Hi,
GCC currently doesn't bootstrap on s390x. The problem is that
gengtype is miscompiled and I suspect the fre - sccvn changes to be
the culprit.
When sccvn performs the depth-first search for uses it might reach
global variable definitions. If the global variable is initialized
with a value that value is taken as constant and used to replace uses
of that variable.
e.g.:
int global = 1;
int
foo (int a)
{
return a != global;
}
int
main ()
{
global = 3;
if (foo (3))
abort ();
}
becomes (compiled with -O1):
foo (a)
{
int global.0;
int D.1626;
<bb 2>:
global.0_1 = 1;
D.1626_3 = a_2(D) != global.0_1;
return D.1626_3;
}
...
The example works fine when removing the initialization of global.
Bye,
-Andreas-
Here is the complete fre output:
;; Function foo (foo)
SCC consists of: global_5(D)
Value numbering global_5(D) stmt = (void) 0;
Setting value number of global_5(D) to global_5(D)
SCC consists of: a_2(D)
Value numbering a_2(D) stmt = (void) 0;
Setting value number of a_2(D) to a_2(D)
SCC consists of: global.0_1
Value numbering global.0_1 stmt = global.0_1 = global;
RHS global simplified to 1 has constants 0
Setting value number of global.0_1 to 1
SCC consists of: D.1626_3
Value numbering D.1626_3 stmt = D.1626_3 = a_2(D) != global.0_1;
Setting value number of D.1626_3 to D.1626_3
Value numbers:
global.0_1 = 1
Created value VH.0 for a_2(D)
SCCVN says global.0_1 value numbers to 1
Created value VH.1 for D.1626_3
Created value VH.2 for <retval>_4
exp_gen[0] := { }
tmp_gen[0] := { }
avail_out[0] := { a_2(D) (VH.0) }
exp_gen[2] := { }
tmp_gen[2] := { <retval>_4 (VH.2) }
avail_out[2] := { a_2(D) (VH.0) , D.1626_3 (VH.1) , <retval>_4 (VH.2) }
exp_gen[1] := { }
tmp_gen[1] := { }
avail_out[1] := { }
Replaced global with 1 in global.0_1 = global;
foo (a)
{
int global.0;
int D.1626;
<bb 2>:
global.0_1 = 1;
D.1626_3 = a_2(D) != global.0_1;
return D.1626_3;
}
;; Function main (main)
SCC consists of: global_2(D)
Value numbering global_2(D) stmt = (void) 0;
Setting value number of global_2(D) to global_2(D)
SCC consists of: global_3
Value numbering global_3 stmt = global = 3;
No store match
Value numbering store global to 3
Setting value number of global_3 to global_3
SCC consists of: D.1630_1
Value numbering D.1630_1 stmt = D.1630_1 = foo (3);
Setting value number of D.1630_1 to D.1630_1
Value numbers:
Created value VH.3 for D.1630_1
exp_gen[0] := { }
tmp_gen[0] := { }
avail_out[0] := { }
exp_gen[2] := { }
tmp_gen[2] := { }
avail_out[2] := { D.1630_1 (VH.3) }
exp_gen[3] := { }
tmp_gen[3] := { }
avail_out[3] := { D.1630_1 (VH.3) }
exp_gen[4] := { }
tmp_gen[4] := { }
avail_out[4] := { D.1630_1 (VH.3) }
exp_gen[1] := { }
tmp_gen[1] := { }
avail_out[1] := { }
main ()
{
int D.1630;
<bb 2>:
global = 3;
D.1630_1 = foo (3);
if (D.1630_1 != 0)
goto <bb 3>;
else
goto <bb 4>;
<bb 3>:
abort ();
<bb 4>:
return;
}
