riscv/lib/memmove.S

18 	 *   a2 - Length of copy n
25 	 * in the 2 misaligned fixup copy loops.
34 	 *      Forward Copy: a1 - Index counter of src
35 	 *      Reverse Copy: a4 - Index counter of src
36 	 *      Forward Copy: t3 - Index counter of dest
37 	 *      Reverse Copy: t4 - Index counter of dest
38 	 *   Both Copy Modes: t5 - Inclusive first multibyte/aligned of dest
39 	 *   Both Copy Modes: t6 - Non-Inclusive last multibyte/aligned of dest
40 	 *   Both Copy Modes: t0 - Link / Temporary for load-store
41 	 *   Both Copy Modes: t1 - Temporary for load-store
42 	 *   Both Copy Modes: t2 - Temporary for load-store
43 	 *   Both Copy Modes: a5 - dest to src alignment offset
44 	 *   Both Copy Modes: a6 - Shift ammount
45 	 *   Both Copy Modes: a7 - Inverse Shift ammount
46 	 *   Both Copy Modes: a2 - Alternate breakpoint for unrolled loops
51 	 * Byte copy does not need t5 or t6.
58 	 * Byte copy if copying less than (2 * SZREG) bytes. This can
59 	 * cause problems with the bulk copy implementation and is
76 	 * we always byte copy if n is less than SZREG.
85 	 * no need for the full rigmarole of a full misaligned fixup copy.
86 	 * Instead, do a simpler co-aligned copy.
91 	/* Fall through to misaligned fixup copy */
115 	 * Fix Misalignment Copy Loop - Forward
156 	j byte_copy_forward /* Copy any remaining bytes */
177 	 * Fix Misalignment Copy Loop - Reverse
218 	j byte_copy_reverse /* Copy any remaining bytes */
221  * Simple copy loops for SZREG co-aligned memory locations.
238 	j byte_copy_forward /* Copy any remaining bytes */
250 	j byte_copy_reverse /* Copy any remaining bytes */
254  * are used to byte copy until the dest pointer is in alignment.
255  * At which point, a bulk copy method can be used by the
257  * copy loops.  Therefore, the register values can be picked
270 	jalr zero, 0x0(t0) /* Return to multibyte copy loop */
281 	jalr zero, 0x0(t0) /* Return to multibyte copy loop */
284  * Simple byte copy loops.
285  * These will byte copy until they reach the end of data to copy.