> I see one case that seems really stupid, and one that's just wrong. I'm > thinking that either I have something really flawed with my port's handing > of DImode or that there was a bug in 4.6.1. The port is only failing > about 2100 dejagnu tests (passing 64000+) and a good chunk of the failures > are due to the ridiculously small data-memory size of the chip.
Please do not use "bad code", it's ambiguous, always use "wrong code" instead. > For > > long long int x; > > if ( x < 0 ) return 0 else return 2; > > I see code that compares MSBs and branches on < (less than) as expected. > But then it goes and checks the MSBs for != , and finally it checks the > LSBS and emits a conditional branch to the ELSE, followed by an > unconditional branch to the ELSE, so that I end up with code that looks > like > > mov $r1,x > mov $r2,x+4 > cmpi $r2,0 > jlt .L5 > cmpi $r2,0 <=== totally redundant for "x < 0" comparisons > jne .L2 > cmpi $r1,0 > jmp .L4 > > .L5 : movi $r1, 0 > jump .L4 > > .L2 : movi $r1, 2 > > .L4: > ret While poor code is expected at -O0, wrong code isn't of course. Could you post a compilable testcase instead of an excerpt and the contents of the .expand dump file (compile with -fdump-rtl-expand to get it)? -- Eric Botcazou
