Index: sys/sparc64/sparc64/machdep.c
===================================================================
--- sys/sparc64/sparc64/machdep.c	(wersja 228125)
+++ sys/sparc64/sparc64/machdep.c	(kopia robocza)
@@ -1007,7 +1007,7 @@
 
 	pcb = td->td_pcb;
 	tf = td->td_frame;
-	sp = rounddown(stack, 16);
+	sp = rounddown2(stack, 16);
 	bzero(pcb, sizeof(*pcb));
 	bzero(tf, sizeof(*tf));
 	tf->tf_out[0] = stack;
Index: sys/dev/firewire/sbp.c
===================================================================
--- sys/dev/firewire/sbp.c	(wersja 228125)
+++ sys/dev/firewire/sbp.c	(kopia robocza)
@@ -161,7 +161,7 @@
 
 #define NEED_RESPONSE 0
 
-#define SBP_SEG_MAX rounddown(0xffff, PAGE_SIZE)
+#define SBP_SEG_MAX rounddown2(0xffff, PAGE_SIZE)
 #ifdef __sparc64__ /* iommu */
 #define SBP_IND_MAX howmany(SBP_MAXPHYS, SBP_SEG_MAX)
 #else
Index: sys/dev/msk/if_msk.c
===================================================================
--- sys/dev/msk/if_msk.c	(wersja 228125)
+++ sys/dev/msk/if_msk.c	(kopia robocza)
@@ -1218,7 +1218,7 @@
 	 * of 1024. Tx/Rx RAM buffer size of Yukon II should be multiple
 	 * of 1024.
 	 */
-	sc->msk_rxqsize = rounddown((sc->msk_ramsize * 1024 * 2) / 3, 1024);
+	sc->msk_rxqsize = rounddown2((sc->msk_ramsize * 1024 * 2) / 3, 1024);
 	sc->msk_txqsize = (sc->msk_ramsize * 1024) - sc->msk_rxqsize;
 	for (i = 0, next = 0; i < sc->msk_num_port; i++) {
 		sc->msk_rxqstart[i] = next;
Index: sys/compat/x86bios/x86bios.c
===================================================================
--- sys/compat/x86bios/x86bios.c	(wersja 228125)
+++ sys/compat/x86bios/x86bios.c	(kopia robocza)
@@ -687,7 +687,7 @@
 	if (x86bios_rom_phys != 0 && x86bios_rom_phys < X86BIOS_ROM_BASE &&
 	    X86BIOS_ROM_BASE - x86bios_rom_phys <= 128 * 1024)
 		x86bios_rom_phys =
-		    rounddown(x86bios_rom_phys, X86BIOS_PAGE_SIZE);
+		    rounddown2(x86bios_rom_phys, X86BIOS_PAGE_SIZE);
 	else
 #else
 	x86bios_ivt = malloc(X86BIOS_IVT_SIZE, M_DEVBUF, M_ZERO | M_WAITOK);
Index: sys/amd64/include/pmap.h
===================================================================
--- sys/amd64/include/pmap.h	(wersja 228125)
+++ sys/amd64/include/pmap.h	(kopia robocza)
@@ -139,7 +139,7 @@
 #define	PML4PML4I	(NPML4EPG/2)	/* Index of recursive pml4 mapping */
 
 #define	KPML4I		(NPML4EPG-1)	/* Top 512GB for KVM */
-#define	DMPML4I		rounddown(KPML4I - NDMPML4E, NDMPML4E) /* Below KVM */
+#define	DMPML4I		rounddown2(KPML4I - NDMPML4E, NDMPML4E) /* Below KVM */
 
 #define	KPDPI		(NPDPEPG-2)	/* kernbase at -2GB */
 
Index: sys/sys/param.h
===================================================================
--- sys/sys/param.h	(wersja 228125)
+++ sys/sys/param.h	(kopia robocza)
@@ -273,7 +273,8 @@
 #ifndef howmany
 #define	howmany(x, y)	(((x)+((y)-1))/(y))
 #endif
-#define	rounddown(x, y)	(((x)/(y))*(y))
+#define	rounddown(x, y)		(((x)/(y))*(y))    /* to any y */
+#define	rounddown2(x, y)	((x)&(~((y)-1)))   /* if y is power of two */
 #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))  /* to any y */
 #define	roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
 #define powerof2(x)	((((x)-1)&(x))==0)