hi,
I'm having some problem during build up of libgcc2 in function
__floatdisf(build up of __floatdisf.o).Actually i'm modifying mips
backend.The error is
../../gcc-4.1.0/gcc/libgcc2.c: In function '__floatdisf':
../../gcc-4.1.0/gcc/libgcc2.c:1354: internal compiler error: Segmentation fault
I tried to debug the reason of crash and following are my findings
before crash following pattern is called
(define_expand "cmp<mode>"
[(set (cc0)
(compare:CC (match_operand:GPR 0 "register_operand")
(match_operand:GPR 1 "nonmemory_operand")))]
""
{
fprintf(stderr," cmp<mode> \n");
branch_cmp[0] = operands[0];
branch_cmp[1] = operands[1];
debug_rtx(branch_cmp[0]);
debug_rtx(branch_cmp[1]);
DONE;
})
as u can see i've printed the operands which are as follows
operand[0]
------------------
(subreg:SI (reg:DI 30) 4)
operand[1]
-----------------
(subreg:SI (reg:DI 25 [ u.0 ]) 4)
after this i think it tries to mach some s bCOND pattern but in this
case it fails .
Is this my proposition correct?
--------------------------------------------
In another working case where no error is being generated.Following is
the sequence of called patterns
(define_expand "cmp<mode>"
[(set (cc0)
(compare:CC (match_operand:GPR 0 "register_operand")
(match_operand:GPR 1 "nonmemory_operand")))]
""
{
fprintf(stderr," cmp<mode> \n");
cmp_operands[0] = operands[0];
cmp_operands[1] = operands[1];
debug_rtx(cmp_operands[0]);
debug_rtx(cmp_operands[1]);
DONE;
})
here the operand are
operands[0]
-------------------
(subreg:SI (reg:DI 30) 0)
operands[1]
-------------------
(subreg:SI (reg:DI 25 [ u.0 ]) 0)
Then the following pattern is matched
(define_expand "bltu"
[(set (pc)
(if_then_else (ltu (cc0) (const_int 0))
(label_ref (match_operand 0 ""))
(pc)))]
""
{
fprintf(stderr,"\n branch_fp 8 bltu\n");
})
So in first failed case it must match the above mentioned pattern but
fails to do so.So the only difference seems to be that bytenum offset
in subreg expression is different.In failed case it is 4 and in
successful case it is 0.
Both directories seems to be copy of each other.Then why operands are
defiierent in cmpsi patterns.There are no floating point registers.The
option passed to gcc is -msoft-float.
I've tried my best to track the problem but could not due my limited
knowledge.Would you please give me some hint to debug the problem .
thanks,
shahzad
