diff --git a/libc/runtime/ftrace-hook.S b/libc/runtime/ftrace-hook.S
index 93d75a751..3d72aac94 100644
--- a/libc/runtime/ftrace-hook.S
+++ b/libc/runtime/ftrace-hook.S
@@ -23,9 +23,8 @@ ftrace_hook:
 #ifdef __x86_64__
 
 	cmp	$0,__ftrace(%rip)
-	jg	1f
-	ret
-1:	push	%rbp
+	jle	1f
+	push	%rbp
 	mov	%rsp,%rbp
 	push	%rax
 	push	%rax
@@ -45,16 +44,15 @@ ftrace_hook:
 	pop	%rax
 	pop	%rax
 	pop	%rbp
-	ret
+1:	ret
 
 #elif defined(__aarch64__)
 
 	adrp	x9,__ftrace
 	ldr	w9,[x9,#:lo12:__ftrace]
-	cmp	w9,1
-	bge	1f
-	ret
-1:	stp	x29,x30,[sp,-96]!
+	cmp	w9,0
+	ble	1f
+	stp	x29,x30,[sp,-96]!
 	mov	x29,sp
 	stp	x0,x1,[sp,16]
 	stp	x2,x3,[sp,32]
@@ -68,7 +66,7 @@ ftrace_hook:
 	ldp	x2,x3,[sp,32]
 	ldp	x0,x1,[sp,16]
 	ldp	x29,x30,[sp],96
-	ret
+1:	ret
 
 #endif /* __x86_64__ */
 	.endfn	ftrace_hook,globl
diff --git a/libc/runtime/init.S b/libc/runtime/init.S
index 2ccc87e55..34ab89d59 100644
--- a/libc/runtime/init.S
+++ b/libc/runtime/init.S
@@ -48,9 +48,7 @@
 	.section .initprologue,"ax",@progbits
 	.type	_init,@function
 	.globl	_init
-	.ftrace1
 _init:
-	.ftrace2
 #ifdef __x86_64__
 	push	%rbp
 	mov	%rsp,%rbp
diff --git a/tool/emacs/cosmo-c-builtins.el b/tool/emacs/cosmo-c-builtins.el
index ae255a493..db25dd4ee 100644
--- a/tool/emacs/cosmo-c-builtins.el
+++ b/tool/emacs/cosmo-c-builtins.el
@@ -68,6 +68,7 @@
            "__builtin_ctzl"
            "__builtin_ctzll"
            "__builtin_expect"
+           "__builtin_memcpy"
            "__builtin_expect_with_probability"
            "__builtin_extract_return_addr"
            "__builtin_isnan"
@@ -97,6 +98,7 @@
            "__builtin_trap"
            "__builtin_types_compatible_p"
            "__builtin_unreachable"
+           "__builtin_ia32_movntdq"
            "__has_attribute"
            "__has_builtin"
            "__has_cpp_attribute"