+ /* Simplify using known-zero bits */
+ mask = -1;
+ affected = -1;
+ switch (op) {
+ CASE_OP_32_64(ext8s):
+ if ((temps[args[1]].mask & 0x80) != 0) {
+ break;
+ }
+ CASE_OP_32_64(ext8u):
+ mask = 0xff;
+ goto and_const;
+ CASE_OP_32_64(ext16s):
+ if ((temps[args[1]].mask & 0x8000) != 0) {
+ break;
+ }
+ CASE_OP_32_64(ext16u):
+ mask = 0xffff;
+ goto and_const;
+ case INDEX_op_ext32s_i64:
+ if ((temps[args[1]].mask & 0x80000000) != 0) {
+ break;
+ }
+ case INDEX_op_ext32u_i64:
+ mask = 0xffffffffU;
+ goto and_const;
+
+ CASE_OP_32_64(and):
+ mask = temps[args[2]].mask;
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ and_const:
+ affected = temps[args[1]].mask & ~mask;
+ }
+ mask = temps[args[1]].mask & mask;
+ break;
+
+ CASE_OP_32_64(sar):
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ mask = ((tcg_target_long)temps[args[1]].mask
+ >> temps[args[2]].val);
+ }
+ break;
+
+ CASE_OP_32_64(shr):
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ mask = temps[args[1]].mask >> temps[args[2]].val;
+ }
+ break;
+
+ CASE_OP_32_64(shl):
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ mask = temps[args[1]].mask << temps[args[2]].val;
+ }
+ break;
+
+ CASE_OP_32_64(neg):
+ /* Set to 1 all bits to the left of the rightmost. */
+ mask = -(temps[args[1]].mask & -temps[args[1]].mask);
+ break;
+
+ CASE_OP_32_64(deposit):
+ tmp = ((1ull << args[4]) - 1);
+ mask = ((temps[args[1]].mask & ~(tmp << args[3]))
+ | ((temps[args[2]].mask & tmp) << args[3]));
+ break;
+
+ CASE_OP_32_64(or):
+ CASE_OP_32_64(xor):
+ mask = temps[args[1]].mask | temps[args[2]].mask;
+ break;
+
+ CASE_OP_32_64(setcond):
+ mask = 1;
+ break;
+
+ CASE_OP_32_64(movcond):
+ mask = temps[args[3]].mask | temps[args[4]].mask;
+ break;
+
+ default:
+ break;
+ }
+
+ if (mask == 0) {
+ assert(def->nb_oargs == 1);
+ s->gen_opc_buf[op_index] = op_to_movi(op);
+ tcg_opt_gen_movi(gen_args, args[0], 0);
+ args += def->nb_oargs + def->nb_iargs + def->nb_cargs;
+ gen_args += 2;
+ continue;
+ }
+ if (affected == 0) {
+ assert(def->nb_oargs == 1);
+ if (temps_are_copies(args[0], args[1])) {
+ s->gen_opc_buf[op_index] = INDEX_op_nop;
+ } else if (temps[args[1]].state != TCG_TEMP_CONST) {
+ s->gen_opc_buf[op_index] = op_to_mov(op);
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
+ gen_args += 2;
+ } else {
+ s->gen_opc_buf[op_index] = op_to_movi(op);
+ tcg_opt_gen_movi(gen_args, args[0], temps[args[1]].val);
+ gen_args += 2;
+ }
+ args += def->nb_iargs + 1;
+ continue;
+ }
+