Re: [avr-gcc-list] Re: Wierd Calls.

[David VanHorn]

 

Well.. Still flogging the horse here.

 

 

 

I have the .S file, but I don't know how to interpret it.

 

I carved up the statement even further, and moved the declarations so all the vars are in ram so I can watch them easily.

 

 A = Raw_Data[0][Raw_Data_Index];         //  Gives the expected result.
 Bin = (A / Data_Divisor);                         // Gives nonsense, AND trashes data in ram!

 

Here's the asm output.  The first line is what I'd expect.

 

1072:      A = Raw_Data[0][Raw_Data_Index];         // Get the old data
+00000337:   91C00076    LDS       R28,0x0076     Load direct from data space
+00000339:   91D00077    LDS       R29,0x0077     Load direct from data space

The second one starts out normally, but then this call to 0x622, which is hosing everything.

 

1073:      Bin = (A / Data_Divisor);          // Find the bin for the old raw data
+0000033B:   01FE        MOVW      R30,R28        Copy register pair
+0000033C:   5FE2        SUBI      R30,0xF2       Subtract immediate
+0000033D:   4FFE        SBCI      R31,0xFE       Subtract immediate with carry
+0000033E:   8180        LDD       R24,Z+0        Load indirect with displacement
+0000033F:   E090        LDI       R25,0x00       Load immediate
+00000340:   E06F        LDI       R22,0x0F       Load immediate
+00000341:   E070        LDI       R23,0x00       Load immediate
+00000342:   940E0622    CALL      0x00000622     Call subroutine
+00000344:   01DB        MOVW      R26,R22        Copy register pair

 

Here's where it calls to, +00000622 below.  Interestingly, the code just walks right off the end if you get past the RET in 650, it does a few things, then wanders off into space.

 

 

607:          lcd_command(dispAttr);                  /* display/cursor control       */
+0000061D:   2F81        MOV       R24,R17        Copy register
+0000061E:   940E057F    CALL      0x0000057F     Call subroutine
609:      }/* lcd_init */
+00000620:   911F        POP       R17            Pop register from stack
+00000621:   9508        RET                      Subroutine return
609:      }/* lcd_init */
+00000622:   1BAA        SUB       R26,R26        Subtract without carry
+00000623:   1BBB        SUB       R27,R27        Subtract without carry
+00000624:   E151        LDI       R21,0x11       Load immediate
+00000625:   C007        RJMP      PC+0x0008      Relative jump
+00000626:   1FAA        ROL       R26            Rotate Left Through Carry
+00000627:   1FBB        ROL       R27            Rotate Left Through Carry
+00000628:   17A6        CP        R26,R22        Compare
+00000629:   07B7        CPC       R27,R23        Compare with carry
+0000062A:   F010        BRCS      PC+0x03        Branch if carry set
+0000062B:   1BA6        SUB       R26,R22        Subtract without carry
+0000062C:   0BB7        SBC       R27,R23        Subtract with carry
+0000062D:   1F88        ROL       R24            Rotate Left Through Carry
+0000062E:   1F99        ROL       R25            Rotate Left Through Carry
+0000062F:   955A        DEC       R21            Decrement
+00000630:   F7A9        BRNE      PC-0x0A        Branch if not equal
+00000631:   9580        COM       R24            One's complement
+00000632:   9590        COM       R25            One's complement
+00000633:   01BC        MOVW      R22,R24        Copy register pair
+00000634:   01CD        MOVW      R24,R26        Copy register pair
+00000635:   9508        RET                      Subroutine return
+00000636:   882A        LDD       R2,Y+18        Load indirect with displacement
+00000637:   8839        LDD       R3,Y+17        Load indirect with displacement
+00000638:   8848        LDD       R4,Y+16        Load indirect with displacement
+00000639:   845F        LDD       R5,Y+15        Load indirect with displacement
+0000063A:   846E        LDD       R6,Y+14        Load indirect with displacement
+0000063B:   847D        LDD       R7,Y+13        Load indirect with displacement
+0000063C:   848C        LDD       R8,Y+12        Load indirect with displacement
+0000063D:   849B        LDD       R9,Y+11        Load indirect with displacement
+0000063E:   84AA        LDD       R10,Y+10       Load indirect with displacement
+0000063F:   84B9        LDD       R11,Y+9        Load indirect with displacement
+00000640:   84C8        LDD       R12,Y+8        Load indirect with displacement
+00000641:   80DF        LDD       R13,Y+7        Load indirect with displacement
+00000642:   80EE        LDD       R14,Y+6        Load indirect with displacement
+00000643:   80FD        LDD       R15,Y+5        Load indirect with displacement
+00000644:   810C        LDD       R16,Y+4        Load indirect with displacement
+00000645:   811B        LDD       R17,Y+3        Load indirect with displacement
+00000646:   81AA        LDD       R26,Y+2        Load indirect with displacement
+00000647:   81B9        LDD       R27,Y+1        Load indirect with displacement
+00000648:   0FCE        ADD       R28,R30        Add without carry
+00000649:   1DD1        ADC       R29,R1         Add with carry
+0000064A:   B60F        IN        R0,0x3F        In from I/O location
+0000064B:   94F8        CLI                      Global Interrupt Disable
+0000064C:   BFDE        OUT       0x3E,R29       Out to I/O location
+0000064D:   BE0F        OUT       0x3F,R0        Out to I/O location
+0000064E:   BFCD        OUT       0x3D,R28       Out to I/O location
+0000064F:   01ED        MOVW      R28,R26        Copy register pair
+00000650:   9508        RET                      Subroutine return
+00000651:   94F8        CLI                      Global Interrupt Disable
+00000652:   CFFF        RJMP      PC-0x0000      Relative jump
+00000653:   614D        ORI       R20,0x1D       Logical OR with immediate
+00000654:   2D67        MOV       R22,R7         Copy register
+00000655:   6553        ORI       R21,0x53       Logical OR with immediate
+00000656:   736E        ANDI      R22,0x3E       Logical AND with immediate
+00000657:   726F        ANDI      R22,0x2F       Logical AND with immediate
+00000658:   3020        CPI       R18,0x00       Compare with immediate
+00000659:   302E        CPI       R18,0x0E       Compare with immediate
+0000065A:   2031        AND       R3,R1          Logical AND
+0000065B:   6400        ORI       R16,0x40       Logical OR with immediate
+0000065C:   8000        LDD       R0,Z+0         Load indirect with displacement
+0000065D:   0064        ???                      Data or unknown opcode
+0000065E:   FFFF        ???                      Data or unknown opcode
+0000065F:   FFFF        ???                      Data or unknown opcode
+00000660:   FFFF        ???                      Data or unknown opcode
+00000661:   FFFF        ???                      Data or unknown opcode
+00000662:   FFFF        ???                      Data or unknown opcode
+00000663:   FFFF        ???                      Data or unknown opcode
+00000664:   FFFF        ???                      Data or unknown opcode
+00000665:   FFFF        ???                      Data or unknown opcode
+00000666:   FFFF        ???                      Data or unknown opcode
+00000667:   FFFF        ???                      Data or unknown opcode