DrSocalkwe3n/luajit
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Abstract out pointer hash to hashrot(). Tune hash constants.

Browse Source
This commit is contained in:
Mike Pall
2010-07-21 21:42:40 +02:00
parent 6667ab0f26
commit d05873ee0a
4 changed files with 32 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
src/lj_asm.c
View File

@@ -1572,7 +1572,7 @@ static void asm_aref(ASMState *as, IRIns *ir)
emit_rr(as, XO_MOV, dest, as->mrm.base);
}
/* Must match with hashkey() and hashrot() in lj_tab.c. */
/* Must match with hash*() in lj_tab.c. */
static uint32_t ir_khash(IRIns *ir)
{
uint32_t lo, hi;
@@ -1587,12 +1587,9 @@ static uint32_t ir_khash(IRIns *ir)
} else {
lua_assert(irt_isgcv(ir->t));
lo = u32ptr(ir_kgc(ir));
hi = lo - 0x04c11db7;
hi = lo + HASH_BIAS;
}
lo ^= hi; hi = lj_rol(hi, 14);
lo -= hi; hi = lj_rol(hi, 5);
hi ^= lo; hi -= lj_rol(lo, 27);
return hi;
return hashrot(lo, hi);
}
/* Merge NE(HREF, niltv) check. */
@@ -1717,11 +1714,11 @@ static void asm_href(ASMState *as, IRIns *ir)
} else { /* Must match with hashrot() in lj_tab.c. */
emit_rmro(as, XO_ARITH(XOg_AND), dest, tab, offsetof(GCtab, hmask));
emit_rr(as, XO_ARITH(XOg_SUB), dest, tmp);
emit_shifti(as, XOg_ROL, tmp, 27);
emit_shifti(as, XOg_ROL, tmp, HASH_ROT3);
emit_rr(as, XO_ARITH(XOg_XOR), dest, tmp);
emit_shifti(as, XOg_ROL, dest, 5);
emit_shifti(as, XOg_ROL, dest, HASH_ROT2);
emit_rr(as, XO_ARITH(XOg_SUB), tmp, dest);
emit_shifti(as, XOg_ROL, dest, 14);
emit_shifti(as, XOg_ROL, dest, HASH_ROT1);
emit_rr(as, XO_ARITH(XOg_XOR), tmp, dest);
if (irt_isnum(kt)) {
emit_rr(as, XO_ARITH(XOg_ADD), dest, dest);
@@ -1735,7 +1732,7 @@ static void asm_href(ASMState *as, IRIns *ir)
#endif
} else {
emit_rr(as, XO_MOV, tmp, key);
emit_rmro(as, XO_LEA, dest, key, -0x04c11db7);
emit_rmro(as, XO_LEA, dest, key, HASH_BIAS);
}
}
}