Fix obvious bugs found by GCC 7.1 (nw)

src/devices/bus/isa/hdc.cpp

@@ -884,7 +884,7 @@ uint8_t xt_hdc_device::data_r()
 			data_cnt = 0;
 		}
 		data = buffer[data_cnt++];
-		if(data_cnt >= ((sector_cnt[drv] * 512) ? (sector_cnt[drv] * 512) : (256 * 512)))
+		if(data_cnt >= ((sector_cnt[drv]!=0) ? (sector_cnt[drv] * 512) : (256 * 512)))
 		{
 			data_cnt = 0;
 			pc_hdc_result(1);

src/devices/cpu/dsp56k/dsp56pcu.cpp

@@ -148,7 +148,7 @@ void pcu_reset(dsp56k_core* cpustate)
 				/* P:$cfff -> Internal P:$07ff high byte */
 				uint8_t mem_value_low  = cpustate->program->read_byte(mem_offset);        /* TODO: IS THIS READING RIGHT? */
 				uint8_t mem_value_high = cpustate->program->read_byte(mem_offset);
-				cpustate->program_ram[i] = (mem_value_high << 8) || mem_value_low;
+				cpustate->program_ram[i] = (mem_value_high << 8) | mem_value_low;
 			}
 
 			/* HACK - Set the PC to 0x0000 as per the boot ROM. */

src/devices/cpu/spc700/spc700.cpp

@@ -1258,7 +1258,7 @@ void spc700_device::state_string_export(const device_state_entry &entry, std::st
 				(m_flag_b)               ? 'B':'.',
 				(m_flag_h & HFLAG_SET)   ? 'H':'.',
 				( m_flag_i)              ? 'I':'.',
-				((!m_flag_z) << 1)       ? 'Z':'.',
+				(((!m_flag_z) << 1) & 1) ? 'Z':'.',
 				((m_flag_c >> 8)&1)      ? 'C':'.'
 			);
 			break;

src/devices/machine/hdc92x4.cpp

@@ -2068,7 +2068,7 @@ void hdc92x4_device::format_track()
 			cont = WAIT;
 			break;
 		case TRACKDONE:
-			if (FORMAT_TRACK && TRACE_SUBSTATES) logerror("Track writing done\n");
+			if (TRACE_FORMAT && TRACE_SUBSTATES) logerror("Track writing done\n");
 			cont = SUCCESS;
 			break;
 		}

src/devices/machine/stvcd.cpp

@@ -2140,7 +2140,7 @@ void saturn_state::read_new_dir(uint32_t fileno)
 // makes the directory pointed to by FAD current
 void saturn_state::make_dir_current(uint32_t fad)
 {
-	int i;
+	uint32_t i;
 	uint32_t nextent, numentries;
 	std::vector<uint8_t> sect(MAX_DIR_SIZE);
 	direntryT *curentry;

src/devices/video/snes_ppu.cpp

@@ -419,7 +419,7 @@ void snes_ppu_device::device_reset()
 	{
 		elem.enable = 0;
 		elem.clip = 0;
-		memset(elem.buffer, 0, SNES_SCR_WIDTH);
+		memset(elem.buffer, 0, SNES_SCR_WIDTH * sizeof(uint16_t));
 		memset(elem.priority, 0, SNES_SCR_WIDTH);
 		memset(elem.layer, 0, SNES_SCR_WIDTH);
 		memset(elem.blend_exception, 0, SNES_SCR_WIDTH);

src/emu/render.h

@@ -1110,7 +1110,7 @@ public:
 	void set_max_texture_size(int maxwidth, int maxheight);
 	void set_transform_container(bool transform_container) { m_transform_container = transform_container; }
 	void set_keepaspect(bool keepaspect) { m_keepaspect = keepaspect; }
-	void set_scale_mode(bool scale_mode) { m_scale_mode = scale_mode; }
+	void set_scale_mode(int scale_mode) { m_scale_mode = scale_mode; }
 
 	// layer config getters
 	bool backdrops_enabled() const { return m_layerconfig.backdrops_enabled(); }

src/mame/machine/n64.cpp

@@ -2720,7 +2720,7 @@ void n64_state::n64_machine_stop()
 	device_image_interface *image = dynamic_cast<device_image_interface *>(periphs->m_nvram_image);
 
 	uint8_t data[0x30800];
-	if (m_sram != nullptr)
+	if (m_sram == nullptr)
 	{
 		memset(data, 0, 0x20000);
 	}

src/mame/video/decodmd1.cpp

@@ -252,7 +252,7 @@ void decodmd_type1_device::device_reset()
 	m_rom = memregion(m_gfxtag);
 
 	memset(RAM,0,0x2000);
-	memset(m_pixels,0,0x200);
+	memset(m_pixels,0,0x200*sizeof(uint32_t));
 
 	ROM = m_rom->base();
 	m_rombank1->configure_entries(0, 8, &ROM[0x0000], 0x4000);

src/mame/video/pc4.cpp

@@ -144,7 +144,7 @@ WRITE8_MEMBER(pc4_state::lcd_control_w)
 
 READ8_MEMBER(pc4_state::lcd_control_r)
 {
-	return m_busy_flag<<7 || m_ac&0x7f;
+	return (m_busy_flag<<7) | (m_ac & 0x7f);
 }
 
 void pc4_state::update_ac(void)