| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | #include <linux/linkage.h> |
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| 3 | |
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| 4 | /* |
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| 5 | * Multiply operation for 32 bit integers. |
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| 6 | * Input : Operand1 in Reg r5 |
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| 7 | * Operand2 in Reg r6 |
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| 8 | * Output: Result [op1 * op2] in Reg r3 |
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| 9 | */ |
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| 10 | .text |
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| 11 | .globl __mulsi3 |
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| 12 | .type __mulsi3, @function |
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| 13 | .ent __mulsi3 |
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| 14 | |
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| 15 | __mulsi3: |
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| 16 | .frame r1, 0, r15 |
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| 17 | add r3, r0, r0 |
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| 18 | beqi r5, result_is_zero /* multiply by zero */ |
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| 19 | beqi r6, result_is_zero /* multiply by zero */ |
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| 20 | bgeid r5, r5_pos |
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| 21 | xor r4, r5, r6 /* get the sign of the result */ |
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| 22 | rsubi r5, r5, 0 /* make r5 positive */ |
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| 23 | r5_pos: |
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| 24 | bgei r6, r6_pos |
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| 25 | rsubi r6, r6, 0 /* make r6 positive */ |
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| 26 | r6_pos: |
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| 27 | bri l1 |
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| 28 | l2: |
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| 29 | add r5, r5, r5 |
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| 30 | l1: |
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| 31 | srl r6, r6 |
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| 32 | addc r7, r0, r0 |
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| 33 | beqi r7, l2 |
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| 34 | bneid r6, l2 |
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| 35 | add r3, r3, r5 |
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| 36 | blti r4, negateresult |
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| 37 | rtsd r15, 8 |
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| 38 | nop |
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| 39 | negateresult: |
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| 40 | rtsd r15, 8 |
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| 41 | rsub r3, r3, r0 |
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| 42 | result_is_zero: |
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| 43 | rtsd r15, 8 |
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| 44 | addi r3, r0, 0 |
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| 45 | |
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| 46 | .size __mulsi3, . - __mulsi3 |
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| 47 | .end __mulsi3 |
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| 48 | |
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