MemoryBuffer.cpp: Consider if PageSize were not 4096 in shouldUseMmap(). Follow-up...

The AllocationGranularity can be 65536 on Win32, even on Cygwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188998 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index cab45c7..1c45c69 100644 (file)
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -276,7 +276,7 @@ static bool shouldUseMmap(int FD,
                           int PageSize) {
   // We don't use mmap for small files because this can severely fragment our
   // address space.
-  if (MapSize < 4096*4)
+  if (MapSize < 4 * 4096 || MapSize < (unsigned)PageSize)
     return false;
 
   if (!RequiresNullTerminator)