diff options
| -rw-r--r-- | rts/sm/NonMoving.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/rts/sm/NonMoving.c b/rts/sm/NonMoving.c index f9fb329154..8b27581386 100644 --- a/rts/sm/NonMoving.c +++ b/rts/sm/NonMoving.c @@ -303,8 +303,10 @@ static inline unsigned long log2_ceil(unsigned long x) // Advance a segment's next_free pointer. Returns true if segment if full. static bool advance_next_free(struct NonmovingSegment *seg) { - uint8_t *bitmap = seg->bitmap; - unsigned int blk_count = nonmovingSegmentBlockCount(seg); + const uint8_t *bitmap = seg->bitmap; + const unsigned int blk_count = nonmovingSegmentBlockCount(seg); +#if defined(NAIVE_ADVANCE_FREE) + // reference implementation for (unsigned int i = seg->next_free+1; i < blk_count; i++) { if (!bitmap[i]) { seg->next_free = i; @@ -313,6 +315,16 @@ static bool advance_next_free(struct NonmovingSegment *seg) } seg->next_free = blk_count; return true; +#else + const uint8_t *c = memchr(&bitmap[seg->next_free+1], 0, blk_count - seg->next_free - 1); + if (c == NULL) { + seg->next_free = blk_count; + return true; + } else { + seg->next_free = c - bitmap; + return false; + } +#endif } static struct NonmovingSegment *pop_active_segment(struct NonmovingAllocator *alloca) |