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Fix struct ret in variadic fct with ARM hardfloat

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The procedure calling standard for ARM architecture mandate the use of
the base standard for variadic function. Therefore, hgen float aggregate
must be returned via stack when greater than 4 bytes and via core
registers else in case of variadic function.

This patch improve gfunc_sret() to take into account whether the
function is variadic or not and make use of gfunc_sret() return value to
determine whether to pass a structure via stack in gfunc_prolog(). It
also take advantage of knowing if a function is variadic or not move
float result value from VFP register to core register in gfunc_epilog().
This commit is contained in:
Thomas Preud'homme
2014-01-06 22:27:39 +08:00
parent bcc1904f9c
commit 8efaa71190
7 changed files with 35 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
arm-gen.c
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@ -839,12 +839,12 @@ int floats_in_core_regs(SValue *sval)
/* Return the number of registers needed to return the struct, or 0 if
returning via struct pointer. */
ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *ret_align) {
ST_FUNC int gfunc_sret(CType *vt, int variadic, CType *ret, int *ret_align) {
#ifdef TCC_ARM_EABI
int size, align;
size = type_size(vt, &align);
#ifdef TCC_ARM_HARDFLOAT
if (is_float(vt->t) || is_hgen_float_aggr(vt)) {
if (!variadic && (is_float(vt->t) || is_hgen_float_aggr(vt))) {
*ret_align = 8;
ret->ref = NULL;
ret->t = VT_DOUBLE;
@ -1221,21 +1221,19 @@ void gfunc_call(int nb_args)
void gfunc_prolog(CType *func_type)
{
Sym *sym,*sym2;
int n,nf,size,align, variadic, struct_ret = 0;
int n, nf, size, align, struct_ret = 0;
#ifdef TCC_ARM_HARDFLOAT
struct avail_regs avregs = AVAIL_REGS_INITIALIZER;
#endif
CType ret_type;
sym = func_type->ref;
func_vt = sym->type;
func_var = (func_type->ref->c == FUNC_ELLIPSIS);
n = nf = 0;
variadic = (func_type->ref->c == FUNC_ELLIPSIS);
if((func_vt.t & VT_BTYPE) == VT_STRUCT
#ifdef TCC_ARM_HARDFLOAT
&& (variadic || !is_hgen_float_aggr(&func_vt))
#endif
&& type_size(&func_vt,&align) > 4)
if ((func_vt.t & VT_BTYPE) == VT_STRUCT &&
!gfunc_sret(&func_vt, func_var, &ret_type, &align))
{
n++;
struct_ret = 1;
@ -1244,7 +1242,7 @@ void gfunc_prolog(CType *func_type)
for(sym2=sym->next;sym2 && (n<4 || nf<16);sym2=sym2->next) {
size = type_size(&sym2->type, &align);
#ifdef TCC_ARM_HARDFLOAT
if (!variadic && (is_float(sym2->type.t)
if (!func_var && (is_float(sym2->type.t)
|| is_hgen_float_aggr(&sym2->type))) {
int tmpnf = assign_vfpreg(&avregs, align, size);
tmpnf += (size + 3) / 4;
@ -1255,9 +1253,9 @@ void gfunc_prolog(CType *func_type)
n += (size + 3) / 4;
}
o(0xE1A0C00D); /* mov ip,sp */
if(variadic)
if (func_var)
n=4;
if(n) {
if (n) {
if(n>4)
n=4;
#ifdef TCC_ARM_EABI
@ -1289,7 +1287,7 @@ void gfunc_prolog(CType *func_type)
size = (size + 3) >> 2;
align = (align + 3) & ~3;
#ifdef TCC_ARM_HARDFLOAT
if (!variadic && (is_float(sym->type.t)
if (!func_var && (is_float(sym->type.t)
|| is_hgen_float_aggr(&sym->type))) {
int fpn = assign_vfpreg(&avregs, align, size << 2);
if (fpn >= 0) {
@ -1329,10 +1327,14 @@ void gfunc_epilog(void)
{
uint32_t x;
int diff;
/* Copy float return value to core register if base standard is used and
float computation is made with VFP */
#ifdef TCC_ARM_EABI
/* Useless but harmless copy of the float result into main register(s) in case
of variadic function in the hardfloat variant */
if(is_float(func_vt.t)) {
if (
#ifdef TCC_ARM_HARDFLOAT
func_var &&
#endif
is_float(func_vt.t)) {
if((func_vt.t & VT_BTYPE) == VT_FLOAT)
o(0xEE100A10); /* fmrs r0, s0 */
else {