tcg: Build ffi data structures for helpers

Add libffi as a build requirement for TCI.
Add libffi to the dockerfiles to satisfy that requirement.

Construct an ffi_cif structure for each unique typemask.
Record the result in a separate hash table for later lookup;
this allows helper_table to stay const.

Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-03-18 12:46:44 -06:00
parent fa52e66062
commit 22f15579fa
12 changed files with 75 additions and 1 deletions

View file

@ -60,6 +60,10 @@
#include "exec/log.h"
#include "tcg-internal.h"
#ifdef CONFIG_TCG_INTERPRETER
#include <ffi.h>
#endif
/* Forward declarations for functions declared in tcg-target.c.inc and
used here. */
static void tcg_target_init(TCGContext *s);
@ -539,6 +543,19 @@ static const TCGHelperInfo all_helpers[] = {
};
static GHashTable *helper_table;
#ifdef CONFIG_TCG_INTERPRETER
static GHashTable *ffi_table;
static ffi_type * const typecode_to_ffi[8] = {
[dh_typecode_void] = &ffi_type_void,
[dh_typecode_i32] = &ffi_type_uint32,
[dh_typecode_s32] = &ffi_type_sint32,
[dh_typecode_i64] = &ffi_type_uint64,
[dh_typecode_s64] = &ffi_type_sint64,
[dh_typecode_ptr] = &ffi_type_pointer,
};
#endif
static int indirect_reg_alloc_order[ARRAY_SIZE(tcg_target_reg_alloc_order)];
static void process_op_defs(TCGContext *s);
static TCGTemp *tcg_global_reg_new_internal(TCGContext *s, TCGType type,
@ -582,6 +599,47 @@ static void tcg_context_init(unsigned max_cpus)
(gpointer)&all_helpers[i]);
}
#ifdef CONFIG_TCG_INTERPRETER
/* g_direct_hash/equal for direct comparisons on uint32_t. */
ffi_table = g_hash_table_new(NULL, NULL);
for (i = 0; i < ARRAY_SIZE(all_helpers); ++i) {
struct {
ffi_cif cif;
ffi_type *args[];
} *ca;
uint32_t typemask = all_helpers[i].typemask;
gpointer hash = (gpointer)(uintptr_t)typemask;
ffi_status status;
int nargs;
if (g_hash_table_lookup(ffi_table, hash)) {
continue;
}
/* Ignoring the return type, find the last non-zero field. */
nargs = 32 - clz32(typemask >> 3);
nargs = DIV_ROUND_UP(nargs, 3);
ca = g_malloc0(sizeof(*ca) + nargs * sizeof(ffi_type *));
ca->cif.rtype = typecode_to_ffi[typemask & 7];
ca->cif.nargs = nargs;
if (nargs != 0) {
ca->cif.arg_types = ca->args;
for (i = 0; i < nargs; ++i) {
int typecode = extract32(typemask, (i + 1) * 3, 3);
ca->args[i] = typecode_to_ffi[typecode];
}
}
status = ffi_prep_cif(&ca->cif, FFI_DEFAULT_ABI, nargs,
ca->cif.rtype, ca->cif.arg_types);
assert(status == FFI_OK);
g_hash_table_insert(ffi_table, hash, (gpointer)&ca->cif);
}
#endif
tcg_target_init(s);
process_op_defs(s);