Avoid •bit._cast aliasing, and all copying by using slices

This commit is contained in:
Marshall Lochbaum 2022-02-04 16:23:05 -05:00
parent 289763d1d1
commit 69e496f7fa
2 changed files with 19 additions and 11 deletions

View File

@ -872,14 +872,14 @@ CastType getCastType(B e) {
} }
return (CastType) { o2s(s), t }; return (CastType) { o2s(s), t };
} }
TyArr* convert(CastType t, B x) { B convert(CastType t, B x) {
switch (t.s) { switch (t.s) {
case 1: return toBitArr(x); case 1: return taga(toBitArr(x));
case 8: return t.t=='c' ? toC8Arr (x) : toI8Arr (x); case 8: return t.t=='c' ? toC8Any (x) : toI8Any (x);
case 16: return t.t=='c' ? toC16Arr(x) : toI16Arr(x); case 16: return t.t=='c' ? toC16Any(x) : toI16Any(x);
case 32: return t.t=='c' ? toC32Arr(x) : toI32Arr(x); case 32: return t.t=='c' ? toC32Any(x) : toI32Any(x);
case 64: return toF64Arr(x); case 64: return toF64Any(x);
default: thrM("•bit._cast: unsupported result width"); default: thrM("•bit._cast: unsupported input width");
} }
} }
u8 typeOfCast(CastType t) { u8 typeOfCast(CastType t) {
@ -903,14 +903,21 @@ B bitcast_c1(Md1D* d, B x) { B f = d->f;
usz s=xt.s*sh[xr-1], zl=s/zt.s; usz s=xt.s*sh[xr-1], zl=s/zt.s;
if (zl*zt.s != s) thrM("•bit._cast: incompatible lengths"); if (zl*zt.s != s) thrM("•bit._cast: incompatible lengths");
// Convert to input type // Convert to input type
B r = taga(convert(xt, x)); B r = convert(xt, x);
if (v(r)->refc!=1) {
r = taga(TI(r,slice)(r, 0, a(r)->ia));
sprnk(v(r),xr);
}
// Cast to output type // Cast to output type
v(r)->type = typeOfCast(zt); u8 rt = typeOfCast(zt); if (IS_SLICE(v(r)->type)) rt = TO_SLICE(rt);
v(r)->type = rt;
// Adjust shape // Adjust shape
if (xr<=1) { if (xr<=1) {
a(r)->sh[xr-1]=zl; Arr* a = a(r);
a->ia = zl;
a->sh = &a->ia;
} else { } else {
if (shObj(r)->refc>1) { if (shObj(x)->refc>1) {
usz* zsh = arr_shAlloc(a(r), xr); usz* zsh = arr_shAlloc(a(r), xr);
memcpy(zsh, sh, (xr-1)*sizeof(usz)); memcpy(zsh, sh, (xr-1)*sizeof(usz));
sh = zsh; sh = zsh;

View File

@ -226,6 +226,7 @@ enum Type {
}; };
#define IS_SLICE(T) ((T)>=t_hslice & (T)<=t_f64slice) #define IS_SLICE(T) ((T)>=t_hslice & (T)<=t_f64slice)
#define IS_ARR(T) ((T)>=t_harr & (T)<=t_bitarr) #define IS_ARR(T) ((T)>=t_harr & (T)<=t_bitarr)
#define TO_SLICE(T) ((T) + t_hslice - t_harr) // Assumes T!=t_bitarr
enum ElType { // a⌈b shall return the type that can store both, if possible enum ElType { // a⌈b shall return the type that can store both, if possible
el_bit=0, el_bit=0,