posix-amd64 changes

2006-05-21 16:35:53 +00:00
parent 5797fdc0c0
commit ee4955c879
5 changed files with 505 additions and 0 deletions
--- a/posix-amd64/tas.c
+++ b/posix-amd64/tas.c
@ -0,0 +1,23 @@
+#include "u.h"
+#include "libc.h"
+
+int
+tas(long *x)
+{
+	int     v;
+
+	__asm__(	"movl   $1, %%eax\n\t"
+				"xchgl  %%eax,(%%rcx)"
+				: "=a" (v)
+				: "c" (x)
+	);
+	switch(v) {
+	case 0:
+	case 1:
+		return v;
+	default:
+		print("canlock: corrupted 0x%lux\n", v);
+		return 1;
+	}
+}
+