Index: usr.sbin/bhyve/bhyverun.c
===================================================================
--- usr.sbin/bhyve/bhyverun.c
+++ usr.sbin/bhyve/bhyverun.c
@@ -388,13 +388,11 @@
 static int
 vmexit_spinup_ap(struct vmctx *ctx, struct vm_exit *vme, int *pvcpu)
 {
-	int newcpu;
-	int retval = VMEXIT_CONTINUE;
 
-	newcpu = spinup_ap(ctx, *pvcpu,
-			   vme->u.spinup_ap.vcpu, vme->u.spinup_ap.rip);
+	(void)spinup_ap(ctx, *pvcpu,
+		    vme->u.spinup_ap.vcpu, vme->u.spinup_ap.rip);
 
-	return (retval);
+	return (VMEXIT_CONTINUE);
 }
 
 #define	DEBUG_EPT_MISCONFIG
Index: usr.sbin/bhyve/pci_ahci.c
===================================================================
--- usr.sbin/bhyve/pci_ahci.c
+++ usr.sbin/bhyve/pci_ahci.c
@@ -1717,19 +1717,25 @@
 ahci_handle_slot(struct ahci_port *p, int slot)
 {
 	struct ahci_cmd_hdr *hdr;
+#ifdef AHCI_DEBUG
 	struct ahci_prdt_entry *prdt;
+#endif
 	struct pci_ahci_softc *sc;
 	uint8_t *cfis;
+#ifdef AHCI_DEBUG
 	int cfl;
+#endif
 
 	sc = p->pr_sc;
 	hdr = (struct ahci_cmd_hdr *)(p->cmd_lst + slot * AHCI_CL_SIZE);
+#ifdef AHCI_DEBUG
 	cfl = (hdr->flags & 0x1f) * 4;
+#endif
 	cfis = paddr_guest2host(ahci_ctx(sc), hdr->ctba,
 			0x80 + hdr->prdtl * sizeof(struct ahci_prdt_entry));
+#ifdef AHCI_DEBUG
 	prdt = (struct ahci_prdt_entry *)(cfis + 0x80);
 
-#ifdef AHCI_DEBUG
 	DPRINTF("\ncfis:");
 	for (i = 0; i < cfl; i++) {
 		if (i % 10 == 0)
Index: usr.sbin/bhyve/pci_emul.c
===================================================================
--- usr.sbin/bhyve/pci_emul.c
+++ usr.sbin/bhyve/pci_emul.c
@@ -755,13 +755,21 @@
 	return (err);
 }
 
+#ifdef __GNU_C__
+#define	WRAPPED_CTASSERT(x)	CTASSERT(x) __unused
+#else
+#define	WRAPPED_CTASSERT(x)	CTASSERT(x)
+#endif
+
+WRAPPED_CTASSERT(sizeof(struct msicap) == 14);
+WRAPPED_CTASSERT(sizeof(struct msixcap) == 12);
+WRAPPED_CTASSERT(sizeof(struct pciecap) == 60);
+
 void
 pci_populate_msicap(struct msicap *msicap, int msgnum, int nextptr)
 {
 	int mmc;
 
-	CTASSERT(sizeof(struct msicap) == 14);
-
 	/* Number of msi messages must be a power of 2 between 1 and 32 */
 	assert((msgnum & (msgnum - 1)) == 0 && msgnum >= 1 && msgnum <= 32);
 	mmc = ffs(msgnum) - 1;
@@ -786,7 +794,6 @@
 pci_populate_msixcap(struct msixcap *msixcap, int msgnum, int barnum,
 		     uint32_t msix_tab_size)
 {
-	CTASSERT(sizeof(struct msixcap) == 12);
 
 	assert(msix_tab_size % 4096 == 0);
 
@@ -937,8 +944,6 @@
 	int err;
 	struct pciecap pciecap;
 
-	CTASSERT(sizeof(struct pciecap) == 60);
-
 	if (type != PCIEM_TYPE_ROOT_PORT)
 		return (-1);
 
Index: usr.sbin/bhyve/pci_passthru.c
===================================================================
--- usr.sbin/bhyve/pci_passthru.c
+++ usr.sbin/bhyve/pci_passthru.c
@@ -361,7 +361,7 @@
 	uint64_t *dest64;
 	size_t entry_offset;
 	uint32_t vector_control;
-	int error, index;
+	int index;
 
 	pi = sc->psc_pi;
 	if (offset >= pi->pi_msix.pba_offset &&
@@ -416,8 +416,8 @@
 		/* If the entry is masked, don't set it up */
 		if ((entry->vector_control & PCIM_MSIX_VCTRL_MASK) == 0 ||
 		    (vector_control & PCIM_MSIX_VCTRL_MASK) == 0) {
-			error = vm_setup_pptdev_msix(ctx, vcpu,
-			    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev, 
+			(void)vm_setup_pptdev_msix(ctx, vcpu,
+			    sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
 			    sc->psc_sel.pc_func, index, entry->addr,
 			    entry->msg_data, entry->vector_control);
 		}
Index: usr.sbin/bhyve/pci_xhci.c
===================================================================
--- usr.sbin/bhyve/pci_xhci.c
+++ usr.sbin/bhyve/pci_xhci.c
@@ -143,10 +143,10 @@
 #define	MASK_64_HI(x)			((x) & ~0xFFFFFFFFULL)
 #define	MASK_64_LO(x)			((x) & 0xFFFFFFFFULL)
 
-#define	FIELD_REPLACE(a,b,m,s)		((a) & ~((m) << (s)) | \
-					((b) & (m)) << (s))
-#define	FIELD_COPY(a,b,m,s)		((a) & ~((m) << (s)) | \
-					((b) & ((m) << (s))))
+#define	FIELD_REPLACE(a,b,m,s)		(((a) & ~((m) << (s))) | \
+					(((b) & (m)) << (s)))
+#define	FIELD_COPY(a,b,m,s)		(((a) & ~((m) << (s))) | \
+					(((b) & ((m) << (s)))))
 
 struct pci_xhci_trb_ring {
 	uint64_t ringaddr;		/* current dequeue guest address */
@@ -1700,7 +1700,7 @@
 	struct xhci_trb *setup_trb;
 	struct usb_data_xfer *xfer;
 	struct usb_data_xfer_block *xfer_block;
-	uint64_t	val, setup_addr, status_addr;
+	uint64_t	val;
 	uint32_t	trbflags;
 	int		do_intr, err;
 	int		do_retry;
@@ -1718,8 +1718,6 @@
 	do_retry = 0;
 	do_intr = 0;
 	setup_trb = NULL;
-	setup_addr = 0;
-	status_addr = 0;
 
 	while (1) {
 		pci_xhci_dump_trb(trb);
@@ -1754,7 +1752,6 @@
 				goto errout;
 			}
 			setup_trb = trb;
-			setup_addr = addr;
 
 			val = trb->qwTrb0;
 			if (!xfer->ureq)
@@ -1786,7 +1783,6 @@
 			break;
 
 		case XHCI_TRB_TYPE_STATUS_STAGE:
-			status_addr = addr;
 			xfer_block = usb_data_xfer_append(xfer, NULL, 0,
 			                                  (void *)addr, ccs);
 			break;
@@ -1842,7 +1838,6 @@
 		err = USB_ERR_NOT_STARTED;
 		if (dev->dev_ue->ue_request != NULL)
 			err = dev->dev_ue->ue_request(dev->dev_sc, xfer);
-		status_addr = 0;
 		setup_trb = NULL;
 	} else {
 		/* handle data transfer */
Index: usr.sbin/bhyve/ps2kbd.c
===================================================================
--- usr.sbin/bhyve/ps2kbd.c
+++ usr.sbin/bhyve/ps2kbd.c
@@ -93,15 +93,6 @@
 	fifo->size = sizeof(((struct fifo *)0)->buf);
 }
 
-static int
-fifo_available(struct ps2kbd_softc *sc)
-{
-	struct fifo *fifo;
-
-	fifo = &sc->fifo;
-	return (fifo->num < fifo->size);
-}
-
 static void
 fifo_put(struct ps2kbd_softc *sc, uint8_t val)
 {
Index: usr.sbin/bhyve/rfb.c
===================================================================
--- usr.sbin/bhyve/rfb.c
+++ usr.sbin/bhyve/rfb.c
@@ -28,10 +28,12 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 #include <sys/select.h>
-#include <sys/param.h>
+#include <machine/cpufunc.h>
+#include <machine/specialreg.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
@@ -46,7 +48,6 @@
 #include <unistd.h>
 
 #include <zlib.h>
-#include <cpuid.h>
 
 #include "bhyvegc.h"
 #include "console.h"
@@ -177,7 +178,6 @@
 {
 	struct bhyvegc_image *gc_image;
 	struct rfb_srvr_info sinfo;
-	int len;
 
 	gc_image = console_get_image();
 
@@ -194,8 +194,8 @@
 	sinfo.pixfmt.green_shift = 8;
 	sinfo.pixfmt.blue_shift = 0;
 	sinfo.namelen = htonl(strlen("bhyve"));
-	len = stream_write(cfd, &sinfo, sizeof(sinfo));
-	len = stream_write(cfd, "bhyve", strlen("bhyve"));
+	(void)stream_write(cfd, &sinfo, sizeof(sinfo));
+	(void)stream_write(cfd, "bhyve", strlen("bhyve"));
 }
 
 static void
@@ -223,9 +223,8 @@
 rfb_recv_set_pixfmt_msg(struct rfb_softc *rc, int cfd)
 {
 	struct rfb_pixfmt_msg pixfmt_msg;
-	int len;
 
-	len = stream_read(cfd, ((void *)&pixfmt_msg)+1, sizeof(pixfmt_msg)-1);
+	(void)stream_read(cfd, ((void *)&pixfmt_msg)+1, sizeof(pixfmt_msg)-1);
 }
 
 
@@ -233,14 +232,14 @@
 rfb_recv_set_encodings_msg(struct rfb_softc *rc, int cfd)
 {
 	struct rfb_enc_msg enc_msg;
-	int len, i;
+	int i;
 	uint32_t encoding;
 
 	assert((sizeof(enc_msg) - 1) == 3);
-	len = stream_read(cfd, ((void *)&enc_msg)+1, sizeof(enc_msg)-1);
+	(void)stream_read(cfd, ((void *)&enc_msg)+1, sizeof(enc_msg)-1);
 
 	for (i = 0; i < htons(enc_msg.numencs); i++) {
-		len = stream_read(cfd, &encoding, sizeof(encoding));
+		(void)stream_read(cfd, &encoding, sizeof(encoding));
 		switch (htonl(encoding)) {
 		case RFB_ENCODING_RAW:
 			rc->enc_raw_ok = true;
@@ -256,27 +255,6 @@
 	}
 }
 
-static void
-rfb_resize_update(struct rfb_softc *rc, int fd)
-{
-	struct rfb_srvr_updt_msg supdt_msg;
-        struct rfb_srvr_rect_hdr srect_hdr;
-
-	/* Number of rectangles: 1 */
-	supdt_msg.type = 0;
-	supdt_msg.pad = 0;
-	supdt_msg.numrects = htons(1);
-	stream_write(fd, &supdt_msg, sizeof(struct rfb_srvr_updt_msg));
-
-	/* Rectangle header */
-	srect_hdr.x = htons(0);
-	srect_hdr.y = htons(0);
-	srect_hdr.width = htons(rc->width);
-	srect_hdr.height = htons(rc->height);
-	srect_hdr.encoding = htonl(RFB_ENCODING_RESIZE);
-	stream_write(fd, &srect_hdr, sizeof(struct rfb_srvr_rect_hdr));
-}
-
 /*
  * Calculate CRC32 using SSE4.2; Intel or AMD Bulldozer+ CPUs only
  */
@@ -636,9 +614,8 @@
 {
 	struct rfb_updt_msg updt_msg;
 	struct bhyvegc_image *gc_image;
-	int len;
 
-	len = stream_read(cfd, ((void *)&updt_msg) + 1 , sizeof(updt_msg) - 1);
+	(void)stream_read(cfd, ((void *)&updt_msg) + 1 , sizeof(updt_msg) - 1);
 
 	console_refresh();
 	gc_image = console_get_image();
@@ -666,9 +643,8 @@
 rfb_recv_key_msg(struct rfb_softc *rc, int cfd)
 {
 	struct rfb_key_msg key_msg;
-	int len;
 
-	len = stream_read(cfd, ((void *)&key_msg) + 1, sizeof(key_msg) - 1);
+	(void)stream_read(cfd, ((void *)&key_msg) + 1, sizeof(key_msg) - 1);
 
 	console_key_event(key_msg.down, htonl(key_msg.code));
 }
@@ -677,9 +653,8 @@
 rfb_recv_ptr_msg(struct rfb_softc *rc, int cfd)
 {
 	struct rfb_ptr_msg ptr_msg;
-	int len;
 
-	len = stream_read(cfd, ((void *)&ptr_msg) + 1, sizeof(ptr_msg) - 1);
+	(void)stream_read(cfd, ((void *)&ptr_msg) + 1, sizeof(ptr_msg) - 1);
 
 	console_ptr_event(ptr_msg.button, htons(ptr_msg.x), htons(ptr_msg.y));
 }
@@ -876,13 +851,15 @@
 }
 
 static int
-sse42_supported()
+sse42_supported(void)
 {
-	unsigned int eax, ebx, ecx, edx;
- 
-	__get_cpuid(1, &eax, &ebx, &ecx, &edx);
- 
-	return ((ecx & bit_SSE42) != 0);
+	u_int cpu_registers[4], ecx;
+
+	do_cpuid(1, cpu_registers);
+
+	ecx = cpu_registers[2];
+
+	return ((ecx & CPUID2_SSE42) != 0);
 }
 
 int
Index: usr.sbin/bhyve/usb_mouse.c
===================================================================
--- usr.sbin/bhyve/usb_mouse.c
+++ usr.sbin/bhyve/usb_mouse.c
@@ -297,9 +297,6 @@
 umouse_init(struct usb_hci *hci, char *opt)
 {
 	struct umouse_softc *sc;
-	char *mopt;
-
-	mopt = opt;
 
 	sc = calloc(1, sizeof(struct umouse_softc));
 	sc->hci = hci;