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Extract vector from pair of vectors.

Copy the indexed byte up to the last byte of the first source vector to the bottom of the result vector, then fill the remainder of the result starting from the first byte of the second source vector. The result is placed destructively in the first source vector. This instruction is unpredicated.

An index that is greater than or equal to the vector length in bytes is treated as zero, leaving the destination and first source vector unmodified.



EXT <Zdn>.B, <Zdn>.B, <Zm>.B, #<imm>

if !HaveSVE() then UNDEFINED;
integer esize = 8;
integer dst = UInt(Zdn);
integer s1 = dst;
integer s2 = UInt(Zm);
integer position = UInt(imm8h:imm8l);

Assembler Symbols


Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field.


Is the name of the second source scalable vector register, encoded in the "Zm" field.


Is the unsigned immediate operand, in the range 0 to 255, encoded in the "imm8h:imm8l" fields.


integer elements = VL DIV esize;
bits(VL) operand1 = Z[s1];
bits(VL) operand2 = Z[s2];
bits(VL) result;

if position >= elements then
    position = 0;

position = position << 3;
bits(VL*2) concat = operand2 : operand1;
result = concat<position+VL-1:position>;

Z[dst] = result;