tint: Optimize sem node lookup
Add a 'NodeID' to each ast::Node which is the sequentially allocated
index of the node. Use this in sem::Info to map the AST node to the
semantic node, instead of using a std::unordered_map.
Optimised very hot code by entirely eliminating map lookups, and
dramatically reducing cache misses (lookups are usually sequentually
ordered).
Timings running
'webgpu:shader,execution,expression,call,builtin,atan2:f32:inputSource="const";vectorize="_undef_"'
with dawn/node, using SwiftShader:
Without change: 3.22647107s
With change: 3.10578879s
Bug: tint:1613
Change-Id: I22ec48d933b2e5f9da04494bff4e979e6f7b1982
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/96140
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
diff --git a/src/tint/ast/var.h b/src/tint/ast/var.h
index 565ebbb..cd12ff4 100644
--- a/src/tint/ast/var.h
+++ b/src/tint/ast/var.h
@@ -42,7 +42,8 @@
class Var final : public Castable<Var, Variable> {
public:
/// Create a 'var' variable
- /// @param program_id the identifier of the program that owns this node
+ /// @param pid the identifier of the program that owns this node
+ /// @param nid the unique node identifier
/// @param source the variable source
/// @param sym the variable symbol
/// @param type the declared variable type
@@ -50,7 +51,8 @@
/// @param declared_access the declared access control
/// @param constructor the constructor expression
/// @param attributes the variable attributes
- Var(ProgramID program_id,
+ Var(ProgramID pid,
+ NodeID nid,
const Source& source,
const Symbol& sym,
const ast::Type* type,
