[PATCH vkd3d 1/5] vkd3d-shader: Check more accurately if swizzle is required.

[Józef Kucia]

From: Józef Kucia <jkucia at codeweavers.com>

Eliminates redundant OpVectorShuffle instructions.

Signed-off-by: Józef Kucia <jkucia at codeweavers.com>
---
 libs/vkd3d-shader/spirv.c                |  8 +++++---
 libs/vkd3d-shader/vkd3d_shader_private.h | 16 ++++++++++++++++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/libs/vkd3d-shader/spirv.c b/libs/vkd3d-shader/spirv.c
index dee561ac033c..9493d53591bb 100644
--- a/libs/vkd3d-shader/spirv.c
+++ b/libs/vkd3d-shader/spirv.c
@@ -2528,10 +2528,13 @@ static uint32_t vkd3d_dxbc_compiler_emit_swizzle_ext(struct vkd3d_dxbc_compiler
     struct vkd3d_spirv_builder *builder = &compiler->spirv_builder;
     uint32_t type_id, components[VKD3D_VEC4_SIZE];
 
-    if (swizzle == VKD3D_NO_SWIZZLE && write_mask == val_write_mask)
+    component_count = vkd3d_write_mask_component_count(write_mask);
+    val_component_count = vkd3d_write_mask_component_count(val_write_mask);
+
+    if (component_count == val_component_count
+            && vkd3d_compact_swizzle(swizzle, write_mask) == vkd3d_compact_swizzle(VKD3D_NO_SWIZZLE, val_write_mask))
         return val_id;
 
-    component_count = vkd3d_write_mask_component_count(write_mask);
     type_id = vkd3d_spirv_get_type_id(builder, component_type, component_count);
 
     if (component_count == 1)
@@ -2541,7 +2544,6 @@ static uint32_t vkd3d_dxbc_compiler_emit_swizzle_ext(struct vkd3d_dxbc_compiler
         return vkd3d_spirv_build_op_composite_extract1(builder, type_id, val_id, component_idx);
     }
 
-    val_component_count = vkd3d_write_mask_component_count(val_write_mask);
     if (val_component_count == 1)
     {
         for (i = 0, component_idx = 0; i < VKD3D_VEC4_SIZE; ++i)
diff --git a/libs/vkd3d-shader/vkd3d_shader_private.h b/libs/vkd3d-shader/vkd3d_shader_private.h
index dd3650b2d828..651a5959f1d1 100644
--- a/libs/vkd3d-shader/vkd3d_shader_private.h
+++ b/libs/vkd3d-shader/vkd3d_shader_private.h
@@ -882,6 +882,22 @@ static inline unsigned int vkd3d_swizzle_get_component(DWORD swizzle,
     return (swizzle >> VKD3D_SWIZZLE_SHIFT(idx)) & VKD3D_SWIZZLE_MASK;
 }
 
+static inline unsigned int vkd3d_compact_swizzle(unsigned int swizzle, unsigned int write_mask)
+{
+    unsigned int i, compacted_swizzle = 0;
+
+    for (i = 0; i < VKD3D_VEC4_SIZE; ++i)
+    {
+        if (write_mask & (VKD3DSP_WRITEMASK_0 << i))
+        {
+            compacted_swizzle <<= VKD3D_SWIZZLE_SHIFT(1);
+            compacted_swizzle |= vkd3d_swizzle_get_component(swizzle, i);
+        }
+    }
+
+    return compacted_swizzle;
+}
+
 #define VKD3D_DXBC_MAX_SOURCE_COUNT 6
 #define VKD3D_DXBC_HEADER_SIZE (8 * sizeof(uint32_t))
 
-- 
2.18.1