diff mbox series

[2/2] riscv: Optimize memset

Message ID 20230509022207.3700-2-zhang_fei_0403@163.com (mailing list archive)
State Superseded, archived
Delegated to: Palmer Dabbelt
Headers show
Series [1/2] RISC-V: lib: Improve memset assembler formatting | expand

Checks

Context Check Description
conchuod/cover_letter success Single patches do not need cover letters
conchuod/tree_selection success Guessed tree name to be for-next at HEAD ac9a78681b92
conchuod/fixes_present success Fixes tag not required for -next series
conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 6 and now 6
conchuod/verify_signedoff success Signed-off-by tag matches author and committer
conchuod/kdoc success Errors and warnings before: 0 this patch: 0
conchuod/build_rv64_clang_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/module_param success Was 0 now: 0
conchuod/build_rv64_gcc_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/build_rv32_defconfig success Build OK
conchuod/dtb_warn_rv64 success Errors and warnings before: 3 this patch: 3
conchuod/header_inline success No static functions without inline keyword in header files
conchuod/checkpatch warning WARNING: From:/Signed-off-by: email name mismatch: 'From: zhangfei <zhangfei@nj.iscas.ac.cn>' != 'Signed-off-by: Fei Zhang <zhangfei@nj.iscas.ac.cn>'
conchuod/source_inline success Was 0 now: 0
conchuod/build_rv64_nommu_k210_defconfig success Build OK
conchuod/verify_fixes success No Fixes tag
conchuod/build_rv64_nommu_virt_defconfig success Build OK

Commit Message

zhangfei May 9, 2023, 2:22 a.m. UTC 
From: zhangfei <zhangfei@nj.iscas.ac.cn>

This patch has been optimized for memset data sizes less than 16 bytes.
Compared to byte by byte storage, significant performance improvement has been achieved.

Signed-off-by: Fei Zhang <zhangfei@nj.iscas.ac.cn>
---
 arch/riscv/lib/memset.S | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/arch/riscv/lib/memset.S b/arch/riscv/lib/memset.S
index e613c5c27998..6113a2696e79 100644
--- a/arch/riscv/lib/memset.S
+++ b/arch/riscv/lib/memset.S
@@ -106,9 +106,36 @@  WEAK(memset)
 	beqz	a2, 6f
 	add	a3, t0, a2
 5:
-	sb	a1, 0(t0)
-	addi	t0, t0, 1
-	bltu	t0, a3, 5b
+       sb      a1,  0(t0)
+       sb      a1, -1(a3)
+       li      a4, 2
+       bgeu    a4, a2, 6f
+
+       sb 	a1,  1(t0)
+       sb 	a1,  2(t0)
+       sb 	a1, -2(a3)
+       sb 	a1, -3(a3)
+       li 	a4, 6
+       bgeu 	a4, a2, 6f
+
+       sb 	a1,  3(t0)
+       sb 	a1, -4(a3)
+       li 	a4, 8
+       bgeu    a4, a2, 6f
+
+       sb 	a1,  4(t0)
+       sb 	a1, -5(a3)
+       li 	a4, 10
+       bgeu 	a4, a2, 6f
+
+       sb 	a1,  5(t0)
+       sb 	a1,  6(t0)
+       sb 	a1, -6(a3)
+       sb 	a1, -7(a3)
+       li 	a4, 14
+       bgeu 	a4, a2, 6f
+
+       sb 	a1, 7(t0)
 6:
 	ret
 END(__memset)