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sy2002 / QNICE-FPGA

QNICE-FPGA is a 16-bit computer system for recreational programming built as a fully-fledged System-on-a-Chip in portable VHDL.
http://qnice-fpga.com
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Assembler listing output contains ghost instructions #163

Closed bernd-ulmann closed 3 years ago

bernd-ulmann commented 3 years ago

The listing produced by the assembler contains "ghost" instructions. The cpu_test program shows this problem. This is the source:

            ABRA    E_MOVE_IMM_34, !1       ; Verify "absolute branch never" is not taken.
            ABRA    L_MOVE_IMM_34, 1        ; Verify "absolute branch always" is taken.
            HALT

E_MOVE_IMM_34 HALT L_MOVE_IMM_34

...while this is the resulting listing file:

000001 0000 FF88 0005 ABRA E_MOVE_IMM_34, !1 ; Verify "absolute branch never" is not taken. 000002 0002 FF80 0006 ABRA L_MOVE_IMM_34, 1 ; Verify "absolute branch always" is taken. 000003 0004 E000 HALT 000004 0005 E000 E_MOVE_IMM_34 HALT 000005 0006 L_MOVE_IMM_34 HALT

EQU-list:

Label-list:

E_MOVE_IMM_34 : 0x0005 L_MOVE_IMM_34 : 0x0006

Note the spurious HALT instruction in line 000005...

bernd-ulmann commented 3 years ago

Fixed it.

A quick remark from my side: The assembler has somehow ;-} turned from a little tool into a rather ugly program. We should think about rewriting or at least fundamentally refactoring it in the future. :-)

sy2002 commented 3 years ago

@bernd-ulmann Thank you for finding and fixing this one. I assume this issue can be closed and closed it.