[llvm] r272442 - [esan|cfrag] Handle complex GEP instr in the cfrag tool
Qin Zhao via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 10 15:28:55 PDT 2016
Author: zhaoqin
Date: Fri Jun 10 17:28:55 2016
New Revision: 272442
URL: http://llvm.org/viewvc/llvm-project?rev=272442&view=rev
Log:
[esan|cfrag] Handle complex GEP instr in the cfrag tool
Summary:
Iterates all (except the first and the last) operands within each GEP
instruction for instrumentation.
Adds test struct_field_gep.ll.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, bruening, llvm-commits
Differential Revision: http://reviews.llvm.org/D21242
Added:
llvm/trunk/test/Instrumentation/EfficiencySanitizer/struct_field_gep.ll
Modified:
llvm/trunk/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
Modified: llvm/trunk/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp?rev=272442&r1=272441&r2=272442&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp Fri Jun 10 17:28:55 2016
@@ -656,45 +656,52 @@ bool EfficiencySanitizer::instrumentMemI
bool EfficiencySanitizer::instrumentGetElementPtr(Instruction *I, Module &M) {
GetElementPtrInst *GepInst = dyn_cast<GetElementPtrInst>(I);
- if (GepInst == nullptr || !isa<StructType>(GepInst->getSourceElementType()) ||
- StructTyMap.count(GepInst->getSourceElementType()) == 0 ||
- !GepInst->hasAllConstantIndices() ||
- // Only handle simple struct field GEP.
- GepInst->getNumIndices() != 2) {
+ bool Res = false;
+ if (GepInst == nullptr || GepInst->getNumIndices() == 1) {
++NumIgnoredGEPs;
return false;
}
- StructType *StructTy = dyn_cast<StructType>(GepInst->getSourceElementType());
- if (shouldIgnoreStructType(StructTy)) {
- ++NumIgnoredGEPs;
- return false;
+ Type *SourceTy = GepInst->getSourceElementType();
+ // Iterate all (except the first and the last) idx within each GEP instruction
+ // for possible nested struct field address calculation.
+ for (unsigned i = 1; i < GepInst->getNumIndices(); ++i) {
+ SmallVector<Value *, 8> IdxVec(GepInst->idx_begin(),
+ GepInst->idx_begin() + i);
+ StructType *StructTy = dyn_cast<StructType>(
+ GetElementPtrInst::getIndexedType(SourceTy, IdxVec));
+ if (StructTy == nullptr || shouldIgnoreStructType(StructTy) ||
+ StructTyMap.count(StructTy) == 0)
+ continue;
+ // Get the StructTy's subfield index.
+ ConstantInt *Idx = dyn_cast<ConstantInt>(GepInst->getOperand(i+1));
+ if (Idx == nullptr || Idx->getZExtValue() > StructTy->getNumElements())
+ continue;
+ GlobalVariable *CounterArray = StructTyMap[StructTy];
+ if (CounterArray == nullptr)
+ return false;
+ IRBuilder<> IRB(I);
+ Constant *Indices[2];
+ // Xref http://llvm.org/docs/LangRef.html#i-getelementptr and
+ // http://llvm.org/docs/GetElementPtr.html.
+ // The first index of the GEP instruction steps through the first operand,
+ // i.e., the array itself.
+ Indices[0] = ConstantInt::get(IRB.getInt32Ty(), 0);
+ // The second index is the index within the array.
+ Indices[1] = ConstantInt::get(IRB.getInt32Ty(), Idx->getZExtValue());
+ Constant *Counter =
+ ConstantExpr::getGetElementPtr(
+ ArrayType::get(IRB.getInt64Ty(), StructTy->getNumElements()),
+ CounterArray, Indices);
+ Value *Load = IRB.CreateLoad(Counter);
+ IRB.CreateStore(IRB.CreateAdd(Load, ConstantInt::get(IRB.getInt64Ty(), 1)),
+ Counter);
+ Res = true;
}
- ++NumInstrumentedGEPs;
- // Use the last index as the index within the struct.
- ConstantInt *Idx = dyn_cast<ConstantInt>(GepInst->getOperand(2));
- if (Idx == nullptr || Idx->getZExtValue() > StructTy->getNumElements())
- return false;
-
- GlobalVariable *CounterArray = StructTyMap[StructTy];
- if (CounterArray == nullptr)
- return false;
- IRBuilder<> IRB(I);
- Constant *Indices[2];
- // Xref http://llvm.org/docs/LangRef.html#i-getelementptr and
- // http://llvm.org/docs/GetElementPtr.html.
- // The first index of the GEP instruction steps through the first operand,
- // i.e., the array itself.
- Indices[0] = ConstantInt::get(IRB.getInt32Ty(), 0);
- // The second index is the index within the array.
- Indices[1] = ConstantInt::get(IRB.getInt32Ty(), Idx->getZExtValue());
- Constant *Counter =
- ConstantExpr::getGetElementPtr(ArrayType::get(IRB.getInt64Ty(),
- StructTy->getNumElements()),
- CounterArray, Indices);
- Value *Load = IRB.CreateLoad(Counter);
- IRB.CreateStore(IRB.CreateAdd(Load, ConstantInt::get(IRB.getInt64Ty(), 1)),
- Counter);
- return true;
+ if (Res)
+ ++NumInstrumentedGEPs;
+ else
+ ++NumIgnoredGEPs;
+ return Res;
}
int EfficiencySanitizer::getMemoryAccessFuncIndex(Value *Addr,
Added: llvm/trunk/test/Instrumentation/EfficiencySanitizer/struct_field_gep.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/EfficiencySanitizer/struct_field_gep.ll?rev=272442&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/EfficiencySanitizer/struct_field_gep.ll (added)
+++ llvm/trunk/test/Instrumentation/EfficiencySanitizer/struct_field_gep.ll Fri Jun 10 17:28:55 2016
@@ -0,0 +1,38 @@
+; Test the complex GetElementPtr instruction handling in the EfficiencySanitizer
+; cache fragmentation tool.
+;
+; RUN: opt < %s -esan -esan-cache-frag -S | FileCheck %s
+
+; Code from http://llvm.org/docs/LangRef.html#getelementptr-instruction
+; struct RT {
+; char A;
+; int B[10][20];
+; char C;
+; };
+; struct ST {
+; int X;
+; double Y;
+; struct RT Z;
+; };
+;
+; int *foo(struct ST *s) {
+; return &s[1].Z.B[5][13];
+; }
+
+%struct.RT = type { i8, [10 x [20 x i32]], i8 }
+%struct.ST = type { i32, double, %struct.RT }
+
+define i32* @foo(%struct.ST* %s) nounwind uwtable readnone optsize ssp {
+entry:
+ %arrayidx = getelementptr inbounds %struct.ST, %struct.ST* %s, i64 1, i32 2, i32 1, i64 5, i64 13
+ ret i32* %arrayidx
+}
+
+; CHECK: %0 = load i64, i64* getelementptr inbounds ([3 x i64], [3 x i64]* @"struct.ST#3#13#3#11", i32 0, i32 2)
+; CHECK-NEXT: %1 = add i64 %0, 1
+; CHECK-NEXT: store i64 %1, i64* getelementptr inbounds ([3 x i64], [3 x i64]* @"struct.ST#3#13#3#11", i32 0, i32 2)
+; CHECK-NEXT: %2 = load i64, i64* getelementptr inbounds ([3 x i64], [3 x i64]* @"struct.RT#3#11#14#11", i32 0, i32 1)
+; CHECK-NEXT: %3 = add i64 %2, 1
+; CHECK-NEXT: store i64 %3, i64* getelementptr inbounds ([3 x i64], [3 x i64]* @"struct.RT#3#11#14#11", i32 0, i32 1)
+; CHECK-NEXT: %arrayidx = getelementptr inbounds %struct.ST, %struct.ST* %s, i64 1, i32 2, i32 1, i64 5, i64 13
+; CHECK-NEXT: ret i32* %arrayidx
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