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| author | Andrew MacLeod <amacleod@redhat.com> | 2021-11-23 14:12:29 -0500 |
|---|---|---|
| committer | Andrew MacLeod <amacleod@redhat.com> | 2021-11-25 08:44:27 -0500 |
| commit | 661c02e54ea72fb55205df0a717951ff28bb739e (patch) | |
| tree | 95da0613a67a1427bd0c59a55fabe050cd158b0e /gcc | |
| parent | f4e470d44e8104bada6a95c12765f6ed8bd505e2 (diff) | |
| download | gcc-661c02e54ea72fb55205df0a717951ff28bb739e.zip gcc-661c02e54ea72fb55205df0a717951ff28bb739e.tar.gz gcc-661c02e54ea72fb55205df0a717951ff28bb739e.tar.bz2 | |
Check for equivalences between PHI argument and def.
If a PHI argument on an edge is equivalent with the DEF, then it doesn't
provide any new information, defer processing it unless they are all
equivalences.
PR tree-optimization/103359
gcc/
* gimple-range-fold.cc (fold_using_range::range_of_phi): If arg is
equivalent to def, don't initially include it's range.
gcc/testsuite/
* gcc.dg/pr103359.c: New.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/gimple-range-fold.cc | 16 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr103359.c | 21 |
2 files changed, 37 insertions, 0 deletions
diff --git a/gcc/gimple-range-fold.cc b/gcc/gimple-range-fold.cc index ec9690b..d66ada5 100644 --- a/gcc/gimple-range-fold.cc +++ b/gcc/gimple-range-fold.cc @@ -771,6 +771,7 @@ fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src) tree phi_def = gimple_phi_result (phi); tree type = gimple_range_type (phi); int_range_max arg_range; + int_range_max equiv_range; unsigned x; if (!type) @@ -794,6 +795,16 @@ 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. @@ -816,6 +827,11 @@ fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src) break; } + // If all arguments were equivalences, use the equivalence ranges as no + // arguments were processed. + if (!seen_arg) + r = equiv_range; + // If the PHI boils down to a single effective argument, look at it. if (single_arg) { diff --git a/gcc/testsuite/gcc.dg/pr103359.c b/gcc/testsuite/gcc.dg/pr103359.c new file mode 100644 index 0000000..13406f9 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr103359.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -fdump-tree-evrp" } */ + +void foo(); +static char a, c; +static int d, e; +static short b(short f, short g) { return f * g; } +int main() { + short h = 4; + for (; d;) + if (h) + if(e) { + if (!b(a & 1 | h, 3)) + c = 0; + h = 1; + } + if (c) + foo(); +} + +/* { dg-final { scan-tree-dump-not "c = 0" "evrp" } } */ |