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| author | mpolacek <mpolacek@138bc75d-0d04-0410-961f-82ee72b054a4> | 2013-04-04 11:03:11 +0000 |
|---|---|---|
| committer | mpolacek <mpolacek@138bc75d-0d04-0410-961f-82ee72b054a4> | 2013-04-04 11:03:11 +0000 |
| commit | 7963c797e08219fd31ef5c2326cbf1d83b6b2fa8 (patch) | |
| tree | 12027e3b925d52bd84f618073e556a01d508de24 | |
| parent | fddee6f5e4579954dc0bc3401c514548da547a34 (diff) | |
| download | gcc-7963c797e08219fd31ef5c2326cbf1d83b6b2fa8.tar.gz | |
Backported from mainline
2013-01-09 Steven Bosscher <steven@gcc.gnu.org>
Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/48189
* predict.c (predict_loops): If max is 0, don't call compare_tree_int.
If nitercst is 0, don't predict the exit edge.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@197478 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 10 | ||||
| -rw-r--r-- | gcc/predict.c | 10 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr48189.c | 13 |
4 files changed, 39 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index f5ddc786f7c..f9b7ec9c8b5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2013-04-04 Marek Polacek <polacek@redhat.com> + + Backported from mainline + 2013-01-09 Steven Bosscher <steven@gcc.gnu.org> + Jakub Jelinek <jakub@redhat.com> + + PR tree-optimization/48189 + * predict.c (predict_loops): If max is 0, don't call compare_tree_int. + If nitercst is 0, don't predict the exit edge. + 2013-04-03 Jakub Jelinek <jakub@redhat.com> Backported from mainline diff --git a/gcc/predict.c b/gcc/predict.c index f00424c3b1c..18fda083da3 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -1,6 +1,6 @@ /* Branch prediction routines for the GNU compiler. Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010 - Free Software Foundation, Inc. + 2011, 2012, 2013 Free Software Foundation, Inc. This file is part of GCC. @@ -966,7 +966,8 @@ predict_loops (void) if (TREE_CODE (niter) == INTEGER_CST) { if (host_integerp (niter, 1) - && compare_tree_int (niter, max-1) == -1) + && max + && compare_tree_int (niter, max - 1) == -1) nitercst = tree_low_cst (niter, 1) + 1; else nitercst = max; @@ -988,6 +989,11 @@ predict_loops (void) else continue; + /* If the prediction for number of iterations is zero, do not + predict the exit edges. */ + if (nitercst == 0) + continue; + probability = ((REG_BR_PROB_BASE + nitercst / 2) / nitercst); predict_edge (ex, predictor, probability); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index cd660f6e3fa..80016c5622f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2013-04-04 Marek Polacek <polacek@redhat.com> + + Backported from mainline + 2013-01-09 Jakub Jelinek <jakub@redhat.com> + + PR tree-optimization/48189 + * gcc.dg/pr48189.c: New test. + 2013-04-04 Tobias Burnus <burnus@net-b.de> Backport from mainline: diff --git a/gcc/testsuite/gcc.dg/pr48189.c b/gcc/testsuite/gcc.dg/pr48189.c new file mode 100644 index 00000000000..86b995dc984 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr48189.c @@ -0,0 +1,13 @@ +/* PR tree-optimization/48189 */ +/* { dg-do compile } */ +/* { dg-options "-O --param max-predicted-iterations=0" } */ + +struct S { int s[8]; }; + +void +foo (int *x, struct S *y) +{ + int i; + for (i = 0; y[i].s[i]; i++) + *x++ = y[i].s[i]; +} |