %float_10 = OpConstant %float 10
+       %bool = OpTypeBool
+        %int = OpTypeInt 32 1
+%_ptr_Function_int = OpTypePointer Function %int
+     %int_10 = OpConstant %int 10
+     %int_20 = OpConstant %int 20
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+  %FragColor = OpVariable %_ptr_Output_v4float Output
+%_ptr_Private_int = OpTypePointer Private %int
+ %uninit_int = OpUndef %int
+      %v4int = OpTypeVector %int 4
+%_ptr_Private_v4int = OpTypePointer Private %v4int
+%uninit_vector = OpUndef %v4int
+%mat4v4float = OpTypeMatrix %v4float 4
+%_ptr_Private_mat4v4float = OpTypePointer Private %mat4v4float
+%uninit_matrix = OpUndef %mat4v4float
+        %Foo = OpTypeStruct %int
+%_ptr_Private_Foo = OpTypePointer Private %Foo
+ %uninit_foo = OpUndef %Foo
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+%uninit_function_int = OpVariable %_ptr_Function_int Function
+         %13 = OpAccessChain %_ptr_Input_float %vColor %uint_0
+         %14 = OpLoad %float %13
+         %17 = OpFOrdGreaterThan %bool %14 %float_10
+               OpSelectionMerge %19 None
+               OpBranchConditional %17 %18 %24
+         %18 = OpLabel
+               OpBranch %19
+         %24 = OpLabel
+               OpBranch %19
+         %19 = OpLabel
+		 %27 = OpPhi %int %int_10 %18 %int_20 %24
+         %28 = OpLoad %v4float %vColor
+               OpStore %FragColor %28
+               OpReturn
+               OpFunctionEnd
diff --git a/shaders-hlsl-no-opt/asm/temporary.zero-initialize.asm.frag b/shaders-hlsl-no-opt/asm/temporary.zero-initialize.asm.frag
new file mode 100644
index 00000000..eccff08b
--- /dev/null
+++ b/shaders-hlsl-no-opt/asm/temporary.zero-initialize.asm.frag
@@ -0,0 +1,93 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 8
+; Bound: 65
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %FragColor %vA %vB
+               OpExecutionMode %main OriginUpperLeft
+               OpSource ESSL 310
+               OpName %main "main"
+               OpName %FragColor "FragColor"
+               OpName %vA "vA"
+               OpName %vB "vB"
+               OpDecorate %FragColor RelaxedPrecision
+               OpDecorate %FragColor Location 0
+               OpDecorate %vA RelaxedPrecision
+               OpDecorate %vA Flat
+               OpDecorate %vA Location 0
+               OpDecorate %25 RelaxedPrecision
+               OpDecorate %30 RelaxedPrecision
+               OpDecorate %vB RelaxedPrecision
+               OpDecorate %vB Flat
+               OpDecorate %vB Location 1
+               OpDecorate %38 RelaxedPrecision
+               OpDecorate %40 RelaxedPrecision
+               OpDecorate %49 RelaxedPrecision
+               OpDecorate %51 RelaxedPrecision
+               OpDecorate %53 RelaxedPrecision
+               OpDecorate %56 RelaxedPrecision
+               OpDecorate %64 RelaxedPrecision
+               OpDecorate %58 RelaxedPrecision
+               OpDecorate %57 RelaxedPrecision
+               OpDecorate %60 RelaxedPrecision
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+  %FragColor = OpVariable %_ptr_Output_v4float Output
+    %float_0 = OpConstant %float 0
+         %11 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0
+        %int = OpTypeInt 32 1
+      %int_0 = OpConstant %int 0
+%_ptr_Input_int = OpTypePointer Input %int
+         %vA = OpVariable %_ptr_Input_int Input
+       %bool = OpTypeBool
+     %int_20 = OpConstant %int 20
+     %int_50 = OpConstant %int 50
+         %vB = OpVariable %_ptr_Input_int Input
+     %int_40 = OpConstant %int 40
+     %int_60 = OpConstant %int 60
+     %int_10 = OpConstant %int 10
+    %float_1 = OpConstant %float 1
+         %63 = OpConstantComposite %v4float %float_1 %float_1 %float_1 %float_1
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+               OpStore %FragColor %11
+               OpBranch %17
+         %17 = OpLabel
+         %60 = OpPhi %int %int_0 %5 %58 %20
+         %57 = OpPhi %int %int_0 %5 %56 %20
+         %25 = OpLoad %int %vA
+         %27 = OpSLessThan %bool %57 %25
+               OpLoopMerge %19 %20 None
+               OpBranchConditional %27 %18 %19
+         %18 = OpLabel
+         %30 = OpIAdd %int %25 %57
+         %32 = OpIEqual %bool %30 %int_20
+               OpSelectionMerge %34 None
+               OpBranchConditional %32 %33 %36
+         %33 = OpLabel
+               OpBranch %34
+         %36 = OpLabel
+         %38 = OpLoad %int %vB
+         %40 = OpIAdd %int %38 %57
+         %42 = OpIEqual %bool %40 %int_40
+         %64 = OpSelect %int %42 %int_60 %60
+               OpBranch %34
+         %34 = OpLabel
+         %58 = OpPhi %int %int_50 %33 %64 %36
+         %49 = OpIAdd %int %58 %int_10
+         %51 = OpLoad %v4float %FragColor
+         %53 = OpFAdd %v4float %51 %63
+               OpStore %FragColor %53
+               OpBranch %20
+         %20 = OpLabel
+         %56 = OpIAdd %int %57 %49
+               OpBranch %17
+         %19 = OpLabel
+               OpReturn
+               OpFunctionEnd
diff --git a/shaders-hlsl-no-opt/frag/variables.zero-initialize.frag b/shaders-hlsl-no-opt/frag/variables.zero-initialize.frag
new file mode 100644
index 00000000..41da8001
--- /dev/null
+++ b/shaders-hlsl-no-opt/frag/variables.zero-initialize.frag
@@ -0,0 +1,21 @@
+#version 450
+
+layout(location = 0) in vec4 vColor;
+layout(location = 0) out vec4 FragColor;
+
+int uninit_int;
+ivec4 uninit_vector;
+mat4 uninit_matrix;
+
+struct Foo { int a; };
+Foo uninit_foo;
+
+void main()
+{
+	int uninit_function_int;
+	if (vColor.x > 10.0)
+		uninit_function_int = 10;
+	else
+		uninit_function_int = 20;
+	FragColor = vColor;
+}