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Added LFSR_BTREE/SHRUB_NULL, dropped lfsr_btree_alloc

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Our B-trees lazily allocate their root blocks, so it makes more sense
for this to be a macro. Added/adopted a similar LFSR_SHRUB_NULL for
consistency.

Unfortunately this added a bit of code. I think because GCC struggles to
optimize compound literals, which both LFSR_BTREE_NULL and
LFSR_SHRUB_NULL expand into:

           code          stack
  before: 33538           2624
  after:  33550 (+0.0%)   2624 (+0.0%)
This commit is contained in:
Christopher Haster
2024-05-27 02:54:23 -05:00
parent 8e50e4d259
commit 5d03416c82
3 changed files with 65 additions and 124 deletions
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lfs.c
+12 -18
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@@ -3900,8 +3900,9 @@ static lfs_scmp_t lfsr_rbyd_namelookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
/// B-tree operations ///
// convenience operations
#define LFSR_BTREE_NULL() ((lfsr_btree_t){.weight=0, .trunk=0})
// convenience operations
static inline int lfsr_btree_cmp(
const lfsr_btree_t *a,
const lfsr_btree_t *b) {
@@ -4036,14 +4037,6 @@ static int lfsr_data_readbtree(lfs_t *lfs, lfsr_data_t *data,
// core btree operations
static int lfsr_btree_alloc(lfs_t *lfs, lfsr_btree_t *btree) {
(void)lfs;
// TODO do we need this function then?
// allocate lazily
*btree = (lfsr_btree_t){.trunk=0, .weight=0};
return 0;
}
static int lfsr_btree_lookupnext_(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_bid_t bid,
lfsr_bid_t *bid_, lfsr_rbyd_t *rbyd_, lfsr_srid_t *rid_,
@@ -5204,6 +5197,14 @@ static int lfsr_sprout_compact(lfs_t *lfs, const lfsr_rbyd_t *rbyd_,
// shrub things
#define LFSR_SHRUB_NULL(_block) \
((lfsr_shrub_t){ \
.weight=0, \
.blocks[0]=_block, \
.trunk=LFSR_RBYD_ISSHRUB | 0, \
/* force estimate recalculation */ \
.estimate=-1})
// helper functions
static inline bool lfsr_shrub_isshrub(const lfsr_shrub_t *shrub) {
return lfsr_rbyd_isshrub((const lfsr_rbyd_t*)shrub);
@@ -6886,10 +6887,7 @@ static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
// new mtree?
if (lfsr_mtree_ismptr(&lfs->mtree)) {
err = lfsr_btree_alloc(lfs, &mtree_.u.btree);
if (err) {
goto failed;
}
mtree_.u.btree = LFSR_BTREE_NULL();
uint8_t mdir_buf[2*LFSR_MPTR_DSIZE];
err = lfsr_btree_commit(lfs, &mtree_.u.btree,
@@ -10553,11 +10551,7 @@ static int lfsr_file_carve(lfs_t *lfs, lfsr_file_t *file,
LFSR_DATA_BPTR_(&file->bshrub.u.bptr, left.buf));
}
file->bshrub.u.bshrub.blocks[0] = file->o.mdir.rbyd.blocks[0];
file->bshrub.u.bshrub.trunk = LFSR_RBYD_ISSHRUB | 0;
file->bshrub.u.bshrub.weight = 0;
// force estimate recalculation
file->bshrub.u.bshrub.estimate = -1;
file->bshrub.u.bshrub = LFSR_SHRUB_NULL(file->o.mdir.rbyd.blocks[0]);
if (attr_count > 0) {
LFS_ASSERT(attr_count <= sizeof(attrs)/sizeof(lfsr_attr_t));