[PATCH] Implement variable-sized alloca instrumentation.

[Maxim Ostapenko]

================
Comment at: lib/Transforms/Instrumentation/AddressSanitizer.cpp:656
@@ +655,3 @@
+                                                       Int32PtrTy);
+    // if (PartialSize) {
+    //   PartialRzMagic = calculatePartialRzMagic(PartialSize);
----------------
kcc wrote:
> instead of creating a new BB for partial RZ, I would do this: 
> make sure that PartialSize is never zero, i.e. instead of being in 0..31 it is in 1..32
> This is better as we will not need to keep both pointers (PartialRz and RightRz) alive throughout the procedure. 
Yes, this is a good idea to avoid new BB creation. But we still need both PartialRz and RightRz, because in case of PartialSize == 32 PartialRz points the same address as RightRz, otherwise RightRz == PartialSize + 32, isn't it?

Or maybe I've misunderstood something?

http://reviews.llvm.org/D6055