[PATCH V3 2/5] raid6: riscv: replace one load with a move to speed up the caculation

Chunyan Zhang zhangchunyan at iscas.ac.cn
Fri Jul 18 00:27:08 PDT 2025


Since wp$$==wq$$, it doesn't need to load the same data twice, use move
instruction to replace one of the loads to let the program run faster.

Reviewed-by: Alexandre Ghiti <alexghiti at rivosinc.com>
Signed-off-by: Chunyan Zhang <zhangchunyan at iscas.ac.cn>
---
 lib/raid6/rvv.c | 60 ++++++++++++++++++++++++-------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/lib/raid6/rvv.c b/lib/raid6/rvv.c
index b193ea176d5d..89da5fc247aa 100644
--- a/lib/raid6/rvv.c
+++ b/lib/raid6/rvv.c
@@ -44,7 +44,7 @@ static void raid6_rvv1_gen_syndrome_real(int disks, unsigned long bytes, void **
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE])
@@ -117,7 +117,7 @@ static void raid6_rvv1_xor_syndrome_real(int disks, int start, int stop,
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE])
@@ -218,9 +218,9 @@ static void raid6_rvv2_gen_syndrome_real(int disks, unsigned long bytes, void **
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      "vle8.v	v4, (%[wp1])\n"
-			      "vle8.v	v5, (%[wp1])\n"
+			      "vmv.v.v	v5, v4\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE]),
@@ -310,9 +310,9 @@ static void raid6_rvv2_xor_syndrome_real(int disks, int start, int stop,
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      "vle8.v	v4, (%[wp1])\n"
-			      "vle8.v	v5, (%[wp1])\n"
+			      "vmv.v.v	v5, v4\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE]),
@@ -440,13 +440,13 @@ static void raid6_rvv4_gen_syndrome_real(int disks, unsigned long bytes, void **
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      "vle8.v	v4, (%[wp1])\n"
-			      "vle8.v	v5, (%[wp1])\n"
+			      "vmv.v.v	v5, v4\n"
 			      "vle8.v	v8, (%[wp2])\n"
-			      "vle8.v	v9, (%[wp2])\n"
+			      "vmv.v.v	v9, v8\n"
 			      "vle8.v	v12, (%[wp3])\n"
-			      "vle8.v	v13, (%[wp3])\n"
+			      "vmv.v.v	v13, v12\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE]),
@@ -566,13 +566,13 @@ static void raid6_rvv4_xor_syndrome_real(int disks, int start, int stop,
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      "vle8.v	v4, (%[wp1])\n"
-			      "vle8.v	v5, (%[wp1])\n"
+			      "vmv.v.v	v5, v4\n"
 			      "vle8.v	v8, (%[wp2])\n"
-			      "vle8.v	v9, (%[wp2])\n"
+			      "vmv.v.v	v9, v8\n"
 			      "vle8.v	v12, (%[wp3])\n"
-			      "vle8.v	v13, (%[wp3])\n"
+			      "vmv.v.v	v13, v12\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE]),
@@ -754,21 +754,21 @@ static void raid6_rvv8_gen_syndrome_real(int disks, unsigned long bytes, void **
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      "vle8.v	v4, (%[wp1])\n"
-			      "vle8.v	v5, (%[wp1])\n"
+			      "vmv.v.v	v5, v4\n"
 			      "vle8.v	v8, (%[wp2])\n"
-			      "vle8.v	v9, (%[wp2])\n"
+			      "vmv.v.v	v9, v8\n"
 			      "vle8.v	v12, (%[wp3])\n"
-			      "vle8.v	v13, (%[wp3])\n"
+			      "vmv.v.v	v13, v12\n"
 			      "vle8.v	v16, (%[wp4])\n"
-			      "vle8.v	v17, (%[wp4])\n"
+			      "vmv.v.v	v17, v16\n"
 			      "vle8.v	v20, (%[wp5])\n"
-			      "vle8.v	v21, (%[wp5])\n"
+			      "vmv.v.v	v21, v20\n"
 			      "vle8.v	v24, (%[wp6])\n"
-			      "vle8.v	v25, (%[wp6])\n"
+			      "vmv.v.v	v25, v24\n"
 			      "vle8.v	v28, (%[wp7])\n"
-			      "vle8.v	v29, (%[wp7])\n"
+			      "vmv.v.v	v29, v28\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE]),
@@ -948,21 +948,21 @@ static void raid6_rvv8_xor_syndrome_real(int disks, int start, int stop,
 		asm volatile (".option	push\n"
 			      ".option	arch,+v\n"
 			      "vle8.v	v0, (%[wp0])\n"
-			      "vle8.v	v1, (%[wp0])\n"
+			      "vmv.v.v	v1, v0\n"
 			      "vle8.v	v4, (%[wp1])\n"
-			      "vle8.v	v5, (%[wp1])\n"
+			      "vmv.v.v	v5, v4\n"
 			      "vle8.v	v8, (%[wp2])\n"
-			      "vle8.v	v9, (%[wp2])\n"
+			      "vmv.v.v	v9, v8\n"
 			      "vle8.v	v12, (%[wp3])\n"
-			      "vle8.v	v13, (%[wp3])\n"
+			      "vmv.v.v	v13, v12\n"
 			      "vle8.v	v16, (%[wp4])\n"
-			      "vle8.v	v17, (%[wp4])\n"
+			      "vmv.v.v	v17, v16\n"
 			      "vle8.v	v20, (%[wp5])\n"
-			      "vle8.v	v21, (%[wp5])\n"
+			      "vmv.v.v	v21, v20\n"
 			      "vle8.v	v24, (%[wp6])\n"
-			      "vle8.v	v25, (%[wp6])\n"
+			      "vmv.v.v	v25, v24\n"
 			      "vle8.v	v28, (%[wp7])\n"
-			      "vle8.v	v29, (%[wp7])\n"
+			      "vmv.v.v	v29, v28\n"
 			      ".option	pop\n"
 			      : :
 			      [wp0]"r"(&dptr[z0][d + 0 * NSIZE]),
-- 
2.34.1




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