double radrate_Hp(t)
double t;
{
  if (t == 0.0) {
    return 0.0;
  }
  return (8.70e-27 * t + 1.83e-21) / sqrt(t) * pow(t / 1e3, -0.2) /
         (1.0 + pow(t / 1e6, 0.7));
}


x86 assembly (clang, -O0):
<radrate_Hp>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
movsd  %xmm0,-0x10(%rbp)
movsd  -0x10(%rbp),%xmm0
xorps  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jne    1152 <radrate_Hp+0x32>
jp     1152 <radrate_Hp+0x32>
xorps  %xmm0,%xmm0
movsd  %xmm0,-0x8(%rbp)
jmp    11f9 <radrate_Hp+0xd9>
movsd  -0x10(%rbp),%xmm0
movsd  0xec9(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xec5(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  -0x10(%rbp),%xmm0
call   1040 <sqrt@plt>
movaps %xmm0,%xmm1
movsd  -0x28(%rbp),%xmm0
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xe84(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  0xe70(%rip),%xmm1
call   1030 <pow@plt>
movaps %xmm0,%xmm1
movsd  -0x20(%rbp),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xe45(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  0xe31(%rip),%xmm1
call   1030 <pow@plt>
movaps %xmm0,%xmm2
movsd  -0x18(%rbp),%xmm0
movsd  0xe14(%rip),%xmm1
addsd  %xmm2,%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x8(%rbp)
movsd  -0x8(%rbp),%xmm0
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<radrate_Hp>:
movapd %xmm0,%xmm1
xorpd  %xmm0,%xmm0
ucomisd %xmm0,%xmm1
jne    1131 <radrate_Hp+0x11>
jp     1131 <radrate_Hp+0x11>
ret
sub    $0x18,%rsp
movsd  0xec3(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xebf(%rip),%xmm0
movsd  %xmm0,0x8(%rsp)
xorpd  %xmm0,%xmm0
ucomisd %xmm0,%xmm1
movsd  %xmm1,0x10(%rsp)
jb     1168 <radrate_Hp+0x48>
xorps  %xmm0,%xmm0
sqrtsd %xmm1,%xmm0
jmp    1177 <radrate_Hp+0x57>
movapd %xmm1,%xmm0
call   1040 <sqrt@plt>
movsd  0x10(%rsp),%xmm1
movsd  0x8(%rsp),%xmm2
divsd  %xmm0,%xmm2
movsd  %xmm2,0x8(%rsp)
movapd %xmm1,%xmm0
divsd  0xe7d(%rip),%xmm0
movsd  0xe7d(%rip),%xmm1
call   1030 <pow@plt>
mulsd  0x8(%rsp),%xmm0
movsd  %xmm0,0x8(%rsp)
movsd  0x10(%rsp),%xmm0
divsd  0xe66(%rip),%xmm0
movsd  0xe66(%rip),%xmm1
call   1030 <pow@plt>
addsd  0xe61(%rip),%xmm0
movsd  0x8(%rsp),%xmm1
divsd  %xmm0,%xmm1
movapd %xmm1,%xmm0
add    $0x18,%rsp
ret

LLVM IR (-O0):
define double @radrate_Hp(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 %22
7: ; preds = %1
%8 = load double, double* %3
%9 = call double @llvm.fmuladd.f64(double 0x3A858A47B55AA151, double %8, double 1.830000e-21)
%10 = load double, double* %3
%11 = call double @sqrt(double %10)
%12 = fdiv double %9, %11
%13 = load double, double* %3
%14 = fdiv double %13, 1.000000e+03
%15 = call double @pow(double %14, double -2.000000e-01)
%16 = fmul double %12, %15
%17 = load double, double* %3
%18 = fdiv double %17, 1.000000e+06
%19 = call double @pow(double %18, double 0x3FE6666666666666)
%20 = fadd double 1.000000e+00, %19
%21 = fdiv double %16, %20
store double %21, double* %2
br label %22
22: ; preds = %7, %6
%23 = load double, double* %2
ret double %23
}

LLVM IR (-O2):
define double @radrate_Hp(double %0) {
%2 = fcmp oeq double %0, 0.000000e+00
br i1 %2, label %14, label %3
3: ; preds = %1
%4 = tail call double @llvm.fmuladd.f64(double %0, double 0x3A858A47B55AA151, double 1.830000e-21)
%5 = tail call double @sqrt(double %0)
%6 = fdiv double %4, %5
%7 = fdiv double %0, 1.000000e+03
%8 = tail call double @pow(double %7, double -2.000000e-01)
%9 = fmul double %6, %8
%10 = fdiv double %0, 1.000000e+06
%11 = tail call double @pow(double %10, double 0x3FE6666666666666)
%12 = fadd double %11, 1.000000e+00
%13 = fdiv double %9, %12
br label %14
14: ; preds = %1, %3
%15 = phi double [ %13, %3 ], [ 0.000000e+00, %1 ]
ret double %15
}