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| author | Richard Henderson <rth@redhat.com> | 2005-09-19 10:01:40 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 2005-09-19 10:01:40 -0700 |
| commit | d289e37a267820946191990603ad70cb29a7ffc9 (patch) | |
| tree | 939f5124bb5cc88af26701e1be41242556942d1d | |
| parent | 3c7d0735f564a48ea13b5246c5675cabaf53d0c6 (diff) | |
| download | gcc-d289e37a267820946191990603ad70cb29a7ffc9.zip gcc-d289e37a267820946191990603ad70cb29a7ffc9.tar.gz gcc-d289e37a267820946191990603ad70cb29a7ffc9.tar.bz2 | |
re PR rtl-optimization/23941 (compress_float_constant creates denormals)
PR 23941
* real.c (exact_real_truncate): Return false if the format cannot
represent the number as a normal.
From-SVN: r104424
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/real.c | 12 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/execute/pr23941.c | 9 |
3 files changed, 27 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 118b6b6..2a56ded 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-09-19 Richard Henderson <rth@redhat.com> + + PR 23941 + * real.c (exact_real_truncate): Return false if the format cannot + represent the number as a normal. + 2005-09-19 Dorit Nuzman <dorit@il.ibm.com> * tree-ssa-operands.c (swap_tree_operands): Export. @@ -2399,7 +2399,19 @@ real_value_truncate (enum machine_mode mode, REAL_VALUE_TYPE a) bool exact_real_truncate (enum machine_mode mode, const REAL_VALUE_TYPE *a) { + const struct real_format *fmt; REAL_VALUE_TYPE t; + int emin2m1; + + fmt = REAL_MODE_FORMAT (mode); + gcc_assert (fmt); + + /* Don't allow conversion to denormals. */ + emin2m1 = (fmt->emin - 1) * fmt->log2_b; + if (REAL_EXP (a) <= emin2m1) + return false; + + /* After conversion to the new mode, the value must be identical. */ real_convert (&t, mode, a); return real_identical (&t, a); } diff --git a/gcc/testsuite/gcc.c-torture/execute/pr23941.c b/gcc/testsuite/gcc.c-torture/execute/pr23941.c new file mode 100644 index 0000000..4dfd645 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr23941.c @@ -0,0 +1,9 @@ +extern void abort (void); +double d = __FLT_MIN__ / 2.0; +int main() +{ + double x = __FLT_MIN__ / 2.0; + if (x != d) + abort (); + return 0; +} |