[PATCH v4 6/7] vkd3d-shader/hlsl: Replace swizzles with constants in copy prop.

[Francisco Casas]

From: Francisco Casas

---
 libs/vkd3d-shader/hlsl_codegen.c        | 68 +++++++++++++++++++++++++
 tests/swizzle-constant-prop.shader_test |  6 +--
 2 files changed, 71 insertions(+), 3 deletions(-)

diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
index 9bdbd57c..4cd08be9 100644
--- a/libs/vkd3d-shader/hlsl_codegen.c
+++ b/libs/vkd3d-shader/hlsl_codegen.c
@@ -753,6 +753,56 @@ static struct hlsl_ir_node *copy_propagation_compute_load_constant_replacement(s
     return &cons->node;
 }

+static struct hlsl_ir_node *copy_propagation_compute_swizzle_constant_replacement(struct hlsl_ctx *ctx,
+        const struct copy_propagation_state *state, const struct hlsl_ir_swizzle *swizzle)
+{
+    unsigned int start, count, i, c, swizzle_bits, n_comps;
+    union hlsl_constant_value values[4] = {0};
+    const struct hlsl_ir_load *load;
+    struct hlsl_ir_constant *cons;
+    const struct hlsl_ir_var *var;
+
+    if (swizzle->val.node->type != HLSL_IR_LOAD)
+        return NULL;
+    load = hlsl_ir_load(swizzle->val.node);
+    var = load->src.var;
+
+    if (load->node.data_type->type != HLSL_CLASS_SCALAR && load->node.data_type->type != HLSL_CLASS_VECTOR)
+        return NULL;
+
+    if (!hlsl_component_index_range_from_deref(ctx, &load->src, &start, &count))
+        return NULL;
+
+    swizzle_bits = swizzle->swizzle;
+    n_comps = swizzle->node.data_type->dimx;
+    for (i = 0; i < n_comps; ++i)
+    {
+        struct copy_propagation_value *value;
+
+        c = swizzle_bits & 3;
+        assert(c < count);
+        value = copy_propagation_get_value(state, var, start + c);
+
+        if (!value || value->node->type != HLSL_IR_CONSTANT)
+            return NULL;
+
+        values[i] = hlsl_ir_constant(value->node)->value[value->component];
+
+        swizzle_bits >>= 2;
+    }
+
+    if (!(cons = hlsl_new_constant(ctx, swizzle->node.data_type, &swizzle->node.loc)))
+        return NULL;
+    cons->value[0] = values[0];
+    cons->value[1] = values[1];
+    cons->value[2] = values[2];
+    cons->value[3] = values[3];
+
+    TRACE("Swizzle from %s[%u-%u]%s turned into a constant %p.\n", var->name, start, start + count,
+            debug_hlsl_swizzle(swizzle->swizzle, n_comps), cons);
+    return &cons->node;
+}
+
 static bool copy_propagation_transform_load(struct hlsl_ctx *ctx,
         struct hlsl_ir_load *load, struct copy_propagation_state *state)
 {
@@ -832,6 +882,20 @@ static bool copy_propagation_transform_resource_load(struct hlsl_ctx *ctx,
     return progress;
 }

+static bool copy_propagation_transform_swizzle(struct hlsl_ctx *ctx,
+    struct hlsl_ir_swizzle *swizzle, struct copy_propagation_state *state)
+{
+    struct hlsl_ir_node *instr = &swizzle->node, *new_instr;
+
+    if ((new_instr = copy_propagation_compute_swizzle_constant_replacement(ctx, state, swizzle)))
+    {
+        list_add_before(&instr->entry, &new_instr->entry);
+        hlsl_replace_node(instr, new_instr);
+        return true;
+    }
+    return false;
+}
+
 static bool copy_propagation_transform_resource_store(struct hlsl_ctx *ctx,
         struct hlsl_ir_resource_store *store, struct copy_propagation_state *state)
 {
@@ -995,6 +1059,10 @@ static bool copy_propagation_transform_block(struct hlsl_ctx *ctx, struct hlsl_b
                 copy_propagation_record_store(ctx, hlsl_ir_store(instr), state);
                 break;

+            case HLSL_IR_SWIZZLE:
+                copy_propagation_transform_swizzle(ctx, hlsl_ir_swizzle(instr), state);
+                break;
+
             case HLSL_IR_IF:
                 progress |= copy_propagation_process_if(ctx, hlsl_ir_if(instr), state);
                 break;
diff --git a/tests/swizzle-constant-prop.shader_test b/tests/swizzle-constant-prop.shader_test
index 0a13b4df..86eb3f19 100644
--- a/tests/swizzle-constant-prop.shader_test
+++ b/tests/swizzle-constant-prop.shader_test
@@ -10,7 +10,7 @@ size (4, 4)
 13 13 13 13   14 14 14 14   14 15 15 15   16 16 16 16

-[pixel shader todo]
+[pixel shader]
 Texture2D tex;
 uniform int i;

@@ -22,8 +22,8 @@ float4 main() : sv_target

[test]
 uniform 0 int 4
-todo draw quad
-todo probe all rgba (110, 210, 410, 410)
+draw quad
+probe all rgba (110, 210, 410, 410)

[pixel shader todo]