[Bug target/35695] New: [4.3/4.4 regression] -funroll-loops breaks inline float divide

schwab at suse dot de gcc-bugzilla@gcc.gnu.org
Tue Mar 25 17:29:00 GMT 2008


$ gcc -O2 div.c
$ ./a.out
 1.000000000000000 0.5000000000000000 0.5000000000000000 0.3333333333333333
$ gcc -O2 -funroll-loops div.c
$ ./a.out
 1.000000000000000 0.4999980926513672 0.4999980926513672 0.3333330154418945

With -funroll-loops the insn that computes e = 1 - (b * y) is optimized in cse2
to e = 0.


-- 
           Summary: [4.3/4.4 regression] -funroll-loops breaks inline float
                    divide
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: schwab at suse dot de
GCC target triplet: ia64-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35695



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