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Unsigned Multiply-Subtract Long

UMSUBL <Xd>, <Wn>, <Wm>, <Xa>

Calculates (Xa - (Wn * Wm)) (Unsigned 64-bit).

Pseudocode Operation

Xd ← Xa - (Wn × Wm)

Example

UMSUBL x0, w1, w2, x5

Encoding

Binary Layout

1

31

00

30:29

11011

28:24

1

23

01

22:21

Rm

20:16

1

15

Ra

14:10

Rn

9:5

Rd

4:0

 

Format Data Processing

Opcode 0x9BA08000

Extension Base

Operands

• Xd
  Destination 64-bit integer register
• Wn
  First source / base 32-bit integer register
• Wm
  Second source / offset 32-bit integer register
• Xa
  Minuend

Related

More in Base

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0x9BA08000	UMSUBL <Xd>, <Wn>, <Wm>, <Xa>		A64		1 | 00 | 11011 | 1 | 01 | Rm | 1 | Ra | Rn | Rd

Description

Unsigned Multiply-Subtract Long multiplies two 32-bit register values, subtracts the product from a 64-bit register value, and writes the result to the 64-bit destination register.

Operation

bits(32) operand1 = X[n, 32];
bits(32) operand2 = X[m, 32];
bits(64) operand3 = X[a, 64];

integer result;

result = Int(operand3, TRUE) - (Int(operand1, TRUE) * Int(operand2, TRUE));
X[d, 64] = result<63:0>;