llvm-mirror/lib/Support/SmallVector.cpp
John McCall b91df6e799 After some discussion with djg, teach SmallVector to grow from a zero
capacity and remove the workaround in SmallVector<T,0>.  There are some
theoretical benefits to a N->2N+1 growth policy anyway.

llvm-svn: 112870
2010-09-02 21:55:03 +00:00

41 lines
1.4 KiB
C++

//===- llvm/ADT/SmallVector.cpp - 'Normally small' vectors ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SmallVector class.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
/// 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) {
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()) {
NewElts = malloc(NewCapacityInBytes);
// Copy the elements over. No need to run dtors on PODs.
memcpy(NewElts, this->BeginX, CurSizeBytes);
} else {
// If this wasn't grown from the inline copy, grow the allocated space.
NewElts = realloc(this->BeginX, NewCapacityInBytes);
}
this->EndX = (char*)NewElts+CurSizeBytes;
this->BeginX = NewElts;
this->CapacityX = (char*)this->BeginX + NewCapacityInBytes;
}