Formura bug sample

diffusion.fmr

dimension :: 1
axes :: x

double :: h = 1/NX
double :: cfl = 0.1
double :: dt = cfl*h*h

dd = fun(q) (q[i+1] + q[i-1] - 2*q[i])/(h**2)

begin function q = init()
double [] :: q = 0
end function

begin function q' = step(q)
q' = q + dt*(dd q)
end function

diffusion.yaml

initial_walls:
    x: [50]
intra_node_shape: [100]
monitor_interval: 2
mpi_grid_shape: [1]
temporal_blocking_interval: 1

diffusion_internal_0.c

#include <mpi.h>
#include <math.h>
#include <stdbool.h>

#include "diffusion.h"

void Formura_internal(){

for (int  ix = 0 ; ix < 2 ;++ ix ){
Facet_1_src__0_dest__1_Send.Ridge_1_St_q[ix]=q[ix+(2)];}

Formura_subroutine_0(3,51,-1,0,1,-1,0);

}
void Formura_internal_0(){

for (int  ix = 0 ; ix < 2 ;++ ix ){
q[ix+(102)]=Facet_1_src__0_dest__1_Recv.Ridge_1_St_q[ix];}

Formura_subroutine_0(51,103,-1,0,1,-1,0);

}
void Formura_internal_1(){

for (int  ix = 0 ; ix < 2 ;++ ix ){
Facet_m1_src__1_dest__0_Send.Ridge_m1_St_q[ix]=q[ix+(100)];}

Formura_subroutine_0(53,101,-1,0,1,1,0);

}
void Formura_internal_2(){

for (int  ix = 0 ; ix < 2 ;++ ix ){
q[ix+(0)]=Facet_m1_src__1_dest__0_Recv.Ridge_m1_St_q[ix];}

Formura_subroutine_0(1,53,-1,0,1,1,0);

}
void Formura_subroutine_0(int argx0,int argx1,int argx2,int argx3,int argx4,int argx5,int argx6){
for (int  ix = argx0 ; ix < argx1 ; ix += 1 ){
  double  a=(1.0/100.0)/*True*/;
  double  a_0=(0.1*a)/*True*/;
 double  a_1=(a_0*a)/*True*/;
 double  a_2=q[ix+(argx2)]/*True*/;
 double  a_3=q[ix+(argx3)]/*True*/;
 double  a_4=q[ix+(argx4)]/*True*/;
 double  a_5=(a_4+a_2)/*True*/;
  double  a_6=(2.0*a_3)/*True*/;
 double  a_7=(a_5-a_6)/*True*/;
  double  a_8=pow(a,2.0)/*True*/;
 double  a_9=(a_7/a_8)/*True*/;
 double  a_10=(a_1*a_9)/*True*/;
 double  a_11=(a_3+a_10)/*True*/;
 
q[ix+(argx5)+(argx6)]=a_11;

}
}

diffusion.fmr と diffusion.yaml から生成されたのが diffusion_internal_0.c.

diffusion_internal_0.c では https://gist.github.com/ishiy1993/801f2a81af6886afcf312868aeafe521#file-diffusion_internal_0-c-L56 のようにqがただちに更新される.

https://gist.github.com/ishiy1993/801f2a81af6886afcf312868aeafe521#file-diffusion_internal_0-c-L29 や https://gist.github.com/ishiy1993/801f2a81af6886afcf312868aeafe521#file-diffusion_internal_0-c-L29 のような呼び出しはこれからの計算で必要になる値を更新してしまっているため計算がおかしくなる.