On 9/2/16, Segher Boessenkool <seg...@kernel.crashing.org> wrote:
> On Fri, Sep 02, 2016 at 09:40:36AM -0400, Eric Gallager wrote:
>> --- a/gcc/combine.c
>> +++ b/gcc/combine.c
>> @@ -1122,7 +1122,7 @@ static int
>> combine_instructions (rtx_insn *f, unsigned int nregs)
>> {
>> rtx_insn *insn, *next;
>> - rtx_insn *prev;
>> + rtx_insn *prev = NULL;
>> struct insn_link *links, *nextlinks;
>> rtx_insn *first;
>> basic_block last_bb;
>
> I don't see any place "prev" is used witout an immediately preceding
> assignment to it. Could you show the warning you see please?
>
>
> Segher
>
Sure. When I remove the initialization I get:
../../gcc/combine.c: In function ‘int combine_instructions(rtx_insn*,
unsigned int)’:
../../gcc/combine.c:1310:8: warning: ‘prev’ may be used uninitialized
in this function [-Wmaybe-uninitialized]
if ((next = try_combine (insn, prev, NULL, NULL,
^~
