Index: sys/powerpc/powerpc/sigcode64.S
===================================================================
--- sys/powerpc/powerpc/sigcode64.S
+++ sys/powerpc/powerpc/sigcode64.S
@@ -58,14 +58,19 @@
 CNAME(sigcode64_elfv2):
 	addi	1,1,-112		/* reserved space for callee */
 	mflr	12			/* ELFv2 wants the address in r12 */
-	blrl
+	blrl				/* Branch back to user code. */
 
+	/* If we get here, the process is exiting via return from main(). */
 	addi	3,1,112+SF_UC		/* restore sp, and get &frame->sf_uc */
 	li	0,SYS_sigreturn
 	sc				/* sigreturn(scp) */
 	li	0,SYS_exit
 	sc				/* exit(errno) */
-	nop				/* align to doubleword */
+	/*
+	 * exec_copyout_strings() prefers (void*) alignment.
+	 * Add an extra nop here if the number of instructions changes
+	 * in the future.
+	 */
 endsigcode64:
 	
 	.data