[PATCH] AArch64 sanitizer support

[Christophe Lyon]

  Thank you for your comments. I'll make some cleanup and re-submit it.


================
Comment at: libsanitizer/asan/asan_mapping.h:63
@@ -62,2 +62,3 @@
 static const u64 kPPC64_ShadowOffset64 = 1ULL << 41;
+static const u64 kAArch64_ShadowOffset64 = 1ULL << 36;
 static const u64 kMIPS32_ShadowOffset32 = 0x0aaa8000;
----------------
Kostya Serebryany wrote:
> Note that on x86 we use 0x7FFF8000 (a small offset that fits into smaller instructions)
> as a performance optimization. 
> I don't know AArch64 well enough to judge whether a smaller offset will give us performance benefits.
> Any ideas? 
No. So far, I haven't been able to make any performance assessment on AArch64.
My first goal was to enable the feature.

================
Comment at: libsanitizer/configure.tgt:35
@@ -34,1 +34,3 @@
 	;;
+  aarch64*-*-linux*)
+	TSAN_SUPPORTED=no
----------------
Kostya Serebryany wrote:
> no such file in llvm
OK, sorry.
When I submitted this patch, I did remove the modifications under the top-level gcc directory and did not think about this one.


http://llvm-reviews.chandlerc.com/D2732