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* [Bug tree-optimization/46027] New: (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) @ 2010-10-14 18:55 pinskia at gcc dot gnu.org 2010-10-14 18:56 ` [Bug tree-optimization/46027] " pinskia at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2010-10-14 18:55 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46027 Summary: (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) Product: gcc Version: 4.5.0 Status: UNCONFIRMED Severity: enhancement Priority: P3 Component: tree-optimization AssignedTo: unassigned@gcc.gnu.org ReportedBy: pinskia@gcc.gnu.org Take: typedef unsigned type1; typedef unsigned char type2; type1 t; void f(type1 tt) { t = (type2)tt; } --- CUT --- In .optimized we have: D.2687_2 = (unsigned char) tt_1(D); t.0_3 = (type1) D.2687_2; t = t.0_3; --- CUT --- This is done on the RTL level, well I think it uses (zero_extend(subreg)) as the conical form (at least on big endian targets). Using &0xFF here would be faster and less memory usage and might be able to optimize more. Here is a testcase which shows where we can optimize more if we do this: typedef unsigned type1; typedef unsigned char type2; type1 t; void f(type1 tt) { type2 t1 = t; type1 t2 = t1; t = t2 & 0xFF; } void f1(type1 tt) { type1 t2 = t & 0xff; t = t2 & 0xFF; } ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/46027] (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) 2010-10-14 18:55 [Bug tree-optimization/46027] New: (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) pinskia at gcc dot gnu.org @ 2010-10-14 18:56 ` pinskia at gcc dot gnu.org 2010-10-19 0:29 ` pinskia at gcc dot gnu.org 2011-11-29 23:42 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2010-10-14 18:56 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46027 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |ASSIGNED Last reconfirmed| |2010.10.14 18:56:06 AssignedTo|unassigned at gcc dot |pinskia at gcc dot gnu.org |gnu.org | Ever Confirmed|0 |1 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2010-10-14 18:56:06 UTC --- I am working on this. I found this while looking into some 4.3 SRA produced trees. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/46027] (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) 2010-10-14 18:55 [Bug tree-optimization/46027] New: (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) pinskia at gcc dot gnu.org 2010-10-14 18:56 ` [Bug tree-optimization/46027] " pinskia at gcc dot gnu.org @ 2010-10-19 0:29 ` pinskia at gcc dot gnu.org 2011-11-29 23:42 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2010-10-19 0:29 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46027 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2010-10-19 00:29:18 UTC --- Here is a full testcase: typedef unsigned type1; typedef unsigned char type2; type1 t; void f(type1 tt) { type2 t1 = t; type1 t2 = t1; t = t2 & 0xFF; } void f2(type1 tt) { type1 t2 = (type2)t; t = t2 & 0xFF; } void f1(type1 tt) { type1 t2 = t & 0xff; t = t2 & 0xFF; } ---- CUT ---- Currently f does not get optimized after my patch. f1 is optimized before my patch and f2 is optimized afterwards. f requires some kind of forward prop/tree combining to do the work. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/46027] (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) 2010-10-14 18:55 [Bug tree-optimization/46027] New: (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) pinskia at gcc dot gnu.org 2010-10-14 18:56 ` [Bug tree-optimization/46027] " pinskia at gcc dot gnu.org 2010-10-19 0:29 ` pinskia at gcc dot gnu.org @ 2011-11-29 23:42 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2011-11-29 23:42 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46027 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution| |FIXED Target Milestone|--- |4.7.0 --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-11-29 23:28:40 UTC --- Fixed on the trunk by: 2011-05-10 Richard Guenther <rguenther@suse.de> * tree-ssa-forwprop.c (combine_conversions): Pattern-match a series of conversions and apply foldings similar to what fold-const does. (tree_ssa_forward_propagate_single_use_vars): Call it. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-11-29 23:28 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2010-10-14 18:55 [Bug tree-optimization/46027] New: (unsignedtype1)(unsignedtype2)(unsignedtype1_var) not changed into unsignedtype1_var & NNN when sizeof(type1) > sizeof(type2) pinskia at gcc dot gnu.org 2010-10-14 18:56 ` [Bug tree-optimization/46027] " pinskia at gcc dot gnu.org 2010-10-19 0:29 ` pinskia at gcc dot gnu.org 2011-11-29 23:42 ` pinskia at gcc dot gnu.org
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