[spirv-writer] Add support for dot call.

This CL adds support for generating OpDot.

Bug: tint:5
Change-Id: I5a77e49ff26ff12b4ed7b2b01665f0928e51a568
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/22624
Reviewed-by: David Neto <dneto@google.com>

src/writer/spirv/builder.cc

@@ -1250,10 +1250,12 @@ uint32_t Builder::GenerateIntrinsic(const std::string& name,
     op = spv::Op::OpAny;
   } else if (name == "all") {
     op = spv::Op::OpAll;
-  } else if (name == "is_nan") {
+  } else if (name == "dot") {
-    op = spv::Op::OpIsNan;
+    op = spv::Op::OpDot;
   } else if (name == "is_inf") {
     op = spv::Op::OpIsInf;
+  } else if (name == "is_nan") {
+    op = spv::Op::OpIsNan;
   }
   if (op == spv::Op::OpNop) {
     error_ = "unable to determine operator for: " + name;

src/writer/spirv/builder_intrinsic_test.cc

@@ -170,6 +170,44 @@ INSTANTIATE_TEST_SUITE_P(BuilderTest,
                          testing::Values(IntrinsicData{"is_nan", "OpIsNan"},
                                          IntrinsicData{"is_inf", "OpIsInf"}));
 
+TEST_F(BuilderTest, Call_Dot) {
+  ast::type::F32Type f32;
+  ast::type::VectorType vec3(&f32, 3);
+
+  auto var =
+      std::make_unique<ast::Variable>("v", ast::StorageClass::kPrivate, &vec3);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::IdentifierExpression>("v"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("v"));
+  ast::CallExpression expr(std::make_unique<ast::IdentifierExpression>("dot"),
+                           std::move(params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  td.RegisterVariableForTesting(var.get());
+
+  ASSERT_TRUE(td.DetermineResultType(&expr)) << td.error();
+
+  Builder b(&mod);
+  b.push_function(Function{});
+  ASSERT_TRUE(b.GenerateGlobalVariable(var.get())) << b.error();
+
+  EXPECT_EQ(b.GenerateCallExpression(&expr), 6u) << b.error();
+  EXPECT_EQ(DumpInstructions(b.types()), R"(%4 = OpTypeFloat 32
+%3 = OpTypeVector %4 3
+%2 = OpTypePointer Private %3
+%5 = OpConstantNull %3
+%1 = OpVariable %2 Private %5
+)");
+  EXPECT_EQ(DumpInstructions(b.functions()[0].instructions()),
+            R"(%7 = OpLoad %3 %1
+%8 = OpLoad %3 %1
+%6 = OpDot %4 %7 %8
+)");
+}
+
 }  // namespace
 }  // namespace spirv
 }  // namespace writer