Fixes: 04091d6c0535("riscv: provide memmove implementation")
Signed-off-by: Chen Lu <[email protected]>
---
arch/riscv/lib/memmove.S | 89 +++++++++++++++++++---------------------
1 file changed, 42 insertions(+), 47 deletions(-)
diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S
index 07d1d2152ba5..8029bc6caeb8 100644
--- a/arch/riscv/lib/memmove.S
+++ b/arch/riscv/lib/memmove.S
@@ -5,60 +5,55 @@
ENTRY(__memmove)
WEAK(memmove)
- move t0, a0
- move t1, a1
+ bltu a0, a1, __memcpy
- beq a0, a1, exit_memcpy
- beqz a2, exit_memcpy
- srli t2, a2, 0x2
-
- slt t3, a0, a1
- beqz t3, do_reverse
-
- andi a2, a2, 0x3
- li t4, 1
- beqz t2, byte_copy
+ add t1, a1, a2
+ bleu t1, a0, __memcpy
-word_copy:
- lw t3, 0(a1)
- addi t2, t2, -1
- addi a1, a1, 4
- sw t3, 0(a0)
- addi a0, a0, 4
- bnez t2, word_copy
+ beq a0, a1, exit_memcpy
beqz a2, exit_memcpy
- j byte_copy
-
-do_reverse:
- add a0, a0, a2
- add a1, a1, a2
- andi a2, a2, 0x3
- li t4, -1
- beqz t2, reverse_byte_copy
-reverse_word_copy:
- addi a1, a1, -4
- addi t2, t2, -1
- lw t3, 0(a1)
- addi a0, a0, -4
- sw t3, 0(a0)
- bnez t2, reverse_word_copy
+ /* reverse src and dst */
+ add t0, a0, a2
+ /* check low-order bits match */
+ andi a3, t0, SZREG-1
+ andi a4, t1, SZREG-1
+ bne a3, a4, copy_tail_loop
+ beqz a4, copy_body
+
+copy_head:
+ /* head misalignment */
+ addi t1, t1, -1
+ lb t3, 0(t1)
+ addi t0, t0, -1
+ addi a4, a4, -1
+ sb t3, 0(t0)
+ bnez a4, copy_head
+ sub a2, a2, a3
+
+copy_body:
+ andi a4, a2, ~(SZREG-1)
+ andi a2, a2, (SZREG-1)
+ beqz a4, copy_tail
+copy_body_loop:
+ addi t1, t1, -SZREG
+ REG_L t3, 0(t1)
+ addi t0, t0, -SZREG
+ addi a4, a4, -SZREG
+ REG_S t3, 0(t0)
+ bnez a4, copy_body_loop
+
+copy_tail:
+ /* tail misalignment */
beqz a2, exit_memcpy
-
-reverse_byte_copy:
- addi a0, a0, -1
- addi a1, a1, -1
-
-byte_copy:
- lb t3, 0(a1)
+copy_tail_loop:
+ addi t1, t1, -1
+ lb t3, 0(t1)
+ addi t0, t0, -1
addi a2, a2, -1
- sb t3, 0(a0)
- add a1, a1, t4
- add a0, a0, t4
- bnez a2, byte_copy
+ sb t3, 0(t0)
+ bnez a2, copy_tail_loop
exit_memcpy:
- move a0, t0
- move a1, t1
ret
END(__memmove)
--
2.30.2