360 Assembly include

From Rosetta Code


An 'include' file to format a floating-point value. <lang 360asm>FORMATF CNOP 0,4 ***WRITE Y,X FORMAT(F13.n)**********

  • (F0,R0)->R1
        STM    R14,R12,@FMTF0F    Store registers

LR R1,R0 R0=decimals

        STH    R1,@FMTFNC         Number of decimals N
        SLA    R1,2               R1=N*4
        ME     F0,@FMTFCO(R1)     F0=F0*10**N
        STE    F0,@FMTFWF         WF=X*10**N
        MVI    @FMTFTS,X'00'      Initialize the sign field
        L      R9,@FMTFWF         Load the floating-point value
        CH     R9,=H'0'           and examine the sign bit.
        BZ     @FMTFDN            The value is zero, nothing to do.
        BNL    @FMTFNN            Is the value negative?
        MVI    @FMTFTS,X'80'      Yes, it is negative.
        N      R9,=X'7FFFFFFF'    Zero out the sign bit.

@FMTFNN LR R8,R9 Copy the value into R8

        N      R8,=X'00FFFFFF'    Examine the fraction.  Is it 0?
        BNZ    @FMTFNZ            No, keep on working
        SR     R9,R9              Yes, the value is zero.  So set
        B      @FMTFDN            the result as 0 and exit.

@FMTFNZ LR R8,R9 Copy the value into R8

        N      R8,=X'FF000000'    Isolate the characteristic field
        SRL    R8,24              Shift to least significant byte
        CH     R8,=H'64'          Is exponent big enough? 16**0
        BH     @FMTFO1            Yes, number is not < 1.
        SR     R9,R9              No, set result to zero
        B      @FMTFDN            and be done with it.

@FMTFO1 CH R8,=H'72' Is the exponent too big? 2**32

        BH     @FMTFOV            overflow (72-64=8 16**8=2**32)
        SR     R8,R8              Set R8 to zero
        SLDL   R8,8               Shift two high-order digits into R8
        CH     R8,=H'72'          Is the exponent an 8?
        BL     @FMTFDI            Yes, we can continue
        CH     R9,=H'0'           Is the sign bit set?
        BNP    @FMTFOV            overflow, the high-order bit is 1

@FMTFDI SH R8,=H'72' Produce (Characteristic - 72)

        LCR    R8,R8              Produce (72 - Characteristic)
        SLL    R8,2               Multiply by 4
        SRL    R9,0(R8)           Shift R9 by the amount in R8

@FMTFSV SR R8,R8 Set R8 to 0.

        IC     R8,@FMTFTS         Load the sign value
        CH     R8,=H'0'           Is the sign bit set?
        BZ     @FMTFDN            No, we are OK
        LCR    R9,R9              Negate the absolute value


        B      @FMTFRT 


        CVD    R9,@FMTFPA         to fixed(15)
        MVC    @FMTFMA,@FMTFMO
        LA     R1,@FMTFMA+10
        SH     R1,@FMTFNC
        MVI    0(R1),X'21'        10-N
        MVC    @FMTFDE,@FMTFMA
        EDMK   @FMTFDE,@FMTFPA+2  fixed(11,N)-> pic' (10-N)#(N+1)9S'
        BCTR   R1,0
        MVC    0(1,R1),@FMTFDE+12
        LA     R1,12              12-N
        SH     R1,@FMTFNC
        EX     R1,@FMTFM1         MVC @FMTFDF(0),@FMTFDE on 13-N
        LA     R2,@FMTFDF+12
        SH     R2,@FMTFNC
        MVI    0(R2),C'.'
        LA     R3,@FMTFDE+12
        SH     R3,@FMTFNC         R3=@(@FMTFDE)+12-@FMTFNC
        LA     R2,1(R2)           R2=@ after the point in @FMTFDF
        LH     R1,@FMTFNC
        BCTR   R1,0
        EX     R1,@FMTFM2         MVC 0(0,R2),0(R3) on @FMTFNC
        B      @FMTFRT

@FMTFM1 MVC @FMTFDF(0),@FMTFDE len=13-N @FMTFM2 MVC 0(0,R2),0(R3) len=N @FMTFRT LM R14,R12,@FMTF0F LA R1,@FMTFDF

        BR     R14


        DC     E'1E1'             10
        DC     E'1E2'             100
        DC     E'1E3'             1000
        DC     E'1E4'             10000
        DC     E'1E5'             100000
        DC     E'1E6'             1000000
        DC     E'1E7'             10000000
        DC     E'1E8'             100000000
        DC     E'1E9'             1000000000

@FMTFWF DS F @FMTFBI DS F dcl 32-bit fixed integer @FMTFTS DS X @FMTFMO DC X'40',11X'20',X'60' CL13 @FMTFMA DS CL13 @FMTFDE DS CL13 pic'B###99999999S' @FMTFDF DS CL13 pic'S###9V.9999999' @FMTFPA DS PL8 dec fixed(15) @FMTF0F DS 15F save regs

  • END FORMATF ------------------------------------</lang>