llvm dev - Dec 2011 - [LLVMdev] load widening conflicts with AddressSanitizer

I'm not opposed to disabling this transformation when asan is on, we just
need a clean way to express this in the IR.

-Chris

On Dec 16, 2011, at 3:08 PM, Kostya Serebryany <kcc at google.com> wrote:
> Why you don't like the idea to disable or restrict the widening when
asan is on?
> 
> --kcc

On 16/12/11 08:46 PM, Chris Lattner wrote:
> I'm not opposed to disabling this transformation when asan is on, we
just need a clean way to express this in the IR.
Could clang be aware of asan being on and introduce a "please don't
widen" metadata on local variable accesses?

Alternatively, could asan analyze the IL to see which bytes are used?
> -Chris
> 
Cheers,
Rafael

On Dec 17, 2011, at 7:40 AM, Rafael Ávila de Espíndola wrote:
> On 16/12/11 08:46 PM, Chris Lattner wrote:
>> I'm not opposed to disabling this transformation when asan is on,
we just need a clean way to express this in the IR.
> 
> Could clang be aware of asan being on and introduce a "please
don't
> widen" metadata on local variable accesses?
Yes, "we just need a clean way to express this in the IR."

LLVM can't have a global "bool ASANIsOn;" that the optimizers
listen to.

-Chris