[Bug middle-end/20432] New: complex reciprocal has too many operations

[Thomas dot Koenig at online dot de]

#include <math.h>
#include <complex.h>

int main()
{
    float complex c,d;
    foo(&c);
    d=1.0/c;
    return creal(d)+cimag(d)<0;
}
$ gcc -S -O -fdump-tree-optimized recip.c
$ tail -25 recip.c.t66.optimized
<bb 0>:
  foo (&c);
  SR.24 = (double) REALPART_EXPR <c>;
  SR.23 = (double) IMAGPART_EXPR <c>;
  if (ABS_EXPR <SR.24> < ABS_EXPR <SR.23>) goto <L1>; else goto <L2>;

<L1>:;
  D.2387 = SR.24 / SR.23;
  D.2389 = SR.23 + SR.24 * D.2387;
  SR.25 = (D.2387 + 0.0) / D.2389;
  SR.26 = (D.2387 * 0.0 - 1.0e+0) / D.2389;
  goto <bb 3>;

<L2>:;
  D.2395 = SR.23 / SR.24;
  D.2397 = SR.24 + SR.23 * D.2395;
  SR.25 = (D.2395 * 0.0 + 1.0e+0) / D.2397;
  SR.26 = (0.0 - D.2395) / D.2397;

<bb 3>:
  return (double) (float) SR.25 + (double) (float) SR.26 < 0.0;

}

$ gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../gcc-4.1/configure --prefix=/home/ig25 
--enable-languages=c,f95
Thread model: posix
gcc version 4.1.0 20050311 (experimental)

I can't see a reason why the +0 and *0 operations should
be necessary.  

Thomas

-- 
           Summary: complex reciprocal has too many operations
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Thomas dot Koenig at online dot de
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20432