LLVM codegen error: example_lmdif1.f90 #12
Comments
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@@ -52,7 +55,7 @@ m = size(fvec)
n = size(x)
allocate(wa(m*n + 5*n + m))
call lmdif1(fcn, size(fvec), size(x), x, fvec, tol, info, iwa, wa, size(wa))
-print 1000, enorm(size(fvec), fvec), info, x
+print 1000, enorm(size(fvec), fvec), info
1000 format(5x, 'FINAL L2 NORM OF THE RESIDUALS', d15.7 // &
5x, 'EXIT PARAMETER', 16x, i10 // &
5x, 'FINAL APPROXIMATE SOLUTION' // &OR @@ -52,7 +55,7 @@ m = size(fvec)
n = size(x)
allocate(wa(m*n + 5*n + m))
call lmdif1(fcn, size(fvec), size(x), x, fvec, tol, info, iwa, wa, size(wa))
-print 1000, enorm(size(fvec), fvec), info, x
+print 1000, enorm(size(fvec), fvec), info
+print *, x
1000 format(5x, 'FINAL L2 NORM OF THE RESIDUALS', d15.7 // &
5x, 'EXIT PARAMETER', 16x, i10 // &
5x, 'FINAL APPROXIMATE SOLUTION' // & |
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Values are good till a few iterations then it begins to diverge For diff diff --git a/examples/example_lmdif1.f90 b/examples/example_lmdif1.f90
index 7da6b75..24b27b3 100644
--- a/examples/example_lmdif1.f90
+++ b/examples/example_lmdif1.f90
@@ -13,6 +13,7 @@ real(dp), intent(in) :: x(n)
real(dp), intent(out) :: fvec(m)
integer :: i
+integer :: j = 0
real(dp) :: tmp1, tmp2, tmp3, y(15)
! Suppress compiler warning:
y(1) = iflag
@@ -25,7 +26,12 @@ do i = 1, 15
tmp3 = tmp1
if (i .gt. 8) tmp3 = tmp2
fvec(i) = y(i) - (x(1) + tmp1/(x(2)*tmp2 + x(3)*tmp3))
+
+ print *, "fvec(", i, ") :", fvec(i)
+ if ( i .eq. 15 ) j = j + 1
+
end do
+print * , "j :", j
end subroutine
end moduleGFortran LFortran |
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Okay so, I investigated more and found out that the following might be cause of divergence For following diff diff --git a/src/lmdif.f b/src/lmdif.f
index fcb61d1..78927e4 100644
--- a/src/lmdif.f
+++ b/src/lmdif.f
@@ -198,7 +198,11 @@ c **********
c
c epsmch is the machine precision.
c
+ print *, "factor in lmdif: ", factor
+
epsmch = dpmpar(1)
+
+ print *, "factor in lmdif here :", factor
c
info = 0
iflag = 0and index 6f28ed2..8c43db6 100644
--- a/src/lmdif1.f
+++ b/src/lmdif1.f
@@ -124,6 +124,8 @@ c
mode = 1
nprint = 0
mp5n = m + 5*n
+ print *, 'lmdif1: calling lmdif'
+ print *, "factor: ", factor
call lmdif(fcn,m,n,x,fvec,ftol,xtol,gtol,maxfev,epsfcn,wa(1),
* mode,factor,nprint,info,nfev,wa(mp5n+1),m,iwa,
* wa(n+1),wa(2*n+1),wa(3*n+1),wa(4*n+1),wa(5*n+1))
Value of |
diff --git a/src/lmdif.f b/src/lmdif.f
index fcb61d1..f1bfc73 100644
--- a/src/lmdif.f
+++ b/src/lmdif.f
@@ -193,12 +193,18 @@ c **********
* one,par,pnorm,prered,p1,p5,p25,p75,p0001,ratio,
* sum,temp,temp1,temp2,xnorm,zero
double precision dpmpar,enorm
+ factor = 100.00
+ print *, "factor in lmdif here2: ", factor
data one,p1,p5,p25,p75,p0001,zero
* /1.0d0,1.0d-1,5.0d-1,2.5d-1,7.5d-1,1.0d-4,0.0d0/The above given diff complies |
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Variable |
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The bug is mentioned at lfortran/lfortran#1118. |
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Okay so with lfortran/lfortran#1119, I get the following output
3.0000000000000000
9.0635960339045418E-002 1
8.2410575864368327E-002 1.1330366265378435 2.3436946649075865
3.00000000000000000e+00
9.06359603390341356e-02 6
8.24105600064365257e-02
1.13303609732462451e+00
2.34369517380158099e+00 |
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The value that diverges is With the following diff we can see cause of divergence diff --git a/examples/example_lmdif1.f90 b/examples/example_lmdif1.f90
index 7da6b75..73d595f 100644
--- a/examples/example_lmdif1.f90
+++ b/examples/example_lmdif1.f90
@@ -43,6 +43,7 @@ real(dp), allocatable :: wa(:)
! The following starting values provide a rough fit.
x = [1._dp, 1._dp, 1._dp]
+print *, dabs(3.0_8)
! Set tol to the square root of the machine precision. Unless high precision
! solutions are required, this is the recommended setting.
@@ -51,8 +52,11 @@ tol = sqrt(epsilon(1._dp))
m = size(fvec)
n = size(x)
allocate(wa(m*n + 5*n + m))
+print *, "tol: ", tol
call lmdif1(fcn, size(fvec), size(x), x, fvec, tol, info, iwa, wa, size(wa))
-print 1000, enorm(size(fvec), fvec), info, x
+print *, enorm(size(fvec), fvec)
+print *, "info: ", info
+print *, x
1000 format(5x, 'FINAL L2 NORM OF THE RESIDUALS', d15.7 // &
5x, 'EXIT PARAMETER', 16x, i10 // &
3.0000000000000000
tol: 1.4901161193847656E-008
9.0635960339045418E-002
info: 1
8.2410575864368327E-002 1.1330366265378435 2.3436946649075865
3.00000000000000000e+00
tol: 1.49166814624004135e-154
9.06359603390341356e-02
info: 6
8.24105600064365257e-02
1.13303609732462451e+00
2.34369517380158099e+00 |
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On using the following diff, the output of GFortran and LFortran matches upto 1e-11 / 1e-12. diff --git a/examples/example_lmdif1.f90 b/examples/example_lmdif1.f90
index 7da6b75..8ef8a04 100644
--- a/examples/example_lmdif1.f90
+++ b/examples/example_lmdif1.f90
@@ -43,16 +43,21 @@ real(dp), allocatable :: wa(:)
! The following starting values provide a rough fit.
x = [1._dp, 1._dp, 1._dp]
+print *, dabs(3.0_8)
! Set tol to the square root of the machine precision. Unless high precision
! solutions are required, this is the recommended setting.
tol = sqrt(epsilon(1._dp))
+tol = 1.4901161193847656E-008
3.0000000000000000
tol: 1.4901161193847656E-008
9.0635960339045418E-002
info: 1
8.2410575864368327E-002 1.1330366265378435 2.3436946649075865
3.00000000000000000e+00
tol: 1.49011611938476562e-08
9.06359603390454183e-02
info: 1
8.24105758643683267e-02
1.13303662653784354e+00
2.34369466490758649e+00 |
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Error comes from
@examples/example_lmdif1.f90#L55.This is same as
comment.Error:
On commenting line,
example_lmdif1.f90compiles, and output is exact same as gfortran.The text was updated successfully, but these errors were encountered: