On Wed, Apr 23, 2025 at 2:03 AM Richard Biener <richard.guent...@gmail.com> wrote: > > On Wed, Apr 23, 2025 at 5:59 AM Andrew Pinski <quic_apin...@quicinc.com> > wrote: > > > > To speed up things slightly so not needing to call all the way through > > to match and simplify, we should return early for true/false on GIMPLE_COND. > > I think we'd still canonicalize the various forms matched by > gimple_cond_true/false_p > to a standard one - we should go through resimplify2 which should constant > fold > the compare and in the end we do gimple_cond_make_true/false. > > I'm also not sure it's worth short-cutting this, it shouldn't be common to > fold > an already canonical if (0) or if (1), no?
yes I agree, I posted a new version of the patch which does similar to the `bool_name != 0` and what was suggested above: https://gcc.gnu.org/pipermail/gcc-patches/2025-May/683018.html Thanks, Andrew > > Richard. > > > gcc/ChangeLog: > > > > * gimple-fold.cc (fold_stmt_1): For GIMPLE_COND return early > > for true/false. > > > > Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com> > > --- > > gcc/gimple-fold.cc | 13 ++++++++++--- > > 1 file changed, 10 insertions(+), 3 deletions(-) > > > > diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc > > index 94d5a1ebbd7..2381a82d2b1 100644 > > --- a/gcc/gimple-fold.cc > > +++ b/gcc/gimple-fold.cc > > @@ -6646,12 +6646,19 @@ fold_stmt_1 (gimple_stmt_iterator *gsi, bool > > inplace, tree (*valueize) (tree), > > break; > > case GIMPLE_COND: > > { > > + gcond *gc = as_a <gcond *> (stmt); > > + /* If the cond is already true/false, just return false. */ > > + if (gimple_cond_true_p (gc) > > + || gimple_cond_false_p (gc)) > > + { > > + fold_undefer_overflow_warnings (false, stmt, 0); > > + return false; > > + } > > /* Canonicalize operand order. */ > > - tree lhs = gimple_cond_lhs (stmt); > > - tree rhs = gimple_cond_rhs (stmt); > > + tree lhs = gimple_cond_lhs (gc); > > + tree rhs = gimple_cond_rhs (gc); > > if (tree_swap_operands_p (lhs, rhs)) > > { > > - gcond *gc = as_a <gcond *> (stmt); > > gimple_cond_set_lhs (gc, rhs); > > gimple_cond_set_rhs (gc, lhs); > > gimple_cond_set_code (gc, > > -- > > 2.43.0 > >
