Index: head/lib/libc/amd64/string/memset.S
===================================================================
--- head/lib/libc/amd64/string/memset.S
+++ head/lib/libc/amd64/string/memset.S
@@ -41,12 +41,12 @@
 	imulq	%r8,%r10
 
 	cmpq	$32,%rcx
-	jb	1016f
+	jbe	101632f
 
 	cmpq	$256,%rcx
 	ja	1256f
 
-1032:
+103200:
 	movq	%r10,(%rdi)
 	movq	%r10,8(%rdi)
 	movq	%r10,16(%rdi)
@@ -54,43 +54,49 @@
 	leaq	32(%rdi),%rdi
 	subq	$32,%rcx
 	cmpq	$32,%rcx
-	jae	1032b
-	cmpb	$0,%cl
-	je	1000f
-1016:
+	ja	103200b
 	cmpb	$16,%cl
-	jl	1008f
+	ja	201632f
+	movq	%r10,-16(%rdi,%rcx)
+	movq	%r10,-8(%rdi,%rcx)
+	ret
+	ALIGN_TEXT
+101632:
+	cmpb	$16,%cl
+	jl	100816f
+201632:
 	movq	%r10,(%rdi)
 	movq	%r10,8(%rdi)
-	subb	$16,%cl
-	jz	1000f
-	leaq	16(%rdi),%rdi
-1008:
+	movq	%r10,-16(%rdi,%rcx)
+	movq	%r10,-8(%rdi,%rcx)
+	ret
+	ALIGN_TEXT
+100816:
 	cmpb	$8,%cl
-	jl	1004f
+	jl	100408f
 	movq	%r10,(%rdi)
-	subb	$8,%cl
-	jz	1000f
-	leaq	8(%rdi),%rdi
-1004:
+	movq	%r10,-8(%rdi,%rcx)
+	ret
+	ALIGN_TEXT
+100408:
 	cmpb	$4,%cl
-	jl	1002f
+	jl	100204f
 	movl	%r10d,(%rdi)
-	subb	$4,%cl
-	jz	1000f
-	leaq	4(%rdi),%rdi
-1002:
+	movl	%r10d,-4(%rdi,%rcx)
+	ret
+	ALIGN_TEXT
+100204:
 	cmpb	$2,%cl
-	jl	1001f
+	jl	100001f
 	movw	%r10w,(%rdi)
-	subb	$2,%cl
-	jz	1000f
-	leaq	2(%rdi),%rdi
-1001:
-	cmpb	$1,%cl
-	jl	1000f
+	movw	%r10w,-2(%rdi,%rcx)
+	ret
+	ALIGN_TEXT
+100001:
+	cmpb	$0,%cl
+	je	100000f
 	movb	%r10b,(%rdi)
-1000:
+100000:
 	ret
 	ALIGN_TEXT
 1256:
@@ -127,6 +133,7 @@
 	leaq	16(%rdi,%r8),%rdi
 	jmp	1b
 .endm
+
 
 ENTRY(memset)
 	MEMSET erms=0
Index: head/sys/amd64/amd64/support.S
===================================================================
--- head/sys/amd64/amd64/support.S
+++ head/sys/amd64/amd64/support.S
@@ -459,12 +459,12 @@
 	imulq	%r8,%r10
 
 	cmpq	$32,%rcx
-	jb	1016f
+	jbe	101632f
 
 	cmpq	$256,%rcx
 	ja	1256f
 
-1032:
+103200:
 	movq	%r10,(%rdi)
 	movq	%r10,8(%rdi)
 	movq	%r10,16(%rdi)
@@ -472,43 +472,54 @@
 	leaq	32(%rdi),%rdi
 	subq	$32,%rcx
 	cmpq	$32,%rcx
-	jae	1032b
-	cmpb	$0,%cl
-	je	1000f
-1016:
+	ja	103200b
 	cmpb	$16,%cl
-	jl	1008f
+	ja	201632f
+	movq	%r10,-16(%rdi,%rcx)
+	movq	%r10,-8(%rdi,%rcx)
+	POP_FRAME_POINTER
+	ret
+	ALIGN_TEXT
+101632:
+	cmpb	$16,%cl
+	jl	100816f
+201632:
 	movq	%r10,(%rdi)
 	movq	%r10,8(%rdi)
-	subb	$16,%cl
-	jz	1000f
-	leaq	16(%rdi),%rdi
-1008:
+	movq	%r10,-16(%rdi,%rcx)
+	movq	%r10,-8(%rdi,%rcx)
+	POP_FRAME_POINTER
+	ret
+	ALIGN_TEXT
+100816:
 	cmpb	$8,%cl
-	jl	1004f
+	jl	100408f
 	movq	%r10,(%rdi)
-	subb	$8,%cl
-	jz	1000f
-	leaq	8(%rdi),%rdi
-1004:
+	movq	%r10,-8(%rdi,%rcx)
+	POP_FRAME_POINTER
+	ret
+	ALIGN_TEXT
+100408:
 	cmpb	$4,%cl
-	jl	1002f
+	jl	100204f
 	movl	%r10d,(%rdi)
-	subb	$4,%cl
-	jz	1000f
-	leaq	4(%rdi),%rdi
-1002:
+	movl	%r10d,-4(%rdi,%rcx)
+	POP_FRAME_POINTER
+	ret
+	ALIGN_TEXT
+100204:
 	cmpb	$2,%cl
-	jl	1001f
+	jl	100001f
 	movw	%r10w,(%rdi)
-	subb	$2,%cl
-	jz	1000f
-	leaq	2(%rdi),%rdi
-1001:
-	cmpb	$1,%cl
-	jl	1000f
+	movw	%r10w,-2(%rdi,%rcx)
+	POP_FRAME_POINTER
+	ret
+	ALIGN_TEXT
+100001:
+	cmpb	$0,%cl
+	je	100000f
 	movb	%r10b,(%rdi)
-1000:
+100000:
 	POP_FRAME_POINTER
 	ret
 	ALIGN_TEXT