gh-mirror/mikepaul-LuaJIT
1
0
Fork 0
mirror of https://github.com/LuaJIT/LuaJIT.git synced 2025-02-08 07:34:07 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

JIT-compile bitfield loads

Browse Source 
This PR implements JIT compilation of bitfield loads.  Stores to
bitfields are still NYI.
This commit is contained in:
Demi Obenour 2017-03-12 14:47:04 -04:00
parent de97b9d52b
commit bc01981736
2 changed files with 48 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
src/lj_crecord.c
View File

@ -42,6 +42,22 @@
#define emitconv(a, dt, st, flags) \
emitir(IRT(IR_CONV, (dt)), (a), (st)|((dt) << 5)|(flags))
/* Get the underlying type of a C bitfield */
static CTypeID ctype_underlying_type(CTypeID info) {
CTypeID id;
lua_assert(ctype_isbitfield(info));
switch (ctype_bitcsz(info)) {
case 1: id = CTID_INT8; break;
case 2: id = CTID_INT16; break;
case 4: id = CTID_INT32; break;
default:
/* VM doesn't support bitfields of size > 8 bytes */
lua_assert(0); return 0;
}
/* Each unsigned id is the signed id plus 1 */
return ((info & CTF_UNSIGNED) != 0) + id;
}
/* -- C type checks ------------------------------------------------------- */
static GCcdata *argv2cdata(jit_State *J, TRef tr, cTValue *o)
@ -542,6 +558,22 @@ static TRef crec_ct_ct(jit_State *J, CType *d, CType *s, TRef dp, TRef sp,
return 0;
}
/* Load a C type from a bitfield ------------------------------------------ */
static TRef crec_bitfield_load(jit_State *J, CTypeID sid, TRef tr) {
uint32_t pos = ctype_bitpos(sid);
uint32_t bsz = ctype_bitbsz(sid);
lua_assert(ctype_isbitfield(sid));
lua_assert(bsz > 0 && "Zero sized bitfield is invalid");
if (!(sid & CTF_BOOL)) {
CTSize shift = 32 - bsz;
tr = emitir(IRT(IR_BSHL, IRT_INT), tr, lj_ir_kint(J, shift - pos));
return emitir(IRT(IR_BSHR, IRT_INT), tr, lj_ir_kint(J, shift));
/* if crosses container boundary: interpreter will throw */
} else {
lj_trace_err(J, LJ_TRERR_NYICONV);
}
}
/* -- Convert C type to TValue (load) ------------------------------------- */
static TRef crec_tv_ct(jit_State *J, CType *s, CTypeID sid, TRef sp)
@ -554,12 +586,18 @@ static TRef crec_tv_ct(jit_State *J, CType *s, CTypeID sid, TRef sp)
if (t == IRT_CDATA)
goto err_nyi; /* NYI: copyval of >64 bit integers. */
tr = emitir(IRT(IR_XLOAD, t), sp, 0);
if (ctype_isbitfield(sid)) {
tr = crec_bitfield_load(J, sid, tr);
if (sid & CTF_BOOL)
goto boolfield;
}
if (t == IRT_FLOAT || t == IRT_U32) { /* Keep uint32_t/float as numbers. */
return emitconv(tr, IRT_NUM, t, 0);
} else if (t == IRT_I64 || t == IRT_U64) { /* Box 64 bit integer. */
sp = tr;
lj_needsplit(J);
} else if ((sinfo & CTF_BOOL)) {
boolfield:
/* Assume not equal to zero. Fixup and emit pending guard later. */
lj_ir_set(J, IRTGI(IR_NE), tr, lj_ir_kint(J, 0));
J->postproc = LJ_POST_FIXGUARD;
@ -585,6 +623,7 @@ static TRef crec_tv_ct(jit_State *J, CType *s, CTypeID sid, TRef sp)
emitir(IRT(IR_XSTORE, t), ptr, tr2);
return dp;
} else {
lua_assert(!ctype_isbitfield(sinfo));
/* NYI: copyval of vectors. */
err_nyi:
lj_trace_err(J, LJ_TRERR_NYICONV);
@ -759,7 +798,8 @@ void LJ_FASTCALL recff_cdata_index(jit_State *J, RecordFFData *rd)
CTState *cts = ctype_ctsG(J2G(J));
CType *ct = ctype_raw(cts, cd->ctypeid);
CTypeID sid = 0;
int isbitfield = 0;
CTypeID bitfield_val = 0;
/* Resolve pointer or reference for cdata object. */
if (ctype_isptr(ct->info)) {
IRType t = (LJ_64 && ct->size == 8) ? IRT_P64 : IRT_P32;
@ -836,7 +876,11 @@ again:
J->base[0] = lj_ir_kint(J, (int32_t)fct->size);
return; /* Interpreter will throw for newindex. */
} else if (ctype_isbitfield(fct->info)) {
lj_trace_err(J, LJ_TRERR_NYICONV);
if (rd->data != 0)
lj_trace_err(J, LJ_TRERR_NYICONV);
isbitfield = 1;
bitfield_val = fct->info;
sid = ctype_underlying_type(bitfield_val);
} else {
lua_assert(ctype_isfield(fct->info));
sid = ctype_cid(fct->info);
@ -882,7 +926,7 @@ again:
ct = ctype_child(cts, ct); /* Skip attributes. */
if (rd->data == 0) { /* __index metamethod. */
J->base[0] = crec_tv_ct(J, ct, sid, ptr);
J->base[0] = crec_tv_ct(J, ct, isbitfield ? bitfield_val : sid, ptr);
} else { /* __newindex metamethod. */
rd->nres = 0;
J->needsnap = 1;

2
src/luaconf.h
View File

@ -141,7 +141,7 @@
#include <assert.h>
#endif
#ifdef LUA_USE_ASSERT
#define lua_assert(x) assert(x)
#define lua_assert assert
#endif
#ifdef LUA_USE_APICHECK
#define luai_apicheck(L, o) { (void)L; assert(o); }