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Reorganized traversal flags again

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One nice thing about merging LOOKAHEAD + LOOKGBMAP, is now our core
traversal flags fit in a single byte. This is useful for organizing
things, especially so as the traversal flags seem to permeate into
basically every flag set.

The main change was to actually group these flags into a byte, which
helps readability and in theory could make some bulk accesses cheaper
(in practice I don't think we currently leverage this):

  T_MODE             0x00000001  ---- ---- ---- ---- ---- ---- ---- ---1
  T_RDONLY           0x00000000  ---- ---- ---- ---- ---- ---- ---- ----
  T_RDWR             0x00000001  ---- ---- ---- ---- ---- ---- ---- ---1
  T_MTREEONLY        0x00000002  ---- ---- ---- ---- ---- ---- ---- --1-
  T_EXCL             0x00000008  ---- ---- ---- ---- ---- ---- ---- 1---
  T_MKCONSISTENT     0x00000100  ---- ---- ---- ---- ---- ---1 ---- ----
  T_LOOKAHEAD        0x00000200  ---- ---- ---- ---- ---- --1- ---- ----
  T_PREERASE*        0x00000400  ---- ---- ---- ---- ---- -1-- ---- ----
  T_COMPACT          0x00000800  ---- ---- ---- ---- ---- 1--- ---- ----
  T_CKMETA           0x00001000  ---- ---- ---- ---- ---1 ---- ---- ----
  T_CKDATA           0x00002000  ---- ---- ---- ---- --1- ---- ---- ----
  T_REPAIRMETA*      0x00004000  ---- ---- ---- ---- -1-- ---- ---- ----
  T_REPAIRDATA*      0x00008000  ---- ---- ---- ---- 1--- ---- ---- ----

  t_EVICT*           0x00000010  ---- ---- ---- ---- ---- ---- ---1 ----
  t_TYPE             0xf0000000  1111 ---- ---- ---- ---- ---- ---- ----
  t_ZOMBIE           0x08000000  ---- 1--- ---- ---- ---- ---- ---- ----
  t_CKPOINTED        0x04000000  ---- -1-- ---- ---- ---- ---- ---- ----
  t_DIRTY            0x02000000  ---- --1- ---- ---- ---- ---- ---- ----
  t_STALE            0x01000000  ---- ---1 ---- ---- ---- ---- ---- ----
  t_BTYPE            0x00ff0000  ---- ---- 1111 1111 ---- ---- ---- ----

  * Planned

This gives btype a full byte as well, which is a bit overkill, but can
be reduced in the future if we run into traversal flag pressure.

This also pushes some future planned flags (DEDUP, COMPR, etc) into
higher-order bits, but that's not the end of the world.

Code changes basically nothing:

                 code          stack          ctx
  before:       35152           2136          660
  after:        35152 (+0.0%)   2136 (+0.0%)  660 (+0.0%)

                 code          stack          ctx
  gbmap before: 38080           2136          776
  gbmap after:  38076 (-0.0%)   2136 (+0.0%)  776 (+0.0%)
This commit is contained in:
Christopher Haster
2025-12-05 01:19:35 -06:00
parent 7a57b1e2bd
commit d54fef8099
3 changed files with 71 additions and 71 deletions
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lfs3.c
+2 -2
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@@ -7255,11 +7255,11 @@ static inline bool lfs3_t_isckdata(uint32_t flags) {
// internal traversal flags
static inline uint8_t lfs3_t_btype(uint32_t flags) {
return (flags >> 20) & 0xf;
return (flags >> 16) & 0xff;
}
static inline uint32_t lfs3_t_btypeflags(uint8_t btype) {
return (uint32_t)btype << 20;
return (uint32_t)btype << 16;
}
static inline void lfs3_t_setbtype(uint32_t *flags, uint8_t btype) {