"Naughty" register error in Cmm

When experimenting with Cmm code, I found the following bug/trap.

This Cmm code,

foo {
    bits8 x;
    x = 5;
    bits8[12] = x;
    R1 = x;
    jump bar;
}

causes the following error

/tmp/ghc6613_0/ghc6613_0.s: Assembler messages:

/tmp/ghc6613_0/ghc6613_0.s:7:0:
     Error: junk `naughty I386 byte register' after expression

The assembly that is produced is:

.text
        .align 4,0x90
.globl foo
foo:
        movl $5,%eax
        movb %al,12
        movb %al,very naughty I386 byte register
        jmp bar

.section .note.GNU-stack,"",@progbits
.ident "GHC 6.7.20070612"

Note the "very naughty I386 byte register" in there.

I am not sure whether this kind of Cmm can be generated from Haskell code.

Trac metadata

Trac field	Value
Version	6.7
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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