Bug 1218643 - remove support for deprecated asm.js heap length. r=luke

--HG--
extra : rebase_source : 898189dfc6fde7d0c818e22c6ef277935d1acd0d

js/src/asmjs/AsmJSLink.cpp

@@ -469,17 +469,6 @@ LinkModuleToHeap(JSContext* cx, AsmJSModule& module, Handle<ArrayBufferObjectMay
 {
     uint32_t heapLength = heap->byteLength();
 
-    if (IsDeprecatedAsmJSHeapLength(heapLength)) {
-        LinkFail(cx, "ArrayBuffer byteLengths smaller than 64KB are deprecated and "
-                     "will cause a link-time failure in the future");
-
-        // The goal of deprecation is to give apps some time before linking
-        // fails. However, if warnings-as-errors is turned on (which happens as
-        // part of asm.js testing) an exception may be raised.
-        if (cx->isExceptionPending())
-            return false;
-    }
-
     if (!IsValidAsmJSHeapLength(heapLength)) {
         ScopedJSFreePtr<char> msg(
             JS_smprintf("ArrayBuffer byteLength 0x%x is not a valid heap length. The next "
@@ -631,7 +620,6 @@ ChangeHeap(JSContext* cx, AsmJSModule& module, const CallArgs& args)
     }
 
     MOZ_ASSERT(IsValidAsmJSHeapLength(heapLength));
-    MOZ_ASSERT(!IsDeprecatedAsmJSHeapLength(heapLength));
 
     if (!ArrayBufferObject::prepareForAsmJS(cx, newBuffer, module.usesSignalHandlersForOOB()))
         return false;

js/src/asmjs/AsmJSValidate.h

@@ -51,9 +51,14 @@ extern bool
 ValidateAsmJS(ExclusiveContext* cx, AsmJSParser& parser, frontend::ParseNode* stmtList,
              bool* validated);
 
+// The minimum heap length for asm.js.
+const size_t AsmJSMinHeapLength = 64 * 1024;
+
 // The assumed page size; dynamically checked in ValidateAsmJS.
 const size_t AsmJSPageSize = 4096;
 
+static_assert(AsmJSMinHeapLength % AsmJSPageSize == 0, "Invalid page size");
+
 #if defined(ASMJS_MAY_USE_SIGNAL_HANDLERS_FOR_OOB)
 
 // Targets define AsmJSImmediateRange to be the size of an address immediate,
@@ -86,8 +91,8 @@ static const size_t AsmJSMappedSize = 4 * 1024ULL * 1024ULL * 1024ULL +
 inline uint32_t
 RoundUpToNextValidAsmJSHeapLength(uint32_t length)
 {
-    if (length <= 4 * 1024)
-        return 4 * 1024;
+    if (length <= AsmJSMinHeapLength)
+        return AsmJSMinHeapLength;
 
     if (length <= 16 * 1024 * 1024)
         return mozilla::RoundUpPow2(length);
@@ -99,7 +104,7 @@ RoundUpToNextValidAsmJSHeapLength(uint32_t length)
 inline bool
 IsValidAsmJSHeapLength(uint32_t length)
 {
-    bool valid = length >= 4 * 1024 &&
+    bool valid = length >= AsmJSMinHeapLength &&
                  (IsPowerOfTwo(length) ||
                   (length & 0x00ffffff) == 0);
 
@@ -109,14 +114,6 @@ IsValidAsmJSHeapLength(uint32_t length)
     return valid;
 }
 
-// For now, power-of-2 lengths in this range are accepted, but in the future
-// we'll change this to cause link-time failure.
-inline bool
-IsDeprecatedAsmJSHeapLength(uint32_t length)
-{
-    return length >= 4 * 1024 && length < 64 * 1024 && IsPowerOfTwo(length);
-}
-
 // Return whether asm.js optimization is inhibited by the platform or
 // dynamically disabled:
 extern bool

js/src/jit-test/tests/asm.js/neuter-during-arguments-coercion.js

@@ -15,7 +15,7 @@ function f(stdlib, foreign, buffer)
 if (isAsmJSCompilationAvailable())
   assertEq(isAsmJSModule(f), true);
 
-var i32 = new Int32Array(4096);
+var i32 = new Int32Array(65536);
 var buffer = i32.buffer;
 var set = f(this, null, buffer);
 if (isAsmJSCompilationAvailable())