Just return `curbrk' for sbrk(0) to avoid syscall overhead.

svn path=/head/; revision=48253
1999-06-26 15:22:33 +00:00 · 1999-06-26 15:22:33 +00:00 · d71d50b89c · 2020-12-20 02:59:44 +00:00
commit d71d50b89c
parent d50c199430
1 changed files with 2 additions and 0 deletions
--- a/lib/libc/alpha/sys/sbrk.S
+++ b/lib/libc/alpha/sys/sbrk.S
@ -40,9 +40,11 @@ LEAF(sbrk, 1)
 	br	pv, L1				/* XXX profiling */
 L1:	LDGP(pv)
 	ldq	a1, curbrk
+	beq	a0, L2
 	addq	a0, a1, a0
 	CALLSYS_ERROR(break)
 	stq	a0, curbrk
+L2:
 	mov	a1, v0
 	RET
 END(sbrk)