compiled with snapshot ppc386 go32v2 ver 1.1 [2000/12/16] asm source and comments see below

CONST
    c1=$80000000;
    c2=$80000001;
    c3=$80000002;
    c4=$80000003;
    cm=$80000007;
VAR v:dword;
BEGIN
  v:=c2;
  CASE (v AND cm) OF
    c1,c2:writeln('case c1,c2');
    c3,c4:writeln('case c3,c4');
    ELSE writeln('case failed, but it should not');
  END;
END.

{
.file "bug1222.pas"

.text
.balign 16
# [bug1222.pas]
# [13] BEGIN
.globl _main
_main:
.globl PASCALMAIN
PASCALMAIN:
.globl program_init
program_init:
pushl %ebp
movl %esp,%ebp
subl $4,%esp
call FPC_INITIALIZEUNITS
# [14] v:=c2;
movl $-2147483647,_V
# [15] CASE (v AND cm) OF

  movl  _V,%eax               EAX := 80000001
  xorl  %edx,%edx             EDX := 00000000
  andl  .L13,%eax             EAX := 80000001  .L13   = 80000007
  andl  .L13+4,%edx           EDX := 00000000  .L13+4 = 00000000
  cmpl  $-1,%edx              00000000 - (-1) = -1   EDX is always 0 in

that case
jl .L12 jumps to .L12 { that shouldn't be } jg .L14
cmpl $-2147483648,%eax
jb .L12
.L14:
cmpl $-1,%edx
jl .L3
jg .L15
cmpl $-2147483647,%eax
jbe .L3
.L15:
cmpl $-1,%edx
jl .L6
jg .L16
cmpl $-2147483645,%eax
jbe .L6
.L16:
jmp .L12
.L6:
.L17:
# [17] c3,c4:writeln('case c3,c4');
leal U_SYSTEM_OUTPUT,%edi
movl %edi,-4(%ebp)
pushl $.L20
pushl -4(%ebp)
pushl $0
call FPC_WRITE_TEXT_SHORTSTR
pushl -4(%ebp)
call FPC_WRITELN_END
pushl $.L17
call FPC_IOCHECK
jmp .L11
.L3:
.L21:
# [16] c1,c2:writeln('case c1,c2');
leal U_SYSTEM_OUTPUT,%edi
movl %edi,-4(%ebp)
pushl $.L24
pushl -4(%ebp)
pushl $0
call FPC_WRITE_TEXT_SHORTSTR
pushl -4(%ebp)
call FPC_WRITELN_END
pushl $.L21
call FPC_IOCHECK
jmp .L11
.L12:
.L25:
# [18] ELSE writeln('case failed, but it should not'); leal U_SYSTEM_OUTPUT,%edi
movl %edi,-4(%ebp)
pushl $.L28
pushl -4(%ebp)
pushl $0
call FPC_WRITE_TEXT_SHORTSTR
pushl -4(%ebp)
call FPC_WRITELN_END
pushl $.L25
call FPC_IOCHECK
.L11:
# [20] END.
call FPC_DO_EXIT
leave
ret
.balign 16

.data
.ascii "FPC 1.1 [2000/12/16] for i386 - GO32V2"
.balign 4
.globl FPC_RESOURCESTRINGTABLES
FPC_RESOURCESTRINGTABLES:
.long 0
.globl INITFINAL
INITFINAL:
.long 1,0
.long INIT$$SYSTEM
.long 0
.globl HEAPSIZE
HEAPSIZE:
.long 2097152
.globl __stklen
__stklen:
.long 16384

.data
.L13:
.long -2147483641,0
.L20:
.ascii "\012case c3,c4\000"
.L24:
.ascii "\012case c1,c2\000"
.L28:
.ascii "\036case failed, but it should not\000"

.data

.bss
# [11] VAR v:dword;
.lcomm _V,4
.comm HEAP,2097152

}