LoongArch: Slightly clean up drdtime()

xry111 · chenhuacai · commit 8146c5b34907 · 2023-12-09T15:49:15.000+08:00
As we are just discarding the stable clock ID, simply write it into
$zero instead of allocating a temporary register.

Signed-off-by: Xi Ruoyao &lt;xry111@xry111.site&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
@@ -1098,12 +1098,11 @@
 
 static __always_inline u64 drdtime(void)
 {
-	int rID = 0;
 	u64 val = 0;
 
 	__asm__ __volatile__(
-		"rdtime.d %0, %1 \n\t"
-		: "=r"(val), "=r"(rID)
+		"rdtime.d %0, $zero\n\t"
+		: "=r"(val)
 		:
 		);
 	return val;

Original file line number	Diff line number	Diff line change
`@@ -1098,12 +1098,11 @@`
`1098`	`1098`
`1099`	`1099`	`static __always_inline u64 drdtime(void)`
`1100`	`1100`	`{`
`1101`		`- int rID = 0;`
`1102`	`1101`	`u64 val = 0;`
`1103`	`1102`
`1104`	`1103`	`__asm__ __volatile__(`
`1105`		`- "rdtime.d %0, %1 \n\t"`
`1106`		`- : "=r"(val), "=r"(rID)`
	`1104`	`+ "rdtime.d %0, $zero\n\t"`
	`1105`	`+ : "=r"(val)`
`1107`	`1106`	`:`
`1108`	`1107`	`);`
`1109`	`1108`	`return val;`