Bug#164554: gcc-3.2: volatile not respected on alpha

[martin@v.loewis.de (Martin v. Loewis)]

Daniel Jacobowitz <dan@debian.org> writes:

> But the value of J is not required to coordinate with any sequence
> points in the implementation, only in the abstract machine...

In the code, there are two modifications to i, namely

 	i++;
 	j = 6;
 	i--;

So at the first sequence point, i should be incremented, and at the
second sequence point, i should be decremented to its original value
(regardless of the value of j, which does not need to be coordinated).
AFAICT, in the sequence

 	ldq $3,i($29)		!literal
 	lda $4,6($31)
 	ldq $1,j($29)		!literal
 	ldl $2,0($3)
 	stl $4,0($1)
 	lda $2,1($2)
 	stl $2,0($3)

the value of i is never changed. Instead, it is loaded into $2, and
then written back from $2 to i. That seems to be in violation of the
volatile requirements to me.

Regards,
Martin