diff --git a/Test/baseResults/hlsl.intrinsics.negative.frag.out b/Test/baseResults/hlsl.intrinsics.negative.frag.out
index e27505432..0325c1c49 100644
--- a/Test/baseResults/hlsl.intrinsics.negative.frag.out
+++ b/Test/baseResults/hlsl.intrinsics.negative.frag.out
@@ -1,6 +1,10 @@
 hlsl.intrinsics.negative.frag
 ERROR: 0:10: 'determinant' : no matching overloaded function found 
 ERROR: 0:12: 'f32tof16' : unimplemented intrinsic: handle natively 
+ERROR: 0:23: 'length' : ambiguous best function under implicit type conversion 
+ERROR: 0:25: 'normalize' : ambiguous best function under implicit type conversion 
+ERROR: 0:26: 'reflect' : ambiguous best function under implicit type conversion 
+ERROR: 0:27: 'refract' : ambiguous best function under implicit type conversion 
 ERROR: 0:28: 'refract' : no matching overloaded function found 
 ERROR: 0:30: 'transpose' : no matching overloaded function found 
 ERROR: 0:39: 'GetRenderTargetSamplePosition' : no matching overloaded function found 
@@ -59,7 +63,7 @@ ERROR: 0:133: 'normalize' : no matching overloaded function found
 ERROR: 0:133: 'reflect' : no matching overloaded function found 
 ERROR: 0:133: 'refract' : no matching overloaded function found 
 ERROR: 0:133: 'reversebits' : no matching overloaded function found 
-ERROR: 60 compilation errors.  No code generated.
+ERROR: 64 compilation errors.  No code generated.
 
 
 Shader version: 450
diff --git a/Test/baseResults/hlsl.params.default.frag.out b/Test/baseResults/hlsl.params.default.frag.out
new file mode 100644
index 000000000..3c62c5db5
--- /dev/null
+++ b/Test/baseResults/hlsl.params.default.frag.out
@@ -0,0 +1,639 @@
+hlsl.params.default.frag
+Shader version: 450
+gl_FragCoord origin is upper left
+0:? Sequence
+0:9  Function Definition: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:9    Function Parameters: 
+0:9      'p0' (in 4-component vector of int)
+0:9      'b1' (in bool)
+0:9      'b2' (in bool)
+0:?     Sequence
+0:10      Branch: Return with expression
+0:10        'p0' (in 4-component vector of int)
+0:17  Function Definition: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:17    Function Parameters: 
+0:17      'p0' (in 4-component vector of int)
+0:17      'p1' (in 4-component vector of int)
+0:17      'p2' (in 2-element array of int)
+0:17      'p3' (in int)
+0:?     Sequence
+0:18      Branch: Return with expression
+0:18        add (temp 4-component vector of int)
+0:18          add (temp 4-component vector of int)
+0:18            add (temp 4-component vector of int)
+0:18              'p0' (in 4-component vector of int)
+0:18              'p1' (in 4-component vector of int)
+0:18            direct index (temp int)
+0:18              'p2' (in 2-element array of int)
+0:18              Constant:
+0:18                0 (const int)
+0:18          'p3' (in int)
+0:23  Function Definition: fn2(vi4;i1; (temp 4-component vector of int)
+0:23    Function Parameters: 
+0:23      'p0' (in 4-component vector of int)
+0:23      'x' (in int)
+0:?     Sequence
+0:24      Branch: Return with expression
+0:?         Constant:
+0:?           10 (const int)
+0:?           11 (const int)
+0:?           12 (const int)
+0:?           13 (const int)
+0:28  Function Definition: fn2(vi4;f1; (temp 4-component vector of int)
+0:28    Function Parameters: 
+0:28      'p0' (in 4-component vector of int)
+0:28      'x' (in float)
+0:?     Sequence
+0:29      Branch: Return with expression
+0:29        add (temp 4-component vector of int)
+0:29          'p0' (in 4-component vector of int)
+0:?           Constant:
+0:?             20 (const int)
+0:?             21 (const int)
+0:?             22 (const int)
+0:?             23 (const int)
+0:32  Function Definition: fn3(i1; (temp void)
+0:32    Function Parameters: 
+0:32      'p0' (in int)
+0:36  Function Definition: main( (temp 4-component vector of int)
+0:36    Function Parameters: 
+0:?     Sequence
+0:37      Sequence
+0:37        move second child to first child (temp 2-element array of int)
+0:37          'myarray' (temp 2-element array of int)
+0:37          Constant:
+0:37            30 (const int)
+0:37            31 (const int)
+0:39      Function Call: fn3(i1; (temp void)
+0:32        Constant:
+0:32          3 (const int)
+0:40      Function Call: fn3(i1; (temp void)
+0:40        Constant:
+0:40          5 (const int)
+0:50      Sequence
+0:50        move second child to first child (temp 4-component vector of int)
+0:?           '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:49          add (temp 4-component vector of int)
+0:47            add (temp 4-component vector of int)
+0:46              add (temp 4-component vector of int)
+0:45                add (temp 4-component vector of int)
+0:44                  add (temp 4-component vector of int)
+0:43                    add (temp 4-component vector of int)
+0:42                      add (temp 4-component vector of int)
+0:42                        Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:42                          Constant:
+0:42                            100 (const int)
+0:42                            100 (const int)
+0:42                            100 (const int)
+0:42                            100 (const int)
+0:?                           Constant:
+0:?                             -1 (const int)
+0:?                             -2 (const int)
+0:?                             -3 (const int)
+0:?                             -4 (const int)
+0:15                          Constant:
+0:15                            1 (const int)
+0:15                            2 (const int)
+0:16                          Constant:
+0:16                            42 (const int)
+0:43                        Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:43                          Constant:
+0:43                            101 (const int)
+0:43                            101 (const int)
+0:43                            101 (const int)
+0:43                            101 (const int)
+0:43                          ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:43                            'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+0:43                            Constant:
+0:43                              0 (const uint)
+0:15                          Constant:
+0:15                            1 (const int)
+0:15                            2 (const int)
+0:16                          Constant:
+0:16                            42 (const int)
+0:44                      Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:44                        Constant:
+0:44                          102 (const int)
+0:44                          102 (const int)
+0:44                          102 (const int)
+0:44                          102 (const int)
+0:44                        ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:44                          'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+0:44                          Constant:
+0:44                            0 (const uint)
+0:44                        'myarray' (temp 2-element array of int)
+0:16                        Constant:
+0:16                          42 (const int)
+0:45                    Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:45                      Constant:
+0:45                        103 (const int)
+0:45                        103 (const int)
+0:45                        103 (const int)
+0:45                        103 (const int)
+0:45                      ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:45                        'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+0:45                        Constant:
+0:45                          0 (const uint)
+0:45                      'myarray' (temp 2-element array of int)
+0:45                      Constant:
+0:45                        99 (const int)
+0:46                  Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:46                    Constant:
+0:46                      104 (const int)
+0:46                      104 (const int)
+0:46                      104 (const int)
+0:46                      104 (const int)
+0:46                    Constant:
+0:46                      false (const bool)
+0:9                    Constant:
+0:9                      false (const bool)
+0:47                Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:47                  Constant:
+0:47                    105 (const int)
+0:47                    105 (const int)
+0:47                    105 (const int)
+0:47                    105 (const int)
+0:47                  Constant:
+0:47                    false (const bool)
+0:47                  Constant:
+0:47                    true (const bool)
+0:49              Function Call: fn2(vi4;f1; (temp 4-component vector of int)
+0:49                Constant:
+0:49                  110 (const int)
+0:49                  110 (const int)
+0:49                  110 (const int)
+0:49                  110 (const int)
+0:49                Constant:
+0:49                  11.110000
+0:50            Function Call: fn2(vi4;i1; (temp 4-component vector of int)
+0:50              Constant:
+0:50                111 (const int)
+0:50                111 (const int)
+0:50                111 (const int)
+0:50                111 (const int)
+0:50              Constant:
+0:50                12 (const int)
+0:50        Branch: Return
+0:?   Linker Objects
+0:?     '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:?     'cia' (const int)
+0:?       -4 (const int)
+0:?     'cib' (const int)
+0:?       -42 (const int)
+0:?     'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+
+
+Linked fragment stage:
+
+
+Shader version: 450
+gl_FragCoord origin is upper left
+0:? Sequence
+0:9  Function Definition: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:9    Function Parameters: 
+0:9      'p0' (in 4-component vector of int)
+0:9      'b1' (in bool)
+0:9      'b2' (in bool)
+0:?     Sequence
+0:10      Branch: Return with expression
+0:10        'p0' (in 4-component vector of int)
+0:17  Function Definition: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:17    Function Parameters: 
+0:17      'p0' (in 4-component vector of int)
+0:17      'p1' (in 4-component vector of int)
+0:17      'p2' (in 2-element array of int)
+0:17      'p3' (in int)
+0:?     Sequence
+0:18      Branch: Return with expression
+0:18        add (temp 4-component vector of int)
+0:18          add (temp 4-component vector of int)
+0:18            add (temp 4-component vector of int)
+0:18              'p0' (in 4-component vector of int)
+0:18              'p1' (in 4-component vector of int)
+0:18            direct index (temp int)
+0:18              'p2' (in 2-element array of int)
+0:18              Constant:
+0:18                0 (const int)
+0:18          'p3' (in int)
+0:23  Function Definition: fn2(vi4;i1; (temp 4-component vector of int)
+0:23    Function Parameters: 
+0:23      'p0' (in 4-component vector of int)
+0:23      'x' (in int)
+0:?     Sequence
+0:24      Branch: Return with expression
+0:?         Constant:
+0:?           10 (const int)
+0:?           11 (const int)
+0:?           12 (const int)
+0:?           13 (const int)
+0:28  Function Definition: fn2(vi4;f1; (temp 4-component vector of int)
+0:28    Function Parameters: 
+0:28      'p0' (in 4-component vector of int)
+0:28      'x' (in float)
+0:?     Sequence
+0:29      Branch: Return with expression
+0:29        add (temp 4-component vector of int)
+0:29          'p0' (in 4-component vector of int)
+0:?           Constant:
+0:?             20 (const int)
+0:?             21 (const int)
+0:?             22 (const int)
+0:?             23 (const int)
+0:32  Function Definition: fn3(i1; (temp void)
+0:32    Function Parameters: 
+0:32      'p0' (in int)
+0:36  Function Definition: main( (temp 4-component vector of int)
+0:36    Function Parameters: 
+0:?     Sequence
+0:37      Sequence
+0:37        move second child to first child (temp 2-element array of int)
+0:37          'myarray' (temp 2-element array of int)
+0:37          Constant:
+0:37            30 (const int)
+0:37            31 (const int)
+0:39      Function Call: fn3(i1; (temp void)
+0:32        Constant:
+0:32          3 (const int)
+0:40      Function Call: fn3(i1; (temp void)
+0:40        Constant:
+0:40          5 (const int)
+0:50      Sequence
+0:50        move second child to first child (temp 4-component vector of int)
+0:?           '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:49          add (temp 4-component vector of int)
+0:47            add (temp 4-component vector of int)
+0:46              add (temp 4-component vector of int)
+0:45                add (temp 4-component vector of int)
+0:44                  add (temp 4-component vector of int)
+0:43                    add (temp 4-component vector of int)
+0:42                      add (temp 4-component vector of int)
+0:42                        Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:42                          Constant:
+0:42                            100 (const int)
+0:42                            100 (const int)
+0:42                            100 (const int)
+0:42                            100 (const int)
+0:?                           Constant:
+0:?                             -1 (const int)
+0:?                             -2 (const int)
+0:?                             -3 (const int)
+0:?                             -4 (const int)
+0:15                          Constant:
+0:15                            1 (const int)
+0:15                            2 (const int)
+0:16                          Constant:
+0:16                            42 (const int)
+0:43                        Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:43                          Constant:
+0:43                            101 (const int)
+0:43                            101 (const int)
+0:43                            101 (const int)
+0:43                            101 (const int)
+0:43                          ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:43                            'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+0:43                            Constant:
+0:43                              0 (const uint)
+0:15                          Constant:
+0:15                            1 (const int)
+0:15                            2 (const int)
+0:16                          Constant:
+0:16                            42 (const int)
+0:44                      Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:44                        Constant:
+0:44                          102 (const int)
+0:44                          102 (const int)
+0:44                          102 (const int)
+0:44                          102 (const int)
+0:44                        ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:44                          'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+0:44                          Constant:
+0:44                            0 (const uint)
+0:44                        'myarray' (temp 2-element array of int)
+0:16                        Constant:
+0:16                          42 (const int)
+0:45                    Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:45                      Constant:
+0:45                        103 (const int)
+0:45                        103 (const int)
+0:45                        103 (const int)
+0:45                        103 (const int)
+0:45                      ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:45                        'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+0:45                        Constant:
+0:45                          0 (const uint)
+0:45                      'myarray' (temp 2-element array of int)
+0:45                      Constant:
+0:45                        99 (const int)
+0:46                  Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:46                    Constant:
+0:46                      104 (const int)
+0:46                      104 (const int)
+0:46                      104 (const int)
+0:46                      104 (const int)
+0:46                    Constant:
+0:46                      false (const bool)
+0:9                    Constant:
+0:9                      false (const bool)
+0:47                Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:47                  Constant:
+0:47                    105 (const int)
+0:47                    105 (const int)
+0:47                    105 (const int)
+0:47                    105 (const int)
+0:47                  Constant:
+0:47                    false (const bool)
+0:47                  Constant:
+0:47                    true (const bool)
+0:49              Function Call: fn2(vi4;f1; (temp 4-component vector of int)
+0:49                Constant:
+0:49                  110 (const int)
+0:49                  110 (const int)
+0:49                  110 (const int)
+0:49                  110 (const int)
+0:49                Constant:
+0:49                  11.110000
+0:50            Function Call: fn2(vi4;i1; (temp 4-component vector of int)
+0:50              Constant:
+0:50                111 (const int)
+0:50                111 (const int)
+0:50                111 (const int)
+0:50                111 (const int)
+0:50              Constant:
+0:50                12 (const int)
+0:50        Branch: Return
+0:?   Linker Objects
+0:?     '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:?     'cia' (const int)
+0:?       -4 (const int)
+0:?     'cib' (const int)
+0:?       -42 (const int)
+0:?     'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4})
+
+// Module Version 10000
+// Generated by (magic number): 80001
+// Id's are bound by 173
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 88
+                              ExecutionMode 4 OriginUpperLeft
+                              Name 4  "main"
+                              Name 15  "fn1(vi4;b1;b1;"
+                              Name 12  "p0"
+                              Name 13  "b1"
+                              Name 14  "b2"
+                              Name 27  "fn1(vi4;vi4;i1[2];i1;"
+                              Name 23  "p0"
+                              Name 24  "p1"
+                              Name 25  "p2"
+                              Name 26  "p3"
+                              Name 32  "fn2(vi4;i1;"
+                              Name 30  "p0"
+                              Name 31  "x"
+                              Name 39  "fn2(vi4;f1;"
+                              Name 37  "p0"
+                              Name 38  "x"
+                              Name 43  "fn3(i1;"
+                              Name 42  "p0"
+                              Name 77  "myarray"
+                              Name 82  "param"
+                              Name 85  "param"
+                              Name 88  "@entryPointOutput"
+                              Name 100  "param"
+                              Name 101  "param"
+                              Name 102  "param"
+                              Name 103  "param"
+                              Name 107  "$Global"
+                              MemberName 107($Global) 0  "ui4"
+                              Name 109  ""
+                              Name 110  "param"
+                              Name 111  "param"
+                              Name 115  "param"
+                              Name 116  "param"
+                              Name 121  "param"
+                              Name 122  "param"
+                              Name 125  "param"
+                              Name 127  "param"
+                              Name 133  "param"
+                              Name 134  "param"
+                              Name 137  "param"
+                              Name 139  "param"
+                              Name 145  "param"
+                              Name 146  "param"
+                              Name 147  "param"
+                              Name 153  "param"
+                              Name 154  "param"
+                              Name 155  "param"
+                              Name 161  "param"
+                              Name 162  "param"
+                              Name 167  "param"
+                              Name 168  "param"
+                              Decorate 88(@entryPointOutput) Location 0
+                              MemberDecorate 107($Global) 0 Offset 0
+                              Decorate 107($Global) Block
+                              Decorate 109 DescriptorSet 0
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeInt 32 1
+               7:             TypeVector 6(int) 4
+               8:             TypePointer Function 7(ivec4)
+               9:             TypeBool
+              10:             TypePointer Function 9(bool)
+              11:             TypeFunction 7(ivec4) 8(ptr) 10(ptr) 10(ptr)
+              17:             TypeInt 32 0
+              18:     17(int) Constant 2
+              19:             TypeArray 6(int) 18
+              20:             TypePointer Function 19
+              21:             TypePointer Function 6(int)
+              22:             TypeFunction 7(ivec4) 8(ptr) 8(ptr) 20(ptr) 21(ptr)
+              29:             TypeFunction 7(ivec4) 8(ptr) 21(ptr)
+              34:             TypeFloat 32
+              35:             TypePointer Function 34(float)
+              36:             TypeFunction 7(ivec4) 8(ptr) 35(ptr)
+              41:             TypeFunction 2 21(ptr)
+              51:      6(int) Constant 0
+              61:      6(int) Constant 10
+              62:      6(int) Constant 11
+              63:      6(int) Constant 12
+              64:      6(int) Constant 13
+              65:    7(ivec4) ConstantComposite 61 62 63 64
+              69:      6(int) Constant 20
+              70:      6(int) Constant 21
+              71:      6(int) Constant 22
+              72:      6(int) Constant 23
+              73:    7(ivec4) ConstantComposite 69 70 71 72
+              78:      6(int) Constant 30
+              79:      6(int) Constant 31
+              80:          19 ConstantComposite 78 79
+              81:      6(int) Constant 3
+              84:      6(int) Constant 5
+              87:             TypePointer Output 7(ivec4)
+88(@entryPointOutput):     87(ptr) Variable Output
+              89:      6(int) Constant 100
+              90:    7(ivec4) ConstantComposite 89 89 89 89
+              91:      6(int) Constant 4294967295
+              92:      6(int) Constant 4294967294
+              93:      6(int) Constant 4294967293
+              94:      6(int) Constant 4294967292
+              95:    7(ivec4) ConstantComposite 91 92 93 94
+              96:      6(int) Constant 1
+              97:      6(int) Constant 2
+              98:          19 ConstantComposite 96 97
+              99:      6(int) Constant 42
+             105:      6(int) Constant 101
+             106:    7(ivec4) ConstantComposite 105 105 105 105
+    107($Global):             TypeStruct 7(ivec4)
+             108:             TypePointer Uniform 107($Global)
+             109:    108(ptr) Variable Uniform
+             112:             TypePointer Uniform 7(ivec4)
+             119:      6(int) Constant 102
+             120:    7(ivec4) ConstantComposite 119 119 119 119
+             130:      6(int) Constant 103
+             131:    7(ivec4) ConstantComposite 130 130 130 130
+             132:      6(int) Constant 99
+             142:      6(int) Constant 104
+             143:    7(ivec4) ConstantComposite 142 142 142 142
+             144:     9(bool) ConstantFalse
+             150:      6(int) Constant 105
+             151:    7(ivec4) ConstantComposite 150 150 150 150
+             152:     9(bool) ConstantTrue
+             158:      6(int) Constant 110
+             159:    7(ivec4) ConstantComposite 158 158 158 158
+             160:   34(float) Constant 1093780111
+             165:      6(int) Constant 111
+             166:    7(ivec4) ConstantComposite 165 165 165 165
+             172:      6(int) Constant 4294967254
+         4(main):           2 Function None 3
+               5:             Label
+     77(myarray):     20(ptr) Variable Function
+       82(param):     21(ptr) Variable Function
+       85(param):     21(ptr) Variable Function
+      100(param):      8(ptr) Variable Function
+      101(param):      8(ptr) Variable Function
+      102(param):     20(ptr) Variable Function
+      103(param):     21(ptr) Variable Function
+      110(param):      8(ptr) Variable Function
+      111(param):      8(ptr) Variable Function
+      115(param):     20(ptr) Variable Function
+      116(param):     21(ptr) Variable Function
+      121(param):      8(ptr) Variable Function
+      122(param):      8(ptr) Variable Function
+      125(param):     20(ptr) Variable Function
+      127(param):     21(ptr) Variable Function
+      133(param):      8(ptr) Variable Function
+      134(param):      8(ptr) Variable Function
+      137(param):     20(ptr) Variable Function
+      139(param):     21(ptr) Variable Function
+      145(param):      8(ptr) Variable Function
+      146(param):     10(ptr) Variable Function
+      147(param):     10(ptr) Variable Function
+      153(param):      8(ptr) Variable Function
+      154(param):     10(ptr) Variable Function
+      155(param):     10(ptr) Variable Function
+      161(param):      8(ptr) Variable Function
+      162(param):     35(ptr) Variable Function
+      167(param):      8(ptr) Variable Function
+      168(param):     21(ptr) Variable Function
+                              Store 77(myarray) 80
+                              Store 82(param) 81
+              83:           2 FunctionCall 43(fn3(i1;) 82(param)
+                              Store 85(param) 84
+              86:           2 FunctionCall 43(fn3(i1;) 85(param)
+                              Store 100(param) 90
+                              Store 101(param) 95
+                              Store 102(param) 98
+                              Store 103(param) 99
+             104:    7(ivec4) FunctionCall 27(fn1(vi4;vi4;i1[2];i1;) 100(param) 101(param) 102(param) 103(param)
+                              Store 110(param) 106
+             113:    112(ptr) AccessChain 109 51
+             114:    7(ivec4) Load 113
+                              Store 111(param) 114
+                              Store 115(param) 98
+                              Store 116(param) 99
+             117:    7(ivec4) FunctionCall 27(fn1(vi4;vi4;i1[2];i1;) 110(param) 111(param) 115(param) 116(param)
+             118:    7(ivec4) IAdd 104 117
+                              Store 121(param) 120
+             123:    112(ptr) AccessChain 109 51
+             124:    7(ivec4) Load 123
+                              Store 122(param) 124
+             126:          19 Load 77(myarray)
+                              Store 125(param) 126
+                              Store 127(param) 99
+             128:    7(ivec4) FunctionCall 27(fn1(vi4;vi4;i1[2];i1;) 121(param) 122(param) 125(param) 127(param)
+             129:    7(ivec4) IAdd 118 128
+                              Store 133(param) 131
+             135:    112(ptr) AccessChain 109 51
+             136:    7(ivec4) Load 135
+                              Store 134(param) 136
+             138:          19 Load 77(myarray)
+                              Store 137(param) 138
+                              Store 139(param) 132
+             140:    7(ivec4) FunctionCall 27(fn1(vi4;vi4;i1[2];i1;) 133(param) 134(param) 137(param) 139(param)
+             141:    7(ivec4) IAdd 129 140
+                              Store 145(param) 143
+                              Store 146(param) 144
+                              Store 147(param) 144
+             148:    7(ivec4) FunctionCall 15(fn1(vi4;b1;b1;) 145(param) 146(param) 147(param)
+             149:    7(ivec4) IAdd 141 148
+                              Store 153(param) 151
+                              Store 154(param) 144
+                              Store 155(param) 152
+             156:    7(ivec4) FunctionCall 15(fn1(vi4;b1;b1;) 153(param) 154(param) 155(param)
+             157:    7(ivec4) IAdd 149 156
+                              Store 161(param) 159
+                              Store 162(param) 160
+             163:    7(ivec4) FunctionCall 39(fn2(vi4;f1;) 161(param) 162(param)
+             164:    7(ivec4) IAdd 157 163
+                              Store 167(param) 166
+                              Store 168(param) 63
+             169:    7(ivec4) FunctionCall 32(fn2(vi4;i1;) 167(param) 168(param)
+             170:    7(ivec4) IAdd 164 169
+                              Store 88(@entryPointOutput) 170
+                              Return
+                              FunctionEnd
+15(fn1(vi4;b1;b1;):    7(ivec4) Function None 11
+          12(p0):      8(ptr) FunctionParameter
+          13(b1):     10(ptr) FunctionParameter
+          14(b2):     10(ptr) FunctionParameter
+              16:             Label
+              45:    7(ivec4) Load 12(p0)
+                              ReturnValue 45
+                              FunctionEnd
+27(fn1(vi4;vi4;i1[2];i1;):    7(ivec4) Function None 22
+          23(p0):      8(ptr) FunctionParameter
+          24(p1):      8(ptr) FunctionParameter
+          25(p2):     20(ptr) FunctionParameter
+          26(p3):     21(ptr) FunctionParameter
+              28:             Label
+              48:    7(ivec4) Load 23(p0)
+              49:    7(ivec4) Load 24(p1)
+              50:    7(ivec4) IAdd 48 49
+              52:     21(ptr) AccessChain 25(p2) 51
+              53:      6(int) Load 52
+              54:    7(ivec4) CompositeConstruct 53 53 53 53
+              55:    7(ivec4) IAdd 50 54
+              56:      6(int) Load 26(p3)
+              57:    7(ivec4) CompositeConstruct 56 56 56 56
+              58:    7(ivec4) IAdd 55 57
+                              ReturnValue 58
+                              FunctionEnd
+ 32(fn2(vi4;i1;):    7(ivec4) Function None 29
+          30(p0):      8(ptr) FunctionParameter
+           31(x):     21(ptr) FunctionParameter
+              33:             Label
+                              ReturnValue 65
+                              FunctionEnd
+ 39(fn2(vi4;f1;):    7(ivec4) Function None 36
+          37(p0):      8(ptr) FunctionParameter
+           38(x):     35(ptr) FunctionParameter
+              40:             Label
+              68:    7(ivec4) Load 37(p0)
+              74:    7(ivec4) IAdd 68 73
+                              ReturnValue 74
+                              FunctionEnd
+     43(fn3(i1;):           2 Function None 41
+          42(p0):     21(ptr) FunctionParameter
+              44:             Label
+                              Return
+                              FunctionEnd
diff --git a/Test/baseResults/hlsl.params.default.negative.frag.out b/Test/baseResults/hlsl.params.default.negative.frag.out
new file mode 100644
index 000000000..fa723f3e1
--- /dev/null
+++ b/Test/baseResults/hlsl.params.default.negative.frag.out
@@ -0,0 +1,379 @@
+hlsl.params.default.negative.frag
+ERROR: 0:27: '' : invalid default parameter value 
+ERROR: 0:32: 'p1' : invalid parameter after default value parameters 
+ERROR: 0:40: 'fn1' : ambiguous best function under implicit type conversion 
+ERROR: 0:47: 'fn2' : ambiguous best function under implicit type conversion 
+ERROR: 4 compilation errors.  No code generated.
+
+
+Shader version: 450
+gl_FragCoord origin is upper left
+ERROR: node is still EOpNull!
+0:7  Function Definition: fn1(vi4; (temp 4-component vector of int)
+0:7    Function Parameters: 
+0:7      'p0' (in 4-component vector of int)
+0:?     Sequence
+0:7      Branch: Return with expression
+0:?         Constant:
+0:?           1 (const int)
+0:?           2 (const int)
+0:?           3 (const int)
+0:?           4 (const int)
+0:9  Function Definition: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:9    Function Parameters: 
+0:9      'p0' (in 4-component vector of int)
+0:9      'b1' (in bool)
+0:9      'b2' (in bool)
+0:?     Sequence
+0:10      Branch: Return with expression
+0:10        'p0' (in 4-component vector of int)
+0:17  Function Definition: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:17    Function Parameters: 
+0:17      'p0' (in 4-component vector of int)
+0:17      'p1' (in 4-component vector of int)
+0:17      'p2' (in 2-element array of int)
+0:17      'p3' (in int)
+0:?     Sequence
+0:18      Branch: Return with expression
+0:18        add (temp 4-component vector of int)
+0:18          add (temp 4-component vector of int)
+0:18            add (temp 4-component vector of int)
+0:18              'p0' (in 4-component vector of int)
+0:18              'p1' (in 4-component vector of int)
+0:18            direct index (temp int)
+0:18              'p2' (in 2-element array of int)
+0:18              Constant:
+0:18                0 (const int)
+0:18          'p3' (in int)
+0:23  Function Definition: fn2(vi4;i1; (temp 4-component vector of int)
+0:23    Function Parameters: 
+0:23      'p0' (in 4-component vector of int)
+0:23      'x' (in int)
+0:?     Sequence
+0:24      Branch: Return with expression
+0:?         Constant:
+0:?           10 (const int)
+0:?           11 (const int)
+0:?           12 (const int)
+0:?           13 (const int)
+0:28  Function Definition: fn2(vi4; (temp 4-component vector of int)
+0:28    Function Parameters: 
+0:28      'p0' (in 4-component vector of int)
+0:?     Sequence
+0:29      Branch: Return with expression
+0:29        add (temp 4-component vector of int)
+0:29          'p0' (in 4-component vector of int)
+0:?           Constant:
+0:?             20 (const int)
+0:?             21 (const int)
+0:?             22 (const int)
+0:?             23 (const int)
+0:33  Function Definition: fn3(i1; (temp void)
+0:33    Function Parameters: 
+0:33      'p0' (in int)
+0:37  Function Definition: main( (temp 4-component vector of int)
+0:37    Function Parameters: 
+0:?     Sequence
+0:38      Sequence
+0:38        move second child to first child (temp 2-element array of int)
+0:38          'myarray' (temp 2-element array of int)
+0:38          Constant:
+0:38            30 (const int)
+0:38            31 (const int)
+0:49      Sequence
+0:49        move second child to first child (temp 4-component vector of int)
+0:?           '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:48          add (temp 4-component vector of int)
+0:47            add (temp 4-component vector of int)
+0:45              add (temp 4-component vector of int)
+0:44                add (temp 4-component vector of int)
+0:43                  add (temp 4-component vector of int)
+0:42                    add (temp 4-component vector of int)
+0:41                      add (temp 4-component vector of int)
+0:40                        add (temp 4-component vector of int)
+0:40                          Function Call: fn1(vi4; (temp 4-component vector of int)
+0:40                            Constant:
+0:40                              100 (const int)
+0:40                              100 (const int)
+0:40                              100 (const int)
+0:40                              100 (const int)
+0:41                          Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:41                            Constant:
+0:41                              101 (const int)
+0:41                              101 (const int)
+0:41                              101 (const int)
+0:41                              101 (const int)
+0:41                            ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:41                              'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+0:41                              Constant:
+0:41                                0 (const uint)
+0:15                            Constant:
+0:15                              1 (const int)
+0:15                              2 (const int)
+0:16                            Constant:
+0:16                              42 (const int)
+0:42                        Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:42                          Constant:
+0:42                            102 (const int)
+0:42                            102 (const int)
+0:42                            102 (const int)
+0:42                            102 (const int)
+0:42                          ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:42                            'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+0:42                            Constant:
+0:42                              0 (const uint)
+0:42                          'myarray' (temp 2-element array of int)
+0:16                          Constant:
+0:16                            42 (const int)
+0:43                      Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:43                        Constant:
+0:43                          103 (const int)
+0:43                          103 (const int)
+0:43                          103 (const int)
+0:43                          103 (const int)
+0:43                        ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:43                          'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+0:43                          Constant:
+0:43                            0 (const uint)
+0:43                        'myarray' (temp 2-element array of int)
+0:43                        Constant:
+0:43                          99 (const int)
+0:44                    Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:44                      Constant:
+0:44                        104 (const int)
+0:44                        104 (const int)
+0:44                        104 (const int)
+0:44                        104 (const int)
+0:44                      Constant:
+0:44                        false (const bool)
+0:9                      Constant:
+0:9                        false (const bool)
+0:45                  Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:45                    Constant:
+0:45                      105 (const int)
+0:45                      105 (const int)
+0:45                      105 (const int)
+0:45                      105 (const int)
+0:45                    Constant:
+0:45                      false (const bool)
+0:45                    Constant:
+0:45                      true (const bool)
+0:47                Function Call: fn2(vi4; (temp 4-component vector of int)
+0:47                  Constant:
+0:47                    112 (const int)
+0:47                    112 (const int)
+0:47                    112 (const int)
+0:47                    112 (const int)
+0:48              Function Call: fn2(vi4;i1; (temp 4-component vector of int)
+0:48                Constant:
+0:48                  110 (const int)
+0:48                  110 (const int)
+0:48                  110 (const int)
+0:48                  110 (const int)
+0:48                Constant:
+0:48                  11 (const int)
+0:49            Function Call: fn2(vi4;i1; (temp 4-component vector of int)
+0:49              Constant:
+0:49                111 (const int)
+0:49                111 (const int)
+0:49                111 (const int)
+0:49                111 (const int)
+0:49              Constant:
+0:49                12 (const int)
+0:49        Branch: Return
+0:?   Linker Objects
+0:?     '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:?     'cia' (const int)
+0:?       -4 (const int)
+0:?     'cib' (const int)
+0:?       -42 (const int)
+0:?     'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+
+
+Linked fragment stage:
+
+
+Shader version: 450
+gl_FragCoord origin is upper left
+ERROR: node is still EOpNull!
+0:7  Function Definition: fn1(vi4; (temp 4-component vector of int)
+0:7    Function Parameters: 
+0:7      'p0' (in 4-component vector of int)
+0:?     Sequence
+0:7      Branch: Return with expression
+0:?         Constant:
+0:?           1 (const int)
+0:?           2 (const int)
+0:?           3 (const int)
+0:?           4 (const int)
+0:9  Function Definition: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:9    Function Parameters: 
+0:9      'p0' (in 4-component vector of int)
+0:9      'b1' (in bool)
+0:9      'b2' (in bool)
+0:?     Sequence
+0:10      Branch: Return with expression
+0:10        'p0' (in 4-component vector of int)
+0:17  Function Definition: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:17    Function Parameters: 
+0:17      'p0' (in 4-component vector of int)
+0:17      'p1' (in 4-component vector of int)
+0:17      'p2' (in 2-element array of int)
+0:17      'p3' (in int)
+0:?     Sequence
+0:18      Branch: Return with expression
+0:18        add (temp 4-component vector of int)
+0:18          add (temp 4-component vector of int)
+0:18            add (temp 4-component vector of int)
+0:18              'p0' (in 4-component vector of int)
+0:18              'p1' (in 4-component vector of int)
+0:18            direct index (temp int)
+0:18              'p2' (in 2-element array of int)
+0:18              Constant:
+0:18                0 (const int)
+0:18          'p3' (in int)
+0:23  Function Definition: fn2(vi4;i1; (temp 4-component vector of int)
+0:23    Function Parameters: 
+0:23      'p0' (in 4-component vector of int)
+0:23      'x' (in int)
+0:?     Sequence
+0:24      Branch: Return with expression
+0:?         Constant:
+0:?           10 (const int)
+0:?           11 (const int)
+0:?           12 (const int)
+0:?           13 (const int)
+0:28  Function Definition: fn2(vi4; (temp 4-component vector of int)
+0:28    Function Parameters: 
+0:28      'p0' (in 4-component vector of int)
+0:?     Sequence
+0:29      Branch: Return with expression
+0:29        add (temp 4-component vector of int)
+0:29          'p0' (in 4-component vector of int)
+0:?           Constant:
+0:?             20 (const int)
+0:?             21 (const int)
+0:?             22 (const int)
+0:?             23 (const int)
+0:33  Function Definition: fn3(i1; (temp void)
+0:33    Function Parameters: 
+0:33      'p0' (in int)
+0:37  Function Definition: main( (temp 4-component vector of int)
+0:37    Function Parameters: 
+0:?     Sequence
+0:38      Sequence
+0:38        move second child to first child (temp 2-element array of int)
+0:38          'myarray' (temp 2-element array of int)
+0:38          Constant:
+0:38            30 (const int)
+0:38            31 (const int)
+0:49      Sequence
+0:49        move second child to first child (temp 4-component vector of int)
+0:?           '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:48          add (temp 4-component vector of int)
+0:47            add (temp 4-component vector of int)
+0:45              add (temp 4-component vector of int)
+0:44                add (temp 4-component vector of int)
+0:43                  add (temp 4-component vector of int)
+0:42                    add (temp 4-component vector of int)
+0:41                      add (temp 4-component vector of int)
+0:40                        add (temp 4-component vector of int)
+0:40                          Function Call: fn1(vi4; (temp 4-component vector of int)
+0:40                            Constant:
+0:40                              100 (const int)
+0:40                              100 (const int)
+0:40                              100 (const int)
+0:40                              100 (const int)
+0:41                          Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:41                            Constant:
+0:41                              101 (const int)
+0:41                              101 (const int)
+0:41                              101 (const int)
+0:41                              101 (const int)
+0:41                            ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:41                              'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+0:41                              Constant:
+0:41                                0 (const uint)
+0:15                            Constant:
+0:15                              1 (const int)
+0:15                              2 (const int)
+0:16                            Constant:
+0:16                              42 (const int)
+0:42                        Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:42                          Constant:
+0:42                            102 (const int)
+0:42                            102 (const int)
+0:42                            102 (const int)
+0:42                            102 (const int)
+0:42                          ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:42                            'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+0:42                            Constant:
+0:42                              0 (const uint)
+0:42                          'myarray' (temp 2-element array of int)
+0:16                          Constant:
+0:16                            42 (const int)
+0:43                      Function Call: fn1(vi4;vi4;i1[2];i1; (temp 4-component vector of int)
+0:43                        Constant:
+0:43                          103 (const int)
+0:43                          103 (const int)
+0:43                          103 (const int)
+0:43                          103 (const int)
+0:43                        ui4: direct index for structure (layout(offset=0 ) uniform 4-component vector of int)
+0:43                          'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+0:43                          Constant:
+0:43                            0 (const uint)
+0:43                        'myarray' (temp 2-element array of int)
+0:43                        Constant:
+0:43                          99 (const int)
+0:44                    Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:44                      Constant:
+0:44                        104 (const int)
+0:44                        104 (const int)
+0:44                        104 (const int)
+0:44                        104 (const int)
+0:44                      Constant:
+0:44                        false (const bool)
+0:9                      Constant:
+0:9                        false (const bool)
+0:45                  Function Call: fn1(vi4;b1;b1; (temp 4-component vector of int)
+0:45                    Constant:
+0:45                      105 (const int)
+0:45                      105 (const int)
+0:45                      105 (const int)
+0:45                      105 (const int)
+0:45                    Constant:
+0:45                      false (const bool)
+0:45                    Constant:
+0:45                      true (const bool)
+0:47                Function Call: fn2(vi4; (temp 4-component vector of int)
+0:47                  Constant:
+0:47                    112 (const int)
+0:47                    112 (const int)
+0:47                    112 (const int)
+0:47                    112 (const int)
+0:48              Function Call: fn2(vi4;i1; (temp 4-component vector of int)
+0:48                Constant:
+0:48                  110 (const int)
+0:48                  110 (const int)
+0:48                  110 (const int)
+0:48                  110 (const int)
+0:48                Constant:
+0:48                  11 (const int)
+0:49            Function Call: fn2(vi4;i1; (temp 4-component vector of int)
+0:49              Constant:
+0:49                111 (const int)
+0:49                111 (const int)
+0:49                111 (const int)
+0:49                111 (const int)
+0:49              Constant:
+0:49                12 (const int)
+0:49        Branch: Return
+0:?   Linker Objects
+0:?     '@entryPointOutput' (layout(location=0 ) out 4-component vector of int)
+0:?     'cia' (const int)
+0:?       -4 (const int)
+0:?     'cib' (const int)
+0:?       -42 (const int)
+0:?     'anon@0' (layout(row_major std140 ) uniform block{layout(offset=0 ) uniform 4-component vector of int ui4, layout(offset=16 ) uniform float ufvar})
+
+SPIR-V is not generated for failed compile or link
diff --git a/Test/hlsl.params.default.frag b/Test/hlsl.params.default.frag
new file mode 100644
index 000000000..42ad84f84
--- /dev/null
+++ b/Test/hlsl.params.default.frag
@@ -0,0 +1,51 @@
+uniform int4 ui4;
+
+static const int cia = -4;
+static const int cib = -42;
+
+// ERROR: Ambiguous with fn1 below.
+// int4 fn1(int4 p0) { return int4(1,2,3,4); }
+
+int4 fn1(int4 p0, bool b1, bool b2 = false) {
+    return p0;
+}
+
+int4 fn1(int4 p0,
+         int4 p1    : FOO = int4(-1,-2,-3, cia),
+         int  p2[2] : BAR = { int(1), 2 },
+         int  p3          = abs(cib) )
+{
+    return p0 + p1 + p2[0] + p3;
+}
+
+// These should not be ambiguous if given either an int or a float explicit second parameter.
+int4 fn2(int4 p0, int x = 3)
+{
+    return int4(10,11,12,13);
+}
+
+int4 fn2(int4 p0, float x = sin(3.3)) // OK to have a const expression as a default value
+{
+    return p0 + int4(20,21,22,23);
+}
+
+void fn3(int p0 = 3) { }
+
+
+int4 main() : SV_Target0
+{
+    int myarray[2] = {30,31};
+
+    fn3();
+    fn3(5);
+
+    return fn1(100) +
+           fn1(101, ui4) +
+           fn1(102, ui4, myarray) +
+           fn1(103, ui4, myarray, 99) +
+           fn1(104, false) +
+           fn1(105, false, true) +
+
+           fn2(110, 11.11) +             // calls int4, float form
+           fn2(111, 12);                // calls int4, int form
+}
diff --git a/Test/hlsl.params.default.negative.frag b/Test/hlsl.params.default.negative.frag
new file mode 100644
index 000000000..c9ff330b5
--- /dev/null
+++ b/Test/hlsl.params.default.negative.frag
@@ -0,0 +1,50 @@
+uniform int4 ui4;
+uniform float ufvar;
+
+static const int cia = -4;
+static const int cib = -42;
+
+int4 fn1(int4 p0) { return int4(1,2,3,4); }
+
+int4 fn1(int4 p0, bool b1, bool b2 = false) {
+    return p0;
+}
+
+int4 fn1(int4 p0,
+         int4 p1 : FOO = int4(-1,-2,-3, cia),
+         int p2[2] : BAR = { int(1), 2 },
+         int p3 = abs(cib) )
+{
+    return p0 + p1 + p2[0] + p3;
+}
+
+// These should not be ambiguous if given either an int or a float explicit second parameter.
+int4 fn2(int4 p0, int x = 3)
+{
+    return int4(10,11,12,13);
+}
+
+int4 fn2(int4 p0, float x = ufvar) // ERROR: non-const expression
+{
+    return p0 + int4(20,21,22,23);
+}
+
+void fn3(int p0 = 5, int p1)  // ERROR no-default param after default param
+{
+}
+
+int4 main() : SV_Target0
+{
+    int myarray[2] = {30,31};
+
+    return fn1(100) +                    // ERROR: ambiguous
+           fn1(101, ui4) +
+           fn1(102, ui4, myarray) +
+           fn1(103, ui4, myarray, 99) +
+           fn1(104, false) +
+           fn1(105, false, true) +
+
+           fn2(112) +                    // ERROR: ambiguous
+           fn2(110, 11.11) +             // calls int4, float form
+           fn2(111, 12);                 // calls int4, int form
+}
diff --git a/glslang/MachineIndependent/Constant.cpp b/glslang/MachineIndependent/Constant.cpp
index 61b6f67e7..537eb5d6a 100644
--- a/glslang/MachineIndependent/Constant.cpp
+++ b/glslang/MachineIndependent/Constant.cpp
@@ -629,6 +629,9 @@ TIntermTyped* TIntermConstantUnion::fold(TOperator op, const TType& returnType)
 //
 TIntermTyped* TIntermediate::fold(TIntermAggregate* aggrNode)
 {
+    if (aggrNode == nullptr)
+        return aggrNode;
+
     if (! areAllChildConst(aggrNode))
         return aggrNode;
 
diff --git a/glslang/MachineIndependent/ParseContextBase.cpp b/glslang/MachineIndependent/ParseContextBase.cpp
index d86e19d24..872c27630 100644
--- a/glslang/MachineIndependent/ParseContextBase.cpp
+++ b/glslang/MachineIndependent/ParseContextBase.cpp
@@ -348,13 +348,18 @@ const TFunction* TParseContextBase::selectFunction(
     for (auto it = candidateList.begin(); it != candidateList.end(); ++it) {
         const TFunction& candidate = *(*it);
 
-        // to even be a potential match, number of arguments has to match
-        if (call.getParamCount() != candidate.getParamCount())
+        // to even be a potential match, number of arguments must be >= the number of
+        // fixed (non-default) parameters, and <= the total (including parameter with defaults).
+        if (call.getParamCount() < candidate.getFixedParamCount() ||
+            call.getParamCount() > candidate.getParamCount())
             continue;
 
         // see if arguments are convertible
         bool viable = true;
-        for (int param = 0; param < candidate.getParamCount(); ++param) {
+
+        // The call can have fewer parameters than the candidate, if some have defaults.
+        const int paramCount = std::min(call.getParamCount(), candidate.getParamCount());
+        for (int param = 0; param < paramCount; ++param) {
             if (candidate[param].type->getQualifier().isParamInput()) {
                 if (! convertible(*call[param].type, *candidate[param].type, candidate.getBuiltInOp(), param)) {
                     viable = false;
@@ -382,7 +387,7 @@ const TFunction* TParseContextBase::selectFunction(
         return viableCandidates.front();
 
     // 4. find best...
-    auto betterParam = [&call, &better](const TFunction& can1, const TFunction& can2) -> bool {
+    const auto betterParam = [&call, &better](const TFunction& can1, const TFunction& can2) -> bool {
         // is call -> can2 better than call -> can1 for any parameter
         bool hasBetterParam = false;
         for (int param = 0; param < call.getParamCount(); ++param) {
@@ -394,6 +399,16 @@ const TFunction* TParseContextBase::selectFunction(
         return hasBetterParam;
     };
 
+    const auto equivalentParams = [&call, &better](const TFunction& can1, const TFunction& can2) -> bool {
+        // is call -> can2 equivalent to call -> can1 for all the call parameters?
+        for (int param = 0; param < call.getParamCount(); ++param) {
+            if (better(*call[param].type, *can1[param].type, *can2[param].type) ||
+                better(*call[param].type, *can2[param].type, *can1[param].type))
+                return false;
+        }
+        return true;
+    };
+    
     const TFunction* incumbent = viableCandidates.front();
     for (auto it = viableCandidates.begin() + 1; it != viableCandidates.end(); ++it) {
         const TFunction& candidate = *(*it);
@@ -406,7 +421,10 @@ const TFunction* TParseContextBase::selectFunction(
         if (incumbent == *it)
             continue;
         const TFunction& candidate = *(*it);
-        if (betterParam(*incumbent, candidate))
+        
+        // In the case of default parameters, it may have an identical initial set, which is
+        // also ambiguous
+        if (betterParam(*incumbent, candidate) || equivalentParams(*incumbent, candidate))
             tie = true;
     }
 
diff --git a/glslang/MachineIndependent/SymbolTable.cpp b/glslang/MachineIndependent/SymbolTable.cpp
index fb09fdf99..d34f4d2ca 100644
--- a/glslang/MachineIndependent/SymbolTable.cpp
+++ b/glslang/MachineIndependent/SymbolTable.cpp
@@ -295,6 +295,7 @@ TFunction::TFunction(const TFunction& copyOf) : TSymbol(copyOf)
     op = copyOf.op;
     defined = copyOf.defined;
     prototyped = copyOf.prototyped;
+    defaultParamCount = copyOf.defaultParamCount;
 }
 
 TFunction* TFunction::clone() const
diff --git a/glslang/MachineIndependent/SymbolTable.h b/glslang/MachineIndependent/SymbolTable.h
index aeec34fc0..1cb08d6de 100644
--- a/glslang/MachineIndependent/SymbolTable.h
+++ b/glslang/MachineIndependent/SymbolTable.h
@@ -191,6 +191,7 @@ protected:
 struct TParameter {
     TString *name;
     TType* type;
+    TIntermTyped* defaultValue;
     void copyParam(const TParameter& param) 
     {
         if (param.name)
@@ -198,6 +199,7 @@ struct TParameter {
         else
             name = 0;
         type = param.type->clone();
+        defaultValue = param.defaultValue;
     }
 };
 
@@ -209,12 +211,12 @@ public:
     explicit TFunction(TOperator o) :
         TSymbol(0),
         op(o),
-        defined(false), prototyped(false) { }
+        defined(false), prototyped(false), defaultParamCount(0) { }
     TFunction(const TString *name, const TType& retType, TOperator tOp = EOpNull) :
         TSymbol(name),
         mangledName(*name + '('),
         op(tOp),
-        defined(false), prototyped(false) { returnType.shallowCopy(retType); }
+        defined(false), prototyped(false), defaultParamCount(0) { returnType.shallowCopy(retType); }
     virtual TFunction* clone() const;
     virtual ~TFunction();
 
@@ -226,6 +228,9 @@ public:
         assert(writable);
         parameters.push_back(p);
         p.type->appendMangledName(mangledName);
+
+        if (p.defaultValue != nullptr)
+            defaultParamCount++;
     }
 
     virtual const TString& getMangledName() const { return mangledName; }
@@ -238,7 +243,13 @@ public:
     virtual void setPrototyped() { assert(writable); prototyped = true; }
     virtual bool isPrototyped() const { return prototyped; }
 
+    // Return total number of parameters
     virtual int getParamCount() const { return static_cast<int>(parameters.size()); }
+    // Return number of parameters with default values.
+    virtual int getDefaultParamCount() const { return defaultParamCount; }
+    // Return number of fixed parameters (without default values)
+    virtual int getFixedParamCount() const { return getParamCount() - getDefaultParamCount(); }
+
     virtual TParameter& operator[](int i) { assert(writable); return parameters[i]; }
     virtual const TParameter& operator[](int i) const { return parameters[i]; }
 
@@ -255,6 +266,7 @@ protected:
     TOperator op;
     bool defined;
     bool prototyped;
+    int  defaultParamCount;
 };
 
 //
diff --git a/gtests/Hlsl.FromFile.cpp b/gtests/Hlsl.FromFile.cpp
index f0332aac6..2acd241a2 100644
--- a/gtests/Hlsl.FromFile.cpp
+++ b/gtests/Hlsl.FromFile.cpp
@@ -160,6 +160,8 @@ INSTANTIATE_TEST_CASE_P(
         {"hlsl.numericsuffixes.frag", "main"},
         {"hlsl.numthreads.comp", "main_aux1"},
         {"hlsl.overload.frag", "PixelShaderFunction"},
+        {"hlsl.params.default.frag", "main"},
+        {"hlsl.params.default.negative.frag", "main"},
         {"hlsl.partialInit.frag", "PixelShaderFunction"},
         {"hlsl.pp.line.frag", "main"},
         {"hlsl.precise.frag", "main"},
diff --git a/hlsl/hlslGrammar.cpp b/hlsl/hlslGrammar.cpp
index b874aa8c9..d0f3b006a 100755
--- a/hlsl/hlslGrammar.cpp
+++ b/hlsl/hlslGrammar.cpp
@@ -1776,9 +1776,55 @@ bool HlslGrammar::acceptFunctionParameters(TFunction& function)
     return true;
 }
 
+
+// default_parameter_declaration
+//      : EQUAL conditional_expression
+//      : EQUAL initializer
+bool HlslGrammar::acceptDefaultParameterDeclaration(const TType& type, TIntermTyped*& node)
+{
+    node = nullptr;
+
+    // Valid not to have a default_parameter_declaration
+    if (!acceptTokenClass(EHTokAssign))
+        return true;
+
+    if (!acceptConditionalExpression(node)) {
+        if (!acceptInitializer(node))
+            return false;
+
+        // For initializer lists, we have to const-fold into a constructor for the type, so build
+        // that.
+        TFunction* constructor = parseContext.handleConstructorCall(token.loc, type);
+        if (constructor == nullptr)  // cannot construct
+            return false;
+
+        TIntermTyped* arguments = nullptr;
+        for (int i=0; i<int(node->getAsAggregate()->getSequence().size()); i++)
+            parseContext.handleFunctionArgument(constructor, arguments, node->getAsAggregate()->getSequence()[i]->getAsTyped());
+        
+        node = parseContext.handleFunctionCall(token.loc, constructor, node);
+    }
+
+    // If this is simply a constant, we can use it directly.
+    if (node->getAsConstantUnion())
+        return true;
+
+    // Otherwise, it has to be const-foldable.
+    TIntermTyped* origNode = node;
+
+    node = intermediate.fold(node->getAsAggregate());
+
+    if (node != nullptr && origNode != node)
+        return true;
+
+    parseContext.error(token.loc, "invalid default parameter value", "", "");
+
+    return false;
+}
+
 // parameter_declaration
-//      : fully_specified_type post_decls
-//      | fully_specified_type identifier array_specifier post_decls
+//      : fully_specified_type post_decls [ = default_parameter_declaration ]
+//      | fully_specified_type identifier array_specifier post_decls [ = default_parameter_declaration ]
 //
 bool HlslGrammar::acceptParameterDeclaration(TFunction& function)
 {
@@ -1806,9 +1852,19 @@ bool HlslGrammar::acceptParameterDeclaration(TFunction& function)
     // post_decls
     acceptPostDecls(type->getQualifier());
 
+    TIntermTyped* defaultValue;
+    if (!acceptDefaultParameterDeclaration(*type, defaultValue))
+        return false;
+
     parseContext.paramFix(*type);
 
-    TParameter param = { idToken.string, type };
+    // If any prior parameters have default values, all the parameters after that must as well.
+    if (defaultValue == nullptr && function.getDefaultParamCount() > 0) {
+        parseContext.error(idToken.loc, "invalid parameter after default value parameters", idToken.string->c_str(), "");
+        return false;
+    }
+
+    TParameter param = { idToken.string, type, defaultValue };
     function.addParameter(param);
 
     return true;
diff --git a/hlsl/hlslGrammar.h b/hlsl/hlslGrammar.h
index 8804b217e..8612c90de 100755
--- a/hlsl/hlslGrammar.h
+++ b/hlsl/hlslGrammar.h
@@ -111,6 +111,7 @@ namespace glslang {
         bool acceptDefaultLabel(TIntermNode*&);
         void acceptArraySpecifier(TArraySizes*&);
         void acceptPostDecls(TQualifier&);
+        bool acceptDefaultParameterDeclaration(const TType&, TIntermTyped*&);
 
         HlslParseContext& parseContext;  // state of parsing and helper functions for building the intermediate
         TIntermediate& intermediate;     // the final product, the intermediate representation, includes the AST
diff --git a/hlsl/hlslParseHelper.cpp b/hlsl/hlslParseHelper.cpp
index 62dac4bfa..46ae8970b 100755
--- a/hlsl/hlslParseHelper.cpp
+++ b/hlsl/hlslParseHelper.cpp
@@ -1375,7 +1375,7 @@ TIntermNode* HlslParseContext::handleReturnValue(const TSourceLoc& loc, TIntermT
 
 void HlslParseContext::handleFunctionArgument(TFunction* function, TIntermTyped*& arguments, TIntermTyped* newArg)
 {
-    TParameter param = { 0, new TType };
+    TParameter param = { 0, new TType, nullptr };
     param.type->shallowCopy(newArg->getType());
     function->addParameter(param);
     if (arguments)
@@ -2643,7 +2643,7 @@ void HlslParseContext::decomposeIntrinsic(const TSourceLoc& loc, TIntermTyped*&
 //  - user function
 //  - subroutine call (not implemented yet)
 //
-TIntermTyped* HlslParseContext::handleFunctionCall(const TSourceLoc& loc, TFunction* function, TIntermNode* arguments)
+TIntermTyped* HlslParseContext::handleFunctionCall(const TSourceLoc& loc, TFunction* function, TIntermTyped* arguments)
 {
     TIntermTyped* result = nullptr;
 
@@ -2783,10 +2783,10 @@ TIntermTyped* HlslParseContext::handleLengthMethod(const TSourceLoc& loc, TFunct
 //
 // Add any needed implicit conversions for function-call arguments to input parameters.
 //
-void HlslParseContext::addInputArgumentConversions(const TFunction& function, TIntermNode*& arguments)
+void HlslParseContext::addInputArgumentConversions(const TFunction& function, TIntermTyped*& arguments)
 {
     TIntermAggregate* aggregate = arguments->getAsAggregate();
-    const auto setArg = [&](int argNum, TIntermNode* arg) {
+    const auto setArg = [&](int argNum, TIntermTyped* arg) {
         if (function.getParamCount() == 1)
             arguments = arg;
         else {
@@ -4483,8 +4483,8 @@ void HlslParseContext::mergeObjectLayoutQualifiers(TQualifier& dst, const TQuali
 //
 // Return the function symbol if found, otherwise nullptr.
 //
-const TFunction* HlslParseContext::findFunction(const TSourceLoc& loc, const TFunction& call, bool& builtIn,
-                                                TIntermNode* args)
+const TFunction* HlslParseContext::findFunction(const TSourceLoc& loc, TFunction& call, bool& builtIn,
+                                                TIntermTyped*& args)
 {
     // const TFunction* function = nullptr;
 
@@ -4583,6 +4583,22 @@ const TFunction* HlslParseContext::findFunction(const TSourceLoc& loc, const TFu
                 return false;
         }
 
+        // Handle sampler betterness: An exact sampler match beats a non-exact match.
+        // (If we just looked at basic type, all EbtSamplers would look the same).
+        // If any type is not a sampler, just use the linearize function below.
+        if (from.getBasicType() == EbtSampler && to1.getBasicType() == EbtSampler && to2.getBasicType() == EbtSampler) {
+            // We can ignore the vector size in the comparison.
+            TSampler to1Sampler = to1.getSampler();
+            TSampler to2Sampler = to2.getSampler();
+
+            to1Sampler.vectorSize = to2Sampler.vectorSize = from.getSampler().vectorSize;
+
+            if (from.getSampler() == to2Sampler)
+                return from.getSampler() != to1Sampler;
+            if (from.getSampler() == to1Sampler)
+                return false;
+        }
+
         // Might or might not be changing shape, which means basic type might
         // or might not match, so within that, the question is how big a
         // basic-type conversion is being done.
@@ -4672,18 +4688,18 @@ const TFunction* HlslParseContext::findFunction(const TSourceLoc& loc, const TFu
             // Handle aggregates: put all args into the new function call
             for (int arg=0; arg<int(args->getAsAggregate()->getSequence().size()); ++arg) {
                 // TODO: But for constness, we could avoid the new & shallowCopy, and use the pointer directly.
-                TParameter param = { 0, new TType };
+                TParameter param = { 0, new TType, nullptr };
                 param.type->shallowCopy(args->getAsAggregate()->getSequence()[arg]->getAsTyped()->getType());
                 convertedCall.addParameter(param);
             }
         } else if (args->getAsUnaryNode()) {
             // Handle unaries: put all args into the new function call
-            TParameter param = { 0, new TType };
+            TParameter param = { 0, new TType, nullptr };
             param.type->shallowCopy(args->getAsUnaryNode()->getOperand()->getAsTyped()->getType());
             convertedCall.addParameter(param);
         } else if (args->getAsTyped()) {
             // Handle bare e.g, floats, not in an aggregate.
-            TParameter param = { 0, new TType };
+            TParameter param = { 0, new TType, nullptr };
             param.type->shallowCopy(args->getAsTyped()->getType());
             convertedCall.addParameter(param);
         } else {
@@ -4701,6 +4717,13 @@ const TFunction* HlslParseContext::findFunction(const TSourceLoc& loc, const TFu
     if (tie)
         error(loc, "ambiguous best function under implicit type conversion", call.getName().c_str(), "");
 
+    // Append default parameter values if needed
+    if (!tie && bestMatch != nullptr) {
+        for (int defParam = call.getParamCount(); defParam < bestMatch->getParamCount(); ++defParam) {
+            handleFunctionArgument(&call, args, (*bestMatch)[defParam].defaultValue);
+        }
+    }
+
     return bestMatch;
 }
 
diff --git a/hlsl/hlslParseHelper.h b/hlsl/hlslParseHelper.h
index d017a2a7c..6280ab424 100755
--- a/hlsl/hlslParseHelper.h
+++ b/hlsl/hlslParseHelper.h
@@ -79,12 +79,12 @@ public:
     TIntermNode* handleReturnValue(const TSourceLoc&, TIntermTyped*);
     void handleFunctionArgument(TFunction*, TIntermTyped*& arguments, TIntermTyped* newArg);
     TIntermTyped* handleAssign(const TSourceLoc&, TOperator, TIntermTyped* left, TIntermTyped* right) const;
-    TIntermTyped* handleFunctionCall(const TSourceLoc&, TFunction*, TIntermNode*);
+    TIntermTyped* handleFunctionCall(const TSourceLoc&, TFunction*, TIntermTyped*);
     void decomposeIntrinsic(const TSourceLoc&, TIntermTyped*& node, TIntermNode* arguments);
     void decomposeSampleMethods(const TSourceLoc&, TIntermTyped*& node, TIntermNode* arguments);
     void decomposeGeometryMethods(const TSourceLoc&, TIntermTyped*& node, TIntermNode* arguments);
     TIntermTyped* handleLengthMethod(const TSourceLoc&, TFunction*, TIntermNode*);
-    void addInputArgumentConversions(const TFunction&, TIntermNode*&);
+    void addInputArgumentConversions(const TFunction&, TIntermTyped*&);
     TIntermTyped* addOutputArgumentConversions(const TFunction&, TIntermOperator&);
     void builtInOpCheck(const TSourceLoc&, const TFunction&, TIntermOperator&);
     TFunction* handleConstructorCall(const TSourceLoc&, const TType&);
@@ -126,7 +126,7 @@ public:
     void mergeObjectLayoutQualifiers(TQualifier& dest, const TQualifier& src, bool inheritOnly);
     void checkNoShaderLayouts(const TSourceLoc&, const TShaderQualifiers&);
 
-    const TFunction* findFunction(const TSourceLoc& loc, const TFunction& call, bool& builtIn, TIntermNode* args);
+    const TFunction* findFunction(const TSourceLoc& loc, TFunction& call, bool& builtIn, TIntermTyped*& args);
     void declareTypedef(const TSourceLoc&, TString& identifier, const TType&, TArraySizes* typeArray = 0);
     TIntermNode* declareVariable(const TSourceLoc&, TString& identifier, TType&, TIntermTyped* initializer = 0);
     void lengthenList(const TSourceLoc&, TIntermSequence& list, int size);
diff --git a/hlsl/hlslParseables.cpp b/hlsl/hlslParseables.cpp
index 8ecaec9dd..ee89af5b0 100755
--- a/hlsl/hlslParseables.cpp
+++ b/hlsl/hlslParseables.cpp
@@ -586,7 +586,7 @@ void TBuiltInParseablesHlsl::initialize(int /*version*/, EProfile /*profile*/, c
         { "DeviceMemoryBarrier",              nullptr, nullptr,   "-",              "-",             EShLangPSCS },
         { "DeviceMemoryBarrierWithGroupSync", nullptr, nullptr,   "-",              "-",             EShLangCS },
         { "distance",                         "S",     "F",       "V,",             "F,",            EShLangAll },
-        { "dot",                              "S",     nullptr,   "V,",             "FI,",           EShLangAll },
+        { "dot",                              "S",     nullptr,   "SV,",            "FI,",           EShLangAll },
         { "dst",                              nullptr, nullptr,   "V4,",            "F,",            EShLangAll },
         // { "errorf",                           "-",     "-",       "",             "",             EShLangAll }, TODO: varargs
         { "EvaluateAttributeAtCentroid",      nullptr, nullptr,   "SVM",            "F",             EShLangPS },