[llvm] r252495 - [sanitizer] Use same shadow offset for ASAN on aarch64

[Adhemerval Zanella via llvm-commits]

Author: azanella
Date: Mon Nov  9 12:03:48 2015
New Revision: 252495

URL: http://llvm.org/viewvc/llvm-project?rev=252495&view=rev
Log:
[sanitizer] Use same shadow offset for ASAN on aarch64

This patch makes ASAN for aarch64 use the same shadow offset for all
currently supported VMAs (39 and 42 bits).  The shadow offset is the
same for 39-bit (36).  Similar to ppc64 port, aarch64 transformation
also requires to use an add instead of 'or' for 42-bit VMA.

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=252495&r1=252494&r2=252495&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Mon Nov  9 12:03:48 2015
@@ -63,16 +63,6 @@ using namespace llvm;
 
 #define DEBUG_TYPE "asan"
 
-// VMA size definition for architecture that support multiple sizes.
-// AArch64 has 3 VMA sizes: 39, 42 and 48.
-#ifndef SANITIZER_AARCH64_VMA
-# define SANITIZER_AARCH64_VMA 39
-#else
-# if SANITIZER_AARCH64_VMA != 39 && SANITIZER_AARCH64_VMA != 42
-#  error "invalid SANITIZER_AARCH64_VMA size"
-# endif
-#endif
-
 static const uint64_t kDefaultShadowScale = 3;
 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
 static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
@@ -82,11 +72,7 @@ static const uint64_t kLinuxKasan_Shadow
 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
-#if SANITIZER_AARCH64_VMA == 39
 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
-#elif SANITIZER_AARCH64_VMA == 42
-static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 39;
-#endif
 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
 static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
@@ -395,7 +381,8 @@ static ShadowMapping getShadowMapping(Tr
   // OR-ing shadow offset if more efficient (at least on x86) if the offset
   // is a power of two, but on ppc64 we have to use add since the shadow
   // offset is not necessary 1/8-th of the address space.
-  Mapping.OrShadowOffset = !IsPPC64 && !(Mapping.Offset & (Mapping.Offset - 1));
+  Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64
+                           && !(Mapping.Offset & (Mapping.Offset - 1));
 
   return Mapping;
 }