From 188235dff14c855c929b8a52378deaf452637e1a Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 27 Nov 2001 01:07:59 -0800 Subject: [PATCH] ifcvt.c (noce_try_store_flag_constants): Test for overflow in computing DIFF. * ifcvt.c (noce_try_store_flag_constants): Test for overflow in computing DIFF. From-SVN: r47374 --- gcc/ChangeLog | 5 +++++ gcc/ifcvt.c | 6 ++++++ 2 files changed, 11 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2d6093552dc..ab355387288 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2001-11-27 Richard Henderson + + * ifcvt.c (noce_try_store_flag_constants): Test for overflow + in computing DIFF. + 2001-11-27 Zack Weinberg * cppfiles.c (read_include_file): Add comment. diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 5dd42fc8d7e..f6a07e96670 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -650,6 +650,12 @@ noce_try_store_flag_constants (if_info) mode = GET_MODE (if_info->x); ifalse = INTVAL (if_info->a); itrue = INTVAL (if_info->b); + + /* Make sure we can represent the difference between the two values. */ + if ((itrue - ifalse > 0) + != ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue)) + return FALSE; + diff = trunc_int_for_mode (itrue - ifalse, mode); can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)