Apply NoContraction to dot()

Implement the change in issue 2708 so `noContraction` is set for `dot()` in the
AST.

Translate `EOpDot` using `createBinaryOperation()`, which handles setting the
`NoContraction` decoration unlike `createMiscOperation()`.

Author: mjn33

SPIRV/GlslangToSpv.cpp

@@ -3282,6 +3282,8 @@ bool TGlslangToSpvTraverser::visitAggregate(glslang::TVisit visit, glslang::TInt
         glslang::TIntermSequence& glslangOperands = node->getSequence();
         if (glslangOperands[0]->getAsTyped()->getVectorSize() == 1)
             binOp = glslang::EOpMul;
+        else if (isTypeFloat(node->getType().getBasicType()))
+            binOp = glslang::EOpDot;
         break;
     }
     case glslang::EOpMod:
@@ -7144,6 +7146,13 @@ spv::Id TGlslangToSpvTraverser::createBinaryOperation(glslang::TOperator op, OpD
         binOp = spv::OpOuterProduct;
         needMatchingVectors = false;
         break;
+    case glslang::EOpDot:
+        if (typeProxy == glslang::EbtBFloat16) {
+            builder.addExtension(spv::E_SPV_KHR_bfloat16);
+            builder.addCapability(spv::CapabilityBFloat16DotProductKHR);
+        }
+        binOp = spv::OpDot;
+        break;
 
     case glslang::EOpDiv:
     case glslang::EOpDivAssign:
@@ -9152,10 +9161,6 @@ spv::Id TGlslangToSpvTraverser::createMiscOperation(glslang::TOperator op, spv::
             if (builder.isFloatType(builder.getScalarTypeId(typeId0)) ||
                 // HLSL supports dot(int,int) which is just a multiply
                 glslangIntermediate->getSource() == glslang::EShSourceHlsl) {
-                if (typeProxy == glslang::EbtBFloat16) {
-                    builder.addExtension(spv::E_SPV_KHR_bfloat16);
-                    builder.addCapability(spv::CapabilityBFloat16DotProductKHR);
-                }
                 opCode = spv::OpDot;
             } else {
                 builder.addExtension(spv::E_SPV_KHR_integer_dot_product);

Test/baseResults/spv.precise.dot.vert.out

@@ -0,0 +1,51 @@
+spv.precise.dot.vert
+// Module Version 10000
+// Generated by (magic number): 8000b
+// Id's are bound by 28
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Vertex 4  "main" 21
+                              Source GLSL 450
+                              Name 4  "main"
+                              Name 9  "v"
+                              Name 11  "u"
+                              Name 15  "f"
+                              Name 19  "gl_PerVertex"
+                              MemberName 19(gl_PerVertex) 0  "gl_Position"
+                              Name 21  ""
+                              Decorate 18 NoContraction
+                              Decorate 19(gl_PerVertex) Block
+                              MemberDecorate 19(gl_PerVertex) 0 BuiltIn Position
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypeVector 6(float) 4
+               8:             TypePointer Function 7(fvec4)
+              10:             TypePointer Private 6(float)
+           11(u):     10(ptr) Variable Private
+              14:             TypePointer Function 6(float)
+19(gl_PerVertex):             TypeStruct 7(fvec4)
+              20:             TypePointer Output 19(gl_PerVertex)
+              21:     20(ptr) Variable Output
+              22:             TypeInt 32 1
+              23:     22(int) Constant 0
+              26:             TypePointer Output 7(fvec4)
+         4(main):           2 Function None 3
+               5:             Label
+            9(v):      8(ptr) Variable Function
+           15(f):     14(ptr) Variable Function
+              12:    6(float) Load 11(u)
+              13:    7(fvec4) CompositeConstruct 12 12 12 12
+                              Store 9(v) 13
+              16:    7(fvec4) Load 9(v)
+              17:    7(fvec4) Load 9(v)
+              18:    6(float) Dot 16 17
+                              Store 15(f) 18
+              24:    6(float) Load 15(f)
+              25:    7(fvec4) CompositeConstruct 24 24 24 24
+              27:     26(ptr) AccessChain 21 23
+                              Store 27 25
+                              Return
+                              FunctionEnd

Test/spv.precise.dot.vert

@@ -0,0 +1,15 @@
+#version 450 core
+
+out gl_PerVertex
+{
+    precise vec4 gl_Position;
+};
+
+float u;
+
+void main()
+{
+    vec4 v = vec4(u);
+    float f = dot(v, v);
+    gl_Position = vec4(f);
+}

glslang/MachineIndependent/propagateNoContraction.cpp

@@ -689,6 +689,10 @@ class TNoContractionPropagator : public glslang::TIntermTraverser {
             }
             return false;
         }
+        // If this is an arithmetic operation, marks this node as 'noContraction'.
+        if (isArithmeticOperation(node->getOp())) {
+            node->getWritableType().getQualifier().noContraction = true;
+        }
         return true;
     }
 

gtests/Spv.FromFile.cpp

@@ -531,6 +531,7 @@ INSTANTIATE_TEST_SUITE_P(
         "spv.subgroupSizeARB.frag",
         "spv.precise.tese",
         "spv.precise.tesc",
+        "spv.precise.dot.vert",
         "spv.viewportindex.tese",
         "spv.volatileAtomic.comp",
         "spv.vulkan100.subgroupArithmetic.comp",