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fix-mixed-struct (patch by Pip Cet)

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Jsut for testing. It works for me (don't break anything)
    Small fixes for x86_64-gen.c in "tccpp: fix issues, add tests"
    are dropped in flavor of this patch.

    Pip Cet:

    Okay, here's a first patch that fixes the problem (but I've found
    another bug, yet unfixed, in the process), though it's not
    particularly pretty code (I tried hard to keep the changes to the
    minimum necessary). If we decide to actually get rid of VT_QLONG and
    VT_QFLOAT (please, can we?), there are some further simplifications in
    tccgen.c that might offset some of the cost of this patch.

    The idea is that an integer is no longer enough to describe how an
    argument is stored in registers. There are a number of possibilities
    (none, integer register, two integer registers, float register, two
    float registers, integer register plus float register, float register
    plus integer register), and instead of enumerating them I've
    introduced a RegArgs type that stores the offsets for each of our
    registers (for the other architectures, it's simply an int specifying
    the number of registers). If someone strongly prefers an enum, we
    could do that instead, but I believe this is a place where keeping
    things general is worth it, because this way it should be doable to
    add SSE or AVX support.

    There is one line in the patch that looks suspicious:

             } else {
                 addr = (addr + align - 1) & -align;
                 param_addr = addr;
                 addr += size;
    -            sse_param_index += reg_count;
             }
             break;

    However, this actually fixes one half of a bug we have when calling a
    function with eight double arguments "interrupted" by a two-double
    structure after the seventh double argument:

    f(double,double,double,double,double,double,double,struct { double
    x,y; },double);

    In this case, the last argument should be passed in %xmm7. This patch
    fixes the problem in gfunc_prolog, but not the corresponding problem
    in gfunc_call, which I'll try tackling next.
This commit is contained in:
seyko
2015-05-14 07:32:24 +03:00
parent 101cc8747f
commit 4e04f67c94
8 changed files with 454 additions and 230 deletions
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86
tccgen.c
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@ -525,7 +525,7 @@ ST_FUNC void vpushv(SValue *v)
*vtop = *v;
}
static void vdup(void)
ST_FUNC void vdup(void)
{
vpushv(vtop);
}
@ -4200,6 +4200,7 @@ ST_FUNC void unary(void)
SValue ret;
Sym *sa;
int nb_args, ret_nregs, ret_align, regsize, variadic;
RegArgs args;
/* function call */
if ((vtop->type.t & VT_BTYPE) != VT_FUNC) {
@ -4224,8 +4225,10 @@ ST_FUNC void unary(void)
/* compute first implicit argument if a structure is returned */
if ((s->type.t & VT_BTYPE) == VT_STRUCT) {
variadic = (s->c == FUNC_ELLIPSIS);
ret_nregs = gfunc_sret(&s->type, variadic, &ret.type,
&ret_align, &regsize);
gfunc_sret(&s->type, variadic, &ret.type,
&ret_align, &regsize, &args);
ret_nregs = regargs_nregs(&args);
if (!ret_nregs) {
/* get some space for the returned structure */
size = type_size(&s->type, &align);
@ -4303,6 +4306,10 @@ ST_FUNC void unary(void)
/* handle packed struct return */
if (((s->type.t & VT_BTYPE) == VT_STRUCT) && ret_nregs) {
int addr, offset;
#if defined(TCC_TARGET_X86_64) && !defined(TCC_TARGET_PE)
int i;
#endif
size = type_size(&s->type, &align);
/* We're writing whole regs often, make sure there's enough
@ -4311,6 +4318,34 @@ ST_FUNC void unary(void)
align = regsize;
loc = (loc - size) & -align;
addr = loc;
#if defined(TCC_TARGET_X86_64) && !defined(TCC_TARGET_PE)
for (i=0; i<REG_ARGS_MAX; i++) {
offset = args.ireg[i];
if (offset == -1)
break;
ret.type.t = VT_LLONG;
vset(&ret.type, VT_LOCAL | VT_LVAL, addr + offset);
vsetc(&ret.type, i ? REG_LRET : REG_IRET, &ret.c);
vstore();
vtop--;
vtop--;
}
for (i=0; i<REG_ARGS_MAX; i++) {
offset = args.freg[i];
if (offset == -1)
break;
ret.type.t = VT_DOUBLE;
vset(&ret.type, VT_LOCAL | VT_LVAL, addr + offset);
vsetc(&ret.type, i ? REG_QRET : REG_FRET, &ret.c);
vstore();
vtop--;
vtop--;
}
#else
offset = 0;
for (;;) {
vset(&ret.type, VT_LOCAL | VT_LVAL, addr + offset);
@ -4321,6 +4356,7 @@ ST_FUNC void unary(void)
break;
offset += regsize;
}
#endif
vset(&s->type, VT_LOCAL | VT_LVAL, addr);
}
} else {
@ -4891,8 +4927,11 @@ 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, ret_nregs, regsize;
ret_nregs = gfunc_sret(&func_vt, func_var, &ret_type,
&ret_align, &regsize);
RegArgs args;
gfunc_sret(&func_vt, func_var, &ret_type,
&ret_align, &regsize, &args);
ret_nregs = regargs_nregs(&args);
if (0 == ret_nregs) {
/* if returning structure, must copy it to implicit
first pointer arg location */
@ -4906,6 +4945,9 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
} else {
/* returning structure packed into registers */
int r, size, addr, align;
#if defined(TCC_TARGET_X86_64) && !defined(TCC_TARGET_PE)
int i;
#endif
size = type_size(&func_vt,&align);
if ((vtop->r != (VT_LOCAL | VT_LVAL) || (vtop->c.i & (ret_align-1)))
&& (align & (ret_align-1))) {
@ -4919,6 +4961,39 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
vset(&ret_type, VT_LOCAL | VT_LVAL, addr);
}
vtop->type = ret_type;
#if defined(TCC_TARGET_X86_64) && !defined(TCC_TARGET_PE)
for (i=0; i<REG_ARGS_MAX; i++) {
int off = args.ireg[i];
if (off == -1)
break;
r = i ? RC_LRET : RC_IRET;
vdup();
vtop->c.i += off;
vtop->type.t = VT_LLONG;
gv(r);
vpop();
}
for (i=0; i<REG_ARGS_MAX; i++) {
int off = args.freg[i];
if (off == -1)
break;
/* We assume that when a structure is returned in multiple
registers, their classes are consecutive values of the
suite s(n) = 2^n */
r = rc_fret(ret_type.t) << i;
vdup();
vtop->c.i += off;
vtop->type.t = VT_DOUBLE;
gv(r);
vpop();
}
#else
if (is_float(ret_type.t))
r = rc_fret(ret_type.t);
else
@ -4935,6 +5010,7 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
vtop->c.i += regsize;
vtop->r = VT_LOCAL | VT_LVAL;
}
#endif
}
} else if (is_float(func_vt.t)) {
gv(rc_fret(func_vt.t));