double _orbita_models_pointmass_psi(const void *M, const double *R) {
  double Rt = sqrt(((R[0]) * (R[0])) + ((R[1]) * (R[1])) + ((R[2]) * (R[2])));
  return -*((double *)M) / Rt;
}


x86 assembly (clang, -O0):
<_orbita_models_pointmass_psi>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm1
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm2
mov    -0x10(%rbp),%rax
movsd  0x8(%rax),%xmm0
mov    -0x10(%rbp),%rax
mulsd  0x8(%rax),%xmm0
mulsd  %xmm2,%xmm1
addsd  %xmm0,%xmm1
mov    -0x10(%rbp),%rax
movsd  0x10(%rax),%xmm0
mov    -0x10(%rbp),%rax
movsd  0x10(%rax),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <sqrt@plt>
movsd  %xmm0,-0x18(%rbp)
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
divsd  -0x18(%rbp),%xmm0
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<_orbita_models_pointmass_psi>:
push   %rbx
mov    %rdi,%rbx
movsd  (%rsi),%xmm1
movsd  0x8(%rsi),%xmm0
mulsd  %xmm0,%xmm0
mulsd  %xmm1,%xmm1
addsd  %xmm0,%xmm1
movsd  0x10(%rsi),%xmm0
mulsd  %xmm0,%xmm0
addsd  %xmm1,%xmm0
xorpd  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jb     1146 <_orbita_models_pointmass_psi+0x36>
sqrtsd %xmm0,%xmm0
jmp    114b <_orbita_models_pointmass_psi+0x3b>
call   1030 <sqrt@plt>
movsd  (%rbx),%xmm1
xorpd  0xea9(%rip),%xmm1
divsd  %xmm0,%xmm1
movapd %xmm1,%xmm0
pop    %rbx
ret

LLVM IR (-O0):
define double @_orbita_models_pointmass_psi(i8* %0, double* %1) {
%3 = alloca i8*
%4 = alloca double*
%5 = alloca double
store i8* %0, i8** %3
store double* %1, double** %4
%6 = load double*, double** %4
%7 = getelementptr inbounds double, double* %6, i64 0
%8 = load double, double* %7
%9 = load double*, double** %4
%10 = getelementptr inbounds double, double* %9, i64 0
%11 = load double, double* %10
%12 = load double*, double** %4
%13 = getelementptr inbounds double, double* %12, i64 1
%14 = load double, double* %13
%15 = load double*, double** %4
%16 = getelementptr inbounds double, double* %15, i64 1
%17 = load double, double* %16
%18 = fmul double %14, %17
%19 = call double @llvm.fmuladd.f64(double %8, double %11, double %18)
%20 = load double*, double** %4
%21 = getelementptr inbounds double, double* %20, i64 2
%22 = load double, double* %21
%23 = load double*, double** %4
%24 = getelementptr inbounds double, double* %23, i64 2
%25 = load double, double* %24
%26 = call double @llvm.fmuladd.f64(double %22, double %25, double %19)
%27 = call double @sqrt(double %26)
store double %27, double* %5
%28 = load i8*, i8** %3
%29 = bitcast i8* %28 to double*
%30 = load double, double* %29
%31 = fneg double %30
%32 = load double, double* %5
%33 = fdiv double %31, %32
ret double %33
}

LLVM IR (-O2):
define double @_orbita_models_pointmass_psi(i8* nocapture %0, double* nocapture %1) {
%3 = load double, double* %1
%4 = getelementptr inbounds double, double* %1, i64 1
%5 = load double, double* %4
%6 = fmul double %5, %5
%7 = tail call double @llvm.fmuladd.f64(double %3, double %3, double %6)
%8 = getelementptr inbounds double, double* %1, i64 2
%9 = load double, double* %8
%10 = tail call double @llvm.fmuladd.f64(double %9, double %9, double %7)
%11 = tail call double @sqrt(double %10)
%12 = bitcast i8* %0 to double*
%13 = load double, double* %12
%14 = fneg double %13
%15 = fdiv double %14, %11
ret double %15
}