Index

UMSUBL

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.

This instruction is used by the alias UMNEGL.

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 0 0 1 1 0 1 1 1 0 1 Rm 1 Ra Rn Rd
U o0

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

integer d = UInt(Rd);
integer n = UInt(Rn);
integer m = UInt(Rm);
integer a = UInt(Ra);

Assembler Symbols

<Xd>

Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.
<Wn>

Is the 32-bit name of the first general-purpose source register holding the multiplicand, encoded in the "Rn" field.
<Wm>

Is the 32-bit name of the second general-purpose source register holding the multiplier, encoded in the "Rm" field.
<Xa>

Is the 64-bit name of the third general-purpose source register holding the minuend, encoded in the "Ra" field.

Alias Conditions

Alias Is preferred when
UMNEGL Ra == '11111'

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>;

Operational information

If PSTATE.DIT is 1: