[Bug fortran/80765] New: [8 Regression] 178.galgel in SPEC CPU 2000 fails to run

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80765

            Bug ID: 80765
           Summary: [8 Regression] 178.galgel in SPEC CPU 2000 fails to
                    run
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: tkoenig at gcc dot gnu.org
  Target Milestone: ---
            Target: i386

On Linux/i686, r247753 caused 178.galgel in SPEC CPU 2000 fails to run:

...
 Solution by global spectral Galerkin method.
________________________________________________________________________________

 Parameters:

 Aspect ratio (length/height) =  4.0000000    
 Prandtl number               = 0.15000000E-01

 Number of basis functions in x-direction =  33
 Number of basis functions in z-direction =  11
________________________________________________________________________________



Program received signal SIGSEGV, Segmentation fault.
0xf7ed2a02 in matmul_r8_avx2 (retarray=<optimized out>, a=<optimized out>, 
    b=<optimized out>, try_blas=<optimized out>, blas_limit=<optimized out>, 
    gemm=<optimized out>)
    at ../../../../src-trunk/libgfortran/generated/matmul_r8.c:911
911                               t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
(gdb) 

=> 0xf7ed2a02 <+2658>:  vmovsd %xmm2,(%edi,%ecx,8)

(gdb) p $edi
$5 = 0
(gdb) p/x $ecx
$7 = 0x20000000
(gdb) p/x 0x20000000 * 8
$10 = 0x0