removing divergence inside hitgrid, thanks to njuffa

fangq · Oct 12, 2016 · df62a0d · df62a0d
1 parent 5905e0b
commit df62a0d
Showing 1 changed file with 9 additions and 6 deletions.
diff --git a/src/mcx_core.cu b/src/mcx_core.cu
@@ -146,6 +146,7 @@ __device__ inline void savedebugdata(MCXpos *p,uint id,float *gdebugdata){
          gdebugdata[pos++]=0;
       }
 }
+
 __device__ inline float mcx_nextafterf(float a, int dir){
       union{
           float f;
@@ -157,7 +158,7 @@ __device__ inline float mcx_nextafterf(float a, int dir){
 }
 
 __device__ inline float hitgrid(float3 *p0, float3 *v, float *htime,float* rv,int *id){
-      float dist;
+      float dist, xi[3];
 
       //time-of-flight to hit the wall in each direction
       htime[0]=fabs((floorf(p0->x)+(v->x>0.f)-p0->x)*rv[0]); // absolute distance of travel in x/y/z
@@ -173,11 +174,13 @@ __device__ inline float hitgrid(float3 *p0, float3 *v, float *htime,float* rv,in
       htime[1]=p0->y+dist*v->y;
       htime[2]=p0->z+dist*v->z;
 
-      (*id==0) ?
-          (htime[0]=mcx_nextafterf(__float2int_rn(htime[0]), (v->x > 0.f)-(v->x < 0.f))) :
-	  ((*id==1) ? 
-	      (htime[1]=mcx_nextafterf(__float2int_rn(htime[1]), (v->y > 0.f)-(v->y < 0.f))) :
-	      (htime[2]=mcx_nextafterf(__float2int_rn(htime[2]), (v->z > 0.f)-(v->z < 0.f))) );
+      xi[0] = mcx_nextafterf(__float2int_rn(htime[0]), (v->x > 0.f)-(v->x < 0.f));
+      xi[1] = mcx_nextafterf(__float2int_rn(htime[1]), (v->y > 0.f)-(v->y < 0.f));
+      xi[2] = mcx_nextafterf(__float2int_rn(htime[2]), (v->z > 0.f)-(v->z < 0.f));
+
+      if (*id == 0) htime[0] = xi[0];
+      if (*id == 1) htime[1] = xi[1];
+      if (*id == 2) htime[2] = xi[2];
 
       return dist;
 }