From b010e434ed3839e5064f7fc8337591a18d6b67cd Mon Sep 17 00:00:00 2001
From: JonasWen <jonaswen@163.com>
Date: Wed, 15 Jun 2022 17:19:51 +0800
Subject: [PATCH] =?UTF-8?q?[libcpu][arm]=20ArmClang=20=E7=BC=96=E8=AF=91?=
 =?UTF-8?q?=E4=BC=98=E5=8C=96=E9=94=99=E8=AF=AF=20(#6071)?=
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---
 libcpu/arm/cortex-m4/cpuport.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/libcpu/arm/cortex-m4/cpuport.c b/libcpu/arm/cortex-m4/cpuport.c
index 6b748255c5..f060fa122d 100644
--- a/libcpu/arm/cortex-m4/cpuport.c
+++ b/libcpu/arm/cortex-m4/cpuport.c
@@ -15,6 +15,7 @@
  * 2013-06-23     aozima       support lazy stack optimized.
  * 2018-07-24     aozima       enhancement hard fault exception handler.
  * 2019-07-03     yangjie      add __rt_ffs() for armclang.
+ * 2022-06-12     jonas        fixed __rt_ffs() for armclang.
  */
 
 #include <rtthread.h>
@@ -473,12 +474,12 @@ exit
 int __rt_ffs(int value)
 {
     __asm volatile(
-        "CMP     r0, #0x00            \n"
+        "CMP     %0, #0x00            \n"
         "BEQ     1f                   \n"
 
-        "RBIT    r0, r0               \n"
-        "CLZ     r0, r0               \n"
-        "ADDS    r0, r0, #0x01        \n"
+        "RBIT    %0, %0               \n"
+        "CLZ     %0, %0               \n"
+        "ADDS    %0, %0, #0x01        \n"
 
         "1:                           \n"