From f8c58778bd1f195cea7850f928ceb2fc591da018 Mon Sep 17 00:00:00 2001
From: Jingru <jingru@synopsys.com>
Date: Mon, 25 May 2020 17:25:52 +0800
Subject: [PATCH] =?UTF-8?q?arch=EF=BC=9Aarc:=20use=20FLS=20instruction=20t?=
 =?UTF-8?q?o=20get=20clz?=
MIME-Version: 1.0
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Signed-off-by: Jingru <jingru@synopsys.com>
---
 arch/arc/arcem/port.h        | 4 +---
 arch/arc/arcem/port_config.h | 2 +-
 arch/arc/arcem/port_s.s      | 2 +-
 arch/arc/common/tos_cpu.c    | 4 ++++
 4 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/arc/arcem/port.h b/arch/arc/arcem/port.h
index ae55a3e0..4cf98c0f 100644
--- a/arch/arc/arcem/port.h
+++ b/arch/arc/arcem/port.h
@@ -23,7 +23,7 @@
 #endif
 
 #if defined(TOS_CFG_CPU_LEAD_ZEROS_ASM_PRESENT) && (TOS_CFG_CPU_LEAD_ZEROS_ASM_PRESENT == 1u)
-__PORT__ uint32_t   port_clz(uint32_t val);
+__PORT__ uint32_t   port_cpu_clz(uint32_t);
 #endif
 
 __PORT__ void       port_int_disable(void);
@@ -36,8 +36,6 @@ __PORT__ void       port_cpsr_restore(cpu_cpsr_t cpsr);
 
 __PORT__ void       port_cpu_reset(void);
 
-__PORT__ uint32_t   port_cpu_clz(uint32_t);
-
 __PORT__ void       port_sched_start(void) __NO_RETURN__;
 
 __PORT__ void       port_context_switch(void);
diff --git a/arch/arc/arcem/port_config.h b/arch/arc/arcem/port_config.h
index 9a8a5e2b..8f247376 100644
--- a/arch/arc/arcem/port_config.h
+++ b/arch/arc/arcem/port_config.h
@@ -22,6 +22,6 @@
 #define TOS_CFG_CPU_DATA_SIZE               CPU_WORD_SIZE_32
 #define TOS_CFG_CPU_STK_GROWTH              CPU_STK_GROWTH_DESCENDING
 #define TOS_CFG_CPU_HRTIMER_EN              0u
-#define TOS_CFG_CPU_LEAD_ZEROS_ASM_PRESENT  0u
+#define TOS_CFG_CPU_LEAD_ZEROS_ASM_PRESENT  1u
 
 #endif /* _PORT_CONFIG_H_ */
diff --git a/arch/arc/arcem/port_s.s b/arch/arc/arcem/port_s.s
index 057dd934..4a7ff582 100644
--- a/arch/arc/arcem/port_s.s
+++ b/arch/arc/arcem/port_s.s
@@ -313,7 +313,7 @@ firq_return:
 	.align 4
 port_cpu_clz:
 	breq r0, 0, cpu_clz_return
-	ffs r1, r0
+	fls r1, r0
 	add r0, r1, 1
 cpu_clz_return:
 	j [blink]
\ No newline at end of file
diff --git a/arch/arc/common/tos_cpu.c b/arch/arc/common/tos_cpu.c
index 1dd32723..aab30a81 100644
--- a/arch/arc/common/tos_cpu.c
+++ b/arch/arc/common/tos_cpu.c
@@ -26,6 +26,7 @@ void tos_cpu_tick_handler(void)
 
 __API__ uint32_t tos_cpu_clz(uint32_t val)
 {
+#if defined(TOS_CFG_CPU_LEAD_ZEROS_ASM_PRESENT) && (TOS_CFG_CPU_LEAD_ZEROS_ASM_PRESENT == 0u)
     uint32_t nbr_lead_zeros = 0;
 
     if (!(val & 0XFFFF0000)) {
@@ -57,6 +58,9 @@ __API__ uint32_t tos_cpu_clz(uint32_t val)
     }
 
     return (nbr_lead_zeros);
+#else
+    return (32 - port_cpu_clz(val));
+#endif
 }
 
 __API__ void tos_cpu_int_disable(void)