From d677d888677bccd0dfc12527c8f40b2c9903c70c Mon Sep 17 00:00:00 2001
From: Qin Zhao <zhaoqin@google.com>
Date: Fri, 10 Jun 2016 00:48:53 +0000
Subject: [esan|cfrag] Disable load/store instrumentation for cfrag

Summary:
Adds ClInstrumentFastpath option to control fastpath instrumentation.

Avoids the load/store instrumentation for the cache fragmentation tool.

Renames cache_frag_basic.ll to working_set_slow.ll for slowpath
instrumentation test.

Adds the __esan_init check in struct_field_count_basic.ll.

Reviewers: aizatsky

Subscribers: llvm-commits, bruening, eugenis, kcc, zhaoqin, vitalybuka

Differential Revision: http://reviews.llvm.org/D21079

llvm-svn: 272355
---
 llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

(limited to 'llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp')

diff --git a/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
index 48a9396a..63391b3 100644
--- a/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
@@ -56,6 +56,9 @@ static cl::opt<bool> ClInstrumentLoadsAndStores(
 static cl::opt<bool> ClInstrumentMemIntrinsics(
     "esan-instrument-memintrinsics", cl::init(true),
     cl::desc("Instrument memintrinsics (memset/memcpy/memmove)"), cl::Hidden);
+static cl::opt<bool> ClInstrumentFastpath(
+    "esan-instrument-fastpath", cl::init(true),
+    cl::desc("Instrument fastpath"), cl::Hidden);
 
 // Experiments show that the performance difference can be 2x or more,
 // and accuracy loss is typically negligible, so we turn this on by default.
@@ -591,7 +594,8 @@ bool EfficiencySanitizer::instrumentLoadOrStore(Instruction *I,
                    {IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
                     ConstantInt::get(IntptrTy, TypeSizeBytes)});
   } else {
-    if (instrumentFastpath(I, DL, IsStore, Addr, Alignment)) {
+    if (ClInstrumentFastpath &&
+        instrumentFastpath(I, DL, IsStore, Addr, Alignment)) {
       NumFastpaths++;
       return true;
     }
@@ -708,8 +712,8 @@ bool EfficiencySanitizer::instrumentFastpathCacheFrag(Instruction *I,
                                                       const DataLayout &DL,
                                                       Value *Addr,
                                                       unsigned Alignment) {
-  // TODO(bruening): implement a fastpath for aligned accesses
-  return false;
+  // Do nothing.
+  return true; // Return true to avoid slowpath instrumentation.
 }
 
 bool EfficiencySanitizer::instrumentFastpathWorkingSet(
-- 
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