[llvm] r178332 - Fix allocations of SmallVector and SmallPtrSet so they are more prone to
Jean-Luc Duprat
jduprat at apple.com
Thu Mar 28 22:45:22 PDT 2013
Author: jduprat
Date: Fri Mar 29 00:45:22 2013
New Revision: 178332
URL: http://llvm.org/viewvc/llvm-project?rev=178332&view=rev
Log:
Fix allocations of SmallVector and SmallPtrSet so they are more prone to
being power-of-two sized.
Modified:
llvm/trunk/include/llvm/ADT/SmallPtrSet.h
llvm/trunk/include/llvm/ADT/SmallVector.h
llvm/trunk/lib/Support/SmallPtrSet.cpp
llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp
Modified: llvm/trunk/include/llvm/ADT/SmallPtrSet.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SmallPtrSet.h?rev=178332&r1=178331&r2=178332&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SmallPtrSet.h (original)
+++ llvm/trunk/include/llvm/ADT/SmallPtrSet.h Fri Mar 29 00:45:22 2013
@@ -54,8 +54,6 @@ protected:
/// then the set is in 'small mode'.
const void **CurArray;
/// CurArraySize - The allocated size of CurArray, always a power of two.
- /// Note that CurArray points to an array that has CurArraySize+1 elements in
- /// it, so that the end iterator actually points to valid memory.
unsigned CurArraySize;
// If small, this is # elts allocated consecutively
@@ -68,9 +66,6 @@ protected:
SmallArray(SmallStorage), CurArray(SmallStorage), CurArraySize(SmallSize) {
assert(SmallSize && (SmallSize & (SmallSize-1)) == 0 &&
"Initial size must be a power of two!");
- // The end pointer, always valid, is set to a valid element to help the
- // iterator.
- CurArray[SmallSize] = 0;
clear();
}
~SmallPtrSetImpl();
@@ -147,9 +142,11 @@ protected:
class SmallPtrSetIteratorImpl {
protected:
const void *const *Bucket;
+ const void *const *End;
public:
- explicit SmallPtrSetIteratorImpl(const void *const *BP) : Bucket(BP) {
- AdvanceIfNotValid();
+ explicit SmallPtrSetIteratorImpl(const void *const *BP, const void*const *E)
+ : Bucket(BP), End(E) {
+ AdvanceIfNotValid();
}
bool operator==(const SmallPtrSetIteratorImpl &RHS) const {
@@ -164,8 +161,10 @@ protected:
/// that is. This is guaranteed to stop because the end() bucket is marked
/// valid.
void AdvanceIfNotValid() {
- while (*Bucket == SmallPtrSetImpl::getEmptyMarker() ||
- *Bucket == SmallPtrSetImpl::getTombstoneMarker())
+ assert(Bucket <= End);
+ while (Bucket != End &&
+ (*Bucket == SmallPtrSetImpl::getEmptyMarker() ||
+ *Bucket == SmallPtrSetImpl::getTombstoneMarker()))
++Bucket;
}
};
@@ -182,12 +181,13 @@ public:
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
- explicit SmallPtrSetIterator(const void *const *BP)
- : SmallPtrSetIteratorImpl(BP) {}
+ explicit SmallPtrSetIterator(const void *const *BP, const void *const *E)
+ : SmallPtrSetIteratorImpl(BP, E) {}
// Most methods provided by baseclass.
const PtrTy operator*() const {
+ assert(Bucket < End);
return PtrTraits::getFromVoidPointer(const_cast<void*>(*Bucket));
}
@@ -236,9 +236,8 @@ template<class PtrType, unsigned SmallSi
class SmallPtrSet : public SmallPtrSetImpl {
// Make sure that SmallSize is a power of two, round up if not.
enum { SmallSizePowTwo = RoundUpToPowerOfTwo<SmallSize>::Val };
- /// SmallStorage - Fixed size storage used in 'small mode'. The extra element
- /// ensures that the end iterator actually points to valid memory.
- const void *SmallStorage[SmallSizePowTwo+1];
+ /// SmallStorage - Fixed size storage used in 'small mode'.
+ const void *SmallStorage[SmallSizePowTwo];
typedef PointerLikeTypeTraits<PtrType> PtrTraits;
public:
SmallPtrSet() : SmallPtrSetImpl(SmallStorage, SmallSizePowTwo) {}
@@ -275,10 +274,10 @@ public:
typedef SmallPtrSetIterator<PtrType> iterator;
typedef SmallPtrSetIterator<PtrType> const_iterator;
inline iterator begin() const {
- return iterator(CurArray);
+ return iterator(CurArray, CurArray+CurArraySize);
}
inline iterator end() const {
- return iterator(CurArray+CurArraySize);
+ return iterator(CurArray+CurArraySize, CurArray+CurArraySize);
}
// Allow assignment from any smallptrset with the same element type even if it
Modified: llvm/trunk/include/llvm/ADT/SmallVector.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SmallVector.h?rev=178332&r1=178331&r2=178332&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SmallVector.h (original)
+++ llvm/trunk/include/llvm/ADT/SmallVector.h Fri Mar 29 00:45:22 2013
@@ -16,6 +16,7 @@
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/MathExtras.h"
#include "llvm/Support/type_traits.h"
#include <algorithm>
#include <cassert>
@@ -267,7 +268,8 @@ template <typename T, bool isPodLike>
void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
size_t CurCapacity = this->capacity();
size_t CurSize = this->size();
- size_t NewCapacity = 2*CurCapacity + 1; // Always grow, even from zero.
+ // Always grow, even from zero.
+ size_t NewCapacity = NextPowerOf2(2*CurCapacity+(CurCapacity==0));
if (NewCapacity < MinSize)
NewCapacity = MinSize;
T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
Modified: llvm/trunk/lib/Support/SmallPtrSet.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/SmallPtrSet.cpp?rev=178332&r1=178331&r2=178332&view=diff
==============================================================================
--- llvm/trunk/lib/Support/SmallPtrSet.cpp (original)
+++ llvm/trunk/lib/Support/SmallPtrSet.cpp Fri Mar 29 00:45:22 2013
@@ -29,13 +29,9 @@ void SmallPtrSetImpl::shrink_and_clear()
NumElements = NumTombstones = 0;
// Install the new array. Clear all the buckets to empty.
- CurArray = (const void**)malloc(sizeof(void*) * (CurArraySize+1));
+ CurArray = (const void**)malloc(sizeof(void*) * CurArraySize);
assert(CurArray && "Failed to allocate memory?");
memset(CurArray, -1, CurArraySize*sizeof(void*));
-
- // The end pointer, always valid, is set to a valid element to help the
- // iterator.
- CurArray[CurArraySize] = 0;
}
bool SmallPtrSetImpl::insert_imp(const void * Ptr) {
@@ -139,15 +135,11 @@ void SmallPtrSetImpl::Grow(unsigned NewS
bool WasSmall = isSmall();
// Install the new array. Clear all the buckets to empty.
- CurArray = (const void**)malloc(sizeof(void*) * (NewSize+1));
+ CurArray = (const void**)malloc(sizeof(void*) * NewSize);
assert(CurArray && "Failed to allocate memory?");
CurArraySize = NewSize;
memset(CurArray, -1, NewSize*sizeof(void*));
- // The end pointer, always valid, is set to a valid element to help the
- // iterator.
- CurArray[NewSize] = 0;
-
// Copy over all the elements.
if (WasSmall) {
// Small sets store their elements in order.
@@ -180,7 +172,7 @@ SmallPtrSetImpl::SmallPtrSetImpl(const v
CurArray = SmallArray;
// Otherwise, allocate new heap space (unless we were the same size)
} else {
- CurArray = (const void**)malloc(sizeof(void*) * (that.CurArraySize+1));
+ CurArray = (const void**)malloc(sizeof(void*) * that.CurArraySize);
assert(CurArray && "Failed to allocate memory?");
}
@@ -188,7 +180,7 @@ SmallPtrSetImpl::SmallPtrSetImpl(const v
CurArraySize = that.CurArraySize;
// Copy over the contents from the other set
- memcpy(CurArray, that.CurArray, sizeof(void*)*(CurArraySize+1));
+ memcpy(CurArray, that.CurArray, sizeof(void*)*CurArraySize);
NumElements = that.NumElements;
NumTombstones = that.NumTombstones;
@@ -200,7 +192,7 @@ void SmallPtrSetImpl::CopyFrom(const Sma
if (isSmall() && RHS.isSmall())
assert(CurArraySize == RHS.CurArraySize &&
"Cannot assign sets with different small sizes");
-
+
// If we're becoming small, prepare to insert into our stack space
if (RHS.isSmall()) {
if (!isSmall())
@@ -209,9 +201,9 @@ void SmallPtrSetImpl::CopyFrom(const Sma
// Otherwise, allocate new heap space (unless we were the same size)
} else if (CurArraySize != RHS.CurArraySize) {
if (isSmall())
- CurArray = (const void**)malloc(sizeof(void*) * (RHS.CurArraySize+1));
+ CurArray = (const void**)malloc(sizeof(void*) * RHS.CurArraySize);
else
- CurArray = (const void**)realloc(CurArray, sizeof(void*)*(RHS.CurArraySize+1));
+ CurArray = (const void**)realloc(CurArray, sizeof(void*)*RHS.CurArraySize);
assert(CurArray && "Failed to allocate memory?");
}
@@ -219,7 +211,7 @@ void SmallPtrSetImpl::CopyFrom(const Sma
CurArraySize = RHS.CurArraySize;
// Copy over the contents from the other set
- memcpy(CurArray, RHS.CurArray, sizeof(void*)*(CurArraySize+1));
+ memcpy(CurArray, RHS.CurArray, sizeof(void*)*CurArraySize);
NumElements = RHS.NumElements;
NumTombstones = RHS.NumTombstones;
Modified: llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp?rev=178332&r1=178331&r2=178332&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp (original)
+++ llvm/trunk/unittests/ADT/SmallPtrSetTest.cpp Fri Mar 29 00:45:22 2013
@@ -17,6 +17,61 @@
using namespace llvm;
// SmallPtrSet swapping test.
+TEST(SmallPtrSetTest, GrowthTest) {
+ int i;
+ int buf[8];
+ for(i=0; i<8; ++i) buf[i]=0;
+
+
+ SmallPtrSet<int *, 4> s;
+ typedef SmallPtrSet<int *, 4>::iterator iter;
+
+ s.insert(&buf[0]);
+ s.insert(&buf[1]);
+ s.insert(&buf[2]);
+ s.insert(&buf[3]);
+ EXPECT_EQ(4U, s.size());
+
+ i = 0;
+ for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
+ (**I)++;
+ EXPECT_EQ(4, i);
+ for(i=0; i<8; ++i)
+ EXPECT_EQ(i<4?1:0,buf[i]);
+
+ s.insert(&buf[4]);
+ s.insert(&buf[5]);
+ s.insert(&buf[6]);
+ s.insert(&buf[7]);
+
+ i = 0;
+ for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
+ (**I)++;
+ EXPECT_EQ(8, i);
+ s.erase(&buf[4]);
+ s.erase(&buf[5]);
+ s.erase(&buf[6]);
+ s.erase(&buf[7]);
+ EXPECT_EQ(4U, s.size());
+
+ i = 0;
+ for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
+ (**I)++;
+ EXPECT_EQ(4, i);
+ for(i=0; i<8; ++i)
+ EXPECT_EQ(i<4?3:1,buf[i]);
+
+ s.clear();
+ for(i=0; i<8; ++i) buf[i]=0;
+ for(i=0; i<128; ++i) s.insert(&buf[i%8]); // test repeated entires
+ EXPECT_EQ(8U, s.size());
+ for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
+ (**I)++;
+ for(i=0; i<8; ++i)
+ EXPECT_EQ(1,buf[i]);
+}
+
+
TEST(SmallPtrSetTest, SwapTest) {
int buf[10];
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