[spirv] Fix out/inout vector parameter assignment (#978)

Some entities, if passed as arguments to out/inout vector parameters,
will need more complicated scheme for assignment.

tools/clang/lib/SPIRV/SPIRVEmitter.cpp

@@ -1737,10 +1737,12 @@ SpirvEvalInfo SPIRVEmitter::processCall(const CallExpr *callExpr) {
   for (uint32_t i = 0; i < numParams; ++i) {
     const auto *param = callee->getParamDecl(i);
     if (canActAsOutParmVar(param)) {
+      const auto *arg = callExpr->getArg(i);
       const uint32_t index = i + isNonStaticMemberCall;
       const uint32_t typeId = typeTranslator.translateType(param->getType());
       const uint32_t value = theBuilder.createLoad(typeId, params[index]);
-      storeValue(args[index], value, param->getType());
+
+      processAssignment(arg, value, false, args[index]);
     }
   }
 

tools/clang/test/CodeGenSPIRV/fn.param.inout.vector.hlsl

@@ -0,0 +1,59 @@
+// Run: %dxc -T vs_6_0 -E main
+
+RWBuffer<float4>    MyRWBuffer;
+RWTexture2D<float3> MyRWTexture;
+
+void foo(inout float4 a, out float3 b);
+void bar(inout float4 x, out float3 y, inout float2 z, out float w);
+
+float4 main() : C {
+// CHECK:          {{%\d+}} = OpFunctionCall %void %foo %param_var_a %param_var_b
+// CHECK-NEXT:   [[a:%\d+]] = OpLoad %v4float %param_var_a
+// CHECK-NEXT: [[buf:%\d+]] = OpLoad %type_buffer_image %MyRWBuffer
+// CHECK-NEXT:                OpImageWrite [[buf]] %uint_5 [[a]]
+// CHECK-NEXT:   [[b:%\d+]] = OpLoad %v3float %param_var_b
+// CHECK-NEXT: [[tex:%\d+]] = OpLoad %type_2d_image %MyRWTexture
+// CHECK-NEXT:                OpImageWrite [[tex]] %36 [[b]]
+    foo(MyRWBuffer[5], MyRWTexture[uint2(6, 7)]);
+
+    float4 val;
+// CHECK:    [[z_ptr:%\d+]] = OpAccessChain %_ptr_Function_float %val %int_2
+// CHECK:          {{%\d+}} = OpFunctionCall %void %bar %param_var_x %param_var_y %param_var_z %param_var_w
+// CHECK-NEXT:   [[x:%\d+]] = OpLoad %v4float %param_var_x
+// CHECK-NEXT:                OpStore %val [[x]]
+// CHECK-NEXT:   [[y:%\d+]] = OpLoad %v3float %param_var_y
+// CHECK-NEXT: [[old:%\d+]] = OpLoad %v4float %val
+    // Write to val.zwx:
+    //   val[2] = out_val[0] => 0 + 4 = 4
+    //   val[3] = out_val[1] => 1 + 4 = 5
+    //   val[0] = out_val[2] => 2 + 4 = 6
+    //   val[1] = val[1]     => 1 + 0 = 1
+// CHECK-NEXT: [[new:%\d+]] = OpVectorShuffle %v4float [[old]] [[y]] 6 1 4 5
+// CHECK-NEXT:                OpStore %val [[new]]
+    // Write to val.xy:
+    //   val[0] = out_val[0] => 0 + 4 = 4
+    //   val[1] = out_val[1] => 1 + 4 = 5
+    //   val[2] = val[2]     => 2 + 0 = 2
+    //   val[3] = val[3]     => 3 + 0 = 3
+// CHECK-NEXT:   [[z:%\d+]] = OpLoad %v2float %param_var_z
+// CHECK-NEXT: [[old:%\d+]] = OpLoad %v4float %val
+// CHECK-NEXT: [[new:%\d+]] = OpVectorShuffle %v4float [[old]] [[z]] 4 5 2 3
+// CHECK-NEXT:                OpStore %val [[new]]
+// CHECK-NEXT:   [[w:%\d+]] = OpLoad %float %param_var_w
+// CHECK-NEXT:                OpStore [[z_ptr]] [[w]]
+    bar(val, val.zwx, val.xy, val.z);
+
+    return MyRWBuffer[0];
+}
+
+void foo(inout float4 a, out float3 b) {
+    a = 4.2;
+    b = 2.4;
+}
+
+void bar(inout float4 x, out float3 y, inout float2 z, out float w) {
+    x = 1.1;
+    y = 2.2;
+    z = 3.3;
+    w = 4.4;
+}

tools/clang/unittests/SPIRV/CodeGenSPIRVTest.cpp

@@ -381,6 +381,9 @@ TEST_F(FileTest, ControlFlowConditionalOp) { runFileTest("cf.cond-op.hlsl"); }
 TEST_F(FileTest, FunctionCall) { runFileTest("fn.call.hlsl"); }
 TEST_F(FileTest, FunctionDefaultArg) { runFileTest("fn.default-arg.hlsl"); }
 TEST_F(FileTest, FunctionInOutParam) { runFileTest("fn.param.inout.hlsl"); }
+TEST_F(FileTest, FunctionInOutParamVector) {
+  runFileTest("fn.param.inout.vector.hlsl");
+}
 TEST_F(FileTest, FunctionFowardDeclaration) {
   runFileTest("fn.foward-declaration.hlsl");
 }