added SSE/AVX/FMA4 real back transformation kernels

ELPA_2011.12.Intrinsics/src/elpa2.f90

@@ -1693,16 +1693,58 @@ contains
     subroutine compute_hh_trafo(off, ncols, istripe)
 
         integer off, ncols, istripe, j, nl, jj
-        real*8 w(nbw,2), ttt
+        real*8 w(nbw,6), ttt
 
         ttt = mpi_wtime()
         nl = merge(stripe_width, last_stripe_width, istripe<stripe_count)
+ 
+        !FORTRAN CODE / X86 INRINISIC CODE / BG ASSEMBLER USING 2 HOUSEHOLDER VECTORS
         do j = ncols, 2, -2
             w(:,1) = bcast_buffer(1:nbw,j+off)
             w(:,2) = bcast_buffer(1:nbw,j+off-1)
-            call double_hh_trafo(a(1,j+off+a_off-1,istripe), w, nbw, nl, stripe_width, nbw)
+            call double_hh_trafo_2hv(a(1,j+off+a_off-1,istripe), w, nbw, nl, stripe_width, nbw)
         enddo
         if(j==1) call single_hh_trafo(a(1,1+off+a_off,istripe),bcast_buffer(1,off+1), nbw, nl, stripe_width)
+                
+        ! X86 INTRINSIC CODE, USING 4 HOUSEHOLDER VECTORS
+        !do j = ncols, 4, -4
+        !    w(:,1) = bcast_buffer(1:nbw,j+off)
+        !    w(:,2) = bcast_buffer(1:nbw,j+off-1)
+        !    w(:,3) = bcast_buffer(1:nbw,j+off-2)
+        !    w(:,4) = bcast_buffer(1:nbw,j+off-3)
+        !    call double_hh_trafo_4hv(a(1,j+off+a_off-3,istripe), w, nbw, nl, stripe_width, nbw)
+        !enddo
+        !do jj = j, 2, -2
+        !    w(:,1) = bcast_buffer(1:nbw,jj+off)
+        !    w(:,2) = bcast_buffer(1:nbw,jj+off-1)
+        !    call double_hh_trafo_2hv(a(1,jj+off+a_off-1,istripe), w, nbw, nl, stripe_width, nbw)
+        !enddo
+        !if(jj==1) call single_hh_trafo(a(1,1+off+a_off,istripe),bcast_buffer(1,off+1), nbw, nl, stripe_width)
+
+        ! X86 INTRINSIC CODE, USING 6 HOUSEHOLDER VECTORS
+        !do j = ncols, 6, -6
+        !    w(:,1) = bcast_buffer(1:nbw,j+off)
+        !    w(:,2) = bcast_buffer(1:nbw,j+off-1)
+        !    w(:,3) = bcast_buffer(1:nbw,j+off-2)
+        !    w(:,4) = bcast_buffer(1:nbw,j+off-3)
+        !    w(:,5) = bcast_buffer(1:nbw,j+off-4)
+        !    w(:,6) = bcast_buffer(1:nbw,j+off-5)
+        !    call double_hh_trafo_6hv(a(1,j+off+a_off-5,istripe), w, nbw, nl, stripe_width, nbw)
+        !enddo
+        !do jj = j, 4, -4
+        !    w(:,1) = bcast_buffer(1:nbw,jj+off)
+        !    w(:,2) = bcast_buffer(1:nbw,jj+off-1)
+        !    w(:,3) = bcast_buffer(1:nbw,jj+off-2)
+        !    w(:,4) = bcast_buffer(1:nbw,jj+off-3)
+        !    call double_hh_trafo_4hv(a(1,jj+off+a_off-3,istripe), w, nbw, nl, stripe_width, nbw)
+        !enddo
+        !do jjj = jj, 2, -2
+        !    w(:,1) = bcast_buffer(1:nbw,jjj+off)
+        !    w(:,2) = bcast_buffer(1:nbw,jjj+off-1)
+        !    call double_hh_trafo_2hv(a(1,jjj+off+a_off-1,istripe), w, nbw, nl, stripe_width, nbw)
+        !enddo
+        !if(jjj==1) call single_hh_trafo(a(1,1+off+a_off,istripe),bcast_buffer(1,off+1), nbw, nl, stripe_width)
+        
         kernel_flops = kernel_flops + 4*int(nl,8)*int(ncols,8)*int(nbw,8)
         kernel_time = kernel_time + mpi_wtime()-ttt
 

ELPA_2011.12.Intrinsics/src/elpa2_kernels/README_elpa2_kernels.txt

+ELPA generally uses BLAS-Routines for all compute intensive work
+so that the performance of ELPA mainly depends on the quality of
+the BLAS implementation used when linking.
+
+The only exception is the backtransformation of the eigenvectors
+for the 2-stage solver (ELPA2). In this case BLAS routines cannot
+be used effectively due to the nature of the problem.
+
+The compute intensive part of the backtransformation of ELPA2
+has been put to a file of its own (elpa2_kernels.f90) so that
+this can be replaced by hand tailored, optimized code for
+specific platforms.
+
+Currently we offer the following alternatives for the ELPA2 kernels:
+
+* elpa2_kernels.f90          - The generic FORTRAN version of the ELPA2 kernels
+                               which should be useable on every platform.
+                               It contains some hand optimizations (loop unrolling)
+                               in the hope to get optimal code from most FORTRAN
+                               compilers.
+
+* elpa2_kernels_simple.f90   - Plain and simple version of elpa2_kernels.f90.
+                               Please note that we observed that some compilers get
+                               get confused by the hand optimizations done in
+                               elpa2_kernels.f90 and give better performance
+                               with this version - so it is worth to try both!
+
+* elpa2_kernels_bg.f90       - Fortran code enhanced with assembler calls
+                               for the IBM BlueGene/P
+
+* elpa2_tum_kernels_*.c      - Optimized intrinisic code for x86_64
+                               systems (i.e. Intel/AMD architecture)
+                               using SSE2/SSE3 operations.
+                               (Use gcc for compiling as Intel compiler generates slower code!)
+
+
+So which version should be used?
+================================
+
+* On x86_64 systems (i.e. almost all Intel/AMD systems) or on the IBM BlueGene/P
+  you should get the optimal performance using the optimized intrinsics/assembler versions
+  in elpa2_tum_kernels_*.c or elpa2_kernels_bg.f90 respectively.
+
+* If you don't compile for one of these systems or you don't like to use assembler
+  for any reason, it is likely that you are best off using elpa2_kernels.f90.
+  Make a perfomance test with elpa2_kernels_simple.f90, however, to check if
+  your compiler doesn't get confused by the hand optimizations.
+
+* If you want to develop your own optimized kernels for you platform, it is
+  easier to start with elpa2_kernels_simple.f90.
+  Don't let you confuse from the huge code in elpa2_kernels.f90, the mathemathics
+  done in the kernels is relatively trivial.

ELPA_2011.12.Intrinsics/src/elpa2_kernels/elpa2_kernels_complex.f90

+! --------------------------------------------------------------------------------------------------
+!
+! This file contains the compute intensive kernels for the Householder transformations.
+! It should be compiled with the highest possible optimization level.
+!
+! On Intel use -O3 -xSSE4.2 (or the SSE level fitting to your CPU)
+! 
+! Copyright of the original code rests with the authors inside the ELPA
+! consortium. The copyright of any additional modifications shall rest
+! with their original authors, but shall adhere to the licensing terms
+! distributed along with the original code in the file "COPYING".
+!
+! --------------------------------------------------------------------------------------------------
+
+subroutine single_hh_trafo_complex(q, hh, nb, nq, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, nq, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   integer i
+
+   ! Safety only:
+
+   if(mod(ldq,4) /= 0) STOP 'double_hh_trafo: ldq not divisible by 4!'
+
+   ! Do the Householder transformations
+
+   ! Always a multiple of 4 Q-rows is transformed, even if nq is smaller
+
+   do i=1,nq-8,12
+      call hh_trafo_complex_kernel_12(q(i,1),hh, nb, ldq)
+   enddo
+
+   ! i > nq-8 now, i.e. at most 8 rows remain
+
+   if(nq-i+1 > 4) then
+      call hh_trafo_complex_kernel_8(q(i,1),hh, nb, ldq)
+   else if(nq-i+1 > 0) then
+      call hh_trafo_complex_kernel_4(q(i,1),hh, nb, ldq)
+   endif
+
+end
+
+! --------------------------------------------------------------------------------------------------
+
+subroutine hh_trafo_complex_kernel_12(q, hh, nb, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   complex*16 x1, x2, x3, x4, x5, x6, x7, x8, x9, xa, xb, xc
+   complex*16 h1, tau1
+   integer i
+
+
+   x1 = q(1,1)
+   x2 = q(2,1)
+   x3 = q(3,1)
+   x4 = q(4,1)
+   x5 = q(5,1)
+   x6 = q(6,1)
+   x7 = q(7,1)
+   x8 = q(8,1)
+   x9 = q(9,1)
+   xa = q(10,1)
+   xb = q(11,1)
+   xc = q(12,1)
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = conjg(hh(i))
+      x1 = x1 + q(1,i)*h1
+      x2 = x2 + q(2,i)*h1
+      x3 = x3 + q(3,i)*h1
+      x4 = x4 + q(4,i)*h1
+      x5 = x5 + q(5,i)*h1
+      x6 = x6 + q(6,i)*h1
+      x7 = x7 + q(7,i)*h1
+      x8 = x8 + q(8,i)*h1
+      x9 = x9 + q(9,i)*h1
+      xa = xa + q(10,i)*h1
+      xb = xb + q(11,i)*h1
+      xc = xc + q(12,i)*h1
+   enddo
+
+   tau1 = hh(1)
+
+   h1 = -tau1
+   x1 = x1*h1
+   x2 = x2*h1
+   x3 = x3*h1
+   x4 = x4*h1
+   x5 = x5*h1
+   x6 = x6*h1
+   x7 = x7*h1
+   x8 = x8*h1
+   x9 = x9*h1
+   xa = xa*h1
+   xb = xb*h1
+   xc = xc*h1
+
+   q(1,1) = q(1,1) + x1
+   q(2,1) = q(2,1) + x2
+   q(3,1) = q(3,1) + x3
+   q(4,1) = q(4,1) + x4
+   q(5,1) = q(5,1) + x5
+   q(6,1) = q(6,1) + x6
+   q(7,1) = q(7,1) + x7
+   q(8,1) = q(8,1) + x8
+   q(9,1) = q(9,1) + x9
+   q(10,1) = q(10,1) + xa
+   q(11,1) = q(11,1) + xb
+   q(12,1) = q(12,1) + xc
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = hh(i)
+      q(1,i) = q(1,i) + x1*h1
+      q(2,i) = q(2,i) + x2*h1
+      q(3,i) = q(3,i) + x3*h1
+      q(4,i) = q(4,i) + x4*h1
+      q(5,i) = q(5,i) + x5*h1
+      q(6,i) = q(6,i) + x6*h1
+      q(7,i) = q(7,i) + x7*h1
+      q(8,i) = q(8,i) + x8*h1
+      q(9,i) = q(9,i) + x9*h1
+      q(10,i) = q(10,i) + xa*h1
+      q(11,i) = q(11,i) + xb*h1
+      q(12,i) = q(12,i) + xc*h1
+   enddo
+
+end
+
+! --------------------------------------------------------------------------------------------------
+
+subroutine hh_trafo_complex_kernel_8(q, hh, nb, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   complex*16 x1, x2, x3, x4, x5, x6, x7, x8
+   complex*16 h1, tau1
+   integer i
+
+
+   x1 = q(1,1)
+   x2 = q(2,1)
+   x3 = q(3,1)
+   x4 = q(4,1)
+   x5 = q(5,1)
+   x6 = q(6,1)
+   x7 = q(7,1)
+   x8 = q(8,1)
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = conjg(hh(i))
+      x1 = x1 + q(1,i)*h1
+      x2 = x2 + q(2,i)*h1
+      x3 = x3 + q(3,i)*h1
+      x4 = x4 + q(4,i)*h1
+      x5 = x5 + q(5,i)*h1
+      x6 = x6 + q(6,i)*h1
+      x7 = x7 + q(7,i)*h1
+      x8 = x8 + q(8,i)*h1
+   enddo
+
+   tau1 = hh(1)
+
+   h1 = -tau1
+   x1 = x1*h1
+   x2 = x2*h1
+   x3 = x3*h1
+   x4 = x4*h1
+   x5 = x5*h1
+   x6 = x6*h1
+   x7 = x7*h1
+   x8 = x8*h1
+
+   q(1,1) = q(1,1) + x1
+   q(2,1) = q(2,1) + x2
+   q(3,1) = q(3,1) + x3
+   q(4,1) = q(4,1) + x4
+   q(5,1) = q(5,1) + x5
+   q(6,1) = q(6,1) + x6
+   q(7,1) = q(7,1) + x7
+   q(8,1) = q(8,1) + x8
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = hh(i)
+      q(1,i) = q(1,i) + x1*h1
+      q(2,i) = q(2,i) + x2*h1
+      q(3,i) = q(3,i) + x3*h1
+      q(4,i) = q(4,i) + x4*h1
+      q(5,i) = q(5,i) + x5*h1
+      q(6,i) = q(6,i) + x6*h1
+      q(7,i) = q(7,i) + x7*h1
+      q(8,i) = q(8,i) + x8*h1
+   enddo
+
+end
+
+! --------------------------------------------------------------------------------------------------
+
+subroutine hh_trafo_complex_kernel_4(q, hh, nb, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   complex*16 x1, x2, x3, x4
+   complex*16 h1, tau1
+   integer i
+
+
+   x1 = q(1,1)
+   x2 = q(2,1)
+   x3 = q(3,1)
+   x4 = q(4,1)
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = conjg(hh(i))
+      x1 = x1 + q(1,i)*h1
+      x2 = x2 + q(2,i)*h1
+      x3 = x3 + q(3,i)*h1
+      x4 = x4 + q(4,i)*h1
+   enddo
+
+   tau1 = hh(1)
+
+   h1 = -tau1
+   x1 = x1*h1
+   x2 = x2*h1
+   x3 = x3*h1
+   x4 = x4*h1
+
+   q(1,1) = q(1,1) + x1
+   q(2,1) = q(2,1) + x2
+   q(3,1) = q(3,1) + x3
+   q(4,1) = q(4,1) + x4
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = hh(i)
+      q(1,i) = q(1,i) + x1*h1
+      q(2,i) = q(2,i) + x2*h1
+      q(3,i) = q(3,i) + x3*h1
+      q(4,i) = q(4,i) + x4*h1
+   enddo
+
+end
+
+! --------------------------------------------------------------------------------------------------

ELPA_2011.12.Intrinsics/src/elpa2_kernels/elpa2_kernels_complex_bg.f90

+! --------------------------------------------------------------------------------------------------
+!
+! This file contains the compute intensive kernels for the Householder transformations.
+!
+! *** Special IBM BlueGene/P version with BlueGene assembler instructions in Fortran ***
+! 
+! Copyright of the original code rests with the authors inside the ELPA
+! consortium. The copyright of any additional modifications shall rest
+! with their original authors, but shall adhere to the licensing terms
+! distributed along with the original code in the file "COPYING".
+!
+! --------------------------------------------------------------------------------------------------
+
+subroutine single_hh_trafo_complex(q, hh, nb, nq, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, nq, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   integer i
+
+   ! Safety only:
+
+   if(mod(ldq,4) /= 0) STOP 'double_hh_trafo: ldq not divisible by 4!'
+
+   ! Do the Householder transformations
+
+   ! Always a multiple of 4 Q-rows is transformed, even if nq is smaller
+
+   do i=1,nq-8,12
+      call hh_trafo_complex_kernel_12(q(i,1),hh, nb, ldq)
+   enddo
+
+   ! i > nq-8 now, i.e. at most 8 rows remain
+
+   if(nq-i+1 > 4) then
+      call hh_trafo_complex_kernel_8(q(i,1),hh, nb, ldq)
+   else if(nq-i+1 > 0) then
+      call hh_trafo_complex_kernel_4(q(i,1),hh, nb, ldq)
+   endif
+
+end
+
+! --------------------------------------------------------------------------------------------------
+
+subroutine hh_trafo_complex_kernel_12(q, hh, nb, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   complex*16 x1, x2, x3, x4, x5, x6, x7, x8, x9, xa, xb, xc
+   complex*16 h1, tau1
+   integer i
+
+
+   x1 = q(1,1)
+   x2 = q(2,1)
+   x3 = q(3,1)
+   x4 = q(4,1)
+   x5 = q(5,1)
+   x6 = q(6,1)
+   x7 = q(7,1)
+   x8 = q(8,1)
+   x9 = q(9,1)
+   xa = q(10,1)
+   xb = q(11,1)
+   xc = q(12,1)
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = conjg(hh(i))
+      x1 = x1 + q(1,i)*h1
+      x2 = x2 + q(2,i)*h1
+      x3 = x3 + q(3,i)*h1
+      x4 = x4 + q(4,i)*h1
+      x5 = x5 + q(5,i)*h1
+      x6 = x6 + q(6,i)*h1
+      x7 = x7 + q(7,i)*h1
+      x8 = x8 + q(8,i)*h1
+      x9 = x9 + q(9,i)*h1
+      xa = xa + q(10,i)*h1
+      xb = xb + q(11,i)*h1
+      xc = xc + q(12,i)*h1
+   enddo
+
+   tau1 = hh(1)
+
+   h1 = -tau1
+   x1 = x1*h1
+   x2 = x2*h1
+   x3 = x3*h1
+   x4 = x4*h1
+   x5 = x5*h1
+   x6 = x6*h1
+   x7 = x7*h1
+   x8 = x8*h1
+   x9 = x9*h1
+   xa = xa*h1
+   xb = xb*h1
+   xc = xc*h1
+
+   q(1,1) = q(1,1) + x1
+   q(2,1) = q(2,1) + x2
+   q(3,1) = q(3,1) + x3
+   q(4,1) = q(4,1) + x4
+   q(5,1) = q(5,1) + x5
+   q(6,1) = q(6,1) + x6
+   q(7,1) = q(7,1) + x7
+   q(8,1) = q(8,1) + x8
+   q(9,1) = q(9,1) + x9
+   q(10,1) = q(10,1) + xa
+   q(11,1) = q(11,1) + xb
+   q(12,1) = q(12,1) + xc
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = hh(i)
+      q(1,i) = q(1,i) + x1*h1
+      q(2,i) = q(2,i) + x2*h1
+      q(3,i) = q(3,i) + x3*h1
+      q(4,i) = q(4,i) + x4*h1
+      q(5,i) = q(5,i) + x5*h1
+      q(6,i) = q(6,i) + x6*h1
+      q(7,i) = q(7,i) + x7*h1
+      q(8,i) = q(8,i) + x8*h1
+      q(9,i) = q(9,i) + x9*h1
+      q(10,i) = q(10,i) + xa*h1
+      q(11,i) = q(11,i) + xb*h1
+      q(12,i) = q(12,i) + xc*h1
+   enddo
+
+end
+
+! --------------------------------------------------------------------------------------------------
+
+subroutine hh_trafo_complex_kernel_8(q, hh, nb, ldq)
+
+   implicit none
+
+   integer, intent(in) :: nb, ldq
+   complex*16, intent(inout) :: q(ldq,*)
+   complex*16, intent(in) :: hh(*)
+
+   complex*16 x1, x2, x3, x4, x5, x6, x7, x8
+   complex*16 h1, tau1
+   integer i
+
+
+   x1 = q(1,1)
+   x2 = q(2,1)
+   x3 = q(3,1)
+   x4 = q(4,1)
+   x5 = q(5,1)
+   x6 = q(6,1)
+   x7 = q(7,1)
+   x8 = q(8,1)
+
+!DEC$ VECTOR ALIGNED
+   do i=2,nb
+      h1 = conjg(hh(i))
+      x1 = x1 + q(1,i)*h1
+      x2 = x2 + q(2,i)*h1
+      x3 = x3 + q(3,i)*h1
+      x4 = x4 + q(4,i)*h1
+      x5 = x5 + q(5,i)*h1
+      x6 = x6 + q(6,i)*h1