perf(codegen): speed up generic registry pipelines

changelog.d/8607-pipeline-null-default-add.md

@@ -0,0 +1,6 @@
+### Performance
+
+- Speed up generic registries and record-processing pipelines by caching stable
+  array fields on proven-contained receivers and using a guarded numeric fast
+  path for null-defaulted counters, while preserving dynamic JavaScript
+  semantics on aliased and non-number fallback paths.

crates/perry-codegen/src/codegen/artifacts.rs

@@ -362,6 +362,7 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                     false,
                     None,
                     Some(nonnegative_index_params),
+                    false,
                 )
                 .with_context(|| {
                     format!(
@@ -395,6 +396,7 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                     .contains_key(&(class.name.clone(), method.name.clone())),
                 None,
                 None,
+                false,
             )
             .with_context(|| format!("lowering method '{}::{}'", class.name, method.name))?;
             // Representation-selection Phase 5a: the additive `internal`
@@ -431,13 +433,56 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                     false,
                     Some(fact.clone()),
                     None,
+                    false,
                 )
                 .with_context(|| {
                     format!(
                         "lowering proven-`this` clone of method '{}::{}'",
                         class.name, method.name
                     )
                 })?;
+
+                // #8607: a second, stricter clone for the Phase 3b
+                // provenance+containment route. Its synthetic immutable
+                // aliases keep stable array-valued fields in local slots, so
+                // existing local-array loop optimizations can see through
+                // repeated `this.field` uses. It is never selected by the
+                // guarded or dispatch-tower `$pshape` routes.
+                if let Some(cached_method) =
+                    crate::collectors::ptr_array_cached_method(class, method)
+                {
+                    compile_method(
+                        llmod,
+                        class,
+                        &cached_method,
+                        func_names,
+                        strings,
+                        class_table,
+                        method_names,
+                        module_globals,
+                        module_global_types,
+                        opts.import_function_prefixes,
+                        enum_table,
+                        static_field_globals,
+                        class_ids,
+                        func_signatures,
+                        func_synthetic_arguments,
+                        module_boxed_vars,
+                        closure_rest_params,
+                        cross_module,
+                        None,
+                        false,
+                        Some(fact.clone()),
+                        None,
+                        true,
+                    )
+                    .with_context(|| {
+                        format!(
+                            "lowering contained-receiver array-cache clone of method '{}::{}'",
+                            class.name, method.name
+                        )
+                    })?;
+                }
             }
         }
         for member in class
@@ -468,6 +513,7 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                 false,
                 None,
                 None,
+                false,
             )
             .with_context(|| {
                 format!(
@@ -534,6 +580,7 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                 false,
                 None,
                 None,
+                false,
             )
             .with_context(|| format!("lowering getter '{}::{}'", class.name, prop))?;
         }
@@ -588,6 +635,7 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                 false,
                 None,
                 None,
+                false,
             )
             .with_context(|| format!("lowering setter '{}::{}'", class.name, prop))?;
         }
@@ -684,6 +732,7 @@ pub(super) fn emit_module_artifacts(c: ModuleArtifactsCtx<'_>) -> Result<()> {
                 false,
                 None,
                 None,
+                false,
             )
             .with_context(|| format!("lowering constructor for '{}'", class.name))?;
         }

crates/perry-codegen/src/codegen/method.rs

@@ -263,6 +263,7 @@ pub(super) fn compile_method(
     force_generic_body: bool,
     proven_this: Option<crate::collectors::PtrShapeLocal>,
     nonnegative_index_params: Option<&[u32]>,
+    ptr_array_cache_clone: bool,
 ) -> Result<()> {
     let public_llvm_name = methods
         .get(&(class.name.clone(), method.name.clone()))
@@ -282,8 +283,11 @@ pub(super) fn compile_method(
     let is_pshape_clone = proven_this.is_some();
     let is_index_clone = nonnegative_index_params.is_some();
     debug_assert!(!(is_pshape_clone && is_index_clone));
+    debug_assert!(!ptr_array_cache_clone || is_pshape_clone);
     let llvm_name = if let Some(params) = nonnegative_index_params {
         crate::codegen::nonnegative_index_method_name(&public_llvm_name, params)
+    } else if ptr_array_cache_clone {
+        crate::collectors::ptr_array_cache_method_name(&public_llvm_name)
     } else if is_pshape_clone {
         crate::collectors::pshape_method_name(&public_llvm_name)
     } else if typed_public_trampoline.is_some() || force_generic_body {

crates/perry-codegen/src/collectors/mod.rs

@@ -84,7 +84,8 @@ pub(crate) use number_by_construction::collect_number_by_construction_locals;
 pub(crate) use param_ranges::{collect_param_int_ranges, ParamIntRanges};
 pub(crate) use pointer_locals::collect_pointer_typed_locals;
 pub(crate) use proven_this::{
-    method_proven_this, prune_unregistered_clones, pshape_method_name,
+    method_proven_this, prune_unregistered_clones, pshape_method_name, ptr_array_cache_fields,
+    ptr_array_cache_method_name, ptr_array_cached_method,
     tower_route_profitable as pshape_tower_route_profitable,
 };
 pub(crate) use ptr_numarray::{NumArrayDensity, NumArrayLocal};