[PATCH vkd3d 4/5] vkd3d-shader/hlsl: Handle loops in copy propagation.

[Giovanni Mascellani]

Signed-off-by: Giovanni Mascellani <gmascellani at codeweavers.com>
---
 libs/vkd3d-shader/hlsl_codegen.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
index 78bcd079..fe6a9908 100644
--- a/libs/vkd3d-shader/hlsl_codegen.c
+++ b/libs/vkd3d-shader/hlsl_codegen.c
@@ -537,6 +537,28 @@ end:
     return progress;
 }
 
+/* The loop body can inherit the variable state avaiable when entering
+ * the "loop", except that all variables that are written in the body
+ * must be invalidated (because at the beginning of each execution we
+ * don't know whether the body has already executed or not). The same
+ * is valid for after the "loop", because we don't know whether the
+ * body has executed or not. */
+static bool copy_propagation_loop(struct hlsl_ctx *ctx, struct hlsl_ir_loop *loop,
+        struct copy_propagation_state *state)
+{
+    bool progress = false;
+
+    copy_propagation_invalidate_from_block(ctx, state, &loop->body);
+    if (!copy_propagation_duplicate(ctx, state))
+        return progress;
+
+    progress |= copy_propagation_recursive(ctx, &loop->body, state);
+
+    copy_propagation_pop(state);
+
+    return progress;
+}
+
 static bool copy_propagation_recursive(struct hlsl_ctx *ctx, struct hlsl_block *block,
         struct copy_propagation_state *state)
 {
@@ -560,7 +582,7 @@ static bool copy_propagation_recursive(struct hlsl_ctx *ctx, struct hlsl_block *
                 return progress;
 
             case HLSL_IR_LOOP:
-                FIXME("Copy propagation doesn't support loops yet, leaving.\n");
+                progress |= copy_propagation_loop(ctx, hlsl_ir_loop(instr), state);
                 return progress;
 
             default:
-- 
2.33.1