diff --git a/src/mame/drivers/chihiro.c b/src/mame/drivers/chihiro.c
index 696caab82be..c47da4e1167 100644
--- a/src/mame/drivers/chihiro.c
+++ b/src/mame/drivers/chihiro.c
@@ -1165,8 +1165,8 @@ static int x,ret;
 	} else if ((offset >= 0x00600000/4) && (offset < 0x00601000/4)) {
 		ret=pcrtc[offset-0x00600000/4];
 		logerror("NV_2A: read PCRTC[%06X] value %08X\n",offset*4-0x00600000,ret);
-	} else if ((offset >= 0x00000000/4) && (offset < 0x00001000/4)) {
-		ret=pmc[offset-0x00000000/4];
+	} else if (                             offset < 0x00001000/4) {
+		ret=pmc[offset];
 		logerror("NV_2A: read PMC[%06X] value %08X\n",offset*4-0x00000000,ret);
 	} else if ((offset >= 0x00800000/4) && (offset < 0x00900000/4)) {
 		// 32 channels size 0x10000 each, 8 subchannels per channel size 0x2000 each
@@ -1200,8 +1200,8 @@ WRITE32_MEMBER( nv2a_renderer::geforce_w )
 	} else if ((offset >= 0x00600000/4) && (offset < 0x00601000/4)) {
 		COMBINE_DATA(pcrtc+offset-0x00600000/4);
 		logerror("NV_2A: write PCRTC[%06X]=%08X\n",offset*4-0x00600000,data & mem_mask);
-	} else if ((offset >= 0x00000000/4) && (offset < 0x00001000/4)) {
-		COMBINE_DATA(pmc+offset-0x00000000/4);
+	} else if (                             offset < 0x00001000/4) {
+		COMBINE_DATA(pmc+offset);
 		logerror("NV_2A: write PMC[%06X]=%08X\n",offset*4-0x00000000,data & mem_mask);
 	} else if ((offset >= 0x00800000/4) && (offset < 0x00900000/4)) {
 		// 32 channels size 0x10000 each, 8 subchannels per channel size 0x2000 each
diff --git a/src/mame/drivers/firebeat.c b/src/mame/drivers/firebeat.c
index c3096aed7da..d3d0c381dd5 100644
--- a/src/mame/drivers/firebeat.c
+++ b/src/mame/drivers/firebeat.c
@@ -841,7 +841,7 @@ READ32_MEMBER(firebeat_state::soundflash_r)
 {
 	UINT32 r = 0;
 	fujitsu_29f016a_device *chip;
-	if (offset >= 0 && offset < 0x200000/4)
+	if (offset < 0x200000/4)
 	{
 		chip = m_flash[1];
 	}
@@ -874,7 +874,7 @@ READ32_MEMBER(firebeat_state::soundflash_r)
 WRITE32_MEMBER(firebeat_state::soundflash_w)
 {
 	fujitsu_29f016a_device *chip;
-	if (offset >= 0 && offset < 0x200000/4)
+	if (offset < 0x200000/4)
 	{
 		chip = m_flash[1];
 	}
@@ -1802,7 +1802,7 @@ ADDRESS_MAP_END
 
 READ8_MEMBER(firebeat_state::soundram_r)
 {
-	if (offset >= 0 && offset < 0x200000)
+	if (offset < 0x200000)
 	{
 		return m_flash[1]->read(offset & 0x1fffff);
 	}
diff --git a/src/mame/drivers/gstream.c b/src/mame/drivers/gstream.c
index a9a84d3f0aa..bf5f4f051d0 100644
--- a/src/mame/drivers/gstream.c
+++ b/src/mame/drivers/gstream.c
@@ -237,9 +237,9 @@ WRITE32_MEMBER(gstream_state::gstream_vram_w)
 
 	if (ACCESSING_BITS_24_31)
 	{
-		if (offset >= 0x000 / 4 && offset < 0x400 / 4)
+		if (offset < 0x400 / 4)
 		{
-			m_tilemap1->mark_tile_dirty(offset - (0x000 / 4));
+			m_tilemap1->mark_tile_dirty(offset);
 		}
 		else if (offset >= 0x400 / 4 && offset < 0x800 / 4)
 		{
diff --git a/src/mame/drivers/megaplay.c b/src/mame/drivers/megaplay.c
index 6265d556f4d..fafd33e8e9a 100644
--- a/src/mame/drivers/megaplay.c
+++ b/src/mame/drivers/megaplay.c
@@ -430,7 +430,7 @@ static READ8_HANDLER( bank_r )
 	UINT8* bank = state->memregion("mtbios")->base();
 	UINT32 fulladdress = state->m_mp_bios_bank_addr + offset;
 
-	if ((fulladdress >= 0x000000) && (fulladdress <= 0x3fffff)) // ROM Addresses
+	if (fulladdress <= 0x3fffff) // ROM Addresses
 	{
 		if (state->m_bios_mode & MP_ROM)
 		{
@@ -470,7 +470,7 @@ static WRITE8_HANDLER( bank_w )
 	mplay_state *state = space.machine().driver_data<mplay_state>();
 	UINT32 fulladdress = state->m_mp_bios_bank_addr + offset;
 
-	if ((fulladdress >= 0x000000) && (fulladdress <= 0x3fffff)) // ROM / Megaplay Custom Addresses
+	if (fulladdress <= 0x3fffff) // ROM / Megaplay Custom Addresses
 	{
 		if (offset <= 0x1fff && (state->m_bios_width & 0x08))
 		{
diff --git a/src/mame/drivers/segas16a.c b/src/mame/drivers/segas16a.c
index 1199bb28386..a4f6fd42b50 100644
--- a/src/mame/drivers/segas16a.c
+++ b/src/mame/drivers/segas16a.c
@@ -585,7 +585,7 @@ READ8_MEMBER( segas16a_state::mcu_io_r )
 	{
 		case 0:
 			// access watchdog? (unsure about this one)
-			if (offset >= 0x0000 && offset < 0x3fff)
+			if (                         offset < 0x3fff)
 				return watchdog_reset_r(space, 0);
 
 			// access main work RAM
diff --git a/src/mame/drivers/taitopjc.c b/src/mame/drivers/taitopjc.c
index d3a0aca30a9..96948b504aa 100644
--- a/src/mame/drivers/taitopjc.c
+++ b/src/mame/drivers/taitopjc.c
@@ -110,7 +110,6 @@ UINT32 taitopjc_state::screen_update_taitopjc(screen_device &screen, bitmap_rgb3
 				tile &= 0xff;
 				tile -= 0x40;
 
-				if (tile < 0) tile = 0;
 				if (tile > 127) tile = 127;
 
 				for (y=0; y < 16; y++)
diff --git a/src/mame/video/artmagic.c b/src/mame/video/artmagic.c
index 976b098cdb8..c33a2840ff1 100644
--- a/src/mame/video/artmagic.c
+++ b/src/mame/video/artmagic.c
@@ -23,7 +23,7 @@ INLINE UINT16 *address_to_vram(artmagic_state *state, offs_t *address)
 {
 	offs_t original = *address;
 	*address = TOWORD(original & 0x001fffff);
-	if (original >= 0x00000000 && original < 0x001fffff)
+	if (original < 0x001fffff)
 		return state->m_vram0;
 	else if (original >= 0x00400000 && original < 0x005fffff)
 		return state->m_vram1;
diff --git a/src/mame/video/konamigx.c b/src/mame/video/konamigx.c
index 3867c05a275..e1ae67c70e8 100644
--- a/src/mame/video/konamigx.c
+++ b/src/mame/video/konamigx.c
@@ -174,7 +174,7 @@ INLINE void K053936GP_copyroz32clip( running_machine &machine,
 				cx += incxx;
 				cy += incxy;
 
-				if (offs<0 || offs>=src_size)
+				if (offs>=src_size)
 					continue;
 
 				if (srcx < src_minx || srcx > src_maxx || srcy < src_miny || srcy > src_maxy)
@@ -244,7 +244,7 @@ INLINE void K053936GP_copyroz32clip( running_machine &machine,
 				cx += incxx;
 				cy += incxy;
 
-				if (offs<0 || offs>=src_size)
+				if (offs>=src_size)
 					continue;
 
 				if (srcx < src_minx || srcx > src_maxx || srcy < src_miny || srcy > src_maxy)
diff --git a/src/mame/video/m90.c b/src/mame/video/m90.c
index 8066a8321dd..5d6c9686a14 100644
--- a/src/mame/video/m90.c
+++ b/src/mame/video/m90.c
@@ -278,7 +278,7 @@ static void markdirty(tilemap_t *tmap,int page,offs_t offset)
 {
 	offset -= page * 0x2000;
 
-	if (offset >= 0 && offset < 0x2000)
+	if (offset < 0x2000)
 		tmap->mark_tile_dirty(offset/2);
 }