emu_nes

commit 1f6e3b054cd7a35c5eb8d908525a261ea83d44e7
parent 745496ccd1a4483cc0955ec0c34acd800991cff3
Author: vin <git@vineetk.net>
Date:   Sun, 16 Jun 2024 17:11:51 +0530

replace bit comparisons with 0 from greater than to not equal

They're both the same and the compiler might have already optimized it
away. It also conveys the message better in my opinion.

Diffstat:
M
cpu.c
 | 
26
+++++++++++++-------------

1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/cpu.c b/cpu.c
@@ -8,7 +8,7 @@
 #define STATUS_UPDATE_ZERO(r)		\
 	(regs.status.zero = r == 0)
 #define STATUS_UPDATE_NEGATIVE(r)	\
-	(regs.status.negative = ((r & (1 << 7)) > 0))
+	(regs.status.negative = ((r & (1 << 7)) != 0))
 
 #define MEMORY_MIRROR(addr)	\
 	if (addr < 0x2000)	\
@@ -197,7 +197,7 @@ adc(uint8_t arg)
 
 	regs.status.carry = sum > 0xFF;
 	/* overflow flag formula: https://stackoverflow.com/a/29224684 */
-	regs.status.overflow = (~(regs.a ^ arg) & (regs.a ^ sum) & 0x80) > 0;
+	regs.status.overflow = (~(regs.a ^ arg) & (regs.a ^ sum) & 0x80) != 0;
 	STATUS_UPDATE_ZERO(regs.a);
 	STATUS_UPDATE_NEGATIVE(regs.a);
 }
@@ -262,7 +262,7 @@ static void
 bit(uint8_t arg)
 {
 	regs.status.zero = (regs.a & arg) == 0;
-	regs.status.overflow = (arg & (1 << 6)) > 0;
+	regs.status.overflow = (arg & (1 << 6)) != 0;
 	STATUS_UPDATE_NEGATIVE(arg);
 }
 
@@ -557,21 +557,21 @@ plp(void)
 
 	status = PULL();
 
-	regs.status.carry = (status & (1 << 7)) > 0;
-	regs.status.zero = (status & (1 << 6)) > 0;
-	regs.status.interrupt_disable = (status & (1 << 5)) > 0;
-	regs.status.decimal_mode = (status & (1 << 4)) > 0;
-	regs.status.brk = (status & (1 << 3)) > 0;
-	regs.status.unused = (status & (1 << 2)) > 0;
-	regs.status.overflow = (status & (1 << 1)) > 0;
-	regs.status.negative = (status & 1) > 0;
+	regs.status.carry = (status & (1 << 7)) != 0;
+	regs.status.zero = (status & (1 << 6)) != 0;
+	regs.status.interrupt_disable = (status & (1 << 5)) != 0;
+	regs.status.decimal_mode = (status & (1 << 4)) != 0;
+	regs.status.brk = (status & (1 << 3)) != 0;
+	regs.status.unused = (status & (1 << 2)) != 0;
+	regs.status.overflow = (status & (1 << 1)) != 0;
+	regs.status.negative = (status & 1) != 0;
 }
 
 static void
 rol_acc(void)
 {
 	uint8_t carry;
-	carry = (regs.a & (1 << 7)) > 0;
+	carry = (regs.a & (1 << 7)) != 0;
 
 	regs.a <<= 1;
 	regs.a |= regs.status.carry;
@@ -585,7 +585,7 @@ static void
 rol(uint16_t mem)
 {
 	uint8_t carry, tmp;
-	carry = (peek(mem) & (1 << 7)) > 0;
+	carry = (peek(mem) & (1 << 7)) != 0;
 
 	tmp = (peek(mem) << 1) | regs.status.carry;
 	memwrite(mem, tmp);