https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62283
--- Comment #4 from Henrik Holst <holst at matmech dot com> ---
Thank you Richard for looking into this issue.
You probably know already exactly why this bug appeared. I just wanted to
stress the severity of this issue, and especially for Fortran which is often
used in "number crunching" applications AND subroutine arguments are passed by
reference by default.
The following F2008 code works as expected:
subroutine test1(x,y)
real x(4),y(4)
gamma=3.141593
block
beta=gamma
y(1)=y(1)+beta*x(1)
y(2)=y(2)+beta*x(2)
y(3)=y(3)+beta*x(3)
y(4)=y(4)+beta*x(4)
end block
end
but when `beta=gamma` is replaced with `beta=alpha` it again fails and
generates scalar code. So I ask: Does this bug force *ALL* computations which
involves directly or indirectly parameter values to subroutines and functions,
to be done in scalar? If so, its pretty bad.
Related or not, the following codes also generates scalar code:
subroutine test2(x,y)
real x(4),y(4)
beta=3.141593
do i=1,4
y(i)=y(i)+beta*x(i)
end do
end
and
subroutine test3(x,y)
real x(4),y(4)
beta=3.141593
y=y+beta*x
end
as well. I can create another bug for this if you think they are unrelated.
