As shown by the following code, the complex matrix product is not vectorized,
even with the patch in http://gcc.gnu.org/ml/gcc-patches/2009-01/msg01174.html:
program mymatmul
implicit none
integer, parameter :: kp = 4
integer, parameter :: n = 2000
real(kp), dimension(n,n) :: rr, ri
complex(kp), dimension(n,n) :: a,b,c
real :: t1, t2
integer :: i, j, k
call random_number (rr)
call random_number (ri)
a = cmplx (rr, ri)
call random_number (rr)
call random_number (ri)
b = cmplx (rr, ri)
call cpu_time (t1)
c = cmplx (0._kp, 0._kp)
do j = 1, n
do k = 1, n
do i = 1, n
c(i,j) = c(i,j) + a(i,k) * b(k,j)
end do
end do
end do
call cpu_time (t2)
write (*,'(F8.4)') t2-t1
end program mymatmul
[ibook-dhum] bug/timing% gfc -m64 -O3 -ffast-math -funroll-loops
-fomit-frame-pointer -ftree-vectorizer-verbose=2 mymatmul_v_c4.f90
mymatmul_v_c4.f90:22: note: not vectorized: can't calculate alignment for data
ref.
mymatmul_v_c4.f90:15: note: not vectorized: complicated access pattern.
mymatmul_v_c4.f90:15: note: not vectorized: can't calculate alignment for data
ref.
mymatmul_v_c4.f90:12: note: not vectorized: complicated access pattern.
mymatmul_v_c4.f90:12: note: not vectorized: can't calculate alignment for data
ref.
mymatmul_v_c4.f90:1: note: vectorized 0 loops in function.
The real corresponding code is vectorized.
--
Summary: Complex matrix product is not vectorized
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dominiq at lps dot ens dot fr
GCC build triplet: i686-apple-darwin9
GCC host triplet: i686-apple-darwin9
GCC target triplet: i686-apple-darwin9
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38968
