fix: Fix growing factor for capacity in Array

std/assembly/array.ts

@@ -6,22 +6,28 @@ import { joinBooleanArray, joinIntegerArray, joinFloatArray, joinStringArray, jo
 import { idof, isArray as builtin_isArray } from "./builtins";
 import { E_INDEXOUTOFRANGE, E_INVALIDLENGTH, E_ILLEGALGENTYPE, E_EMPTYARRAY, E_HOLEYARRAY } from "./util/error";
 
+// @ts-ignore: decorator
+@inline @lazy const MIN_SIZE: usize = 8;
+
 /** Ensures that the given array has _at least_ the specified backing size. */
-function ensureSize(array: usize, minSize: usize, alignLog2: u32): void {
-  // depends on the fact that Arrays mimic ArrayBufferView
-  var oldCapacity = changetype<ArrayBufferView>(array).byteLength;
-  if (minSize > <usize>oldCapacity >>> alignLog2) {
-    if (minSize > BLOCK_MAXSIZE >>> alignLog2) throw new RangeError(E_INVALIDLENGTH);
+function ensureCapacity(array: usize, newSize: usize, alignLog2: u32, canGrow: bool = true): void {
+  // Depends on the fact that Arrays mimic ArrayBufferView
+  var oldCapacity = <usize>changetype<ArrayBufferView>(array).byteLength;
+  if (newSize > oldCapacity >>> alignLog2) {
+    if (newSize > BLOCK_MAXSIZE >>> alignLog2) throw new RangeError(E_INVALIDLENGTH);
     let oldData = changetype<usize>(changetype<ArrayBufferView>(array).buffer);
-    let newCapacity = minSize << alignLog2;
+    // Grows old capacity by factor of two.
+    // Make sure we don't reach BLOCK_MAXSIZE for new growed capacity.
+    let newCapacity = max(newSize, MIN_SIZE) << alignLog2;
+    if (canGrow) newCapacity = max(min(oldCapacity << 1, BLOCK_MAXSIZE), newCapacity);
     let newData = __renew(oldData, newCapacity);
     memory.fill(newData + oldCapacity, 0, newCapacity - oldCapacity);
     if (newData !== oldData) { // oldData has been free'd
       store<usize>(array, newData, offsetof<ArrayBufferView>("buffer"));
       store<usize>(array, newData, offsetof<ArrayBufferView>("dataStart"));
       __link(array, changetype<usize>(newData), false);
     }
-    store<u32>(array, newCapacity, offsetof<ArrayBufferView>("byteLength"));
+    store<u32>(array, <u32>newCapacity, offsetof<ArrayBufferView>("byteLength"));
   }
 }
 
@@ -56,7 +62,8 @@ export class Array<T> {
 
   constructor(length: i32 = 0) {
     if (<u32>length > <u32>BLOCK_MAXSIZE >>> alignof<T>()) throw new RangeError(E_INVALIDLENGTH);
-    var bufferSize = <usize>length << alignof<T>();
+    // reserve capacity for at least MIN_SIZE elements
+    var bufferSize = <usize>max(length, MIN_SIZE) << alignof<T>();
     var buffer = changetype<ArrayBuffer>(__new(bufferSize, idof<ArrayBuffer>()));
     memory.fill(changetype<usize>(buffer), 0, bufferSize);
     this.buffer = buffer; // links
@@ -70,7 +77,7 @@ export class Array<T> {
   }
 
   set length(newLength: i32) {
-    ensureSize(changetype<usize>(this), newLength, alignof<T>());
+    ensureCapacity(changetype<usize>(this), newLength, alignof<T>(), false);
     this.length_ = newLength;
   }
 
@@ -106,7 +113,7 @@ export class Array<T> {
   @operator("[]=") private __set(index: i32, value: T): void {
     if (<u32>index >= <u32>this.length_) {
       if (index < 0) throw new RangeError(E_INDEXOUTOFRANGE);
-      ensureSize(changetype<usize>(this), index + 1, alignof<T>());
+      ensureCapacity(changetype<usize>(this), index + 1, alignof<T>());
       this.length_ = index + 1;
     }
     this.__uset(index, value);
@@ -204,7 +211,7 @@ export class Array<T> {
   push(value: T): i32 {
     var length = this.length_;
     var newLength = length + 1;
-    ensureSize(changetype<usize>(this), newLength, alignof<T>());
+    ensureCapacity(changetype<usize>(this), newLength, alignof<T>());
     if (isManaged<T>()) {
       store<usize>(this.dataStart + (<usize>length << alignof<T>()), changetype<usize>(value));
       __link(changetype<usize>(this), changetype<usize>(value), true);
@@ -353,7 +360,7 @@ export class Array<T> {
 
   unshift(value: T): i32 {
     var newLength = this.length_ + 1;
-    ensureSize(changetype<usize>(this), newLength, alignof<T>());
+    ensureCapacity(changetype<usize>(this), newLength, alignof<T>());
     var dataStart = this.dataStart;
     memory.copy(
       dataStart + sizeof<T>(),

tests/compiler/assert-nonnull.optimized.wat

@@ -58,7 +58,7 @@
   if
    i32.const 1184
    i32.const 1248
-   i32.const 92
+   i32.const 99
    i32.const 42
    call $~lib/builtins/abort
    unreachable
@@ -212,7 +212,7 @@
   if
    i32.const 1184
    i32.const 1248
-   i32.const 92
+   i32.const 99
    i32.const 42
    call $~lib/builtins/abort
    unreachable
@@ -228,7 +228,7 @@
   if
    i32.const 1296
    i32.const 1248
-   i32.const 96
+   i32.const 103
    i32.const 40
    call $~lib/builtins/abort
    unreachable

tests/compiler/assert-nonnull.untouched.wat

@@ -309,7 +309,7 @@
   if
    i32.const 160
    i32.const 224
-   i32.const 92
+   i32.const 99
    i32.const 42
    call $~lib/builtins/abort
    unreachable
@@ -334,7 +334,7 @@
   if
    i32.const 272
    i32.const 224
-   i32.const 96
+   i32.const 103
    i32.const 40
    call $~lib/builtins/abort
    unreachable
@@ -365,7 +365,7 @@
   if
    i32.const 160
    i32.const 224
-   i32.const 92
+   i32.const 99
    i32.const 42
    call $~lib/builtins/abort
    unreachable

tests/compiler/class.optimized.wat

@@ -1820,13 +1820,13 @@
   i32.const 0
   i32.store offset=12
   global.get $~lib/memory/__stack_pointer
-  i32.const 0
+  i32.const 32
   i32.const 0
   call $~lib/rt/itcms/__new
   local.tee $1
   i32.store offset=4
   local.get $1
-  i32.const 0
+  i32.const 32
   call $~lib/memory/memory.fill
   local.get $0
   local.get $1
@@ -1835,7 +1835,7 @@
   local.get $1
   i32.store offset=4
   local.get $0
-  i32.const 0
+  i32.const 32
   i32.store offset=8
   local.get $0
   i32.const 0

tests/compiler/class.untouched.wat

@@ -2683,6 +2683,8 @@
   (local $2 i32)
   (local $3 i32)
   (local $4 i32)
+  (local $5 i32)
+  (local $6 i32)
   global.get $~lib/memory/__stack_pointer
   i32.const 8
   i32.sub
@@ -2721,44 +2723,51 @@
   if
    i32.const 432
    i32.const 480
-   i32.const 58
+   i32.const 64
    i32.const 60
    call $~lib/builtins/abort
    unreachable
   end
   local.get $1
+  local.tee $2
+  i32.const 8
+  local.tee $3
+  local.get $2
+  local.get $3
+  i32.gt_s
+  select
   i32.const 2
   i32.shl
-  local.set $2
+  local.set $4
   global.get $~lib/memory/__stack_pointer
-  local.get $2
+  local.get $4
   i32.const 0
   call $~lib/rt/itcms/__new
-  local.tee $3
+  local.tee $5
   i32.store offset=4
-  local.get $3
+  local.get $5
   i32.const 0
-  local.get $2
+  local.get $4
   call $~lib/memory/memory.fill
   local.get $0
-  local.get $3
+  local.get $5
   call $~lib/array/Array<i32>#set:buffer
   local.get $0
-  local.get $3
+  local.get $5
   call $~lib/array/Array<i32>#set:dataStart
   local.get $0
-  local.get $2
+  local.get $4
   call $~lib/array/Array<i32>#set:byteLength
   local.get $0
   local.get $1
   call $~lib/array/Array<i32>#set:length_
   local.get $0
-  local.set $4
+  local.set $6
   global.get $~lib/memory/__stack_pointer
   i32.const 8
   i32.add
   global.set $~lib/memory/__stack_pointer
-  local.get $4
+  local.get $6
  )
  (func $class/GenericInitializer<i32>#constructor (param $0 i32) (result i32)
   (local $1 i32)

tests/compiler/extends-baseaggregate.optimized.wat

@@ -2150,15 +2150,14 @@
   i32.store offset=4
   i32.const 1180
   i32.load
-  local.tee $9
+  local.tee $8
   i32.const 1
   i32.add
-  local.tee $5
-  local.set $1
-  local.get $5
+  local.tee $9
+  local.tee $1
   i32.const 1176
   i32.load
-  local.tee $6
+  local.tee $4
   i32.const 2
   i32.shr_u
   i32.gt_u
@@ -2169,45 +2168,65 @@
    if
     i32.const 1616
     i32.const 1664
-    i32.const 14
+    i32.const 17
     i32.const 48
     call $~lib/builtins/abort
     unreachable
    end
    i32.const 1168
    i32.load
-   local.tee $7
+   local.tee $6
    local.set $0
    block $__inlined_func$~lib/rt/itcms/__renew
+    local.get $4
+    i32.const 1
+    i32.shl
+    local.tee $3
+    i32.const 1073741820
+    local.get $3
+    i32.const 1073741820
+    i32.lt_u
+    select
+    local.tee $3
+    local.get $1
+    i32.const 8
     local.get $1
+    i32.const 8
+    i32.gt_u
+    select
     i32.const 2
     i32.shl
-    local.tee $8
+    local.tee $1
+    local.get $1
+    local.get $3
+    i32.lt_u
+    select
+    local.tee $7
     local.tee $3
-    local.get $7
+    local.get $6
     i32.const 20
     i32.sub
-    local.tee $4
+    local.tee $5
     i32.load
     i32.const -4
     i32.and
     i32.const 16
     i32.sub
     i32.le_u
     if
-     local.get $4
+     local.get $5
      local.get $3
      i32.store offset=16
      br $__inlined_func$~lib/rt/itcms/__renew
     end
     local.get $3
-    local.get $4
+    local.get $5
     i32.load offset=12
     call $~lib/rt/itcms/__new
     local.tee $1
     local.get $0
     local.get $3
-    local.get $4
+    local.get $5
     i32.load offset=16
     local.tee $0
     local.get $0
@@ -2219,14 +2238,14 @@
     local.set $0
    end
    local.get $0
-   local.get $6
+   local.get $4
    i32.add
-   local.get $8
-   local.get $6
+   local.get $7
+   local.get $4
    i32.sub
    call $~lib/memory/memory.fill
    local.get $0
-   local.get $7
+   local.get $6
    i32.ne
    if
     i32.const 1168
@@ -2241,12 +2260,12 @@
     call $~lib/rt/itcms/__link
    end
    i32.const 1176
-   local.get $8
+   local.get $7
    i32.store
   end
   i32.const 1172
   i32.load
-  local.get $9
+  local.get $8
   i32.const 2
   i32.shl
   i32.add
@@ -2257,7 +2276,7 @@
   i32.const 1
   call $~lib/rt/itcms/__link
   i32.const 1180
-  local.get $5
+  local.get $9
   i32.store
   global.get $~lib/memory/__stack_pointer
   i32.const 8