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* [Bug middle-end/108990] New: Too restrictive precision check in fold and simplify pattern for PR70920 @ 2023-03-02 13:49 hubicka at gcc dot gnu.org 2023-03-02 23:21 ` [Bug middle-end/108990] " pinskia at gcc dot gnu.org 2023-03-03 8:21 ` rguenth at gcc dot gnu.org 0 siblings, 2 replies; 3+ messages in thread From: hubicka at gcc dot gnu.org @ 2023-03-02 13:49 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108990 Bug ID: 108990 Summary: Too restrictive precision check in fold and simplify pattern for PR70920 Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end Assignee: unassigned at gcc dot gnu.org Reporter: hubicka at gcc dot gnu.org Target Milestone: --- While experimenting with a new gimple pass we noticed that pr70920.c is sensitive on order of substitutions made. If 0 is propagated first into if stmt, match and simplify fails to simplify the conditional since it compares pointer type 0 with integer converted to pointer type. TYPE_PRECISION of int is 32. (for cmp (ne eq) (simplify (cmp (convert @0) INTEGER_CST@1) (if (((POINTER_TYPE_P (TREE_TYPE (@0)) && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@0))) && INTEGRAL_TYPE_P (TREE_TYPE (@1)) /* Don't perform this optimization in GENERIC if @0 has reference type when sanitizing. See PR101210. */ && !(GENERIC && TREE_CODE (TREE_TYPE (@0)) == REFERENCE_TYPE && (flag_sanitize & (SANITIZE_NULL | SANITIZE_ALIGNMENT)))) || (INTEGRAL_TYPE_P (TREE_TYPE (@0)) && POINTER_TYPE_P (TREE_TYPE (@1)) && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@1))))) && TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1))) (cmp @0 (convert @1))))) So last conditional is false (32 and 64) In this adjusted testcase: #include <stdint.h> void f1(); void f2(); void foo (int a) { int *b = (int *)a; if (b == (void *)0) { f1 (); } } the unnecessary cast survives to forwprop while it chould be caught by cpp1 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/108990] Too restrictive precision check in fold and simplify pattern for PR70920 2023-03-02 13:49 [Bug middle-end/108990] New: Too restrictive precision check in fold and simplify pattern for PR70920 hubicka at gcc dot gnu.org @ 2023-03-02 23:21 ` pinskia at gcc dot gnu.org 2023-03-03 8:21 ` rguenth at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-03-02 23:21 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108990 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |missed-optimization Status|UNCONFIRMED |NEW Ever confirmed|0 |1 See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=70920 Last reconfirmed| |2023-03-02 Severity|normal |enhancement --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- There are other patterns which handle different precision integeral types though. e.g. match.pd:5780 /* If possible, express the comparison in the shorter mode. */ (if ((cmp == EQ_EXPR || cmp == NE_EXPR || TYPE_UNSIGNED (TREE_TYPE (@0)) == TYPE_UNSIGNED (TREE_TYPE (@00)) || (!TYPE_UNSIGNED (TREE_TYPE (@0)) && TYPE_UNSIGNED (TREE_TYPE (@00)))) && (types_match (TREE_TYPE (@10), TREE_TYPE (@00)) || ((TYPE_PRECISION (TREE_TYPE (@00)) >= TYPE_PRECISION (TREE_TYPE (@10))) && (TYPE_UNSIGNED (TREE_TYPE (@00)) == TYPE_UNSIGNED (TREE_TYPE (@10)))) || (TREE_CODE (@10) == INTEGER_CST && INTEGRAL_TYPE_P (TREE_TYPE (@00)) && int_fits_type_p (@10, TREE_TYPE (@00))))) (cmp @00 (convert @10)) I wonder if the pattern for PR 70920 should be combined with the above one and fixed up. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/108990] Too restrictive precision check in fold and simplify pattern for PR70920 2023-03-02 13:49 [Bug middle-end/108990] New: Too restrictive precision check in fold and simplify pattern for PR70920 hubicka at gcc dot gnu.org 2023-03-02 23:21 ` [Bug middle-end/108990] " pinskia at gcc dot gnu.org @ 2023-03-03 8:21 ` rguenth at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: rguenth at gcc dot gnu.org @ 2023-03-03 8:21 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108990 --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Consolidating these kind of duplicates would be nice. Note in this particular case we should order the more specific pattern earlier (diagnosing that with -v would be nice). Implementing order preserving differently, for example by expressing 'A must be matched before B' explicitely would be a good improvement as well. If you add -v to the genmatch command-line you'll see 273 cases where we forcefully re-start matching because of intermediate "more specific" patterns. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-03-03 8:21 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-03-02 13:49 [Bug middle-end/108990] New: Too restrictive precision check in fold and simplify pattern for PR70920 hubicka at gcc dot gnu.org 2023-03-02 23:21 ` [Bug middle-end/108990] " pinskia at gcc dot gnu.org 2023-03-03 8:21 ` rguenth at gcc dot gnu.org
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