double prismDisp(double coeff[], double ix_r) {
  double x;
  double wl;
  x = ix_r - coeff[0] + 1.;
  wl = coeff[5] / x;
  wl = (coeff[4] + wl) / x;
  wl = (coeff[3] + wl) / x;
  wl = (coeff[2] + wl) / x;
  wl += coeff[1];
  return (wl);
}


x86 assembly (clang, -O0):
<prismDisp>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
movsd  %xmm0,-0x10(%rbp)
movsd  -0x10(%rbp),%xmm0
mov    -0x8(%rbp),%rax
subsd  (%rax),%xmm0
movsd  0xede(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
mov    -0x8(%rbp),%rax
movsd  0x28(%rax),%xmm0
divsd  -0x18(%rbp),%xmm0
movsd  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movsd  0x20(%rax),%xmm0
addsd  -0x20(%rbp),%xmm0
divsd  -0x18(%rbp),%xmm0
movsd  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movsd  0x18(%rax),%xmm0
addsd  -0x20(%rbp),%xmm0
divsd  -0x18(%rbp),%xmm0
movsd  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movsd  0x10(%rax),%xmm0
addsd  -0x20(%rbp),%xmm0
divsd  -0x18(%rbp),%xmm0
movsd  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movsd  0x8(%rax),%xmm0
addsd  -0x20(%rbp),%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x20(%rbp),%xmm0
pop    %rbp
ret

x86 assembly (clang, -O2):
<prismDisp>:
subsd  (%rdi),%xmm0
addsd  0xef4(%rip),%xmm0
movsd  0x28(%rdi),%xmm1
divsd  %xmm0,%xmm1
addsd  0x20(%rdi),%xmm1
divsd  %xmm0,%xmm1
addsd  0x18(%rdi),%xmm1
divsd  %xmm0,%xmm1
addsd  0x10(%rdi),%xmm1
divsd  %xmm0,%xmm1
addsd  0x8(%rdi),%xmm1
movapd %xmm1,%xmm0
ret

LLVM IR (-O0):
define double @prismDisp(double* %0, double %1) {
%3 = alloca double*
%4 = alloca double
%5 = alloca double
%6 = alloca double
store double* %0, double** %3
store double %1, double* %4
%7 = load double, double* %4
%8 = load double*, double** %3
%9 = getelementptr inbounds double, double* %8, i64 0
%10 = load double, double* %9
%11 = fsub double %7, %10
%12 = fadd double %11, 1.000000e+00
store double %12, double* %5
%13 = load double*, double** %3
%14 = getelementptr inbounds double, double* %13, i64 5
%15 = load double, double* %14
%16 = load double, double* %5
%17 = fdiv double %15, %16
store double %17, double* %6
%18 = load double*, double** %3
%19 = getelementptr inbounds double, double* %18, i64 4
%20 = load double, double* %19
%21 = load double, double* %6
%22 = fadd double %20, %21
%23 = load double, double* %5
%24 = fdiv double %22, %23
store double %24, double* %6
%25 = load double*, double** %3
%26 = getelementptr inbounds double, double* %25, i64 3
%27 = load double, double* %26
%28 = load double, double* %6
%29 = fadd double %27, %28
%30 = load double, double* %5
%31 = fdiv double %29, %30
store double %31, double* %6
%32 = load double*, double** %3
%33 = getelementptr inbounds double, double* %32, i64 2
%34 = load double, double* %33
%35 = load double, double* %6
%36 = fadd double %34, %35
%37 = load double, double* %5
%38 = fdiv double %36, %37
store double %38, double* %6
%39 = load double*, double** %3
%40 = getelementptr inbounds double, double* %39, i64 1
%41 = load double, double* %40
%42 = load double, double* %6
%43 = fadd double %42, %41
store double %43, double* %6
%44 = load double, double* %6
ret double %44
}

LLVM IR (-O2):
define double @prismDisp(double* nocapture %0, double %1) {
%3 = load double, double* %0
%4 = fsub double %1, %3
%5 = fadd double %4, 1.000000e+00
%6 = getelementptr inbounds double, double* %0, i64 5
%7 = load double, double* %6
%8 = fdiv double %7, %5
%9 = getelementptr inbounds double, double* %0, i64 4
%10 = load double, double* %9
%11 = fadd double %10, %8
%12 = fdiv double %11, %5
%13 = getelementptr inbounds double, double* %0, i64 3
%14 = load double, double* %13
%15 = fadd double %14, %12
%16 = fdiv double %15, %5
%17 = getelementptr inbounds double, double* %0, i64 2
%18 = load double, double* %17
%19 = fadd double %18, %16
%20 = fdiv double %19, %5
%21 = getelementptr inbounds double, double* %0, i64 1
%22 = load double, double* %21
%23 = fadd double %22, %20
ret double %23
}