From 8c98d3439525c0150661ddfb3a556ba1dc62d795 Mon Sep 17 00:00:00 2001
From: Ryan Govostes <rzg@apple.com>
Date: Thu, 5 May 2016 01:27:04 +0000
Subject: [PATCH] Revert "[asan] add option to set shadow mapping offset"

This reverts commit ba89768f97b1d4326acb5e33c14eb23a05c7bea7.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268588 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Instrumentation/AddressSanitizer.cpp      | 11 +-----
 .../AddressSanitizer/scale-offset.ll          | 39 -------------------
 2 files changed, 2 insertions(+), 48 deletions(-)
 delete mode 100644 test/Instrumentation/AddressSanitizer/scale-offset.ll

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 7648352d0b9..f2b5179b436 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -204,13 +204,10 @@ static cl::opt<bool> ClSkipPromotableAllocas(
 
 // These flags allow to change the shadow mapping.
 // The shadow mapping looks like
-//    Shadow = (Mem >> scale) + offset
+//    Shadow = (Mem >> scale) + (1 << offset_log)
 static cl::opt<int> ClMappingScale("asan-mapping-scale",
                                    cl::desc("scale of asan shadow mapping"),
                                    cl::Hidden, cl::init(0));
-static cl::opt<uint64_t> ClMappingOffset("asan-mapping-offset",
-                                   cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"),
-                                   cl::Hidden, cl::init(0));
 
 // Optimization flags. Not user visible, used mostly for testing
 // and benchmarking the tool.
@@ -407,14 +404,10 @@ static ShadowMapping getShadowMapping(Triple &TargetTriple, int LongSize,
   }
 
   Mapping.Scale = kDefaultShadowScale;
-  if (ClMappingScale.getNumOccurrences() > 0) {
+  if (ClMappingScale) {
     Mapping.Scale = ClMappingScale;
   }
 
-  if (ClMappingOffset.getNumOccurrences() > 0) {
-    Mapping.Offset = ClMappingOffset;
-  }
-
   // 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.  On SystemZ,
diff --git a/test/Instrumentation/AddressSanitizer/scale-offset.ll b/test/Instrumentation/AddressSanitizer/scale-offset.ll
deleted file mode 100644
index 8345586fec4..00000000000
--- a/test/Instrumentation/AddressSanitizer/scale-offset.ll
+++ /dev/null
@@ -1,39 +0,0 @@
-; Test that the scale (-asan-mapping-scale) and offset (-asan-mapping-offset) command-line options work as expected
-;
-; RUN: opt < %s -asan -asan-module -asan-mapping-offset 0xdeadbeef -S | FileCheck --check-prefix=CHECK-OFFSET %s
-; RUN: opt < %s -asan -asan-module -asan-mapping-scale 1 -S | FileCheck --check-prefix=CHECK-SCALE %s
-; RUN: opt < %s -asan -asan-module -asan-mapping-offset 0xc0ffee -asan-mapping-scale 0 -S | FileCheck --check-prefix=CHECK-BOTH %s
-target triple = "x86_64-unknown-linux-gnu"
-
-define i32 @read_offset(i32* %a) sanitize_address {
-entry:
-  %tmp1 = load i32, i32* %a, align 4
-  ret i32 %tmp1
-}
-; CHECK-OFFSET-LABEL: @read_offset
-; CHECK-OFFSET-NOT: ret
-; CHECK-OFFSET: lshr {{.*}} 3
-; CHECK-OFFSET-NEXT: add{{.*}}3735928559
-; CHECK-OFFSET: ret
-
-define i32 @read_scale(i32* %a) sanitize_address {
-entry:
-  %tmp1 = load i32, i32* %a, align 4
-  ret i32 %tmp1
-}
-; CHECK-SCALE-LABEL: @read_scale
-; CHECK-SCALE-NOT: ret
-; CHECK-SCALE: lshr {{.*}} 1
-; CHECK-SCALE-NEXT: add{{.*}}
-; CHECK-SCALE: ret
-
-define i32 @read_both(i32* %a) sanitize_address {
-entry:
-  %tmp1 = load i32, i32* %a, align 4
-  ret i32 %tmp1
-}
-; CHECK-BOTH-LABEL: @read_both
-; CHECK-BOTH-NOT: ret
-; CHECK-BOTH: lshr {{.*}} 0
-; CHECK-BOTH-NEXT: add{{.*}}12648430
-; CHECK-BOTH: ret