[Bug target/98671] New: gcc/config/i386/i386-options.c:787:redundantAssignment

[Bug target/98671] New: gcc/config/i386/i386-options.c:787:redundantAssignment

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

            Bug ID: 98671
           Summary: gcc/config/i386/i386-options.c:787:redundantAssignment
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

trunk.git/gcc/config/i386/i386-options.c:787:28: style: Variable
'opts->x_ix86_branch_cost' is reassigned a value before the old one has been
used. [redundantAssignment]

Source code is

  opts->x_ix86_branch_cost = ptr->branch_cost;
...
  opts->x_ix86_branch_cost = ptr->x_ix86_branch_cost;

Suggest delete first assignment.

[Bug target/98671] gcc/config/i386/i386-options.c:787:redundantAssignment

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

--- Comment #1 from Hongtao.liu <crazylht at gmail dot com> ---
Seems so.

[Bug target/98671] gcc/config/i386/i386-options.c:787:redundantAssignment

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-01-14
           Assignee|unassigned at gcc dot gnu.org      |ubizjak at gmail dot com
   Target Milestone|---                         |11.0

--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> ---
Let me fix this.

[Bug target/98671] gcc/config/i386/i386-options.c:787:redundantAssignment

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

--- Comment #3 from David Binderman <dcb314 at hotmail dot com> ---
For the same source code file, cppcheck finds these other very minor problems:

1.

trunk.git/gcc/config/i386/i386-options.c:1520:11: warning:inconclusive: Width
10 given in format string (no. 3) is smaller than destination buffer
'align[16]'. [invalidScanfFormatWidth_smaller]

The buffer size could probably be reduced. It won't make much difference,
since there are much larger variables nearby.

2.

trunk.git/gcc/config/i386/i386-options.c:1092:12: style: Local variable 'ret'
shadows outer variable [shadowVariable]
trunk.git/gcc/config/i386/i386-options.c:918:8: note: Shadowed declaration
trunk.git/gcc/config/i386/i386-options.c:1092:12: note: Shadow variable

3.

trunk.git/gcc/config/i386/i386-options.c:2856:26: style: Local variable 'i'
shadows outer variable [shadowVariable]
trunk.git/gcc/config/i386/i386-options.c:1786:7: note: Shadowed declaration
trunk.git/gcc/config/i386/i386-options.c:2856:26: note: Shadow variable

[Bug target/98671] gcc/config/i386/i386-options.c:787:redundantAssignment

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> ---
Fixed all but:

> trunk.git/gcc/config/i386/i386-options.c:1520:11: warning:inconclusive: Width 10
> given in format string (no. 3) is smaller than destination buffer 'align[16]'.
> [invalidScanfFormatWidth_smaller]

I'm not sure if solving this would bring us anything.

[Bug target/98671] gcc/config/i386/i386-options.c:787:redundantAssignment

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

--- Comment #5 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to Uroš Bizjak from comment #4)
> I'm not sure if solving this would bring us anything.

For clarity, at very most a 4% reduction in the size of the stack frame
for function ix86_parse_stringop_strategy_string.

[Bug target/98671] gcc/config/i386/i386-options.c:787:redundantAssignment

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98671

--- Comment #6 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to David Binderman from comment #5)
> (In reply to Uroš Bizjak from comment #4)
> > I'm not sure if solving this would bring us anything.
> 
> For clarity, at very most a 4% reduction in the size of the stack frame
> for function ix86_parse_stringop_strategy_string.

Unfortunately, patched and unpatched compiler results in the same frame size:

00000000011dc690 <_ZL35ix86_parse_stringop_strategy_stringPcb>:
 11dc690:       41 57                   push   %r15
 11dc692:       41 56                   push   %r14
 11dc694:       41 55                   push   %r13
 11dc696:       41 54                   push   %r12
 11dc698:       55                      push   %rbp
 11dc699:       53                      push   %rbx
 11dc69a:       48 89 fb                mov    %rdi,%rbx
 11dc69d:       48 81 ec 08 01 00 00    sub    $0x108,%rsp
 ...