+/**
+ * Following conversion rules apply:
+ *
+ * INT -> INT
+ * ============
+ * 1) n bit -> m bit n > m (downscale)
+ * a) target is signed: movsx
+ * b) target is unsigned: and with lower bits sets
+ * 2) n bit -> m bit n == m (sign change)
+ * always ignored
+ * 3) n bit -> m bit n < m (upscale)
+ * a) source is signed: movsx
+ * b) source is unsigned: and with lower bits sets
+ *
+ * INT -> FLOAT
+ * ==============
+ * SSE(1/2) convert to float or double (cvtsi2ss/sd)
+ *
+ * FLOAT -> INT
+ * ==============
+ * SSE(1/2) convert from float or double to 32bit int (cvtss/sd2si)
+ * if target mode < 32bit: additional INT -> INT conversion (see above)
+ *
+ * FLOAT -> FLOAT
+ * ================
+ * SSE(1/2) convert from float or double to double or float (cvtss/sd2sd/ss)
+ * x87 is mode_E internally, conversions happen only at load and store
+ * in non-strict semantic
+ */
+
+/**
+ * Create a conversion from x87 state register to general purpose.
+ */
+static ir_node *gen_x87_fp_to_gp(ia32_transform_env_t *env, ir_mode *tgt_mode) {
+ ia32_code_gen_t *cg = env->cg;
+ entity *ent = cg->fp_to_gp;
+ ir_graph *irg = env->irg;
+ ir_node *block = env->block;
+ ir_node *noreg = ia32_new_NoReg_gp(env->cg);
+ ir_node *op = get_Conv_op(env->irn);
+ ir_node *fist, *mem, *load;
+
+ if (! ent) {
+ int size = get_mode_size_bytes(ia32_reg_classes[CLASS_ia32_vfp].mode);
+ ent = cg->fp_to_gp =
+ frame_alloc_area(get_irg_frame_type(env->irg), size, 16, 0);
+ }
+
+ /* do a fist */
+ fist = new_rd_ia32_vfist(env->dbg, irg, block, get_irg_frame(irg), noreg, op, get_irg_no_mem(irg));
+
+ set_ia32_frame_ent(fist, ent);
+ set_ia32_use_frame(fist);
+ set_ia32_am_support(fist, ia32_am_Dest);
+ set_ia32_op_type(fist, ia32_AddrModeD);
+ set_ia32_am_flavour(fist, ia32_B);
+ set_ia32_ls_mode(fist, mode_E);
+
+ mem = new_r_Proj(irg, block, fist, mode_M, pn_ia32_vfist_M);
+
+ /* do a Load */
+ load = new_rd_ia32_Load(env->dbg, irg, block, get_irg_frame(irg), noreg, mem);
+
+ set_ia32_frame_ent(load, ent);
+ set_ia32_use_frame(load);
+ set_ia32_am_support(load, ia32_am_Source);
+ set_ia32_op_type(load, ia32_AddrModeS);
+ set_ia32_am_flavour(load, ia32_B);
+ set_ia32_ls_mode(load, tgt_mode);
+
+ return new_r_Proj(irg, block, load, tgt_mode, pn_ia32_Load_res);
+}
+
+/**
+ * Create a conversion from x87 state register to general purpose.
+ */
+static ir_node *gen_x87_gp_to_fp(ia32_transform_env_t *env, ir_mode *src_mode) {
+ ia32_code_gen_t *cg = env->cg;
+ entity *ent = cg->gp_to_fp;
+ ir_graph *irg = env->irg;
+ ir_node *block = env->block;
+ ir_node *noreg = ia32_new_NoReg_gp(env->cg);
+ ir_node *nomem = get_irg_no_mem(irg);
+ ir_node *op = get_Conv_op(env->irn);
+ ir_node *fild, *store, *mem;
+ int src_bits;
+
+ if (! ent) {
+ int size = get_mode_size_bytes(ia32_reg_classes[CLASS_ia32_gp].mode);
+ ent = cg->gp_to_fp =
+ frame_alloc_area(get_irg_frame_type(env->irg), size, size, 0);
+ }
+
+ /* first convert to 32 bit */
+ src_bits = get_mode_size_bits(src_mode);
+ if (src_bits == 8) {
+ op = new_rd_ia32_Conv_I2I8Bit(env->dbg, irg, block, noreg, noreg, op, nomem);
+ op = new_r_Proj(irg, block, op, mode_Is, 0);
+ }
+ else if (src_bits < 32) {
+ op = new_rd_ia32_Conv_I2I(env->dbg, irg, block, noreg, noreg, op, nomem);
+ op = new_r_Proj(irg, block, op, mode_Is, 0);
+ }
+
+ /* do a store */
+ store = new_rd_ia32_Store(env->dbg, irg, block, get_irg_frame(irg), noreg, op, nomem);
+
+ set_ia32_frame_ent(store, ent);
+ set_ia32_use_frame(store);
+
+ set_ia32_am_support(store, ia32_am_Dest);
+ set_ia32_op_type(store, ia32_AddrModeD);
+ set_ia32_am_flavour(store, ia32_B);
+ set_ia32_ls_mode(store, mode_Is);
+
+ mem = new_r_Proj(irg, block, store, mode_M, 0);
+
+ /* do a fild */
+ fild = new_rd_ia32_vfild(env->dbg, irg, block, get_irg_frame(irg), noreg, mem);
+
+ set_ia32_frame_ent(fild, ent);
+ set_ia32_use_frame(fild);
+ set_ia32_am_support(fild, ia32_am_Source);
+ set_ia32_op_type(fild, ia32_AddrModeS);
+ set_ia32_am_flavour(fild, ia32_B);
+ set_ia32_ls_mode(fild, mode_E);
+
+ return new_r_Proj(irg, block, fild, mode_E, 0);
+}