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From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/37490] New: [4.4 Regression] IRA causes FP code to have more spills Date: Thu, 11 Sep 2008 23:46:00 -0000 [thread overview] Message-ID: <bug-37490-6528@http.gcc.gnu.org/bugzilla/> (raw) I had quickly looked at PR 37488 and decided to try it out on PPC and noticed that IRA generates worse code than what was being generated before. Here is a simple testcase which does not have any indirect gotos in it: void g(void); const void* test(int action, void* ptr, int a, int *b) { if (action == 0) { return 0; } else { char* ip = ptr; double reg_f_a; double reg_f[1]; reg_f_a = 0.0; reg_f[0] = 0.0; if(a) goto L2; L1: { int t1 = *(int*)(++ip); reg_f_a = reg_f_a + reg_f[t1]; g(); if(*(++b)) goto L1; } L2: g(); *(double*)ptr = reg_f_a; } return 0; } --- CUT --- - fmr 31,0 + std 0,128(1) + lfd 31,128(1) - fmr 31,0 - mr 31,4 - addi 29,1,112 + std 0,128(1) + mr 29,4 + lfd 31,128(1) + addi 28,1,112 For some reason IRA decides it is better to use the GPRs for 0.0 than it is to use the FPRs. -- Summary: [4.4 Regression] IRA causes FP code to have more spills Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: rtl-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pinskia at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37490
next reply other threads:[~2008-09-11 23:46 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-09-11 23:46 pinskia at gcc dot gnu dot org [this message] 2008-09-11 23:46 ` [Bug rtl-optimization/37490] " pinskia at gcc dot gnu dot org 2008-09-11 23:49 ` pinskia at gcc dot gnu dot org 2008-09-11 23:55 ` pinskia at gcc dot gnu dot org 2008-09-13 12:43 ` rguenth at gcc dot gnu dot org 2008-10-22 3:11 ` mmitchel at gcc dot gnu dot org 2008-12-24 23:03 ` pinskia at gcc dot gnu dot org 2009-02-16 9:12 ` bonzini at gnu dot org 2009-02-17 20:48 ` pinskia at gcc dot gnu dot org 2009-04-21 15:59 ` [Bug rtl-optimization/37490] [4.4/4.5 " jakub at gcc dot gnu dot org 2009-07-22 10:35 ` jakub at gcc dot gnu dot org 2009-10-15 12:54 ` jakub at gcc dot gnu dot org 2010-01-21 13:15 ` jakub at gcc dot gnu dot org 2010-02-25 18:56 ` law at redhat dot com
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