#include "qemu-common.h"
#include "tcg-op.h"
-#if TCG_TARGET_REG_BITS == 64
#define CASE_OP_32_64(x) \
glue(glue(case INDEX_op_, x), _i32): \
glue(glue(case INDEX_op_, x), _i64)
-#else
-#define CASE_OP_32_64(x) \
- glue(glue(case INDEX_op_, x), _i32)
-#endif
+typedef enum {
+ TCG_TEMP_UNDEF = 0,
+ TCG_TEMP_CONST,
+ TCG_TEMP_COPY,
+ TCG_TEMP_HAS_COPY,
+ TCG_TEMP_ANY
+} tcg_temp_state;
+
+struct tcg_temp_info {
+ tcg_temp_state state;
+ uint16_t prev_copy;
+ uint16_t next_copy;
+ tcg_target_ulong val;
+};
+
+static struct tcg_temp_info temps[TCG_MAX_TEMPS];
+
+/* Reset TEMP's state to TCG_TEMP_ANY. If TEMP was a representative of some
+ class of equivalent temp's, a new representative should be chosen in this
+ class. */
+static void reset_temp(TCGArg temp, int nb_temps, int nb_globals)
+{
+ int i;
+ TCGArg new_base = (TCGArg)-1;
+ if (temps[temp].state == TCG_TEMP_HAS_COPY) {
+ for (i = temps[temp].next_copy; i != temp; i = temps[i].next_copy) {
+ if (i >= nb_globals) {
+ temps[i].state = TCG_TEMP_HAS_COPY;
+ new_base = i;
+ break;
+ }
+ }
+ for (i = temps[temp].next_copy; i != temp; i = temps[i].next_copy) {
+ if (new_base == (TCGArg)-1) {
+ temps[i].state = TCG_TEMP_ANY;
+ } else {
+ temps[i].val = new_base;
+ }
+ }
+ temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
+ temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
+ } else if (temps[temp].state == TCG_TEMP_COPY) {
+ temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
+ temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
+ new_base = temps[temp].val;
+ }
+ temps[temp].state = TCG_TEMP_ANY;
+ if (new_base != (TCGArg)-1 && temps[new_base].next_copy == new_base) {
+ temps[new_base].state = TCG_TEMP_ANY;
+ }
+}
+
+static int op_bits(TCGOpcode op)
+{
+ const TCGOpDef *def = &tcg_op_defs[op];
+ return def->flags & TCG_OPF_64BIT ? 64 : 32;
+}
+
+static TCGOpcode op_to_movi(TCGOpcode op)
+{
+ switch (op_bits(op)) {
+ case 32:
+ return INDEX_op_movi_i32;
+ case 64:
+ return INDEX_op_movi_i64;
+ default:
+ fprintf(stderr, "op_to_movi: unexpected return value of "
+ "function op_bits.\n");
+ tcg_abort();
+ }
+}
+
+static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args, TCGArg dst,
+ TCGArg src, int nb_temps, int nb_globals)
+{
+ reset_temp(dst, nb_temps, nb_globals);
+ assert(temps[src].state != TCG_TEMP_COPY);
+ /* Don't try to copy if one of temps is a global or either one
+ is local and another is register */
+ if (src >= nb_globals && dst >= nb_globals &&
+ tcg_arg_is_local(s, src) == tcg_arg_is_local(s, dst)) {
+ assert(temps[src].state != TCG_TEMP_CONST);
+ if (temps[src].state != TCG_TEMP_HAS_COPY) {
+ temps[src].state = TCG_TEMP_HAS_COPY;
+ temps[src].next_copy = src;
+ temps[src].prev_copy = src;
+ }
+ temps[dst].state = TCG_TEMP_COPY;
+ temps[dst].val = src;
+ temps[dst].next_copy = temps[src].next_copy;
+ temps[dst].prev_copy = src;
+ temps[temps[dst].next_copy].prev_copy = dst;
+ temps[src].next_copy = dst;
+ }
+ gen_args[0] = dst;
+ gen_args[1] = src;
+}
+
+static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val,
+ int nb_temps, int nb_globals)
+{
+ reset_temp(dst, nb_temps, nb_globals);
+ temps[dst].state = TCG_TEMP_CONST;
+ temps[dst].val = val;
+ gen_args[0] = dst;
+ gen_args[1] = val;
+}
+
+static TCGOpcode op_to_mov(TCGOpcode op)
+{
+ switch (op_bits(op)) {
+ case 32:
+ return INDEX_op_mov_i32;
+ case 64:
+ return INDEX_op_mov_i64;
+ default:
+ fprintf(stderr, "op_to_mov: unexpected return value of "
+ "function op_bits.\n");
+ tcg_abort();
+ }
+}
+
+static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y)
+{
+ switch (op) {
+ CASE_OP_32_64(add):
+ return x + y;
+
+ CASE_OP_32_64(sub):
+ return x - y;
+
+ CASE_OP_32_64(mul):
+ return x * y;
+
+ CASE_OP_32_64(and):
+ return x & y;
+
+ CASE_OP_32_64(or):
+ return x | y;
+
+ CASE_OP_32_64(xor):
+ return x ^ y;
+
+ case INDEX_op_shl_i32:
+ return (uint32_t)x << (uint32_t)y;
+
+ case INDEX_op_shl_i64:
+ return (uint64_t)x << (uint64_t)y;
+
+ case INDEX_op_shr_i32:
+ return (uint32_t)x >> (uint32_t)y;
+
+ case INDEX_op_shr_i64:
+ return (uint64_t)x >> (uint64_t)y;
+
+ case INDEX_op_sar_i32:
+ return (int32_t)x >> (int32_t)y;
+
+ case INDEX_op_sar_i64:
+ return (int64_t)x >> (int64_t)y;
+
+ case INDEX_op_rotr_i32:
+ x = ((uint32_t)x << (32 - y)) | ((uint32_t)x >> y);
+ return x;
+
+ case INDEX_op_rotr_i64:
+ x = ((uint64_t)x << (64 - y)) | ((uint64_t)x >> y);
+ return x;
+
+ case INDEX_op_rotl_i32:
+ x = ((uint32_t)x << y) | ((uint32_t)x >> (32 - y));
+ return x;
+
+ case INDEX_op_rotl_i64:
+ x = ((uint64_t)x << y) | ((uint64_t)x >> (64 - y));
+ return x;
+
+ CASE_OP_32_64(not):
+ return ~x;
+
+ CASE_OP_32_64(neg):
+ return -x;
+
+ CASE_OP_32_64(andc):
+ return x & ~y;
+
+ CASE_OP_32_64(orc):
+ return x | ~y;
+
+ CASE_OP_32_64(eqv):
+ return ~(x ^ y);
+
+ CASE_OP_32_64(nand):
+ return ~(x & y);
+
+ CASE_OP_32_64(nor):
+ return ~(x | y);
+
+ CASE_OP_32_64(ext8s):
+ return (int8_t)x;
+
+ CASE_OP_32_64(ext16s):
+ return (int16_t)x;
+
+ CASE_OP_32_64(ext8u):
+ return (uint8_t)x;
+
+ CASE_OP_32_64(ext16u):
+ return (uint16_t)x;
+
+ case INDEX_op_ext32s_i64:
+ return (int32_t)x;
+
+ case INDEX_op_ext32u_i64:
+ return (uint32_t)x;
+
+ default:
+ fprintf(stderr,
+ "Unrecognized operation %d in do_constant_folding.\n", op);
+ tcg_abort();
+ }
+}
+
+static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y)
+{
+ TCGArg res = do_constant_folding_2(op, x, y);
+ if (op_bits(op) == 32) {
+ res &= 0xffffffff;
+ }
+ return res;
+}
+
+/* Propagate constants and copies, fold constant expressions. */
static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
TCGArg *args, TCGOpDef *tcg_op_defs)
{
- int i, nb_ops, op_index, op, nb_temps, nb_globals;
+ int i, nb_ops, op_index, nb_temps, nb_globals, nb_call_args;
+ TCGOpcode op;
const TCGOpDef *def;
TCGArg *gen_args;
+ TCGArg tmp;
+ /* Array VALS has an element for each temp.
+ If this temp holds a constant then its value is kept in VALS' element.
+ If this temp is a copy of other ones then this equivalence class'
+ representative is kept in VALS' element.
+ If this temp is neither copy nor constant then corresponding VALS'
+ element is unused. */
nb_temps = s->nb_temps;
nb_globals = s->nb_globals;
+ memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
nb_ops = tcg_opc_ptr - gen_opc_buf;
gen_args = args;
for (op_index = 0; op_index < nb_ops; op_index++) {
op = gen_opc_buf[op_index];
def = &tcg_op_defs[op];
+ /* Do copy propagation */
+ if (!(def->flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS))) {
+ assert(op != INDEX_op_call);
+ for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) {
+ if (temps[args[i]].state == TCG_TEMP_COPY) {
+ args[i] = temps[args[i]].val;
+ }
+ }
+ }
+
+ /* For commutative operations make constant second argument */
+ switch (op) {
+ CASE_OP_32_64(add):
+ CASE_OP_32_64(mul):
+ CASE_OP_32_64(and):
+ CASE_OP_32_64(or):
+ CASE_OP_32_64(xor):
+ CASE_OP_32_64(eqv):
+ CASE_OP_32_64(nand):
+ CASE_OP_32_64(nor):
+ if (temps[args[1]].state == TCG_TEMP_CONST) {
+ tmp = args[1];
+ args[1] = args[2];
+ args[2] = tmp;
+ }
+ break;
+ default:
+ break;
+ }
+
+ /* Simplify expression if possible. */
switch (op) {
+ CASE_OP_32_64(add):
+ CASE_OP_32_64(sub):
+ CASE_OP_32_64(shl):
+ CASE_OP_32_64(shr):
+ CASE_OP_32_64(sar):
+ CASE_OP_32_64(rotl):
+ CASE_OP_32_64(rotr):
+ if (temps[args[1]].state == TCG_TEMP_CONST) {
+ /* Proceed with possible constant folding. */
+ break;
+ }
+ if (temps[args[2]].state == TCG_TEMP_CONST
+ && temps[args[2]].val == 0) {
+ if ((temps[args[0]].state == TCG_TEMP_COPY
+ && temps[args[0]].val == args[1])
+ || args[0] == args[1]) {
+ args += 3;
+ gen_opc_buf[op_index] = INDEX_op_nop;
+ } else {
+ gen_opc_buf[op_index] = op_to_mov(op);
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1],
+ nb_temps, nb_globals);
+ gen_args += 2;
+ args += 3;
+ }
+ continue;
+ }
+ break;
+ CASE_OP_32_64(mul):
+ if ((temps[args[2]].state == TCG_TEMP_CONST
+ && temps[args[2]].val == 0)) {
+ gen_opc_buf[op_index] = op_to_movi(op);
+ tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals);
+ args += 3;
+ gen_args += 2;
+ continue;
+ }
+ break;
+ CASE_OP_32_64(or):
+ CASE_OP_32_64(and):
+ if (args[1] == args[2]) {
+ if (args[1] == args[0]) {
+ args += 3;
+ gen_opc_buf[op_index] = INDEX_op_nop;
+ } else {
+ gen_opc_buf[op_index] = op_to_mov(op);
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1], nb_temps,
+ nb_globals);
+ gen_args += 2;
+ args += 3;
+ }
+ continue;
+ }
+ break;
+ default:
+ break;
+ }
+
+ /* Propagate constants through copy operations and do constant
+ folding. Constants will be substituted to arguments by register
+ allocator where needed and possible. Also detect copies. */
+ switch (op) {
+ CASE_OP_32_64(mov):
+ if ((temps[args[1]].state == TCG_TEMP_COPY
+ && temps[args[1]].val == args[0])
+ || args[0] == args[1]) {
+ args += 2;
+ gen_opc_buf[op_index] = INDEX_op_nop;
+ break;
+ }
+ if (temps[args[1]].state != TCG_TEMP_CONST) {
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1],
+ nb_temps, nb_globals);
+ gen_args += 2;
+ args += 2;
+ break;
+ }
+ /* Source argument is constant. Rewrite the operation and
+ let movi case handle it. */
+ op = op_to_movi(op);
+ gen_opc_buf[op_index] = op;
+ args[1] = temps[args[1]].val;
+ /* fallthrough */
+ CASE_OP_32_64(movi):
+ tcg_opt_gen_movi(gen_args, args[0], args[1], nb_temps, nb_globals);
+ gen_args += 2;
+ args += 2;
+ break;
+ CASE_OP_32_64(not):
+ CASE_OP_32_64(neg):
+ CASE_OP_32_64(ext8s):
+ CASE_OP_32_64(ext8u):
+ CASE_OP_32_64(ext16s):
+ CASE_OP_32_64(ext16u):
+ case INDEX_op_ext32s_i64:
+ case INDEX_op_ext32u_i64:
+ if (temps[args[1]].state == TCG_TEMP_CONST) {
+ gen_opc_buf[op_index] = op_to_movi(op);
+ tmp = do_constant_folding(op, temps[args[1]].val, 0);
+ tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals);
+ gen_args += 2;
+ args += 2;
+ break;
+ } else {
+ reset_temp(args[0], nb_temps, nb_globals);
+ gen_args[0] = args[0];
+ gen_args[1] = args[1];
+ gen_args += 2;
+ args += 2;
+ break;
+ }
+ CASE_OP_32_64(add):
+ CASE_OP_32_64(sub):
+ CASE_OP_32_64(mul):
+ CASE_OP_32_64(or):
+ CASE_OP_32_64(and):
+ CASE_OP_32_64(xor):
+ CASE_OP_32_64(shl):
+ CASE_OP_32_64(shr):
+ CASE_OP_32_64(sar):
+ CASE_OP_32_64(rotl):
+ CASE_OP_32_64(rotr):
+ CASE_OP_32_64(andc):
+ CASE_OP_32_64(orc):
+ CASE_OP_32_64(eqv):
+ CASE_OP_32_64(nand):
+ CASE_OP_32_64(nor):
+ if (temps[args[1]].state == TCG_TEMP_CONST
+ && temps[args[2]].state == TCG_TEMP_CONST) {
+ gen_opc_buf[op_index] = op_to_movi(op);
+ tmp = do_constant_folding(op, temps[args[1]].val,
+ temps[args[2]].val);
+ tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals);
+ gen_args += 2;
+ args += 3;
+ break;
+ } else {
+ reset_temp(args[0], nb_temps, nb_globals);
+ gen_args[0] = args[0];
+ gen_args[1] = args[1];
+ gen_args[2] = args[2];
+ gen_args += 3;
+ args += 3;
+ break;
+ }
case INDEX_op_call:
- i = (args[0] >> 16) + (args[0] & 0xffff) + 3;
+ nb_call_args = (args[0] >> 16) + (args[0] & 0xffff);
+ if (!(args[nb_call_args + 1] & (TCG_CALL_CONST | TCG_CALL_PURE))) {
+ for (i = 0; i < nb_globals; i++) {
+ reset_temp(i, nb_temps, nb_globals);
+ }
+ }
+ for (i = 0; i < (args[0] >> 16); i++) {
+ reset_temp(args[i + 1], nb_temps, nb_globals);
+ }
+ i = nb_call_args + 3;
while (i) {
*gen_args = *args;
args++;
case INDEX_op_jmp:
case INDEX_op_br:
CASE_OP_32_64(brcond):
+ memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
for (i = 0; i < def->nb_args; i++) {
*gen_args = *args;
args++;
}
break;
default:
+ /* Default case: we do know nothing about operation so no
+ propagation is done. We only trash output args. */
+ for (i = 0; i < def->nb_oargs; i++) {
+ reset_temp(args[i], nb_temps, nb_globals);
+ }
for (i = 0; i < def->nb_args; i++) {
gen_args[i] = args[i];
}
projects / qemu.git / blobdiff