shader_recompiler: Add swizzle support for unsupported formats. (#1869)

* shader_recompiler: Add swizzle support for unsupported formats.

* renderer_vulkan: Rework MRT swizzles and add unsupported format swizzle support.

* shader_recompiler: Clean up swizzle handling and handle ImageRead storage swizzle.

* shader_recompiler: Fix type errors

* liverpool_to_vk: Remove redundant clear color swizzles.

* shader_recompiler: Reduce CompositeConstruct to constants where possible.

* shader_recompiler: Fix ImageRead/Write and StoreBufferFormatF32 types.

* amdgpu: Add a few more unsupported format remaps.

src/shader_recompiler/ir/reinterpret.h

@@ -0,0 +1,24 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "shader_recompiler/ir/ir_emitter.h"
+#include "video_core/amdgpu/resource.h"
+
+namespace Shader::IR {
+
+/// Applies a component swizzle to a vec4.
+inline Value ApplySwizzle(IREmitter& ir, const Value& vector, const AmdGpu::CompMapping& swizzle) {
+    // Constants are indexed as 0 and 1, and components are 4-7. Thus we can apply a swizzle
+    // using two vectors and a shuffle, using one vector of constants and one of the components.
+    const auto zero = ir.Imm32(0.f);
+    const auto one = ir.Imm32(1.f);
+    const auto constants_vec = ir.CompositeConstruct(zero, one, zero, zero);
+    const auto swizzled =
+        ir.CompositeShuffle(constants_vec, vector, size_t(swizzle.r), size_t(swizzle.g),
+                            size_t(swizzle.b), size_t(swizzle.a));
+    return swizzled;
+}
+
+} // namespace Shader::IR