[PATCH] D48935: [llvm-exegesis] Provide a way to handle memory instructions.

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


================
Comment at: tools/llvm-exegesis/lib/BenchmarkRunner.h:77
+        : UnalignedPtr(new char[kSize + kAlignment]),
+          AlignedPtr(UnalignedPtr + kAlignment -
+                     (reinterpret_cast<intptr_t>(UnalignedPtr) % kAlignment)) {}
----------------
gchatelet wrote:
> courbet wrote:
> > gchatelet wrote:
> > > courbet wrote:
> > > > gchatelet wrote:
> > > > > Why not [aligned_alloc](https://en.cppreference.com/w/c/memory/aligned_alloc) ?
> > > > > 
> > > > the alignment of aligned_alloc has to be an alignment for a valid object. Some X86 instructions require 512 byte alignment, wich is not the alignment of any valid object. 
> > > I don't understand why you can't use `aligned_alloc(1024, 1<<20);`?
> > aligned_alloc is c++17...
> I read C++11 on the link I provided.
> https://en.cppreference.com/w/c/memory/aligned_alloc
C11, not C**++**11.


Repository:
  rL LLVM

https://reviews.llvm.org/D48935