[RISCV][ASAN] instrumentation pass now uses proper shadow offset

[10/11] patch series to port ASAN for riscv64

Depends On D87580

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D87581

Author: EccoTheDolphin

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

@@ -105,6 +105,7 @@ static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
+static const uint64_t kRISCV64_ShadowOffset64 = 0x20000000;
 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
 static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
@@ -447,6 +448,7 @@ static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
   bool IsMIPS64 = TargetTriple.isMIPS64();
   bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
   bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
+  bool IsRISCV64 = TargetTriple.getArch() == Triple::riscv64;
   bool IsWindows = TargetTriple.isOSWindows();
   bool IsFuchsia = TargetTriple.isOSFuchsia();
   bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
@@ -515,6 +517,8 @@ static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
       Mapping.Offset = kDynamicShadowSentinel;
     else if (IsAArch64)
       Mapping.Offset = kAArch64_ShadowOffset64;
+    else if (IsRISCV64)
+      Mapping.Offset = kRISCV64_ShadowOffset64;
     else
       Mapping.Offset = kDefaultShadowOffset64;
   }
@@ -533,6 +537,7 @@ static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
   // we could OR the constant in a single instruction, but it's more
   // efficient to load it once and use indexed addressing.
   Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
+                           !IsRISCV64 &&
                            !(Mapping.Offset & (Mapping.Offset - 1)) &&
                            Mapping.Offset != kDynamicShadowSentinel;
   bool IsAndroidWithIfuncSupport =