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aarch64: Improve is_hfa

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The set of functions get_homogeneous_type, element_count, and is_hfa
are all intertwined and recompute data.  Return a compound quantity
from is_hfa that contains all the data and avoids the recomputation.
This commit is contained in:
Richard Henderson
2014-10-21 13:17:39 -04:00
committed by Richard Henderson
parent 18b74ce54a
commit 38b54b9c18
1 changed files with 143 additions and 93 deletions
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234
src/aarch64/ffi.c
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@@ -242,89 +242,133 @@ is_floating_type (unsigned short type)
|| type == FFI_TYPE_LONGDOUBLE);
}
/* Test for a homogeneous structure. */
static unsigned short
get_homogeneous_type (ffi_type *ty)
{
if (ty->type == FFI_TYPE_STRUCT && ty->elements)
{
unsigned i;
unsigned short candidate_type
= get_homogeneous_type (ty->elements[0]);
for (i =1; ty->elements[i]; i++)
{
unsigned short iteration_type = 0;
/* If we have a nested struct, we must find its homogeneous type.
If that fits with our candidate type, we are still
homogeneous. */
if (ty->elements[i]->type == FFI_TYPE_STRUCT
&& ty->elements[i]->elements)
{
iteration_type = get_homogeneous_type (ty->elements[i]);
}
else
{
iteration_type = ty->elements[i]->type;
}
/* If we are not homogeneous, return FFI_TYPE_STRUCT. */
if (candidate_type != iteration_type)
return FFI_TYPE_STRUCT;
}
return candidate_type;
}
/* Base case, we have no more levels of nesting, so we
are a basic type, and so, trivially homogeneous in that type. */
return ty->type;
}
/* Determine the number of elements within a STRUCT.
Note, we must handle nested structs.
If ty is not a STRUCT this function will return 0. */
static unsigned
element_count (ffi_type *ty)
{
if (ty->type == FFI_TYPE_STRUCT && ty->elements)
{
unsigned n;
unsigned elems = 0;
for (n = 0; ty->elements[n]; n++)
{
if (ty->elements[n]->type == FFI_TYPE_STRUCT
&& ty->elements[n]->elements)
elems += element_count (ty->elements[n]);
else
elems++;
}
return elems;
}
return 0;
}
/* Test for a homogeneous floating point aggregate.
A homogeneous floating point aggregate is a homogeneous aggregate of
a half- single- or double- precision floating point type with one
to four elements. Note that this includes nested structs of the
basic type. */
/* A subroutine of is_hfa. Given a structure type, return the type code
of the first non-structure element. Recurse for structure elements.
Return -1 if the structure is in fact empty, i.e. no nested elements. */
static int
is_hfa (ffi_type *ty)
is_hfa0 (const ffi_type *ty)
{
if (ty->type == FFI_TYPE_STRUCT
&& ty->elements[0]
&& is_floating_type (get_homogeneous_type (ty)))
ffi_type **elements = ty->elements;
int i, ret = -1;
if (elements != NULL)
for (i = 0; elements[i]; ++i)
{
unsigned n = element_count (ty);
return n >= 1 && n <= 4;
ret = elements[i]->type;
if (ret == FFI_TYPE_STRUCT)
{
ret = is_hfa0 (elements[i]);
if (ret < 0)
continue;
}
break;
}
return ret;
}
/* A subroutine of is_hfa. Given a structure type, return true if all
of the non-structure elements are the same as CANDIDATE. */
static int
is_hfa1 (const ffi_type *ty, int candidate)
{
ffi_type **elements = ty->elements;
int i;
if (elements != NULL)
for (i = 0; elements[i]; ++i)
{
int t = elements[i]->type;
if (t == FFI_TYPE_STRUCT)
{
if (!is_hfa1 (elements[i], candidate))
return 0;
}
else if (t != candidate)
return 0;
}
return 1;
}
/* Determine if TY is an homogenous floating point aggregate (HFA).
That is, a structure consisting of 1 to 4 members of all the same type,
where that type is a floating point scalar.
Returns non-zero iff TY is an HFA. The result is an encoded value where
bits 0-7 contain the type code, and bits 8-10 contain the element count. */
static int
is_hfa(const ffi_type *ty)
{
ffi_type **elements;
int candidate, i;
size_t size, ele_count;
/* Quickest tests first. */
if (ty->type != FFI_TYPE_STRUCT)
return 0;
/* No HFA types are smaller than 4 bytes, or larger than 64 bytes. */
size = ty->size;
if (size < 4 || size > 64)
return 0;
/* Find the type of the first non-structure member. */
elements = ty->elements;
candidate = elements[0]->type;
if (candidate == FFI_TYPE_STRUCT)
{
for (i = 0; ; ++i)
{
candidate = is_hfa0 (elements[i]);
if (candidate >= 0)
break;
}
}
/* If the first member is not a floating point type, it's not an HFA.
Also quickly re-check the size of the structure. */
switch (candidate)
{
case FFI_TYPE_FLOAT:
ele_count = size / sizeof(float);
if (size != ele_count * sizeof(float))
return 0;
break;
case FFI_TYPE_DOUBLE:
ele_count = size / sizeof(double);
if (size != ele_count * sizeof(double))
return 0;
break;
case FFI_TYPE_LONGDOUBLE:
ele_count = size / sizeof(long double);
if (size != ele_count * sizeof(long double))
return 0;
break;
default:
return 0;
}
if (ele_count > 4)
return 0;
/* Finally, make sure that all scalar elements are the same type. */
for (i = 0; elements[i]; ++i)
{
if (elements[i]->type == FFI_TYPE_STRUCT)
{
if (!is_hfa1 (elements[i], candidate))
return 0;
}
else if (elements[i]->type != candidate)
return 0;
}
/* All tests succeeded. Encode the result. */
return (ele_count << 8) | candidate;
}
/* Test if an ffi_type is a candidate for passing in a register.
@@ -559,7 +603,10 @@ copy_hfa_to_reg_or_stack (void *memory,
unsigned char *stack,
struct arg_state *state)
{
unsigned elems = element_count (ty);
int h = is_hfa (ty);
int type = h & 0xff;
unsigned elems = h >> 8;
if (available_v (state) < elems)
{
/* There are insufficient V registers. Further V register allocations
@@ -573,7 +620,6 @@ copy_hfa_to_reg_or_stack (void *memory,
else
{
int i;
unsigned short type = get_homogeneous_type (ty);
for (i = 0; i < elems; i++)
{
void *reg = allocate_to_v (context, state);
@@ -813,6 +859,7 @@ void
ffi_call (ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
{
extended_cif ecif;
int h;
ecif.cif = cif;
ecif.avalue = avalue;
@@ -861,11 +908,12 @@ ffi_call (ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
}
case FFI_TYPE_STRUCT:
if (is_hfa (cif->rtype))
h = is_hfa (cif->rtype);
if (h)
{
int j;
unsigned short type = get_homogeneous_type (cif->rtype);
unsigned elems = element_count (cif->rtype);
int type = h & 0xff;
int elems = h >> 8;
for (j = 0; j < elems; j++)
{
void *reg = get_basic_type_addr (type, &context, j);
@@ -967,7 +1015,7 @@ ffi_closure_SYSV_inner (ffi_closure *closure, struct call_context *context,
ffi_cif *cif = closure->cif;
void **avalue = (void**) alloca (cif->nargs * sizeof (void*));
void *rvalue = NULL;
int i;
int i, h;
struct arg_state state;
arg_init (&state, ALIGN(cif->bytes, 16));
@@ -1002,9 +1050,10 @@ ffi_closure_SYSV_inner (ffi_closure *closure, struct call_context *context,
#endif
case FFI_TYPE_STRUCT:
if (is_hfa (ty))
h = is_hfa (ty);
if (h)
{
unsigned n = element_count (ty);
unsigned n = h >> 8;
if (available_v (&state) < n)
{
state.nsrn = N_V_ARG_REG;
@@ -1013,7 +1062,7 @@ ffi_closure_SYSV_inner (ffi_closure *closure, struct call_context *context,
}
else
{
switch (get_homogeneous_type (ty))
switch (h & 0xff)
{
case FFI_TYPE_FLOAT:
{
@@ -1027,9 +1076,9 @@ ffi_closure_SYSV_inner (ffi_closure *closure, struct call_context *context,
correctly. The fake can be tossed once the
closure function has returned hence alloca()
is sufficient. */
int j;
unsigned j;
UINT32 *p = avalue[i] = alloca (ty->size);
for (j = 0; j < element_count (ty); j++)
for (j = 0; j < n; j++)
memcpy (&p[j],
allocate_to_s (context, &state),
sizeof (*p));
@@ -1048,9 +1097,9 @@ ffi_closure_SYSV_inner (ffi_closure *closure, struct call_context *context,
correctly. The fake can be tossed once the
closure function has returned hence alloca()
is sufficient. */
int j;
unsigned j;
UINT64 *p = avalue[i] = alloca (ty->size);
for (j = 0; j < element_count (ty); j++)
for (j = 0; j < n; j++)
memcpy (&p[j],
allocate_to_d (context, &state),
sizeof (*p));
@@ -1143,11 +1192,12 @@ ffi_closure_SYSV_inner (ffi_closure *closure, struct call_context *context,
break;
}
case FFI_TYPE_STRUCT:
if (is_hfa (cif->rtype))
h = is_hfa (cif->rtype);
if (h)
{
int j;
unsigned short type = get_homogeneous_type (cif->rtype);
unsigned elems = element_count (cif->rtype);
int type = h & 0xff;
int elems = h >> 8;
for (j = 0; j < elems; j++)
{
void *reg = get_basic_type_addr (type, context, j);