Index: sys/mips/mips/pm_machdep.c
===================================================================
--- sys/mips/mips/pm_machdep.c
+++ sys/mips/mips/pm_machdep.c
@@ -74,6 +74,12 @@
 
 #define	UCONTEXT_MAGIC	0xACEDBADE
 
+#if defined(__mips_n32) || defined(__mips_n64)
+#define	STACK_ALIGN	16
+#else
+#define	STACK_ALIGN	8
+#endif
+
 /*
  * Send an interrupt to process.
  *
@@ -132,10 +138,10 @@
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
 		sfp = (struct sigframe *)(((uintptr_t)td->td_sigstk.ss_sp +
 		    td->td_sigstk.ss_size - sizeof(struct sigframe))
-		    & ~(sizeof(__int64_t) - 1));
+		    & ~(STACK_ALIGN - 1));
 	} else
 		sfp = (struct sigframe *)((vm_offset_t)(regs->sp - 
-		    sizeof(struct sigframe)) & ~(sizeof(__int64_t) - 1));
+		    sizeof(struct sigframe)) & ~(STACK_ALIGN - 1));
 
 	/* Build the argument list for the signal handler. */
 	regs->a0 = sig;
@@ -408,12 +414,7 @@
 
 	bzero((caddr_t)td->td_frame, sizeof(struct trapframe));
 
-	/*
-	 * The stack pointer has to be aligned to accommodate the largest
-	 * datatype at minimum.  This probably means it should be 16-byte
-	 * aligned, but for now we're 8-byte aligning it.
-	 */
-	td->td_frame->sp = ((register_t) stack) & ~(sizeof(__int64_t) - 1);
+	td->td_frame->sp = ((register_t)stack) & ~(STACK_ALIGN - 1);
 
 	/*
 	 * If we're running o32 or n32 programs but have 64-bit registers,