[PATCH] D14199: [compiler-rt] [tsan] Unify aarch64 mapping

[Adhemerval Zanella via llvm-commits]

zatrazz added inline comments.

================
Comment at: lib/tsan/rtl/tsan_platform.h:186
@@ -152,3 +185,3 @@
   return (mem >= kHeapMemBeg && mem < kHeapMemEnd) ||
          (mem >= kLoAppMemBeg && mem < kLoAppMemEnd) ||
          (mem >= kHiAppMemBeg && mem < kHiAppMemEnd);
----------------
dvyukov wrote:
> Won't it then be faster to inline all 3 variants?
> 
> E.g. 
> 
>   struct Mapping39 {
>     static const uptr kLoAppMemBeg = 0x...;
>     static const uptr kLoAppMemEnd = 0x...;
>     static const uptr kShadowBeg = 0x...;
>     ...
>   };
>   
>   struct Mapping42 {
>     static const uptr kLoAppMemBeg = 0x...;
>     static const uptr kLoAppMemEnd = 0x...;
>     static const uptr kShadowBeg = 0x...;
>     ...
>   };
>   
>   template<typename Mapping>
>   uptr MemToShadowImpl(uptr x) {
>     return (((x) & ~(Mapping::kAppMemMsk | (kShadowCell - 1)))
>         ^ Mapping::kAppMemXor) * kShadowCnt;
>   }
>   
>   uptr MemToShadow(uptr x) {
>     if (vma_size == 39)
>       return MemToShadowImpl<Mapping39>(x);
>     else
>       return MemToShadowImpl<Mapping42>(x);
>     DCHECK(0);
>   }
> 
> I suspect it can be faster as it is inlinable. And probably compiler will be able to do some common expressions merging, so the code won't be too large.
I will check this out, thanks!


http://reviews.llvm.org/D14199