Want me to compile it on the imagecraft compiler so you have a 2nd listing to look at?
-----Original Message-----
From: David VanHorn <microbrix@gmail.com>
To: AVR-Chat@yahoogroups.com
Sent: Wed, 11 Mar 2009 10:28 am
Subject: [AVR-Chat] GCC on M32, WIERD happenings.
I've asked about this over on the AVR-GCC list, but I thought it
wouldn't hurt to ask here too.
What's happening is that the compiled code isn't producing sane ASM.
This happens intermittently, and I haven't been able to pin down what
the dependency is. It appears that if I change the C code enough, it
will go away for a while. If I recompile a given file, I always get
the same result.
I have the .S file, but I don't know how to interpret it.
I carved up the problem 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!
Data_Divisor is a constant, = 16.
I am getting "9" in Bin, even when A is zero.
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: 884
8 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
--
"The very powerful and the very stupid have one thing in common. Instead of
altering their views to fit the facts, they alter the facts to fit their
views... which can be very uncomfortable if you happen to be one of the
facts that needs altering." Doctor Who, Face of Evil
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[Non-text portions of this message have been removed]Message
Re: [AVR-Chat] GCC on M32, WIERD happenings.
2009-03-12 by BobGardner@aol.com