diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/fold-const.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr19988.c | 14 |
4 files changed, 30 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 90061ec..207d680 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2010-01-21 Richard Guenther <rguenther@suse.de> + + PR middle-end/19988 + * fold-const.c (negate_expr_p): Pretend only negative + real constants are easily negatable. + 2010-01-20 Janis Johnson <janis187@us.ibm.com> Jason Merrill <jason@redhat.com> diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 9d249cc..e7a4b8c 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -1129,10 +1129,14 @@ negate_expr_p (tree t) && TYPE_OVERFLOW_WRAPS (type)); case FIXED_CST: - case REAL_CST: case NEGATE_EXPR: return true; + case REAL_CST: + /* We want to canonicalize to positive real constants. Pretend + that only negative ones can be easily negated. */ + return REAL_VALUE_NEGATIVE (TREE_REAL_CST (t)); + case COMPLEX_CST: return negate_expr_p (TREE_REALPART (t)) && negate_expr_p (TREE_IMAGPART (t)); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 9c89203..2bfa419 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2010-01-21 Richard Guenther <rguenther@suse.de> + + PR middle-end/19988 + * gcc.dg/pr19988.c: New testcase. + 2010-01-20 Janis Johnson <janis187@us.ibm.com> * g++.dg/compat/decimal/compat-common.h: New file. diff --git a/gcc/testsuite/gcc.dg/pr19988.c b/gcc/testsuite/gcc.dg/pr19988.c new file mode 100644 index 0000000..aa2fed1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr19988.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-optimized -fdump-tree-original" } */ + +double foo(double x, double y) +{ + return ((x + 0.1234 * y) * (x - 0.1234 * y)); +} + +/* Keep positive constants during folding. */ +/* { dg-final { scan-tree-dump-times " 1.23" 2 "original" } } */ +/* CSE one multiplication. */ +/* { dg-final { scan-tree-dump-times " \\\* " 2 "optimized" } } */ +/* { dg-final { cleanup-tree-dump "original" } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ |