[PATCH 1/2] RISC-V: lib: Improve memset assembler formatting

From: zhangfei
Date: Tue May 09 2023 - 23:53:23 EST


From: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>

Aligning the first operand of each instructions with a tab is a
typical style which improves readability. Apply it to memset.S.
While there, we also make a small grammar change to a comment.

No functional change intended.

Signed-off-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
---
arch/riscv/lib/memset.S | 143 ++++++++++++++++++++--------------------
1 file changed, 72 insertions(+), 71 deletions(-)

diff --git a/arch/riscv/lib/memset.S b/arch/riscv/lib/memset.S
index 34c5360c6705..e613c5c27998 100644
--- a/arch/riscv/lib/memset.S
+++ b/arch/riscv/lib/memset.S
@@ -3,111 +3,112 @@
* Copyright (C) 2013 Regents of the University of California
*/

-
#include <linux/linkage.h>
#include <asm/asm.h>

/* void *memset(void *, int, size_t) */
ENTRY(__memset)
WEAK(memset)
- move t0, a0 /* Preserve return value */
+ move t0, a0 /* Preserve return value */

/* Defer to byte-oriented fill for small sizes */
- sltiu a3, a2, 16
- bnez a3, 4f
+ sltiu a3, a2, 16
+ bnez a3, 4f

/*
* Round to nearest XLEN-aligned address
- * greater than or equal to start address
+ * greater than or equal to the start address.
*/
- addi a3, t0, SZREG-1
- andi a3, a3, ~(SZREG-1)
- beq a3, t0, 2f /* Skip if already aligned */
+ addi a3, t0, SZREG-1
+ andi a3, a3, ~(SZREG-1)
+ beq a3, t0, 2f /* Skip if already aligned */
+
/* Handle initial misalignment */
- sub a4, a3, t0
+ sub a4, a3, t0
1:
- sb a1, 0(t0)
- addi t0, t0, 1
- bltu t0, a3, 1b
- sub a2, a2, a4 /* Update count */
+ sb a1, 0(t0)
+ addi t0, t0, 1
+ bltu t0, a3, 1b
+ sub a2, a2, a4 /* Update count */

2: /* Duff's device with 32 XLEN stores per iteration */
/* Broadcast value into all bytes */
- andi a1, a1, 0xff
- slli a3, a1, 8
- or a1, a3, a1
- slli a3, a1, 16
- or a1, a3, a1
+ andi a1, a1, 0xff
+ slli a3, a1, 8
+ or a1, a3, a1
+ slli a3, a1, 16
+ or a1, a3, a1
#ifdef CONFIG_64BIT
- slli a3, a1, 32
- or a1, a3, a1
+ slli a3, a1, 32
+ or a1, a3, a1
#endif

/* Calculate end address */
- andi a4, a2, ~(SZREG-1)
- add a3, t0, a4
+ andi a4, a2, ~(SZREG-1)
+ add a3, t0, a4

- andi a4, a4, 31*SZREG /* Calculate remainder */
- beqz a4, 3f /* Shortcut if no remainder */
- neg a4, a4
- addi a4, a4, 32*SZREG /* Calculate initial offset */
+ andi a4, a4, 31*SZREG /* Calculate remainder */
+ beqz a4, 3f /* Shortcut if no remainder */
+ neg a4, a4
+ addi a4, a4, 32*SZREG /* Calculate initial offset */

/* Adjust start address with offset */
- sub t0, t0, a4
+ sub t0, t0, a4

/* Jump into loop body */
/* Assumes 32-bit instruction lengths */
- la a5, 3f
+ la a5, 3f
#ifdef CONFIG_64BIT
- srli a4, a4, 1
+ srli a4, a4, 1
#endif
- add a5, a5, a4
- jr a5
+ add a5, a5, a4
+ jr a5
3:
- REG_S a1, 0(t0)
- REG_S a1, SZREG(t0)
- REG_S a1, 2*SZREG(t0)
- REG_S a1, 3*SZREG(t0)
- REG_S a1, 4*SZREG(t0)
- REG_S a1, 5*SZREG(t0)
- REG_S a1, 6*SZREG(t0)
- REG_S a1, 7*SZREG(t0)
- REG_S a1, 8*SZREG(t0)
- REG_S a1, 9*SZREG(t0)
- REG_S a1, 10*SZREG(t0)
- REG_S a1, 11*SZREG(t0)
- REG_S a1, 12*SZREG(t0)
- REG_S a1, 13*SZREG(t0)
- REG_S a1, 14*SZREG(t0)
- REG_S a1, 15*SZREG(t0)
- REG_S a1, 16*SZREG(t0)
- REG_S a1, 17*SZREG(t0)
- REG_S a1, 18*SZREG(t0)
- REG_S a1, 19*SZREG(t0)
- REG_S a1, 20*SZREG(t0)
- REG_S a1, 21*SZREG(t0)
- REG_S a1, 22*SZREG(t0)
- REG_S a1, 23*SZREG(t0)
- REG_S a1, 24*SZREG(t0)
- REG_S a1, 25*SZREG(t0)
- REG_S a1, 26*SZREG(t0)
- REG_S a1, 27*SZREG(t0)
- REG_S a1, 28*SZREG(t0)
- REG_S a1, 29*SZREG(t0)
- REG_S a1, 30*SZREG(t0)
- REG_S a1, 31*SZREG(t0)
- addi t0, t0, 32*SZREG
- bltu t0, a3, 3b
- andi a2, a2, SZREG-1 /* Update count */
+ REG_S a1, 0(t0)
+ REG_S a1, SZREG(t0)
+ REG_S a1, 2*SZREG(t0)
+ REG_S a1, 3*SZREG(t0)
+ REG_S a1, 4*SZREG(t0)
+ REG_S a1, 5*SZREG(t0)
+ REG_S a1, 6*SZREG(t0)
+ REG_S a1, 7*SZREG(t0)
+ REG_S a1, 8*SZREG(t0)
+ REG_S a1, 9*SZREG(t0)
+ REG_S a1, 10*SZREG(t0)
+ REG_S a1, 11*SZREG(t0)
+ REG_S a1, 12*SZREG(t0)
+ REG_S a1, 13*SZREG(t0)
+ REG_S a1, 14*SZREG(t0)
+ REG_S a1, 15*SZREG(t0)
+ REG_S a1, 16*SZREG(t0)
+ REG_S a1, 17*SZREG(t0)
+ REG_S a1, 18*SZREG(t0)
+ REG_S a1, 19*SZREG(t0)
+ REG_S a1, 20*SZREG(t0)
+ REG_S a1, 21*SZREG(t0)
+ REG_S a1, 22*SZREG(t0)
+ REG_S a1, 23*SZREG(t0)
+ REG_S a1, 24*SZREG(t0)
+ REG_S a1, 25*SZREG(t0)
+ REG_S a1, 26*SZREG(t0)
+ REG_S a1, 27*SZREG(t0)
+ REG_S a1, 28*SZREG(t0)
+ REG_S a1, 29*SZREG(t0)
+ REG_S a1, 30*SZREG(t0)
+ REG_S a1, 31*SZREG(t0)
+
+ addi t0, t0, 32*SZREG
+ bltu t0, a3, 3b
+ andi a2, a2, SZREG-1 /* Update count */

4:
/* Handle trailing misalignment */
- beqz a2, 6f
- add a3, t0, a2
+ beqz a2, 6f
+ add a3, t0, a2
5:
- sb a1, 0(t0)
- addi t0, t0, 1
- bltu t0, a3, 5b
+ sb a1, 0(t0)
+ addi t0, t0, 1
+ bltu t0, a3, 5b
6:
ret
END(__memset)
--
2.33.0