Use memchr to scan the card table.
Change-Id: I8066b2818d360d3f383d1b90bbbea0b2983d4519
diff --git a/vm/alloc/MarkSweep.c b/vm/alloc/MarkSweep.c
index ae57080..9ef3da7 100644
--- a/vm/alloc/MarkSweep.c
+++ b/vm/alloc/MarkSweep.c
@@ -538,81 +538,6 @@
}
/*
- * Scans each byte from start below end returning the address of the
- * first dirty card. Returns NULL if no dirty card is found.
- */
-static const u1 *scanBytesForDirtyCard(const u1 *start, const u1 *end)
-{
- const u1 *ptr;
-
- assert(start <= end);
- for (ptr = start; ptr < end; ++ptr) {
- if (*ptr == GC_CARD_DIRTY) {
- return ptr;
- }
- }
- return NULL;
-}
-
-/*
- * Like scanBytesForDirtyCard but scans the range from start below end
- * by words. Assumes start and end are word aligned.
- */
-static const u1 *scanWordsForDirtyCard(const u1 *start, const u1 *end)
-{
- const u1 *ptr;
-
- assert((uintptr_t)start % kWordSize == 0);
- assert((uintptr_t)end % kWordSize == 0);
- assert(start <= end);
- for (ptr = start; ptr < end; ptr += kWordSize) {
- if (*(const Word *)ptr != 0) {
- const u1 *dirty = scanBytesForDirtyCard(ptr, ptr + kWordSize);
- if (dirty != NULL) {
- return dirty;
- }
- }
- }
- return NULL;
-}
-
-/*
- * Scans the card table as quickly as possible looking for a dirty
- * card. Returns the address of the first dirty card found or NULL if
- * no dirty cards were found.
- */
-static const u1 *nextDirtyCard(const u1 *start, const u1 *end)
-{
- const u1 *wstart = (u1 *)ALIGN_UP(start, kWordSize);
- const u1 *wend = (u1 *)ALIGN_DOWN(end, kWordSize);
- const u1 *ptr, *dirty;
-
- assert(start <= end);
- assert(start <= wstart);
- assert(end >= wend);
- ptr = start;
- if (wstart < end) {
- /* Scan the leading unaligned bytes. */
- dirty = scanBytesForDirtyCard(ptr, wstart);
- if (dirty != NULL) {
- return dirty;
- }
- /* Scan the range of aligned words. */
- dirty = scanWordsForDirtyCard(wstart, wend);
- if (dirty != NULL) {
- return dirty;
- }
- ptr = wend;
- }
- /* Scan trailing unaligned bytes. */
- dirty = scanBytesForDirtyCard(ptr, end);
- if (dirty != NULL) {
- return dirty;
- }
- return NULL;
-}
-
-/*
* Scans range of dirty cards between start and end. A range of dirty
* cards is composed consecutively dirty cards or dirty cards spanned
* by a gray object. Returns the address of a clean card if the scan
@@ -666,7 +591,7 @@
ptr = base;
for (;;) {
- dirty = nextDirtyCard(ptr, limit);
+ dirty = (const u1 *)memchr(ptr, GC_CARD_DIRTY, limit - ptr);
if (dirty == NULL) {
break;
}
