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Project Support Forums => 64 Bit Assembler => Topic started by: GUAN DE DIO on June 15, 2010, 07:39:26 AM

Title: Float point in 64bit
Post by: GUAN DE DIO on June 15, 2010, 07:39:26 AM
Hi everybody,

     Working on GDI+ I need to make some floating operation to draw somethings.

     Currently I need to make the translation of Polar coordinate to Cartesian Coordinates.  In 32bits I used the FPU instruction, but in 64bit I don't know what is wrong in my code.

      I try to check it using IDA 5.2 Debugger and my surprise when the instructions :
    -  FINIT
    -  FLD1
     
       didn't  do anything, the ST0 register is always set to 0.0

    I miss something?

   I'm working with MASM64.

Thanks in advance,
GUAN
Title: Re: Float point in 64bit
Post by: qWord on June 15, 2010, 01:33:11 PM
Quote from: GUAN DE DIO on June 15, 2010, 07:39:26 AM
      I try to check it using IDA 5.2 Debugger and my surprise when the instructions :
    -  FINIT
    -  FLD1
     
       didn't  do anything, the ST0 register is always set to 0.0
mainly a problem by IDA.
Title: Re: Float point in 64bit
Post by: GUAN DE DIO on June 18, 2010, 06:45:53 AM

   I have used windbg and all is right now.

  But, is there another debugger for 64bits more frendly?

Thanks,
GUAN

Title: Re: Float point in 64bit
Post by: D.F. on August 03, 2010, 07:53:44 PM
Quote from: GUAN DE DIO on June 18, 2010, 06:45:53 AM
I have used windbg and all is right now.
But, is there another debugger for 64bits more frendly?
FDBG - fdbg for AMD64 is assembler level debugger for user-mode (ring3) binary applications, running in long mode (64-bit).
Title: Re: Float point in 64bit
Post by: GregL on August 03, 2010, 11:37:00 PM
Visual C++ 2008 or 2010 debugger, even the Express Edition debugs 64-bit (on 64-bit OS).