[wasm] Increase WebAssembly.Memory maximum size to ~2GB

test/mjsunit/wasm/grow-memory.js

Index: test/mjsunit/wasm/grow-memory.js
diff --git a/test/mjsunit/wasm/grow-memory.js b/test/mjsunit/wasm/grow-memory.js
index 71eb4fec95a7971ab0b824480b66304ea565ef59..3222bba90c76e3183d862fb7448b27b4cf202b8e 100644
--- a/test/mjsunit/wasm/grow-memory.js
+++ b/test/mjsunit/wasm/grow-memory.js
@@ -8,7 +8,7 @@ load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 var kPageSize = 0x10000;
-var kV8MaxPages = 16384;
+var kV8MaxPages = 32767;
 
 function genGrowMemoryBuilder() {
   var builder = new WasmModuleBuilder();
@@ -298,9 +298,8 @@ function testGrowMemoryTrapMaxPagesZeroInitialMemory() {
   var builder = genGrowMemoryBuilder();
   builder.addMemory(0, kV8MaxPages, false);
   var module = builder.instantiate();
-  var maxPages = 16385;
   function growMem(pages) { return module.exports.grow_memory(pages); }
-  assertEquals(-1, growMem(maxPages));
+  assertEquals(-1, growMem(kV8MaxPages + 1));
 }
 
 testGrowMemoryTrapMaxPagesZeroInitialMemory();
@@ -309,9 +308,8 @@ function testGrowMemoryTrapMaxPages() {
   var builder = genGrowMemoryBuilder();
   builder.addMemory(1, 1, false);
   var module = builder.instantiate();
-  var maxPages = 16384;
   function growMem(pages) { return module.exports.grow_memory(pages); }
-  assertEquals(-1, growMem(maxPages));
+  assertEquals(-1, growMem(kV8MaxPages));
 }
 
 testGrowMemoryTrapMaxPages();
@@ -493,3 +491,44 @@ function testGrowMemoryDeclaredSpecMaxTraps() {
 }
 
 testGrowMemoryDeclaredSpecMaxTraps();
+
+function testGrowMemory2Gb() {
+  print("testGrowMemory2Gb");

[Eric Holk, 2017/06/13 16:19:48]

Thanks for printing the test name! This makes it a lot easier to debug when we
need to.

[gdeepti, 2017/06/13 21:25:43]

I agree it makes easier debugging. :)
I have an AI to retroactively refactor this file/print names for tests .

+  var builder = genGrowMemoryBuilder();
+  builder.addMemory(1, kV8MaxPages, false);
+  var module = builder.instantiate();
+  var offset, val;
+  function peek() { return module.exports.load(offset); }
+  function poke(value) { return module.exports.store(offset, value); }
+  function growMem(pages) { return module.exports.grow_memory(pages); }
+
+  for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
+    poke(100000 - offset);
+    assertEquals(100000 - offset, peek());
+  }
+
+  let result = growMem(kV8MaxPages - 1);
+  if (result == 1 ){
+    for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
+      assertEquals(100000 - offset, peek());
+    }
+
+    // Bounds check for large mem size
+    for(offset = (kV8MaxPages - 1) * kPageSize;
+        offset <= (kV8MaxPages * kPageSize - 4); offset+=4) {
+      poke(0xaced);
+      assertEquals(0xaced, peek());
+    }
+
+    for (offset = kV8MaxPages * kPageSize - 3;
+        offset <= kV8MaxPages * kPageSize + 4; offset++) {
+      assertTraps(kTrapMemOutOfBounds, poke);

[Eric Holk, 2017/06/13 16:19:48]

I think it'd be good to test a couple of addresses in the 3GB to 4GB range,
since this is where we can run into sign extension problems. It looks like this
test gets up to 2GB + 4 bytes, but going further out of bounds would be useful.

There might be other tests that cover this range, although I wonder if high
addresses with a large memory size might lead to different problems.

[gdeepti, 2017/06/13 21:25:43]

Done.

+    }
+  } else {
+    // Allocating big chunks of memory can fail on gc_stress, especially on 32
+    // bit platforms. When grow_memory fails, expected result is -1.
+    assertEquals(-1, result);
+  }
+}
+
+testGrowMemory2Gb();