[llvm-commits] [llvm] r162331 - in /llvm/trunk: include/llvm/ADT/ArrayRef.h include/llvm/ADT/SmallVector.h lib/Support/SmallVector.cpp
Richard Smith
richard-llvm at metafoo.co.uk
Tue Aug 21 17:11:07 PDT 2012
Author: rsmith
Date: Tue Aug 21 19:11:07 2012
New Revision: 162331
URL: http://llvm.org/viewvc/llvm-project?rev=162331&view=rev
Log:
Reduce alignment of SmallVector<T> to the required amount, rather than forcing 16-byte alignment. This fixes misaligned SmallVector accesses via ExtractValueInst's SmallVector data member.
Modified:
llvm/trunk/include/llvm/ADT/ArrayRef.h
llvm/trunk/include/llvm/ADT/SmallVector.h
llvm/trunk/lib/Support/SmallVector.cpp
Modified: llvm/trunk/include/llvm/ADT/ArrayRef.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/ArrayRef.h?rev=162331&r1=162330&r2=162331&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/ArrayRef.h (original)
+++ llvm/trunk/include/llvm/ADT/ArrayRef.h Tue Aug 21 19:11:07 2012
@@ -59,12 +59,17 @@
ArrayRef(const T *begin, const T *end)
: Data(begin), Length(end - begin) {}
- /// Construct an ArrayRef from a SmallVector.
- /*implicit*/ ArrayRef(const SmallVectorTemplateCommon<T> &Vec)
- : Data(Vec.data()), Length(Vec.size()) {}
+ /// Construct an ArrayRef from a SmallVector. This is templated in order to
+ /// avoid instantiating SmallVectorTemplateCommon<T> whenever we
+ /// copy-construct an ArrayRef.
+ template<typename U>
+ /*implicit*/ ArrayRef(const SmallVectorTemplateCommon<T, U> &Vec)
+ : Data(Vec.data()), Length(Vec.size()) {
+ }
/// Construct an ArrayRef from a std::vector.
- /*implicit*/ ArrayRef(const std::vector<T> &Vec)
+ template<typename A>
+ /*implicit*/ ArrayRef(const std::vector<T, A> &Vec)
: Data(Vec.empty() ? (T*)0 : &Vec[0]), Length(Vec.size()) {}
/// Construct an ArrayRef from a C array.
Modified: llvm/trunk/include/llvm/ADT/SmallVector.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SmallVector.h?rev=162331&r1=162330&r2=162331&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SmallVector.h (original)
+++ llvm/trunk/include/llvm/ADT/SmallVector.h Tue Aug 21 19:11:07 2012
@@ -14,6 +14,7 @@
#ifndef LLVM_ADT_SMALLVECTOR_H
#define LLVM_ADT_SMALLVECTOR_H
+#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/type_traits.h"
#include <algorithm>
@@ -32,44 +33,20 @@
protected:
void *BeginX, *EndX, *CapacityX;
- // Allocate raw space for N elements of type T. If T has a ctor or dtor, we
- // don't want it to be automatically run, so we need to represent the space as
- // something else. An array of char would work great, but might not be
- // aligned sufficiently. Instead we use some number of union instances for
- // the space, which guarantee maximal alignment.
- union U {
- double D;
- long double LD;
- long long L;
- void *P;
- } FirstEl;
- // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
-
protected:
- SmallVectorBase(size_t Size)
- : BeginX(&FirstEl), EndX(&FirstEl), CapacityX((char*)&FirstEl+Size) {}
-
- /// isSmall - Return true if this is a smallvector which has not had dynamic
- /// memory allocated for it.
- bool isSmall() const {
- return BeginX == static_cast<const void*>(&FirstEl);
- }
-
- /// resetToSmall - Put this vector in a state of being small.
- void resetToSmall() {
- BeginX = EndX = CapacityX = &FirstEl;
- }
+ SmallVectorBase(void *FirstEl, size_t Size)
+ : BeginX(FirstEl), EndX(FirstEl), CapacityX((char*)FirstEl+Size) {}
/// grow_pod - This is an implementation of the grow() method which only works
/// on POD-like data types and is out of line to reduce code duplication.
- void grow_pod(size_t MinSizeInBytes, size_t TSize);
+ void grow_pod(void *FirstEl, size_t MinSizeInBytes, size_t TSize);
public:
/// size_in_bytes - This returns size()*sizeof(T).
size_t size_in_bytes() const {
return size_t((char*)EndX - (char*)BeginX);
}
-
+
/// capacity_in_bytes - This returns capacity()*sizeof(T).
size_t capacity_in_bytes() const {
return size_t((char*)CapacityX - (char*)BeginX);
@@ -78,11 +55,41 @@
bool empty() const { return BeginX == EndX; }
};
+template <typename T, unsigned N> struct SmallVectorStorage;
-template <typename T>
+/// SmallVectorTemplateCommon - This is the part of SmallVectorTemplateBase
+/// which does not depend on whether the type T is a POD. The extra dummy
+/// template argument is used by ArrayRef to avoid unnecessarily requiring T
+/// to be complete.
+template <typename T, typename = void>
class SmallVectorTemplateCommon : public SmallVectorBase {
+private:
+ template <typename, unsigned> friend struct SmallVectorStorage;
+
+ // Allocate raw space for N elements of type T. If T has a ctor or dtor, we
+ // don't want it to be automatically run, so we need to represent the space as
+ // something else. Use an array of char of sufficient alignment.
+ typedef llvm::AlignedCharArrayUnion<T> U;
+ U FirstEl;
+ // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
+
protected:
- SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(Size) {}
+ SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(&FirstEl, Size) {}
+
+ void grow_pod(size_t MinSizeInBytes, size_t TSize) {
+ SmallVectorBase::grow_pod(&FirstEl, MinSizeInBytes, TSize);
+ }
+
+ /// isSmall - Return true if this is a smallvector which has not had dynamic
+ /// memory allocated for it.
+ bool isSmall() const {
+ return BeginX == static_cast<const void*>(&FirstEl);
+ }
+
+ /// resetToSmall - Put this vector in a state of being small.
+ void resetToSmall() {
+ BeginX = EndX = CapacityX = &FirstEl;
+ }
void setEnd(T *P) { this->EndX = P; }
public:
@@ -844,6 +851,17 @@
}
#endif
+/// Storage for the SmallVector elements which aren't contained in
+/// SmallVectorTemplateCommon. There are 'N-1' elements here. The remaining '1'
+/// element is in the base class. This is specialized for the N=1 and N=0 cases
+/// to avoid allocating unnecessary storage.
+template <typename T, unsigned N>
+struct SmallVectorStorage {
+ typename SmallVectorTemplateCommon<T>::U InlineElts[N - 1];
+};
+template <typename T> struct SmallVectorStorage<T, 1> {};
+template <typename T> struct SmallVectorStorage<T, 0> {};
+
/// SmallVector - This is a 'vector' (really, a variable-sized array), optimized
/// for the case when the array is small. It contains some number of elements
/// in-place, which allows it to avoid heap allocation when the actual number of
@@ -854,41 +872,23 @@
///
template <typename T, unsigned N>
class SmallVector : public SmallVectorImpl<T> {
- /// InlineElts - These are 'N-1' elements that are stored inline in the body
- /// of the vector. The extra '1' element is stored in SmallVectorImpl.
- typedef typename SmallVectorImpl<T>::U U;
- enum {
- // MinUs - The number of U's require to cover N T's.
- MinUs = (static_cast<unsigned int>(sizeof(T))*N +
- static_cast<unsigned int>(sizeof(U)) - 1) /
- static_cast<unsigned int>(sizeof(U)),
-
- // NumInlineEltsElts - The number of elements actually in this array. There
- // is already one in the parent class, and we have to round up to avoid
- // having a zero-element array.
- NumInlineEltsElts = MinUs > 1 ? (MinUs - 1) : 1,
-
- // NumTsAvailable - The number of T's we actually have space for, which may
- // be more than N due to rounding.
- NumTsAvailable = (NumInlineEltsElts+1)*static_cast<unsigned int>(sizeof(U))/
- static_cast<unsigned int>(sizeof(T))
- };
- U InlineElts[NumInlineEltsElts];
+ /// Storage - Inline space for elements which aren't stored in the base class.
+ SmallVectorStorage<T, N> Storage;
public:
- SmallVector() : SmallVectorImpl<T>(NumTsAvailable) {
+ SmallVector() : SmallVectorImpl<T>(N) {
}
explicit SmallVector(unsigned Size, const T &Value = T())
- : SmallVectorImpl<T>(NumTsAvailable) {
+ : SmallVectorImpl<T>(N) {
this->assign(Size, Value);
}
template<typename ItTy>
- SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(NumTsAvailable) {
+ SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
this->append(S, E);
}
- SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(NumTsAvailable) {
+ SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(N) {
if (!RHS.empty())
SmallVectorImpl<T>::operator=(RHS);
}
@@ -899,7 +899,7 @@
}
#if LLVM_USE_RVALUE_REFERENCES
- SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(NumTsAvailable) {
+ SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(N) {
if (!RHS.empty())
SmallVectorImpl<T>::operator=(::std::move(RHS));
}
@@ -912,48 +912,6 @@
};
-/// Specialize SmallVector at N=0. This specialization guarantees
-/// that it can be instantiated at an incomplete T if none of its
-/// members are required.
-template <typename T>
-class SmallVector<T,0> : public SmallVectorImpl<T> {
-public:
- SmallVector() : SmallVectorImpl<T>(0) {
- }
-
- explicit SmallVector(unsigned Size, const T &Value = T())
- : SmallVectorImpl<T>(0) {
- this->assign(Size, Value);
- }
-
- template<typename ItTy>
- SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(0) {
- this->append(S, E);
- }
-
- SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(0) {
- if (!RHS.empty())
- SmallVectorImpl<T>::operator=(RHS);
- }
-
- const SmallVector &operator=(const SmallVector &RHS) {
- SmallVectorImpl<T>::operator=(RHS);
- return *this;
- }
-
-#if LLVM_USE_RVALUE_REFERENCES
- SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(0) {
- if (!RHS.empty())
- SmallVectorImpl<T>::operator=(::std::move(RHS));
- }
-
- const SmallVector &operator=(SmallVector &&RHS) {
- SmallVectorImpl<T>::operator=(::std::move(RHS));
- return *this;
- }
-#endif
-};
-
template<typename T, unsigned N>
static inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
return X.capacity_in_bytes();
Modified: llvm/trunk/lib/Support/SmallVector.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/SmallVector.cpp?rev=162331&r1=162330&r2=162331&view=diff
==============================================================================
--- llvm/trunk/lib/Support/SmallVector.cpp (original)
+++ llvm/trunk/lib/Support/SmallVector.cpp Tue Aug 21 19:11:07 2012
@@ -16,14 +16,15 @@
/// grow_pod - This is an implementation of the grow() method which only works
/// on POD-like datatypes and is out of line to reduce code duplication.
-void SmallVectorBase::grow_pod(size_t MinSizeInBytes, size_t TSize) {
+void SmallVectorBase::grow_pod(void *FirstEl, size_t MinSizeInBytes,
+ size_t TSize) {
size_t CurSizeBytes = size_in_bytes();
size_t NewCapacityInBytes = 2 * capacity_in_bytes() + TSize; // Always grow.
if (NewCapacityInBytes < MinSizeInBytes)
NewCapacityInBytes = MinSizeInBytes;
void *NewElts;
- if (this->isSmall()) {
+ if (BeginX == FirstEl) {
NewElts = malloc(NewCapacityInBytes);
// Copy the elements over. No need to run dtors on PODs.
@@ -37,4 +38,3 @@
this->BeginX = NewElts;
this->CapacityX = (char*)this->BeginX + NewCapacityInBytes;
}
-
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