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47 lines
839 B
ArmAsm
47 lines
839 B
ArmAsm
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#include <linux/linkage.h>
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/*
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* Multiply operation for 32 bit integers.
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* Input : Operand1 in Reg r5
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* Operand2 in Reg r6
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* Output: Result [op1 * op2] in Reg r3
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*/
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.text
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.globl __mulsi3
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.type __mulsi3, @function
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.ent __mulsi3
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__mulsi3:
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.frame r1, 0, r15
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add r3, r0, r0
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beqi r5, result_is_zero /* multiply by zero */
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beqi r6, result_is_zero /* multiply by zero */
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bgeid r5, r5_pos
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xor r4, r5, r6 /* get the sign of the result */
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rsubi r5, r5, 0 /* make r5 positive */
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r5_pos:
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bgei r6, r6_pos
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rsubi r6, r6, 0 /* make r6 positive */
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r6_pos:
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bri l1
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l2:
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add r5, r5, r5
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l1:
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srl r6, r6
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addc r7, r0, r0
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beqi r7, l2
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bneid r6, l2
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add r3, r3, r5
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blti r4, negateresult
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rtsd r15, 8
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nop
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negateresult:
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rtsd r15, 8
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rsub r3, r3, r0
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result_is_zero:
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rtsd r15, 8
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addi r3, r0, 0
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.size __mulsi3, . - __mulsi3
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.end __mulsi3
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