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Always track arguments, even when ignoring equiv params.

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To "ignore" ranges from equivalences, we should track the range separately,
but still do the other name processing which determiens if there is a single
name or not for equivalence.  Otherwise we mistakently think we can introduce
an equivalences.

	gcc/
	PR tree-optimization/103440
	* gimple-range-fold.cc (fold_using_range::range_of_phi): Continue
	normal param processing for equiv params.

	gcc/testsuite/
	* gcc.dg/pr103440.c: New.
This commit is contained in:
Andrew MacLeod 2021-11-29 09:19:34 -05:00
parent fa01e206c8
commit e43b15c88c
2 changed files with 33 additions and 12 deletions
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21
gcc/gimple-range-fold.cc
View File

@ -795,20 +795,17 @@ fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src)
// Get the range of the argument on its edge.
src.get_phi_operand (arg_range, arg, e);
// Likewise, if the incoming PHI argument is equivalent to this
// PHI definition, it provides no new info. Accumulate these ranges
// in case all arguments are equivalences.
if (src.query ()->query_relation (e, arg, phi_def, false) == EQ_EXPR)
{
single_arg = arg;
equiv_range.union_(arg_range);
continue;
}
if (!arg_range.undefined_p ())
{
// Register potential dependencies for stale value tracking.
r.union_ (arg_range);
// Likewise, if the incoming PHI argument is equivalent to this
// PHI definition, it provides no new info. Accumulate these ranges
// in case all arguments are equivalences.
if (src.query ()->query_relation (e, arg, phi_def, false) == EQ_EXPR)
equiv_range.union_(arg_range);
else
r.union_ (arg_range);
if (gimple_range_ssa_p (arg) && src.gori ())
src.gori ()->register_dependency (phi_def, arg);
@ -829,7 +826,7 @@ fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src)
// If all arguments were equivalences, use the equivalence ranges as no
// arguments were processed.
if (!seen_arg)
if (r.undefined_p () && !equiv_range.undefined_p ())
r = equiv_range;
// If the PHI boils down to a single effective argument, look at it.

24
gcc/testsuite/gcc.dg/pr103440.c Normal file
View File

@ -0,0 +1,24 @@
/* { dg-do run } */
/* { dg-options "-Os" } */
/* { dg-timeout 10 } */
int a, b, c, d, e;
int main() {
int f = 2, g = 1, h = -3;
L1:
c = b ^ 1;
if (!f)
goto L3;
if (d)
g = e;
f = h;
if (!c)
goto L1;
L2:
if (g)
a = 0;
L3:
if (d == g)
goto L2;
return 0;
}