Re: optimization/4046: redundant conditional branch

Re: optimization/4046: redundant conditional branch

[sayle]

Synopsis: redundant conditional branch

State-Changed-From-To: analyzed->closed
State-Changed-By: sayle
State-Changed-When: Mon Jul  1 19:51:35 2002
State-Changed-Why:
    This problem has now been fixed on mainline CVS by the
    combination of the following two patches.  We now generate
    only a single branch in the GNATS testcase.
    
    2002-07-01  Roger Sayle  <roger@eyesopen.com>
    
            PR opt/4046
            * fold-const.c (fold) [COND_EXPR]: Simplify A ? 0 : 1 to !A,
            A ? B : 0 to A && B and A ? B : 1 into !A || B if both A and
            B are truth values.
    
    2002-06-15  Roger Sayle  <roger@eyesopen.com>
    
            * fold-const.c (comparison_to_compcode): New function to convert
            an comparison TREE CODE into a bit-based representation.
            (compcode_to_comparison): New function to convert from this bit
            based representation back to a comparison TREE CODE.
            (fold_truthop): Simplify (x<y) && (x==y) and related composite
            comparisons.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=4046

Re: optimization/4046: redundant conditional branch

[rth]

Old Synopsis: redundant comparison introduced with gcc-3.0 (regression from gcc 2)
New Synopsis: redundant conditional branch

State-Changed-From-To: open->analyzed
State-Changed-By: rth
State-Changed-When: Tue Apr  2 19:53:47 2002
State-Changed-Why:
    In gcc 3.1, the regression from gcc 2 is gone, i.e. we once again get
    
            jl      .L8
            jle     .L8
            incl    %eax
    .L8:
    
    However, I'm not closing the PR since we really should have
    eliminated one of the branches.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=4046