Obtaining different results while executing a kernel on GPU or FPGA

Hello,

# pragma OPENCL EXTENSION cl_amd_printf : enable
struct __attribute__ ((packed)) gm_component {
           float w;
           float4 m;
           float16 P;
       };
struct __attribute__ ((packed)) gm_component_survive {
        float w;
        float4 m;
        float16 P;
        float2 eta;
        float4 S;
        float8 K;
    };    
       
//4x4 matrix multiplication
 float16 matrixMult4x4f(float16 M, float16 N,float4 unit4)
{
    //return M*N
float4 a=M.s0123;
float4 b=M.s4567;
float4 c=M.s89ab;
float4 d=M.scdef;
float4 e=N.s048c;
float4 f=N.s159d;
float4 g=N.s26ae;
float4 h=N.s37bf;  
float16 tmp = (float16){dot(a*e,unit4),dot(a*f,unit4),dot(a*g,unit4),dot(a*h,unit4),
              dot(b*e,unit4),dot(b*f,unit4),dot(b*g,unit4),dot(b*h,unit4),
              dot(c*e,unit4),dot(c*f,unit4),dot(c*g,unit4),dot(c*h,unit4),
              dot(d*e,unit4),dot(d*f,unit4),dot(d*g,unit4),dot(d*h,unit4)};
return tmp;
}
// OpenCL Kernel to compute multiplication and addition
__kernel void
update(__global struct gm_component_survive * restrict predict_mixture, 
           float8 Hk, __global float2 *Zk,
          __global struct gm_component * restrict update_mixture,int size, float pr_dk, int updateMixtureSize)
{
  int zk_index=get_global_id(0);
  
  int survive_index = get_global_id(1);
 
if(zk_index<size && survive_index<updateMixtureSize){
   __global struct gm_component *um = &update_mixture; 
 
 __global struct gm_component_survive *pm = &predict_mixture; 
 
  float2 unit2={1.f,1.f};
  float4 unit4={1.f,1.f,1.f,1.f};
  
  //Multivarate guassian calculation
  //calculate miu
  float2 miu = Zk -pm->eta;
       
  //Inverse of covarience.. start
  float4 inv_covariance = pm->S;
  //calculate denominator 
  float determenent = inv_covariance.s3*inv_covariance.s0 - inv_covariance.s2*inv_covariance.s1;
  
  inv_covariance =(float4){inv_covariance.s3,-inv_covariance.s1,-inv_covariance.s2,inv_covariance.s0};
  inv_covariance = inv_covariance/determenent;               //inverse calculation end
  
  //multiplication of miu.T*covariance*miu
  float2 number = { dot(miu*inv_covariance.even,unit2),dot(miu*inv_covariance.odd,unit2)};
  number=number*miu;
  
  //Calculate denominator :pow(2*M_PI, 2)* determenent   39.4784
  float denom = 39.4784* determenent;
  
  denom=sqrt(denom);  
 
 //calculate weight
  um->w = pr_dk*pm->w*native_exp(-0.5f * dot(number,unit2)) / denom;
  
 //calculate mean 
  number = (float2){dot(Hk.lo*pm->m,unit4) , dot(Hk.hi*pm->m,unit4)};
 
  number = Zk-number;    
  inv_covariance =(float4){dot(pm->K.lo.lo*number,unit2),dot(pm->K.lo.hi*number,unit2),dot(pm->K.hi.lo*number,unit2),dot(pm->K.hi.hi*number,unit2)};
  um->m = pm->m+inv_covariance;
  //calculate covarince
  
  float16 temp1 = (float16){1-dot(pm->K.lo.lo*Hk.s04,unit2),-dot(pm->K.lo.lo*Hk.s15,unit2),-dot(pm->K.lo.lo*Hk.s26,unit2),-dot(pm->K.lo.lo*Hk.s37,unit2),
                          -dot(pm->K.lo.hi*Hk.s04,unit2),1-dot(pm->K.lo.hi*Hk.s15,unit2),-dot(pm->K.lo.hi*Hk.s26,unit2),-dot(pm->K.lo.hi*Hk.s37,unit2),
              -dot(pm->K.hi.lo*Hk.s04,unit2),-dot(pm->K.hi.lo*Hk.s15,unit2),1-dot(pm->K.hi.lo*Hk.s26,unit2),-dot(pm->K.hi.lo*Hk.s37,unit2),
                          -dot(pm->K.hi.hi*Hk.s04,unit2),-dot(pm->K.hi.hi*Hk.s15,unit2),-dot(pm->K.hi.hi*Hk.s26,unit2),1-dot(pm->K.hi.hi*Hk.s37,unit2)}; 
  um->P = matrixMult4x4f(temp1, pm->P,unit4);;  
  }
}