39 lines
679 B
ArmAsm
39 lines
679 B
ArmAsm
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; mulsi3 for H8/300H - based on Renesas SH implementation
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; by Toshiyasu Morita
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;
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; Old code:
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;
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; 16b * 16b = 372 states (worst case)
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; 32b * 32b = 724 states (worst case)
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;
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; New code:
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;
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; 16b * 16b = 48 states
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; 16b * 32b = 72 states
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; 32b * 32b = 92 states
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;
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.global __mulsi3
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__mulsi3:
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mov.w r1,r2 ; ( 2 states) b * d
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mulxu r0,er2 ; (22 states)
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mov.w e0,r3 ; ( 2 states) a * d
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beq L_skip1 ; ( 4 states)
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mulxu r1,er3 ; (22 states)
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add.w r3,e2 ; ( 2 states)
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L_skip1:
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mov.w e1,r3 ; ( 2 states) c * b
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beq L_skip2 ; ( 4 states)
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mulxu r0,er3 ; (22 states)
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add.w r3,e2 ; ( 2 states)
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L_skip2:
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mov.l er2,er0 ; ( 2 states)
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rts ; (10 states)
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.end
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