cmp1.c

volatile long int a = 123;
volatile long int b = 456;
char foo;

int main() {
  foo = a < b;
}

cmp1.dump

00000028 <main>:
  28:	cf 93       	push	r28
  2a:	df 93       	push	r29
  2c:	cd b7       	in	r28, 0x3d	; 61
  2e:	de b7       	in	r29, 0x3e	; 62
  30:	20 91 60 00 	lds	r18, 0x0060
  34:	30 91 61 00 	lds	r19, 0x0061
  38:	40 91 62 00 	lds	r20, 0x0062
  3c:	50 91 63 00 	lds	r21, 0x0063
  40:	80 91 64 00 	lds	r24, 0x0064
  44:	90 91 65 00 	lds	r25, 0x0065
  48:	a0 91 66 00 	lds	r26, 0x0066
  4c:	b0 91 67 00 	lds	r27, 0x0067
  50:	61 e0       	ldi	r22, 0x01	; 1
  52:	28 17       	cp	r18, r24
  54:	39 07       	cpc	r19, r25
  56:	4a 07       	cpc	r20, r26
  58:	5b 07       	cpc	r21, r27
  5a:	0c f0       	brlt	.+2      	; 0x5e <__SREG__+0x1f>
  5c:	60 e0       	ldi	r22, 0x00	; 0
  5e:	86 2f       	mov	r24, r22
  60:	80 93 68 00 	sts	0x0068, r24
  64:	df 91       	pop	r29
  66:	cf 91       	pop	r28
  68:	08 95       	ret

cmp2.c

volatile char a_hrs = 1;
volatile char a_mins = 2;
volatile char a_secs = 3;
volatile char b_hrs = 4;
volatile char b_mins = 5;
volatile char b_secs = 6;
char foo;

int main() {
  foo = (a_hrs < b_hrs) || (a_hrs == b_hrs && a_mins < b_mins) || (a_hrs == b_hrs && a_mins == b_mins && a_secs < b_secs);
}

cmp2.dump

00000028 <main>:
  28:	cf 93       	push	r28
  2a:	df 93       	push	r29
  2c:	cd b7       	in	r28, 0x3d	; 61
  2e:	de b7       	in	r29, 0x3e	; 62
  30:	90 91 60 00 	lds	r25, 0x0060
  34:	80 91 63 00 	lds	r24, 0x0063
  38:	98 17       	cp	r25, r24
  3a:	f4 f0       	brlt	.+60     	; 0x78 <__SREG__+0x39>
  3c:	90 91 60 00 	lds	r25, 0x0060
  40:	80 91 63 00 	lds	r24, 0x0063
  44:	98 17       	cp	r25, r24
  46:	31 f4       	brne	.+12     	; 0x54 <__SREG__+0x15>
  48:	90 91 61 00 	lds	r25, 0x0061
  4c:	80 91 64 00 	lds	r24, 0x0064
  50:	98 17       	cp	r25, r24
  52:	94 f0       	brlt	.+36     	; 0x78 <__SREG__+0x39>
  54:	90 91 60 00 	lds	r25, 0x0060
  58:	80 91 63 00 	lds	r24, 0x0063
  5c:	98 17       	cp	r25, r24
  5e:	79 f4       	brne	.+30     	; 0x7e <__SREG__+0x3f>
  60:	90 91 61 00 	lds	r25, 0x0061
  64:	80 91 64 00 	lds	r24, 0x0064
  68:	98 17       	cp	r25, r24
  6a:	49 f4       	brne	.+18     	; 0x7e <__SREG__+0x3f>
  6c:	90 91 62 00 	lds	r25, 0x0062
  70:	80 91 65 00 	lds	r24, 0x0065
  74:	98 17       	cp	r25, r24
  76:	1c f4       	brge	.+6      	; 0x7e <__SREG__+0x3f>
  78:	81 e0       	ldi	r24, 0x01	; 1
  7a:	90 e0       	ldi	r25, 0x00	; 0
  7c:	02 c0       	rjmp	.+4      	; 0x82 <__SREG__+0x43>
  7e:	80 e0       	ldi	r24, 0x00	; 0
  80:	90 e0       	ldi	r25, 0x00	; 0
  82:	80 93 66 00 	sts	0x0066, r24
  86:	df 91       	pop	r29
  88:	cf 91       	pop	r28
  8a:	08 95       	ret