UMAX (immediate)
Unsigned maximum (immediate)
This instruction determines the unsigned maximum of the source
register value and immediate, and writes the result to the destination
register.
If PSTATE.DIT is 1:
The execution time of this instruction is independent of:
The values of the data supplied in any of its registers.
The values of the NZCV flags.
The response of this instruction to asynchronous exceptions does not vary based on:
The values of the data supplied in any of its registers.
The values of the NZCV flags.
0
0
1
0
0
0
1
1
1
0
0
0
1
0
UMAX <Wd>, <Wn>, #<uimm>
1
UMAX <Xd>, <Xn>, #<uimm>
if !IsFeatureImplemented(FEAT_CSSC) then UNDEFINED;
constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer datasize = 32 << UInt(sf);
constant integer imm = UInt(imm8);
<Wd>
Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field.
<Wn>
Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field.
<uimm>
Is an unsigned immediate, in the range 0 to 255, encoded in the "imm8" field.
<Xd>
Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.
<Xn>
Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field.
constant bits(datasize) operand1 = X[n, datasize];
constant integer result = Max(UInt(operand1), imm);
X[d, datasize] = result<datasize-1:0>;