[PATCH] [ASan] Use less shadow on Win 32-bit

[Timur Iskhodzhanov]

================
Comment at: lib/asan/asan_rtl.cc:334
@@ +333,3 @@
+  kHighMemEnd = kHighMemEnd | (GetPageSizeCached() - 1);
+  while (kHighMemBeg % GetPageSizeCached())
+    kHighMemEnd += GetPageSizeCached();
----------------
Timur Iskhodzhanov wrote:
> Alexey Samsonov wrote:
> > I don't understand this loop.
> That's covered by the above "make sure everything is fine" comment.
> 
>   Not only we want the kHighMemEnd to be page-aligned,
>   we also want kHighMemBeg to be page-aligned in order to map shadow.
> 
> Should I add this answer to the comment?
Ah, I see the confusion.

kHighMemBeg is defined as (drum roll please!) 

  #define kHighMemBeg     (MEM_TO_SHADOW(kHighMemEnd) + 1)

so....

Thoughts?
How to explain that better?


http://llvm-reviews.chandlerc.com/D1139