On Tue, Apr 8, 2008 at 5:36 PM, Richard Guenther <[EMAIL PROTECTED]> wrote: > > On Tue, Apr 8, 2008 at 4:46 PM, Pranav Bhandarkar > <[EMAIL PROTECTED]> wrote: > > Hi, > > > > Consider the attached testcase. > > > > Working on a private port (Infact I see this problem on > > arm-none-eabi-gcc too). I see the following in test.c.003t.original > > > > fail = (short int) usi <= ssi; > > > > And then in test.c.025t.ssa > > usi.2_5 = (short int) usi_4; > > fail.3_6 = usi.2_5 <= ssi_2; > > > > Now ccp1 does constant propagation and we are left with > > usi.2_5 = -256; > > > > This causes the test to fail. > > > > Clearly the problem seems to be that since usi is unsigned short int a > > short int cant represent all the possible values of usi > > > > I reverted the following patch and the test passed. > > PR middle-end/35163 > > * fold-const.c (fold_widened_comparison): Use get_unwidened in > > value-preserving mode. Disallow final truncation. > > > > Now with the patch reverted, test.c.003t.original has > > > > fail = (int) ssi >= (int) usi; > > > > And this problem vanished. > > > > > > Am I missing something here ? > > Please file a bugreport about this.
Btw, I have a fix. Richard.
