From 275b395f894f16ac389cd8c5799e374080d3b188 Mon Sep 17 00:00:00 2001 From: sandra <sandra@138bc75d-0d04-0410-961f-82ee72b054a4> Date: Fri, 15 May 2009 17:28:47 +0000 Subject: [PATCH] 2009-05-15 Sandra Loosemore <sandra@codesourcery.com> gcc/ * fold-const.c (fold_convert_const_real_from_real): Check for overflow. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@147589 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 5 +++++ gcc/fold-const.c | 19 ++++++++++++++++++- 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2cd3e2556605..b347aff1db80 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2009-05-15 Sandra Loosemore <sandra@codesourcery.com> + + * fold-const.c (fold_convert_const_real_from_real): Check for + overflow. + 2009-05-15 H.J. Lu <hongjiu.lu@intel.com> * config/i386/i386.c (ix86_reorg): Call optimize_function_for_speed_p diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 32de681e8da3..1a1a80f1f7f8 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -2327,7 +2327,24 @@ fold_convert_const_real_from_real (tree type, const_tree arg1) real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1)); t = build_real (type, value); - TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1); + /* If converting an infinity or NAN to a representation that doesn't + have one, set the overflow bit so that we can produce some kind of + error message at the appropriate point if necessary. It's not the + most user-friendly message, but it's better than nothing. */ + if (REAL_VALUE_ISINF (TREE_REAL_CST (arg1)) + && !MODE_HAS_INFINITIES (TYPE_MODE (type))) + TREE_OVERFLOW (t) = 1; + else if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)) + && !MODE_HAS_NANS (TYPE_MODE (type))) + TREE_OVERFLOW (t) = 1; + /* Regular overflow, conversion produced an infinity in a mode that + can't represent them. */ + else if (!MODE_HAS_INFINITIES (TYPE_MODE (type)) + && REAL_VALUE_ISINF (value) + && !REAL_VALUE_ISINF (TREE_REAL_CST (arg1))) + TREE_OVERFLOW (t) = 1; + else + TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1); return t; } -- GitLab