Instruction: Get a value, or its additive inverse, based on C.

NEGC RValue, < # > Value

Result: Value or –Value is stored in RValue.

RValue (d-field) is the register in which to write Value or –Value.
Value (s-field) is a register or a 9-bit literal whose value (if C = 0) or additive inverse value (if C = 1) will be written to RValue.

Opcode Table:

–INSTR– ZCRI –CON– –DEST– –SRC–	Z Result	C Result	Result	Clocks
101100 001i 1111 ddddddddd sssssssss	Result = 0	S[31]	Written	4

Concise Truth Table:

In					Out
Destination	Source	Z	C	Effects	Destination	Z	C
$----_----; -	$FFFF_FFFF; -1	-	0	wz wc	$FFFF_FFFF; -1	0	1
$----_----; -	$FFFF_FFFF; -1	-	1	wz wc	$0000_0001; 1	0	1
$----_----; -	$0000_0000; 0	-	x	wz wc	$0000_0000; 0	1	0
$----_----; -	$0000_0001; 1	-	0	wz wc	$0000_0001; 1	0	0
$----_----; -	$0000_0001; 1	-	1	wz wc	$FFFF_FFFF; -1	0	0
$----_----; -	$7FFF_FFFF; 2,147,483,647	-	0	wz wc	$7FFF_FFFF; 2,147,483,647	0	0
$----_----; -	$7FFF_FFFF; 2,147,483,647	-	1	wz wc	$8000_0001; -2,147,483,647	0	0
$----_----; -	$8000_0000; -2,147,483,648	-	x	wz wc	$8000_0000; -2,147,483,648¹	0	1
$----_----; -	$8000_0001; -2,147,483,647	-	0	wz wc	$8000_0001; -2,147,483,647	0	1
$----_----; -	$8000_0001; -2,147,483,647	-	1	wz wc	$7FFF_FFFF; 2,147,483,647	0	1

¹ The smallest negative number (-2,147,483,648) has no corresponding positive value in 32-bit two's-complement math.

Explanation

NEGC stores Value (if C = 0) or –Value (if C = 1) into RValue.

If the WZ effect is specified, the Z flag is set (1) if Value is zero. If the WC effect is specified, the C flag is set (1) if Value is negative or cleared (0) if Value is positive. The result is written to RValue unless the NR effect is specified.