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Bit shift operations:
arithmetic |
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000000 |
00000 |
01001 |
01010 |
00011 |
000011 |
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R-type |
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b31-26 |
b25-21 |
b20-16 |
b15-11 |
b10-6 |
b5-0 |
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opcode |
$rs |
$rt |
$rd |
shamt |
function |
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arithmetic shift: sign
bit shifted in |
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# bits |
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sra $rd, $rt, shift_amt |
# R[d] <-- R[t]
>> shift_amt |
const |
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srav $rd, $rt, $rs |
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# R[d] <-- R[t]
>> R[s] |
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var |
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0110 |
0000 |
0000 |
0000 |
0000 |
0000 |
0000 |
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0011 |
0000 |
0000 |
0000 |
0000 |
0000 |
0000 |
0010 |
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1110 |
0000 |
0000 |
0000 |
0000 |
0000 |
0000 |
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1111 |
0000 |
0000 |
0000 |
0000 |
0000 |
0000 |
0010 |
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bits of $rt are shifted
to the right by the number of bits given in shift_amt |
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or by value in register
$rs |
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sign bit (arithmetic) is
shifted into most significant bit |
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if shift_amt, $rs is unused |
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why isn't there a sla or
slav? |
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