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47 lines
1.6 KiB
47 lines
1.6 KiB
// convert a 32 bit integer into 32 bit float
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.globl ..__itof
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// build code table
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.pdata
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.ualong ..__itof,__itof.e,0,0,__itof.b
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// define the function
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.text
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..__itof:
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.function ..__itof
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__itof.b:
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xoris r3,r3,0x8000 // invert the sign bit
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addis r4,r0,0x4330 // make a 2 to 52 exponent for the double
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stw r3,-8(sp) // store the int into the last four bytes of the
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// double
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stw r4,-4(sp) // store the 2 to 52 exponent part for the double
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lfd f1,-8(sp) // load double format into f1
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addis r3,r0,0x5980 // load float format of number 2 to 52
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ori r3,r3,4 // with inverted sign bit too
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stw r3,-8(sp)
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lfs f0,-8(sp) // load float format into f0
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fsub f1,f1,f0 // substract f0 from f1, if r3 is negative,
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// the result will be negative here
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frsp f1,f1 // convert f1 to single precision
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blr
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__itof.e:
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.debug$S
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.ualong 1
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.uashort 15
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.uashort 0x9 # S_OBJNAME
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.ualong 0
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.byte 8, "itof.obj"
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.uashort 24
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.uashort 0x1 # S_COMPILE
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.byte 0x42 # Target processor = PPC 604
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.byte 3 # Language = ASM
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.byte 0
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.byte 0
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.byte 17, "PowerPC Assembler"
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