https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80975
Bug ID: 80975
Summary: [7 Regression] matmul for zero-length arrays
Product: gcc
Version: 7.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: Melven.Roehrig-Zoellner at DLR dot de
Target Milestone: ---
Hi,
the following code fails in GCC 7.1 (at least for my setup):
program bogus_matmul
implicit none
real :: M(3,0), v(0), w(3)
w = 7
w = matmul(M,v)
if( any(w .ne. 0) ) then
call exit(1)
end if
end program vast_chk_bogus_matmul
The correct result for w should be zero (at least "mathematically", I didn't
check the standard!)
However, with GCC 7.1 it is not zero. Works fine in 6.2 and any other previous
version I used before.
I'm using mingw-w64:
https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/7.1.0/threads-posix/seh/
And I used the following compile flags:
-std=f2008 -ffree-line-length-none -fall-intrinsics -fno-realloc-lhs
-fdefault-real-8 -fdefault-double-8 -finit-real=snan -g -O0 -Wall
-Wimplicit-interface -fcheck=all -fbacktrace -Wno-unused-dummy-argument
-Wno-surprising -Wno-unused-variable -fopenmp
Unfortunately I cannot easily check if it also fails on Linux!
