[Mesa-dev] [PATCH 2/4] i965: Add a copy constructor (of sorts) for cfg_t.

[Kenneth Graunke]

This clones an existing CFG.

We can't properly copy the instruction lists from cfg_t itself, as
it's fs_inst/vec4_instruction agnostic, and we don't use templates.
To accomplish this, we pass in an instruction-list-copying function.
---
 src/intel/compiler/brw_cfg.cpp | 41 +++++++++++++++++++++++++++++++++++++++++
 src/intel/compiler/brw_cfg.h   |  6 ++++++
 2 files changed, 47 insertions(+)

diff --git a/src/intel/compiler/brw_cfg.cpp b/src/intel/compiler/brw_cfg.cpp
index 600b428a492..06cb6324a7e 100644
--- a/src/intel/compiler/brw_cfg.cpp
+++ b/src/intel/compiler/brw_cfg.cpp
@@ -386,6 +386,47 @@ cfg_t::cfg_t(exec_list *instructions)
    make_block_array();
 }
 
+cfg_t::cfg_t(const cfg_t &other,
+             void (*copy_instruction_list)(void *mem_ctx, exec_list *dst,
+                                           exec_list *src))
+{
+   mem_ctx = ralloc_context(NULL);
+   idom_dirty = other.idom_dirty;
+   num_blocks = other.num_blocks;
+   cycle_count = other.cycle_count;
+
+   foreach_block(other_block, &other) {
+      bblock_t *block = new(mem_ctx) bblock_t(this);
+
+      block->start_ip = other_block->start_ip;
+      block->end_ip = other_block->end_ip;
+      block->num = other_block->num;
+      block->cycle_count = other_block->cycle_count;
+
+      block_list.push_tail(&block->link);
+   }
+
+   make_block_array();
+
+   for (int b = 0; b < num_blocks; b++) {
+      copy_instruction_list(mem_ctx,
+                            &blocks[b]->instructions,
+                            &other.blocks[b]->instructions);
+      foreach_list_typed(bblock_link, predecessor, link,
+                         &other.blocks[b]->parents) {
+         bblock_link *new_link =
+            new(mem_ctx) bblock_link(blocks[predecessor->block->num]);
+         blocks[b]->parents.push_tail(&new_link->link);
+      }
+      foreach_list_typed(bblock_link, successor, link,
+                         &other.blocks[b]->children) {
+         bblock_link *new_link =
+            new(mem_ctx) bblock_link(blocks[successor->block->num]);
+         blocks[b]->children.push_tail(&new_link->link);
+      }
+   }
+}
+
 cfg_t::~cfg_t()
 {
    ralloc_free(mem_ctx);
diff --git a/src/intel/compiler/brw_cfg.h b/src/intel/compiler/brw_cfg.h
index 0c5d1268f1a..7d9f4ba9622 100644
--- a/src/intel/compiler/brw_cfg.h
+++ b/src/intel/compiler/brw_cfg.h
@@ -273,9 +273,15 @@ bblock_t::last_non_control_flow_inst()
 
 struct cfg_t {
 #ifdef __cplusplus
+private:
+   cfg_t(const cfg_t &other);
+
+public:
    DECLARE_RALLOC_CXX_OPERATORS(cfg_t)
 
    cfg_t(exec_list *instructions);
+   cfg_t(const cfg_t &other,
+         void (*copy_instlist)(void *mem_ctx, exec_list *dst, exec_list *src));
    ~cfg_t();
 
    void remove_block(bblock_t *block);
-- 
2.16.1