void convert44d44f(double *dbl, float *flt) {
  flt[0] = (float)dbl[0];
  flt[1] = (float)dbl[1];
  flt[2] = (float)dbl[2];
  flt[3] = (float)dbl[3];
  flt[4] = (float)dbl[4];
  flt[5] = (float)dbl[5];
  flt[6] = (float)dbl[6];
  flt[7] = (float)dbl[7];
  flt[8] = (float)dbl[8];
  flt[9] = (float)dbl[9];
  flt[10] = (float)dbl[10];
  flt[11] = (float)dbl[11];
  flt[12] = (float)dbl[12];
  flt[13] = (float)dbl[13];
  flt[14] = (float)dbl[14];
  flt[15] = (float)dbl[15];
}


x86 assembly (clang, -O0):
<convert44d44f>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,(%rax)
mov    -0x8(%rbp),%rax
movsd  0x8(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x4(%rax)
mov    -0x8(%rbp),%rax
movsd  0x10(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x8(%rax)
mov    -0x8(%rbp),%rax
movsd  0x18(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0xc(%rax)
mov    -0x8(%rbp),%rax
movsd  0x20(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x10(%rax)
mov    -0x8(%rbp),%rax
movsd  0x28(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x14(%rax)
mov    -0x8(%rbp),%rax
movsd  0x30(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x18(%rax)
mov    -0x8(%rbp),%rax
movsd  0x38(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x1c(%rax)
mov    -0x8(%rbp),%rax
movsd  0x40(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x20(%rax)
mov    -0x8(%rbp),%rax
movsd  0x48(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x24(%rax)
mov    -0x8(%rbp),%rax
movsd  0x50(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x28(%rax)
mov    -0x8(%rbp),%rax
movsd  0x58(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x2c(%rax)
mov    -0x8(%rbp),%rax
movsd  0x60(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x30(%rax)
mov    -0x8(%rbp),%rax
movsd  0x68(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x34(%rax)
mov    -0x8(%rbp),%rax
movsd  0x70(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x38(%rax)
mov    -0x8(%rbp),%rax
movsd  0x78(%rax),%xmm0
cvtsd2ss %xmm0,%xmm0
mov    -0x10(%rbp),%rax
movss  %xmm0,0x3c(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<convert44d44f>:
movupd (%rdi),%xmm0
movupd 0x10(%rdi),%xmm1
cvtpd2ps %xmm1,%xmm1
cvtpd2ps %xmm0,%xmm0
unpcklpd %xmm1,%xmm0
movupd %xmm0,(%rsi)
movupd 0x20(%rdi),%xmm0
movupd 0x30(%rdi),%xmm1
cvtpd2ps %xmm1,%xmm1
cvtpd2ps %xmm0,%xmm0
unpcklpd %xmm1,%xmm0
movupd %xmm0,0x10(%rsi)
movupd 0x40(%rdi),%xmm0
movupd 0x50(%rdi),%xmm1
cvtpd2ps %xmm1,%xmm1
cvtpd2ps %xmm0,%xmm0
unpcklpd %xmm1,%xmm0
movupd %xmm0,0x20(%rsi)
movupd 0x60(%rdi),%xmm0
movupd 0x70(%rdi),%xmm1
cvtpd2ps %xmm1,%xmm1
cvtpd2ps %xmm0,%xmm0
unpcklpd %xmm1,%xmm0
movupd %xmm0,0x30(%rsi)
ret

LLVM IR (-O0):
define void @convert44d44f(double* %0, float* %1) {
%3 = alloca double*
%4 = alloca float*
store double* %0, double** %3
store float* %1, float** %4
%5 = load double*, double** %3
%6 = getelementptr inbounds double, double* %5, i64 0
%7 = load double, double* %6
%8 = fptrunc double %7 to float
%9 = load float*, float** %4
%10 = getelementptr inbounds float, float* %9, i64 0
store float %8, float* %10
%11 = load double*, double** %3
%12 = getelementptr inbounds double, double* %11, i64 1
%13 = load double, double* %12
%14 = fptrunc double %13 to float
%15 = load float*, float** %4
%16 = getelementptr inbounds float, float* %15, i64 1
store float %14, float* %16
%17 = load double*, double** %3
%18 = getelementptr inbounds double, double* %17, i64 2
%19 = load double, double* %18
%20 = fptrunc double %19 to float
%21 = load float*, float** %4
%22 = getelementptr inbounds float, float* %21, i64 2
store float %20, float* %22
%23 = load double*, double** %3
%24 = getelementptr inbounds double, double* %23, i64 3
%25 = load double, double* %24
%26 = fptrunc double %25 to float
%27 = load float*, float** %4
%28 = getelementptr inbounds float, float* %27, i64 3
store float %26, float* %28
%29 = load double*, double** %3
%30 = getelementptr inbounds double, double* %29, i64 4
%31 = load double, double* %30
%32 = fptrunc double %31 to float
%33 = load float*, float** %4
%34 = getelementptr inbounds float, float* %33, i64 4
store float %32, float* %34
%35 = load double*, double** %3
%36 = getelementptr inbounds double, double* %35, i64 5
%37 = load double, double* %36
%38 = fptrunc double %37 to float
%39 = load float*, float** %4
%40 = getelementptr inbounds float, float* %39, i64 5
store float %38, float* %40
%41 = load double*, double** %3
%42 = getelementptr inbounds double, double* %41, i64 6
%43 = load double, double* %42
%44 = fptrunc double %43 to float
%45 = load float*, float** %4
%46 = getelementptr inbounds float, float* %45, i64 6
store float %44, float* %46
%47 = load double*, double** %3
%48 = getelementptr inbounds double, double* %47, i64 7
%49 = load double, double* %48
%50 = fptrunc double %49 to float
%51 = load float*, float** %4
%52 = getelementptr inbounds float, float* %51, i64 7
store float %50, float* %52
%53 = load double*, double** %3
%54 = getelementptr inbounds double, double* %53, i64 8
%55 = load double, double* %54
%56 = fptrunc double %55 to float
%57 = load float*, float** %4
%58 = getelementptr inbounds float, float* %57, i64 8
store float %56, float* %58
%59 = load double*, double** %3
%60 = getelementptr inbounds double, double* %59, i64 9
%61 = load double, double* %60
%62 = fptrunc double %61 to float
%63 = load float*, float** %4
%64 = getelementptr inbounds float, float* %63, i64 9
store float %62, float* %64
%65 = load double*, double** %3
%66 = getelementptr inbounds double, double* %65, i64 10
%67 = load double, double* %66
%68 = fptrunc double %67 to float
%69 = load float*, float** %4
%70 = getelementptr inbounds float, float* %69, i64 10
store float %68, float* %70
%71 = load double*, double** %3
%72 = getelementptr inbounds double, double* %71, i64 11
%73 = load double, double* %72
%74 = fptrunc double %73 to float
%75 = load float*, float** %4
%76 = getelementptr inbounds float, float* %75, i64 11
store float %74, float* %76
%77 = load double*, double** %3
%78 = getelementptr inbounds double, double* %77, i64 12
%79 = load double, double* %78
%80 = fptrunc double %79 to float
%81 = load float*, float** %4
%82 = getelementptr inbounds float, float* %81, i64 12
store float %80, float* %82
%83 = load double*, double** %3
%84 = getelementptr inbounds double, double* %83, i64 13
%85 = load double, double* %84
%86 = fptrunc double %85 to float
%87 = load float*, float** %4
%88 = getelementptr inbounds float, float* %87, i64 13
store float %86, float* %88
%89 = load double*, double** %3
%90 = getelementptr inbounds double, double* %89, i64 14
%91 = load double, double* %90
%92 = fptrunc double %91 to float
%93 = load float*, float** %4
%94 = getelementptr inbounds float, float* %93, i64 14
store float %92, float* %94
%95 = load double*, double** %3
%96 = getelementptr inbounds double, double* %95, i64 15
%97 = load double, double* %96
%98 = fptrunc double %97 to float
%99 = load float*, float** %4
%100 = getelementptr inbounds float, float* %99, i64 15
store float %98, float* %100
ret void
}

LLVM IR (-O2):
define void @convert44d44f(double* nocapture %0, float* nocapture writeonly %1) {
%3 = bitcast double* %0 to <4 x double>*
%4 = load <4 x double>, <4 x double>* %3
%5 = fptrunc <4 x double> %4 to <4 x float>
%6 = bitcast float* %1 to <4 x float>*
store <4 x float> %5, <4 x float>* %6
%7 = getelementptr inbounds double, double* %0, i64 4
%8 = getelementptr inbounds float, float* %1, i64 4
%9 = bitcast double* %7 to <4 x double>*
%10 = load <4 x double>, <4 x double>* %9
%11 = fptrunc <4 x double> %10 to <4 x float>
%12 = bitcast float* %8 to <4 x float>*
store <4 x float> %11, <4 x float>* %12
%13 = getelementptr inbounds double, double* %0, i64 8
%14 = getelementptr inbounds float, float* %1, i64 8
%15 = bitcast double* %13 to <4 x double>*
%16 = load <4 x double>, <4 x double>* %15
%17 = fptrunc <4 x double> %16 to <4 x float>
%18 = bitcast float* %14 to <4 x float>*
store <4 x float> %17, <4 x float>* %18
%19 = getelementptr inbounds double, double* %0, i64 12
%20 = getelementptr inbounds float, float* %1, i64 12
%21 = bitcast double* %19 to <4 x double>*
%22 = load <4 x double>, <4 x double>* %21
%23 = fptrunc <4 x double> %22 to <4 x float>
%24 = bitcast float* %20 to <4 x float>*
store <4 x float> %23, <4 x float>* %24
ret void
}