On Tue, Jun 24, 2008 at 08:20:12AM +0200, Mike Hommey wrote: > It could make sense, if sparc needs this uint64_t to be 64-bit aligned. > And it looks like so: > > (gdb) print $pc > $1 = (void (*)(void)) 0xf7e3b880 <WTF::TCMalloc_PageHeap::GrowHeap(unsigned > int)+104> > > (gdb) disassemble $pc $npc > Dump of assembler code from 0xf7e3b880 to 0xf7e3b884: > 0xf7e3b880 <_ZN3WTF17TCMalloc_PageHeap8GrowHeapEj+104>: ldd [ %i0 + %g2 ], > %o4 > End of assembler dump. > > (gdb) info registers i0 g2 > i0 0xf7f9cdc4 -134623804 > g2 0x50b8 20664 > > 0x50b8 & 7 is 0, but 0xf7f9cdc4 & 7 is not, so i0 + g2 is not 64-bit > aligned. > > If the diagnostic is correct, what would be the best way to fix this ? > Split the assignment into 2 uint32_t ones ? Or is there a way to have > the class 64-bit aligned ? Or maybe a way to get gcc to split the > uint64_t assignment itself ?
Or maybe something like this: diff --git a/JavaScriptCore/wtf/FastMalloc.cpp b/JavaScriptCore/wtf/FastMalloc.cpp index 8afc70d..496d1ee 100644 --- a/JavaScriptCore/wtf/FastMalloc.cpp +++ b/JavaScriptCore/wtf/FastMalloc.cpp @@ -1820,7 +1820,7 @@ static TCMalloc_Central_FreeListPadded central_cache[kNumClasses]; // Page-level allocator static SpinLock pageheap_lock = SPINLOCK_INITIALIZER; -static void* pageheap_memory[(sizeof(TCMalloc_PageHeap) + sizeof(void*) - 1) / sizeof(void*)]; +static uint64_t* pageheap_memory[(sizeof(TCMalloc_PageHeap) + sizeof(uint64_t*) - 1) / sizeof(uint64_t*)]; static bool phinited = false; // Avoid extra level of indirection by making "pageheap" be just an alias The relevant code is: http://git.debian.org/?p=pkg-webkit/webkit.git;a=blob;f=JavaScriptCore/wtf/FastMalloc.cpp;h=8afc70d9d6ded4cd4a056220ac750c1abd1044d2;hb=1f5af570264d9bac805c25c6ccdff320782bb243#l1821 The stacktrace being: #0 WTF::TCMalloc_PageHeap::GrowHeap (this=0xf7f68dc4, n=1) at ../JavaScriptCore/wtf/FastMalloc.cpp:1466 #1 0xf7e6753c in WTF::TCMalloc_PageHeap::New (this=0xf7f68dc4, n=1) at ../JavaScriptCore/wtf/FastMalloc.cpp:1186 #2 0xf7e07ca0 in WTF::TCMalloc_Central_FreeList::FetchFromSpansSafe (this=0xf7f6fdf0) at ../JavaScriptCore/wtf/FastMalloc.cpp:2116 And line 2116 reading: span = pageheap->New(npages); Where pageheap is a macro for getPageHeap(). So what is actually not 64-bit aligned is not allocated through the a dynamic allocator... So, I'd say forcing this to be 64-bit aligned should be enough, and the above diff should be doing just this. What do you think? Mike -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
