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Add support for struct > 4B returned via registers

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On ARM with hardfloat calling convention, structure containing 4 fields
or less of the same float type are returned via float registers. This
means that a structure can be returned in up to 4 double registers in a
structure is composed of 4 doubles. This commit adds support for return
of structures in several registers.
This commit is contained in:
Thomas Preud'homme
2013-11-22 09:27:15 +08:00
parent d9d60a1ebd
commit dcec8673f2
5 changed files with 77 additions and 49 deletions
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46
tccgen.c
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@ -3927,7 +3927,7 @@ ST_FUNC void unary(void)
} else if (tok == '(') {
SValue ret;
Sym *sa;
int nb_args, sret;
int nb_args, sret, ret_align;
/* function call */
if ((vtop->type.t & VT_BTYPE) != VT_FUNC) {
@ -3951,9 +3951,8 @@ ST_FUNC void unary(void)
ret.r2 = VT_CONST;
/* compute first implicit argument if a structure is returned */
if ((s->type.t & VT_BTYPE) == VT_STRUCT) {
int ret_align;
sret = gfunc_sret(&s->type, &ret.type, &ret_align);
if (sret) {
if (!sret) {
/* get some space for the returned structure */
size = type_size(&s->type, &align);
loc = (loc - size) & -align;
@ -3966,11 +3965,11 @@ ST_FUNC void unary(void)
nb_args++;
}
} else {
sret = 0;
sret = 1;
ret.type = s->type;
}
if (!sret) {
if (sret) {
/* return in register */
if (is_float(ret.type.t)) {
ret.r = reg_fret(ret.type.t);
@ -4010,18 +4009,23 @@ ST_FUNC void unary(void)
vtop -= (nb_args + 1);
}
/* return value */
vsetc(&ret.type, ret.r, &ret.c);
vtop->r2 = ret.r2;
for (r = ret.r + sret + !sret; r-- > ret.r;) {
vsetc(&ret.type, r, &ret.c);
vtop->r2 = ret.r2; /* Loop only happens when r2 is VT_CONST */
}
/* handle packed struct return */
if (((s->type.t & VT_BTYPE) == VT_STRUCT) && !sret) {
int addr;
if (((s->type.t & VT_BTYPE) == VT_STRUCT) && sret) {
int addr, offset;
size = type_size(&s->type, &align);
loc = (loc - size) & -align;
addr = loc;
vset(&ret.type, VT_LOCAL | VT_LVAL, addr);
vswap();
vstore();
vtop--;
for(offset = 0; offset < size; offset += ret_align) {
vset(&ret.type, VT_LOCAL | VT_LVAL, addr + offset);
vswap();
vstore();
vtop--;
}
vset(&s->type, VT_LOCAL | VT_LVAL, addr);
}
} else {
@ -4593,7 +4597,7 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
if ((func_vt.t & VT_BTYPE) == VT_STRUCT) {
CType type, ret_type;
int ret_align;
if (gfunc_sret(&func_vt, &ret_type, &ret_align)) {
if (!gfunc_sret(&func_vt, &ret_type, &ret_align)) {
/* if returning structure, must copy it to implicit
first pointer arg location */
type = func_vt;
@ -4605,7 +4609,7 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
vstore();
} else {
/* returning structure packed into registers */
int size, addr, align;
int r, size, addr, offset, align;
size = type_size(&func_vt,&align);
if ((vtop->r != (VT_LOCAL | VT_LVAL) || (vtop->c.i & (ret_align-1)))
&& (align & (ret_align-1))) {
@ -4619,9 +4623,17 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
}
vtop->type = ret_type;
if (is_float(ret_type.t))
gv(rc_fret(ret_type.t));
r = rc_fret(ret_type.t);
else
gv(RC_IRET);
r = RC_IRET;
/* We assume that when a structure is returned in multiple
registers, their classes are consecutive values of the
suite s(n) = 2^n */
for (offset = 0; offset < size; offset += ret_align, r<<=1) {
gv(r);
vtop->c.i += ret_align;
vtop->r = VT_LOCAL | VT_LVAL;
}
}
} else if (is_float(func_vt.t)) {
gv(rc_fret(func_vt.t));