double radrate_Hep(t)
double t;
{
  if (t == 0.0) {
    return 0.0;
  }
  return (1.55e-26 * t + 5.91e-21) * pow(t, -0.6353) +
         4.95e-22 * sqrt(t) * exp(-631515.0 / t) / (1.0 + sqrt(t / 1e5)) +
         5.54e-17 * pow(t, -.397) * exp(-473638.0 / t) / (1.0 + sqrt(t / 1e5)) +
         1.99e-13 * pow(t, -1.5) * exp(-4.7e5 / t) *
             (exp(-9.4e4 / t) * .3 + 1.0);
}


x86 assembly (clang, -O0):
<radrate_Hep>:
push   %rbp
mov    %rsp,%rbp
sub    $0x60,%rsp
movsd  %xmm0,-0x10(%rbp)
movsd  -0x10(%rbp),%xmm0
xorps  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jne    1162 <radrate_Hep+0x32>
jp     1162 <radrate_Hep+0x32>
xorps  %xmm0,%xmm0
movsd  %xmm0,-0x8(%rbp)
jmp    1333 <radrate_Hep+0x203>
movsd  -0x10(%rbp),%xmm0
movsd  0xef9(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xef5(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x48(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xecf(%rip),%xmm1
call   1040 <pow@plt>
movsd  %xmm0,-0x50(%rbp)
movsd  -0x10(%rbp),%xmm0
call   1050 <sqrt@plt>
movaps %xmm0,%xmm1
movsd  0xea8(%rip),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x60(%rbp)
movsd  0xe8f(%rip),%xmm0
divsd  -0x10(%rbp),%xmm0
call   1030 <exp@plt>
movaps %xmm0,%xmm1
movsd  -0x60(%rbp),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x58(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xe47(%rip),%xmm1
divsd  %xmm1,%xmm0
call   1050 <sqrt@plt>
movsd  -0x58(%rbp),%xmm1
movsd  -0x50(%rbp),%xmm2
movaps %xmm0,%xmm4
movsd  -0x48(%rbp),%xmm0
movsd  0xdfc(%rip),%xmm3
addsd  %xmm4,%xmm3
divsd  %xmm3,%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xe1a(%rip),%xmm1
call   1040 <pow@plt>
movaps %xmm0,%xmm1
movsd  0xe02(%rip),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x40(%rbp)
movsd  0xde9(%rip),%xmm0
divsd  -0x10(%rbp),%xmm0
call   1030 <exp@plt>
movaps %xmm0,%xmm1
movsd  -0x40(%rbp),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x38(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xdb9(%rip),%xmm1
divsd  %xmm1,%xmm0
call   1050 <sqrt@plt>
movsd  -0x38(%rbp),%xmm1
movaps %xmm0,%xmm3
movsd  -0x30(%rbp),%xmm0
movsd  0xd73(%rip),%xmm2
addsd  %xmm3,%xmm2
divsd  %xmm2,%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xd75(%rip),%xmm1
call   1040 <pow@plt>
movaps %xmm0,%xmm1
movsd  0xd5d(%rip),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  0xd44(%rip),%xmm0
divsd  -0x10(%rbp),%xmm0
call   1030 <exp@plt>
movaps %xmm0,%xmm1
movsd  -0x28(%rbp),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  0xd19(%rip),%xmm0
divsd  -0x10(%rbp),%xmm0
call   1030 <exp@plt>
movsd  -0x20(%rbp),%xmm1
movaps %xmm0,%xmm2
movsd  -0x18(%rbp),%xmm0
movsd  0xcea(%rip),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xce6(%rip),%xmm3
addsd  %xmm3,%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x8(%rbp)
movsd  -0x8(%rbp),%xmm0
add    $0x60,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<radrate_Hep>:
xorpd  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jne    1141 <radrate_Hep+0x11>
jp     1141 <radrate_Hep+0x11>
xorpd  %xmm0,%xmm0
ret
sub    $0x38,%rsp
movsd  0xeb3(%rip),%xmm1
mulsd  %xmm0,%xmm1
movsd  %xmm1,0x18(%rsp)
movsd  %xmm0,0x10(%rsp)
movsd  0xeab(%rip),%xmm1
movsd  0x10(%rsp),%xmm0
call   1040 <pow@plt>
movsd  0x10(%rsp),%xmm1
movsd  %xmm0,0x20(%rsp)
ucomisd 0xef4(%rip),%xmm1
jb     118c <radrate_Hep+0x5c>
sqrtsd %xmm1,%xmm2
jmp    119f <radrate_Hep+0x6f>
movapd %xmm1,%xmm0
call   1050 <sqrt@plt>
movsd  0x10(%rsp),%xmm1
movapd %xmm0,%xmm2
movsd  0x18(%rsp),%xmm0
addsd  0xe5b(%rip),%xmm0
movsd  %xmm0,0x18(%rsp)
mulsd  0xe5d(%rip),%xmm2
movsd  %xmm2,0x8(%rsp)
movsd  0xe57(%rip),%xmm0
divsd  %xmm1,%xmm0
call   1030 <exp@plt>
movapd %xmm0,%xmm3
mulsd  0x8(%rsp),%xmm3
movsd  0x10(%rsp),%xmm1
divsd  0xe3e(%rip),%xmm1
xorps  %xmm0,%xmm0
sqrtsd %xmm1,%xmm0
xorpd  %xmm2,%xmm2
movsd  %xmm1,0x8(%rsp)
ucomisd %xmm2,%xmm1
movsd  %xmm0,0x30(%rsp)
jae    121e <radrate_Hep+0xee>
movsd  0x8(%rsp),%xmm0
movsd  %xmm3,0x28(%rsp)
call   1050 <sqrt@plt>
movsd  0x28(%rsp),%xmm3
addsd  0xe0a(%rip),%xmm0
divsd  %xmm0,%xmm3
movsd  0x18(%rsp),%xmm0
mulsd  0x20(%rsp),%xmm0
addsd  %xmm3,%xmm0
movsd  %xmm0,0x18(%rsp)
movsd  0xdf0(%rip),%xmm1
movsd  0x10(%rsp),%xmm0
call   1040 <pow@plt>
mulsd  0xde5(%rip),%xmm0
movsd  %xmm0,0x20(%rsp)
movsd  0xddf(%rip),%xmm0
divsd  0x10(%rsp),%xmm0
call   1030 <exp@plt>
movapd %xmm0,%xmm1
mulsd  0x20(%rsp),%xmm1
movsd  0x8(%rsp),%xmm0
ucomisd 0xdec(%rip),%xmm0
movsd  0x30(%rsp),%xmm0
jae    12ab <radrate_Hep+0x17b>
movsd  0x8(%rsp),%xmm0
movsd  %xmm1,0x8(%rsp)
call   1050 <sqrt@plt>
movsd  0x8(%rsp),%xmm1
addsd  0xd7d(%rip),%xmm0
divsd  %xmm0,%xmm1
movsd  0x18(%rsp),%xmm0
addsd  %xmm1,%xmm0
movsd  %xmm0,0x18(%rsp)
movsd  0xd81(%rip),%xmm1
movsd  0x10(%rsp),%xmm0
call   1040 <pow@plt>
mulsd  0xd76(%rip),%xmm0
movsd  %xmm0,0x8(%rsp)
movsd  0xd70(%rip),%xmm0
divsd  0x10(%rsp),%xmm0
call   1030 <exp@plt>
mulsd  0x8(%rsp),%xmm0
movsd  %xmm0,0x8(%rsp)
movsd  0xd59(%rip),%xmm0
divsd  0x10(%rsp),%xmm0
call   1030 <exp@plt>
mulsd  0xd4e(%rip),%xmm0
addsd  0xd06(%rip),%xmm0
mulsd  0x8(%rsp),%xmm0
addsd  0x18(%rsp),%xmm0
add    $0x38,%rsp
ret

LLVM IR (-O0):
define double @radrate_Hep(double %0) {
%2 = alloca double
%3 = alloca double
store double %0, double* %3
%4 = load double, double* %3
%5 = fcmp oeq double %4, 0.000000e+00
br i1 %5, label %6, label %7
6: ; preds = %1
store double 0.000000e+00, double* %2
br label %50
7: ; preds = %1
%8 = load double, double* %3
%9 = call double @llvm.fmuladd.f64(double 1.550000e-26, double %8, double 5.910000e-21)
%10 = load double, double* %3
%11 = call double @pow(double %10, double -6.353000e-01)
%12 = load double, double* %3
%13 = call double @sqrt(double %12)
%14 = fmul double 4.950000e-22, %13
%15 = load double, double* %3
%16 = fdiv double -6.315150e+05, %15
%17 = call double @exp(double %16)
%18 = fmul double %14, %17
%19 = load double, double* %3
%20 = fdiv double %19, 1.000000e+05
%21 = call double @sqrt(double %20)
%22 = fadd double 1.000000e+00, %21
%23 = fdiv double %18, %22
%24 = call double @llvm.fmuladd.f64(double %9, double %11, double %23)
%25 = load double, double* %3
%26 = call double @pow(double %25, double -3.970000e-01)
%27 = fmul double 5.540000e-17, %26
%28 = load double, double* %3
%29 = fdiv double -4.736380e+05, %28
%30 = call double @exp(double %29)
%31 = fmul double %27, %30
%32 = load double, double* %3
%33 = fdiv double %32, 1.000000e+05
%34 = call double @sqrt(double %33)
%35 = fadd double 1.000000e+00, %34
%36 = fdiv double %31, %35
%37 = fadd double %24, %36
%38 = load double, double* %3
%39 = call double @pow(double %38, double -1.500000e+00)
%40 = fmul double 1.990000e-13, %39
%41 = load double, double* %3
%42 = fdiv double -4.700000e+05, %41
%43 = call double @exp(double %42)
%44 = fmul double %40, %43
%45 = load double, double* %3
%46 = fdiv double -9.400000e+04, %45
%47 = call double @exp(double %46)
%48 = call double @llvm.fmuladd.f64(double %47, double 3.000000e-01, double 1.000000e+00)
%49 = call double @llvm.fmuladd.f64(double %44, double %48, double %37)
store double %49, double* %2
br label %50
50: ; preds = %7, %6
%51 = load double, double* %2
ret double %51
}

LLVM IR (-O2):
define double @radrate_Hep(double %0) {
%2 = fcmp oeq double %0, 0.000000e+00
br i1 %2, label %34, label %3
3: ; preds = %1
%4 = tail call double @llvm.fmuladd.f64(double %0, double 1.550000e-26, double 5.910000e-21)
%5 = tail call double @pow(double %0, double -6.353000e-01)
%6 = tail call double @sqrt(double %0)
%7 = fmul double %6, 4.950000e-22
%8 = fdiv double -6.315150e+05, %0
%9 = tail call double @exp(double %8)
%10 = fmul double %7, %9
%11 = fdiv double %0, 1.000000e+05
%12 = tail call double @sqrt(double %11)
%13 = fadd double %12, 1.000000e+00
%14 = fdiv double %10, %13
%15 = tail call double @llvm.fmuladd.f64(double %4, double %5, double %14)
%16 = tail call double @pow(double %0, double -3.970000e-01)
%17 = fmul double %16, 5.540000e-17
%18 = fdiv double -4.736380e+05, %0
%19 = tail call double @exp(double %18)
%20 = fmul double %17, %19
%21 = tail call double @sqrt(double %11)
%22 = fadd double %21, 1.000000e+00
%23 = fdiv double %20, %22
%24 = fadd double %15, %23
%25 = tail call double @pow(double %0, double -1.500000e+00)
%26 = fmul double %25, 1.990000e-13
%27 = fdiv double -4.700000e+05, %0
%28 = tail call double @exp(double %27)
%29 = fmul double %26, %28
%30 = fdiv double -9.400000e+04, %0
%31 = tail call double @exp(double %30)
%32 = tail call double @llvm.fmuladd.f64(double %31, double 3.000000e-01, double 1.000000e+00)
%33 = tail call double @llvm.fmuladd.f64(double %29, double %32, double %24)
br label %34
34: ; preds = %1, %3
%35 = phi double [ %33, %3 ], [ 0.000000e+00, %1 ]
ret double %35
}