/* Predicates */
+/* This is a list of legal subregs of hard regs. */
+static struct {
+ enum machine_mode outer_mode_size;
+ enum machine_mode inner_mode_size;
+ unsigned int regno;
+ int byte_mask;
+ int legal_when;
+} legal_subregs[] = {
+ {1, 2, R0_REGNO, 0x03, 1}, /* r0h r0l */
+ {1, 2, R1_REGNO, 0x03, 1}, /* r1h r1l */
+ {1, 2, A0_REGNO, 0x01, 1},
+ {1, 2, A1_REGNO, 0x01, 1},
+
+ {1, 4, A0_REGNO, 0x01, 1},
+ {1, 4, A1_REGNO, 0x01, 1},
+
+ {2, 4, R0_REGNO, 0x05, 1}, /* r2 r0 */
+ {2, 4, R1_REGNO, 0x05, 1}, /* r3 r1 */
+ {2, 4, A0_REGNO, 0x05, 16}, /* a1 a0 */
+ {2, 4, A0_REGNO, 0x01, 24}, /* a1 a0 */
+ {2, 4, A1_REGNO, 0x01, 24}, /* a1 a0 */
+
+ {4, 8, R0_REGNO, 0x55, 1}, /* r3 r1 r2 r0 */
+};
+
+/* Returns TRUE if OP is a subreg of a hard reg which we don't
+ support. */
+bool
+m32c_illegal_subreg_p (rtx op)
+{
+ rtx orig_op = op;
+ int offset;
+ unsigned int i;
+ int src_mode, dest_mode;
+
+ if (GET_CODE (op) != SUBREG)
+ return false;
+
+ dest_mode = GET_MODE (op);
+ offset = SUBREG_BYTE (op);
+ op = SUBREG_REG (op);
+ src_mode = GET_MODE (op);
+
+ if (GET_MODE_SIZE (dest_mode) == GET_MODE_SIZE (src_mode))
+ return false;
+ if (GET_CODE (op) != REG)
+ return false;
+ if (REGNO (op) >= MEM0_REGNO)
+ return false;
+
+ offset = (1 << offset);
+
+ for (i = 0; i < sizeof(legal_subregs)/sizeof(legal_subregs[0]); i ++)
+ if (legal_subregs[i].outer_mode_size == GET_MODE_SIZE (dest_mode)
+ && legal_subregs[i].regno == REGNO (op)
+ && legal_subregs[i].inner_mode_size == GET_MODE_SIZE (src_mode)
+ && legal_subregs[i].byte_mask & offset)
+ {
+ switch (legal_subregs[i].legal_when)
+ {
+ case 1:
+ return false;
+ case 16:
+ if (TARGET_A16)
+ return false;
+ break;
+ case 24:
+ if (TARGET_A24)
+ return false;
+ break;
+ }
+ }
+ return true;
+}
+
/* Returns TRUE if we support a move between the first two operands.
At the moment, we just want to discourage mem to mem moves until
after reload, because reload has a hard time with our limited