[Bug fortran/35220] New: zdotu (copy of BLAS version) works in x86, x86_64, segfaults in arm.

[akumar at ee dot iitm dot ac dot in]

Hi!

The following programs are built like this:

gfortran -c zdotu.f -ggdb
g++ -c ztest.cpp -ggdb
g++ -o ztest zdotu.o ztest.o

The generated ztest segfaults on ARM on line 37 of zdotu.f with SIGSEGV, while
it is perfect on other arches.

Thanks!

Kumar

zdotu.f
-------
      DOUBLE COMPLEX FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
*     .. Scalar Arguments ..
      INTEGER INCX,INCY,N
*     ..
*     .. Array Arguments ..
      DOUBLE COMPLEX ZX(*),ZY(*)
*     ..
*
*  Purpose
*  =======
*
*     ZDOTU forms the dot product of two vectors.
*
*  Further Details
*  ===============
*
*     jack dongarra, 3/11/78.
*     modified 12/3/93, array(1) declarations changed to array(*)
*
*     .. Local Scalars ..
      DOUBLE COMPLEX ZTEMP
      INTEGER I,IX,IY
*     ..
      ZTEMP = (0.0d0,0.0d0)
      ZDOTU = (0.0d0,0.0d0)
      IF (N.LE.0) RETURN
      IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20
*
*        code for unequal increments or equal increments
*          not equal to 1
*
      IX = 1
      IY = 1
      IF (INCX.LT.0) IX = (-N+1)*INCX + 1
      IF (INCY.LT.0) IY = (-N+1)*INCY + 1
      DO 10 I = 1,N
          ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
          IX = IX + INCX
          IY = IY + INCY
   10 CONTINUE
      ZDOTU = ZTEMP
      RETURN
*
*        code for both increments equal to 1
*
   20 DO 30 I = 1,N
          ZTEMP = ZTEMP + ZX(I)*ZY(I)
   30 CONTINUE
      ZDOTU = ZTEMP
      RETURN
      END

ztest.cpp
---------
#include <complex>

typedef std::complex<double> cdouble;
extern "C" {
        cdouble zdotu_(const int *, const cdouble *, const int *,
                       const cdouble *, const int *);
}
int main() {
        int incr = 1;
        int size = 6;
        cdouble a[] = {cdouble( 0.7219, 0.8871), cdouble( 0.7073,-0.7953),
                       cdouble( 0.2610, 0.4325), cdouble(-0.0565,-0.0719),
                       cdouble( 0.7277,-0.9754), cdouble(-0.3780, 1.0718)};
        cdouble b[] = {cdouble(-0.0821,+0.8410), cdouble(-0.0749, 0.0729),
                       cdouble(-0.6094,-0.2975), cdouble( 0.2106,-0.2026),
                       cdouble( 0.1043,-0.8300), cdouble( 0.0806, 0.3698)};
        cdouble x_ref(-2.01767031,-0.45861365);
        cdouble x = zdotu_(&size, a, &incr, b, &incr);
        return (std::abs(x - x_ref) < 1e-6) ? 0 : 1;
}


-- 
           Summary: zdotu (copy of BLAS version) works in x86, x86_64,
                    segfaults in arm.
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: akumar at ee dot iitm dot ac dot in
 GCC build triplet: arm-linux-gnu
  GCC host triplet: arm-linux-gnu
GCC target triplet: arm-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35220