diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 0b48dfcd..b15a19f0 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -2248,8 +2248,10 @@ void TGlslangToSpvTraverser::decorateStructType(const glslang::TType& type,
             addMemberDecoration(spvType, member, TranslateLayoutDecoration(glslangMember, memberQualifier.layoutMatrix));
             addMemberDecoration(spvType, member, TranslatePrecisionDecoration(glslangMember));
             // Add interpolation and auxiliary storage decorations only to top-level members of Input and Output storage classes
-            if (type.getQualifier().storage == glslang::EvqVaryingIn || type.getQualifier().storage == glslang::EvqVaryingOut) {
-                if (type.getBasicType() == glslang::EbtBlock) {
+            if (type.getQualifier().storage == glslang::EvqVaryingIn ||
+                type.getQualifier().storage == glslang::EvqVaryingOut) {
+                if (type.getBasicType() == glslang::EbtBlock ||
+                    glslangIntermediate->getSource() == glslang::EShSourceHlsl) {
                     addMemberDecoration(spvType, member, TranslateInterpolationDecoration(memberQualifier));
                     addMemberDecoration(spvType, member, TranslateAuxiliaryStorageDecoration(memberQualifier));
                 }
diff --git a/Test/baseResults/hlsl.struct.frag.out b/Test/baseResults/hlsl.struct.frag.out
index c9161d04..8b19c025 100755
--- a/Test/baseResults/hlsl.struct.frag.out
+++ b/Test/baseResults/hlsl.struct.frag.out
@@ -284,6 +284,10 @@ gl_FragCoord origin is upper left
                               MemberName 94($Global) 2  "ff6"
                               Name 96  ""
                               Decorate 43(input) Location 0
+                              MemberDecorate 46(IN_S) 1 Flat
+                              MemberDecorate 46(IN_S) 2 NoPerspective
+                              MemberDecorate 46(IN_S) 2 Centroid
+                              MemberDecorate 46(IN_S) 3 Centroid
                               Decorate 48(s) Location 1
                               Decorate 71(s_ff1) BuiltIn FrontFacing
                               Decorate 86(@entryPointOutput) Location 0
diff --git a/Test/baseResults/hlsl.structIoFourWay.frag.out b/Test/baseResults/hlsl.structIoFourWay.frag.out
new file mode 100755
index 00000000..8b6d75af
--- /dev/null
+++ b/Test/baseResults/hlsl.structIoFourWay.frag.out
@@ -0,0 +1,255 @@
+hlsl.structIoFourWay.frag
+Shader version: 450
+gl_FragCoord origin is upper left
+using depth_greater
+0:? Sequence
+0:15  Function Definition: @main(struct-T-f1-f1-f1-vf41; (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15    Function Parameters: 
+0:15      't' (in structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?     Sequence
+0:17      Branch: Return with expression
+0:17        'local' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15  Function Definition: main( (temp void)
+0:15    Function Parameters: 
+0:?     Sequence
+0:15      move second child to first child (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?         't' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?         't' (layout(location=0 ) in structure{temp float f, centroid temp float g, temp float d, temp 4-component vector of float normal})
+0:15      Sequence
+0:15        move second child to first child (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15          'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15          Function Call: @main(struct-T-f1-f1-f1-vf41; (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?             't' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15        move second child to first child (temp float)
+0:?           'f' (layout(location=0 ) out float)
+0:15          f: direct index for structure (temp float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              0 (const int)
+0:15        move second child to first child (temp float)
+0:?           'g' (layout(location=1 ) out float)
+0:15          g: direct index for structure (temp float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              1 (const int)
+0:15        move second child to first child (temp float)
+0:?           'd' (out float FragDepth)
+0:15          d: direct index for structure (temp float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              2 (const int)
+0:15        move second child to first child (temp 4-component vector of float)
+0:?           'normal' (layout(location=2 ) out 4-component vector of float)
+0:15          normal: direct index for structure (temp 4-component vector of float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              3 (const int)
+0:?   Linker Objects
+0:?     'anon@0' (layout(row_major std140 ) uniform block{layout(row_major std140 offset=88 ) uniform structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal} t})
+0:?     'f' (layout(location=0 ) out float)
+0:?     'g' (layout(location=1 ) out float)
+0:?     'd' (out float FragDepth)
+0:?     'normal' (layout(location=2 ) out 4-component vector of float)
+0:?     't' (layout(location=0 ) in structure{temp float f, centroid temp float g, temp float d, temp 4-component vector of float normal})
+0:?     'anon@1' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform structure{layout(offset=68 ) temp float f, temp float g, temp float d, temp 4-component vector of float normal} s})
+
+
+Linked fragment stage:
+
+
+Shader version: 450
+gl_FragCoord origin is upper left
+using depth_greater
+0:? Sequence
+0:15  Function Definition: @main(struct-T-f1-f1-f1-vf41; (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15    Function Parameters: 
+0:15      't' (in structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?     Sequence
+0:17      Branch: Return with expression
+0:17        'local' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15  Function Definition: main( (temp void)
+0:15    Function Parameters: 
+0:?     Sequence
+0:15      move second child to first child (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?         't' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?         't' (layout(location=0 ) in structure{temp float f, centroid temp float g, temp float d, temp 4-component vector of float normal})
+0:15      Sequence
+0:15        move second child to first child (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15          'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15          Function Call: @main(struct-T-f1-f1-f1-vf41; (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:?             't' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15        move second child to first child (temp float)
+0:?           'f' (layout(location=0 ) out float)
+0:15          f: direct index for structure (temp float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              0 (const int)
+0:15        move second child to first child (temp float)
+0:?           'g' (layout(location=1 ) out float)
+0:15          g: direct index for structure (temp float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              1 (const int)
+0:15        move second child to first child (temp float)
+0:?           'd' (out float FragDepth)
+0:15          d: direct index for structure (temp float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              2 (const int)
+0:15        move second child to first child (temp 4-component vector of float)
+0:?           'normal' (layout(location=2 ) out 4-component vector of float)
+0:15          normal: direct index for structure (temp 4-component vector of float)
+0:15            'flattenTemp' (temp structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal})
+0:15            Constant:
+0:15              3 (const int)
+0:?   Linker Objects
+0:?     'anon@0' (layout(row_major std140 ) uniform block{layout(row_major std140 offset=88 ) uniform structure{temp float f, temp float g, temp float d, temp 4-component vector of float normal} t})
+0:?     'f' (layout(location=0 ) out float)
+0:?     'g' (layout(location=1 ) out float)
+0:?     'd' (out float FragDepth)
+0:?     'normal' (layout(location=2 ) out 4-component vector of float)
+0:?     't' (layout(location=0 ) in structure{temp float f, centroid temp float g, temp float d, temp 4-component vector of float normal})
+0:?     'anon@1' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform structure{layout(offset=68 ) temp float f, temp float g, temp float d, temp 4-component vector of float normal} s})
+
+// Module Version 10000
+// Generated by (magic number): 80001
+// Id's are bound by 64
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 21 43 46 49 53
+                              ExecutionMode 4 OriginUpperLeft
+                              ExecutionMode 4 DepthGreater
+                              Name 4  "main"
+                              Name 8  "T"
+                              MemberName 8(T) 0  "f"
+                              MemberName 8(T) 1  "g"
+                              MemberName 8(T) 2  "d"
+                              MemberName 8(T) 3  "normal"
+                              Name 12  "@main(struct-T-f1-f1-f1-vf41;"
+                              Name 11  "t"
+                              Name 14  "local"
+                              Name 18  "t"
+                              Name 19  "T"
+                              MemberName 19(T) 0  "f"
+                              MemberName 19(T) 1  "g"
+                              MemberName 19(T) 2  "d"
+                              MemberName 19(T) 3  "normal"
+                              Name 21  "t"
+                              Name 38  "flattenTemp"
+                              Name 39  "param"
+                              Name 43  "f"
+                              Name 46  "g"
+                              Name 49  "d"
+                              Name 53  "normal"
+                              Name 56  "T"
+                              MemberName 56(T) 0  "f"
+                              MemberName 56(T) 1  "g"
+                              MemberName 56(T) 2  "d"
+                              MemberName 56(T) 3  "normal"
+                              Name 57  "buff"
+                              MemberName 57(buff) 0  "t"
+                              Name 59  ""
+                              Name 60  "T"
+                              MemberName 60(T) 0  "f"
+                              MemberName 60(T) 1  "g"
+                              MemberName 60(T) 2  "d"
+                              MemberName 60(T) 3  "normal"
+                              Name 61  "$Global"
+                              MemberName 61($Global) 0  "s"
+                              Name 63  ""
+                              MemberDecorate 19(T) 1 Centroid
+                              Decorate 21(t) Location 0
+                              Decorate 43(f) Location 0
+                              Decorate 46(g) Location 1
+                              Decorate 49(d) BuiltIn FragDepth
+                              Decorate 53(normal) Location 2
+                              MemberDecorate 56(T) 0 Offset 0
+                              MemberDecorate 56(T) 1 Offset 4
+                              MemberDecorate 56(T) 2 Offset 8
+                              MemberDecorate 56(T) 3 Offset 16
+                              MemberDecorate 57(buff) 0 Offset 96
+                              Decorate 57(buff) Block
+                              Decorate 59 DescriptorSet 0
+                              MemberDecorate 60(T) 0 Offset 68
+                              MemberDecorate 60(T) 1 Offset 72
+                              MemberDecorate 60(T) 2 Offset 76
+                              MemberDecorate 60(T) 3 Offset 80
+                              MemberDecorate 61($Global) 0 Offset 0
+                              Decorate 61($Global) Block
+                              Decorate 63 DescriptorSet 0
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypeVector 6(float) 4
+            8(T):             TypeStruct 6(float) 6(float) 6(float) 7(fvec4)
+               9:             TypePointer Function 8(T)
+              10:             TypeFunction 8(T) 9(ptr)
+           19(T):             TypeStruct 6(float) 6(float) 6(float) 7(fvec4)
+              20:             TypePointer Input 19(T)
+           21(t):     20(ptr) Variable Input
+              24:             TypeInt 32 1
+              25:     24(int) Constant 0
+              26:             TypePointer Function 6(float)
+              29:     24(int) Constant 1
+              32:     24(int) Constant 2
+              35:     24(int) Constant 3
+              36:             TypePointer Function 7(fvec4)
+              42:             TypePointer Output 6(float)
+           43(f):     42(ptr) Variable Output
+           46(g):     42(ptr) Variable Output
+           49(d):     42(ptr) Variable Output
+              52:             TypePointer Output 7(fvec4)
+      53(normal):     52(ptr) Variable Output
+           56(T):             TypeStruct 6(float) 6(float) 6(float) 7(fvec4)
+        57(buff):             TypeStruct 56(T)
+              58:             TypePointer Uniform 57(buff)
+              59:     58(ptr) Variable Uniform
+           60(T):             TypeStruct 6(float) 6(float) 6(float) 7(fvec4)
+     61($Global):             TypeStruct 60(T)
+              62:             TypePointer Uniform 61($Global)
+              63:     62(ptr) Variable Uniform
+         4(main):           2 Function None 3
+               5:             Label
+           18(t):      9(ptr) Variable Function
+ 38(flattenTemp):      9(ptr) Variable Function
+       39(param):      9(ptr) Variable Function
+              22:       19(T) Load 21(t)
+              23:    6(float) CompositeExtract 22 0
+              27:     26(ptr) AccessChain 18(t) 25
+                              Store 27 23
+              28:    6(float) CompositeExtract 22 1
+              30:     26(ptr) AccessChain 18(t) 29
+                              Store 30 28
+              31:    6(float) CompositeExtract 22 2
+              33:     26(ptr) AccessChain 18(t) 32
+                              Store 33 31
+              34:    7(fvec4) CompositeExtract 22 3
+              37:     36(ptr) AccessChain 18(t) 35
+                              Store 37 34
+              40:        8(T) Load 18(t)
+                              Store 39(param) 40
+              41:        8(T) FunctionCall 12(@main(struct-T-f1-f1-f1-vf41;) 39(param)
+                              Store 38(flattenTemp) 41
+              44:     26(ptr) AccessChain 38(flattenTemp) 25
+              45:    6(float) Load 44
+                              Store 43(f) 45
+              47:     26(ptr) AccessChain 38(flattenTemp) 29
+              48:    6(float) Load 47
+                              Store 46(g) 48
+              50:     26(ptr) AccessChain 38(flattenTemp) 32
+              51:    6(float) Load 50
+                              Store 49(d) 51
+              54:     36(ptr) AccessChain 38(flattenTemp) 35
+              55:    7(fvec4) Load 54
+                              Store 53(normal) 55
+                              Return
+                              FunctionEnd
+12(@main(struct-T-f1-f1-f1-vf41;):        8(T) Function None 10
+           11(t):      9(ptr) FunctionParameter
+              13:             Label
+       14(local):      9(ptr) Variable Function
+              15:        8(T) Load 14(local)
+                              ReturnValue 15
+                              FunctionEnd
diff --git a/Test/baseResults/hlsl.structin.vert.out b/Test/baseResults/hlsl.structin.vert.out
index 50e4b9c6..e64202fb 100755
--- a/Test/baseResults/hlsl.structin.vert.out
+++ b/Test/baseResults/hlsl.structin.vert.out
@@ -92,7 +92,7 @@ Shader version: 450
 0:?             'e' (temp 4-component vector of float)
 0:8        move second child to first child (temp 2-element array of 4-component vector of float)
 0:8          m: direct index for structure (temp 2-element array of 4-component vector of float)
-0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:8            Constant:
 0:8              0 (const int)
 0:8          m: direct index for structure (temp 2-element array of 4-component vector of float)
@@ -101,7 +101,7 @@ Shader version: 450
 0:8              0 (const int)
 0:8        move second child to first child (temp 2-component vector of uint)
 0:8          coord: direct index for structure (temp 2-component vector of uint)
-0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:8            Constant:
 0:8              1 (const int)
 0:8          coord: direct index for structure (temp 2-component vector of uint)
@@ -109,8 +109,8 @@ Shader version: 450
 0:8            Constant:
 0:8              1 (const int)
 0:8        move second child to first child (temp 4-component vector of float)
-0:8          b: direct index for structure (smooth temp 4-component vector of float)
-0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:8          b: direct index for structure (temp 4-component vector of float)
+0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:8            Constant:
 0:8              2 (const int)
 0:8          b: direct index for structure (temp 4-component vector of float)
@@ -118,7 +118,7 @@ Shader version: 450
 0:8            Constant:
 0:8              2 (const int)
 0:?   Linker Objects
-0:?     '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:?     '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:?     'd' (layout(location=0 ) in 4-component vector of float)
 0:?     'm[0]' (layout(location=1 ) in 4-component vector of float)
 0:?     'm[1]' (layout(location=2 ) in 4-component vector of float)
@@ -225,7 +225,7 @@ Shader version: 450
 0:?             'e' (temp 4-component vector of float)
 0:8        move second child to first child (temp 2-element array of 4-component vector of float)
 0:8          m: direct index for structure (temp 2-element array of 4-component vector of float)
-0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:8            Constant:
 0:8              0 (const int)
 0:8          m: direct index for structure (temp 2-element array of 4-component vector of float)
@@ -234,7 +234,7 @@ Shader version: 450
 0:8              0 (const int)
 0:8        move second child to first child (temp 2-component vector of uint)
 0:8          coord: direct index for structure (temp 2-component vector of uint)
-0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:8            Constant:
 0:8              1 (const int)
 0:8          coord: direct index for structure (temp 2-component vector of uint)
@@ -242,8 +242,8 @@ Shader version: 450
 0:8            Constant:
 0:8              1 (const int)
 0:8        move second child to first child (temp 4-component vector of float)
-0:8          b: direct index for structure (smooth temp 4-component vector of float)
-0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:8          b: direct index for structure (temp 4-component vector of float)
+0:8            '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:8            Constant:
 0:8              2 (const int)
 0:8          b: direct index for structure (temp 4-component vector of float)
@@ -251,7 +251,7 @@ Shader version: 450
 0:8            Constant:
 0:8              2 (const int)
 0:?   Linker Objects
-0:?     '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, smooth temp 4-component vector of float b})
+0:?     '@entryPointOutput' (out structure Position{temp 2-element array of 4-component vector of float m, temp 2-component vector of uint coord, temp 4-component vector of float b})
 0:?     'd' (layout(location=0 ) in 4-component vector of float)
 0:?     'm[0]' (layout(location=1 ) in 4-component vector of float)
 0:?     'm[1]' (layout(location=2 ) in 4-component vector of float)
diff --git a/Test/hlsl.structIoFourWay.frag b/Test/hlsl.structIoFourWay.frag
new file mode 100755
index 00000000..bca135e7
--- /dev/null
+++ b/Test/hlsl.structIoFourWay.frag
@@ -0,0 +1,18 @@
+struct T {
+    float f : packoffset(c4.y);    // artificial, but validates all different treatments: uniform offset
+    centroid float g;              // interpolant input
+    float d: SV_DepthGreaterEqual; // fragment output
+    float4 normal;                 // non-IO
+};
+
+T s;  // loose uniform
+
+cbuffer buff {
+    T t : packoffset(c5.z);
+};
+
+T main(T t : myInput) : SV_Target0
+{
+    T local;
+    return local;
+}
diff --git a/glslang/Include/Types.h b/glslang/Include/Types.h
index a1ba5423..605f5f16 100644
--- a/glslang/Include/Types.h
+++ b/glslang/Include/Types.h
@@ -410,6 +410,13 @@ public:
     }
 
     void clearInterstage()
+    {
+        clearInterpolation();
+        patch = false;
+        sample = false;
+    }
+
+    void clearInterpolation()
     {
         centroid     = false;
         smooth       = false;
@@ -418,8 +425,6 @@ public:
 #ifdef AMD_EXTENSIONS
         explicitInterp = false;
 #endif
-        patch        = false;
-        sample       = false;
     }
 
     void clearMemory()
diff --git a/glslang/Include/revision.h b/glslang/Include/revision.h
index a46f0451..e67629f8 100644
--- a/glslang/Include/revision.h
+++ b/glslang/Include/revision.h
@@ -2,5 +2,5 @@
 // For the version, it uses the latest git tag followed by the number of commits.
 // For the date, it uses the current date (when then script is run).
 
-#define GLSLANG_REVISION "Overload400-PrecQual.1791"
-#define GLSLANG_DATE "05-Feb-2017"
+#define GLSLANG_REVISION "Overload400-PrecQual.1792"
+#define GLSLANG_DATE "06-Feb-2017"
diff --git a/glslang/MachineIndependent/ParseContextBase.cpp b/glslang/MachineIndependent/ParseContextBase.cpp
index 2f5401c1..946eb715 100644
--- a/glslang/MachineIndependent/ParseContextBase.cpp
+++ b/glslang/MachineIndependent/ParseContextBase.cpp
@@ -530,7 +530,7 @@ void TParseContextBase::parseSwizzleSelector(const TSourceLoc& loc, const TStrin
 // Make the passed-in variable information become a member of the
 // global uniform block.  If this doesn't exist yet, make it.
 //
-void TParseContextBase::growGlobalUniformBlock(TSourceLoc& loc, TType& memberType, TString& memberName)
+void TParseContextBase::growGlobalUniformBlock(TSourceLoc& loc, TType& memberType, TString& memberName, TTypeList* typeList)
 {
     // make the global block, if not yet made
     if (globalUniformBlock == nullptr) {
@@ -548,6 +548,8 @@ void TParseContextBase::growGlobalUniformBlock(TSourceLoc& loc, TType& memberTyp
     TType* type = new TType;
     type->shallowCopy(memberType);
     type->setFieldName(memberName);
+    if (typeList)
+        type->setStruct(typeList);
     TTypeLoc typeLoc = {type, loc};
     globalUniformBlock->getType().getWritableStruct()->push_back(typeLoc);
 }
diff --git a/glslang/MachineIndependent/ParseHelper.h b/glslang/MachineIndependent/ParseHelper.h
index e77089aa..ff4a3945 100644
--- a/glslang/MachineIndependent/ParseHelper.h
+++ b/glslang/MachineIndependent/ParseHelper.h
@@ -139,7 +139,7 @@ public:
     // TODO: This could perhaps get its own object, but the current design doesn't work
     // yet when new uniform variables are declared between function definitions, so
     // this is pending getting a fully functional design.
-    virtual void growGlobalUniformBlock(TSourceLoc&, TType&, TString& memberName);
+    virtual void growGlobalUniformBlock(TSourceLoc&, TType&, TString& memberName, TTypeList* typeList = nullptr);
     virtual bool insertGlobalUniformBlock();
 
     virtual bool lValueErrorCheck(const TSourceLoc&, const char* op, TIntermTyped*);
diff --git a/gtests/Hlsl.FromFile.cpp b/gtests/Hlsl.FromFile.cpp
index 74a4f5d2..701863ac 100644
--- a/gtests/Hlsl.FromFile.cpp
+++ b/gtests/Hlsl.FromFile.cpp
@@ -219,6 +219,7 @@ INSTANTIATE_TEST_CASE_P(
         {"hlsl.structarray.flatten.frag", "main"},
         {"hlsl.structarray.flatten.geom", "main"},
         {"hlsl.structin.vert", "main"},
+        {"hlsl.structIoFourWay.frag", "main"},
         {"hlsl.intrinsics.vert", "VertexShaderFunction"},
         {"hlsl.matType.frag", "PixelShaderFunction"},
         {"hlsl.matType.bool.frag", "main"},
diff --git a/hlsl/hlslParseHelper.cpp b/hlsl/hlslParseHelper.cpp
index 1f7bd6ab..280ab93c 100755
--- a/hlsl/hlslParseHelper.cpp
+++ b/hlsl/hlslParseHelper.cpp
@@ -159,10 +159,16 @@ bool HlslParseContext::shouldConvertLValue(const TIntermNode* node) const
     return false;
 }
 
-void HlslParseContext::growGlobalUniformBlock(TSourceLoc& loc, TType& memberType, TString& memberName)
+void HlslParseContext::growGlobalUniformBlock(TSourceLoc& loc, TType& memberType, TString& memberName, TTypeList* newTypeList)
 {
+    newTypeList = nullptr;
     correctUniform(memberType.getQualifier());
-    TParseContextBase::growGlobalUniformBlock(loc, memberType, memberName);
+    if (memberType.isStruct()) {
+        auto it = ioTypeMap.find(memberType.getStruct());
+        if (it != ioTypeMap.end() && it->second.uniform)
+            newTypeList = it->second.uniform;
+    }
+    TParseContextBase::growGlobalUniformBlock(loc, memberType, memberName, newTypeList);
 }
 
 //
@@ -5381,8 +5387,12 @@ void HlslParseContext::declareStruct(const TSourceLoc& loc, TString& structName,
     }
     if (newLists.uniform == nullptr &&
         newLists.input   == nullptr &&
-        newLists.output  == nullptr)
+        newLists.output  == nullptr) {
+        // Won't do any IO caching, clear up the type and get out now.
+        for (auto member = type.getStruct()->begin(); member != type.getStruct()->end(); ++member)
+            clearUniformInputOutput(member->type->getQualifier());
         return;
+    }
 
     // We have IO involved.
 
@@ -5471,6 +5481,11 @@ TIntermNode* HlslParseContext::declareVariable(const TSourceLoc& loc, TString& i
     case EvqUniform:
     case EvqBuffer:
         correctUniform(type.getQualifier());
+        if (type.isStruct()) {
+            auto it = ioTypeMap.find(type.getStruct());
+            if (it != ioTypeMap.end())
+                type.setStruct(it->second.uniform);
+        }
         break;
     default:
         break;
@@ -6011,6 +6026,22 @@ void HlslParseContext::declareBlock(const TSourceLoc& loc, TType& type, const TS
 {
     assert(type.getWritableStruct() != nullptr);
 
+    // Clean up top-level decorations that don't belong.
+    switch (type.getQualifier().storage) {
+    case EvqUniform:
+    case EvqBuffer:
+        correctUniform(type.getQualifier());
+        break;
+    case EvqVaryingIn:
+        correctInput(type.getQualifier());
+        break;
+    case EvqVaryingOut:
+        correctOutput(type.getQualifier());
+        break;
+    default:
+        break;
+    }
+
     TTypeList& typeList = *type.getWritableStruct();
     // fix and check for member storage qualifiers and types that don't belong within a block
     for (unsigned int member = 0; member < typeList.size(); ++member) {
@@ -6019,6 +6050,31 @@ void HlslParseContext::declareBlock(const TSourceLoc& loc, TType& type, const TS
         const TSourceLoc& memberLoc = typeList[member].loc;
         globalQualifierFix(memberLoc, memberQualifier);
         memberQualifier.storage = type.getQualifier().storage;
+
+        if (memberType.isStruct()) {
+            // clean up and pick up the right set of decorations
+            auto it = ioTypeMap.find(memberType.getStruct());
+            switch (type.getQualifier().storage) {
+            case EvqUniform:
+            case EvqBuffer:
+                correctUniform(type.getQualifier());
+                if (it != ioTypeMap.end() && it->second.uniform)
+                    type.setStruct(it->second.uniform);
+                break;
+            case EvqVaryingIn:
+                correctInput(type.getQualifier());
+                if (it != ioTypeMap.end() && it->second.input)
+                    type.setStruct(it->second.input);
+                break;
+            case EvqVaryingOut:
+                correctOutput(type.getQualifier());
+                if (it != ioTypeMap.end() && it->second.output)
+                    type.setStruct(it->second.output);
+                break;
+            default:
+                break;
+            }
+        }
     }
 
     // This might be a redeclaration of a built-in block.  If so, redeclareBuiltinBlock() will
@@ -6602,15 +6658,16 @@ bool HlslParseContext::isInputBuiltIn(const TQualifier& qualifier) const
     }
 }
 
-// Return true if there are decorations to preserve for input-like storage,
-// except for builtIn.
+// Return true if there are decorations to preserve for input-like storage.
 bool HlslParseContext::hasInput(const TQualifier& qualifier) const
 {
     if (qualifier.hasAnyLocation())
         return true;
 
-    if (language != EShLangVertex && language != EShLangCompute &&
-        (qualifier.isInterpolation() || qualifier.isAuxiliary()))
+    if (language == EShLangFragment && (qualifier.isInterpolation() || qualifier.centroid || qualifier.sample))
+        return true;
+
+    if (language == EShLangTessEvaluation && qualifier.patch)
         return true;
 
     if (isInputBuiltIn(qualifier))
@@ -6630,6 +6687,8 @@ bool HlslParseContext::isOutputBuiltIn(const TQualifier& qualifier) const
     case EbvCullDistance:
         return language != EShLangFragment && language != EShLangCompute;
     case EbvFragDepth:
+    case EbvFragDepthGreater:
+    case EbvFragDepthLesser:
     case EbvSampleMask:
         return language == EShLangFragment;
     case EbvLayer:
@@ -6645,15 +6704,16 @@ bool HlslParseContext::isOutputBuiltIn(const TQualifier& qualifier) const
     }
 }
 
-// Return true if there are decorations to preserve for output-like storage,
-// except for builtIn.
+// Return true if there are decorations to preserve for output-like storage.
 bool HlslParseContext::hasOutput(const TQualifier& qualifier) const
 {
     if (qualifier.hasAnyLocation())
         return true;
 
-    if (language != EShLangFragment && language != EShLangCompute &&
-        (qualifier.hasXfb() || qualifier.isInterpolation() || qualifier.isAuxiliary()))
+    if (language != EShLangFragment && language != EShLangCompute && qualifier.hasXfb())
+        return true;
+
+    if (language == EShLangTessControl && qualifier.patch)
         return true;
 
     if (language == EShLangGeometry && qualifier.hasStream())
@@ -6671,6 +6731,13 @@ void HlslParseContext::correctInput(TQualifier& qualifier)
     clearUniform(qualifier);
     if (language == EShLangVertex)
         qualifier.clearInterstage();
+    if (language != EShLangTessEvaluation)
+        qualifier.patch = false;
+    if (language != EShLangFragment) {
+        qualifier.clearInterpolation();
+        qualifier.sample = false;
+    }
+
     qualifier.clearStreamLayout();
     qualifier.clearXfbLayout();
 
@@ -6688,6 +6755,8 @@ void HlslParseContext::correctOutput(TQualifier& qualifier)
         qualifier.clearStreamLayout();
     if (language == EShLangFragment)
         qualifier.clearXfbLayout();
+    if (language != EShLangTessControl)
+        qualifier.patch = false;
 
     switch (qualifier.builtIn) {
     case EbvFragDepthGreater:
diff --git a/hlsl/hlslParseHelper.h b/hlsl/hlslParseHelper.h
index d0bfcdf3..4caa73c5 100755
--- a/hlsl/hlslParseHelper.h
+++ b/hlsl/hlslParseHelper.h
@@ -161,7 +161,7 @@ public:
     void pushSwitchSequence(TIntermSequence* sequence) { switchSequenceStack.push_back(sequence); }
     void popSwitchSequence() { switchSequenceStack.pop_back(); }
 
-    virtual void growGlobalUniformBlock(TSourceLoc&, TType&, TString& memberName) override;
+    virtual void growGlobalUniformBlock(TSourceLoc&, TType&, TString& memberName, TTypeList* typeList = nullptr) override;
 
     // Apply L-value conversions.  E.g, turning a write to a RWTexture into an ImageStore.
     TIntermTyped* handleLvalue(const TSourceLoc&, const char* op, TIntermTyped* node);