From ae25db4568034756df727d432dd48caa5e5f41dc Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 27 Jan 2012 10:26:48 +0100 Subject: [PATCH] re PR debug/52001 (Huge compile-time regression with var-tracking) PR debug/52001 * var-tracking.c (reverse_op): Don't add any reverse operation if V already has any constant locations. From-SVN: r183608 --- gcc/ChangeLog | 6 ++++++ gcc/var-tracking.c | 9 +++++++++ 2 files changed, 15 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 0a4e08b..fe748f4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2012-01-27 Jakub Jelinek + + PR debug/52001 + * var-tracking.c (reverse_op): Don't add any reverse operation + if V already has any constant locations. + 2012-01-27 Sandra Loosemore * doc/invoke.texi: Correct usage of "command line" (noun) diff --git a/gcc/var-tracking.c b/gcc/var-tracking.c index 557a2ca..1f4903a 100644 --- a/gcc/var-tracking.c +++ b/gcc/var-tracking.c @@ -5298,6 +5298,7 @@ reverse_op (rtx val, const_rtx expr, rtx insn) { rtx src, arg, ret; cselib_val *v; + struct elt_loc_list *l; enum rtx_code code; if (GET_CODE (expr) != SET) @@ -5333,6 +5334,14 @@ reverse_op (rtx val, const_rtx expr, rtx insn) if (!v || !cselib_preserved_value_p (v)) return; + /* Adding a reverse op isn't useful if V already has an always valid + location. Ignore ENTRY_VALUE, while it is always constant, we should + prefer non-ENTRY_VALUE locations whenever possible. */ + for (l = v->locs; l; l = l->next) + if (CONSTANT_P (l->loc) + && (GET_CODE (l->loc) != CONST || !references_value_p (l->loc, 0))) + return; + switch (GET_CODE (src)) { case NOT: -- 2.7.4