AuroraMiddleware/scuffed-code
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ICU-20650 Memory alignment of buffers used by sort functions.

Browse Source
This commit is contained in:
Andy Heninger 2019-06-28 16:36:10 -07:00
parent 0367d4c135
commit 5a23d83fa2
1 changed files with 17 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
icu4c/source/common/uarrsort.cpp
View File

@ -34,6 +34,10 @@ enum {
STACK_ITEM_SIZE=200
};
static constexpr int32_t sizeInMaxAlignTs(int32_t sizeInBytes) {
return (sizeInBytes + sizeof(max_align_t) - 1) / sizeof(max_align_t);
}
/* UComparator convenience implementations ---------------------------------- */
U_CAPI int32_t U_EXPORT2
@ -134,25 +138,15 @@ doInsertionSort(char *array, int32_t length, int32_t itemSize,
static void
insertionSort(char *array, int32_t length, int32_t itemSize,
UComparator *cmp, const void *context, UErrorCode *pErrorCode) {
alignas(max_align_t) char v[STACK_ITEM_SIZE];
void *pv;
/* allocate an intermediate item variable (v) */
if(itemSize<=STACK_ITEM_SIZE) {
pv=v;
} else {
pv=uprv_malloc(itemSize);
if(pv==NULL) {
*pErrorCode=U_MEMORY_ALLOCATION_ERROR;
return;
}
icu::MaybeStackArray<max_align_t, sizeInMaxAlignTs(STACK_ITEM_SIZE)> v;
if (sizeInMaxAlignTs(itemSize) > v.getCapacity() &&
v.resize(sizeInMaxAlignTs(itemSize)) == nullptr) {
*pErrorCode = U_MEMORY_ALLOCATION_ERROR;
return;
}
doInsertionSort(array, length, itemSize, cmp, context, pv);
if(pv!=v) {
uprv_free(pv);
}
doInsertionSort(array, length, itemSize, cmp, context, v.getAlias());
}
/* QuickSort ---------------------------------------------------------------- */
@ -238,27 +232,16 @@ subQuickSort(char *array, int32_t start, int32_t limit, int32_t itemSize,
static void
quickSort(char *array, int32_t length, int32_t itemSize,
UComparator *cmp, const void *context, UErrorCode *pErrorCode) {
alignas(max_align_t) char xw[2*STACK_ITEM_SIZE];
void *p;
/* allocate two intermediate item variables (x and w) */
if(itemSize<=STACK_ITEM_SIZE) {
p=xw;
} else {
p=uprv_malloc(2*itemSize);
if(p==NULL) {
*pErrorCode=U_MEMORY_ALLOCATION_ERROR;
return;
}
icu::MaybeStackArray<max_align_t, sizeInMaxAlignTs(STACK_ITEM_SIZE) * 2> xw;
if(sizeInMaxAlignTs(itemSize)*2 > xw.getCapacity() &&
xw.resize(sizeInMaxAlignTs(itemSize) * 2) == nullptr) {
*pErrorCode=U_MEMORY_ALLOCATION_ERROR;
return;
}
// TODO ICU-20650 check alignment of 2nd ptr.
subQuickSort(array, 0, length, itemSize,
cmp, context, p, (char *)p+itemSize);
if(p!=xw) {
uprv_free(p);
}
subQuickSort(array, 0, length, itemSize, cmp, context,
xw.getAlias(), xw.getAlias() + sizeInMaxAlignTs(itemSize));
}
/* uprv_sortArray() API ----------------------------------------------------- */