runtime: use RDCYCLE for cputicks on riscv64

Use RDCYCLE instruction instead of RDTIME emulation

Change-Id: Id7b3de42a36d2d1b163c39cc79870eee7c840ad5
Reviewed-on: https://go-review.googlesource.com/c/go/+/332954
Trust: Meng Zhuo <mzh@golangcn.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

diff --git a/src/runtime/asm_riscv64.s b/src/runtime/asm_riscv64.s
index d7ab90d1abfbf4b7387367bc2a0a2214799f8eea..531b46927c98f03a9469f2ddadc47f20745f7c09 100644 (file)
--- a/src/runtime/asm_riscv64.s
+++ b/src/runtime/asm_riscv64.s
@@ -81,7 +81,7 @@ TEXT setg_gcc<>(SB),NOSPLIT,$0-0
 
 // func cputicks() int64
 TEXT runtime·cputicks(SB),NOSPLIT,$0-8
-       RDTIME  A0
+       RDCYCLE A0
        MOV     A0, ret+0(FP)
        RET