double rate_Hepp(t)
double t;
{
  if (t == 0.0)
    return 0.0;
  return 3.48e-26 * sqrt(t) * pow(t / 1e3, -0.2) / (1.0 + pow(t / 1e6, 0.7));
}


x86 assembly (clang, -O0):
<rate_Hepp>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movsd  %xmm0,-0x10(%rbp)
movsd  -0x10(%rbp),%xmm0
xorps  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jne    1152 <rate_Hepp+0x32>
jp     1152 <rate_Hepp+0x32>
xorps  %xmm0,%xmm0
movsd  %xmm0,-0x8(%rbp)
jmp    11da <rate_Hepp+0xba>
movsd  -0x10(%rbp),%xmm0
call   1040 <sqrt@plt>
movaps %xmm0,%xmm1
movsd  0xec1(%rip),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  0xea3(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  0xe8f(%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  0xe64(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  0xe50(%rip),%xmm1
call   1030 <pow@plt>
movaps %xmm0,%xmm2
movsd  -0x18(%rbp),%xmm0
movsd  0xe33(%rip),%xmm1
addsd  %xmm2,%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x8(%rbp)
movsd  -0x8(%rbp),%xmm0
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<rate_Hepp>:
movapd %xmm0,%xmm1
xorpd  %xmm0,%xmm0
ucomisd %xmm0,%xmm1
jne    1131 <rate_Hepp+0x11>
jp     1131 <rate_Hepp+0x11>
ret
sub    $0x18,%rsp
xorpd  %xmm0,%xmm0
ucomisd %xmm0,%xmm1
movsd  %xmm1,0x10(%rsp)
jb     114e <rate_Hepp+0x2e>
xorps  %xmm0,%xmm0
sqrtsd %xmm1,%xmm0
jmp    115d <rate_Hepp+0x3d>
movapd %xmm1,%xmm0
call   1040 <sqrt@plt>
movsd  0x10(%rsp),%xmm1
mulsd  0xe9b(%rip),%xmm0
movsd  %xmm0,0x8(%rsp)
movapd %xmm1,%xmm0
divsd  0xe91(%rip),%xmm0
movsd  0xe91(%rip),%xmm1
call   1030 <pow@plt>
mulsd  0x8(%rsp),%xmm0
movsd  %xmm0,0x8(%rsp)
movsd  0x10(%rsp),%xmm0
divsd  0xe7a(%rip),%xmm0
movsd  0xe7a(%rip),%xmm1
call   1030 <pow@plt>
addsd  0xe75(%rip),%xmm0
movsd  0x8(%rsp),%xmm1
divsd  %xmm0,%xmm1
movapd %xmm1,%xmm0
add    $0x18,%rsp
ret

LLVM IR (-O0):
define double @rate_Hepp(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 %20
7: ; preds = %1
%8 = load double, double* %3
%9 = call double @sqrt(double %8)
%10 = fmul double 3.480000e-26, %9
%11 = load double, double* %3
%12 = fdiv double %11, 1.000000e+03
%13 = call double @pow(double %12, double -2.000000e-01)
%14 = fmul double %10, %13
%15 = load double, double* %3
%16 = fdiv double %15, 1.000000e+06
%17 = call double @pow(double %16, double 0x3FE6666666666666)
%18 = fadd double 1.000000e+00, %17
%19 = fdiv double %14, %18
store double %19, double* %2
br label %20
20: ; preds = %7, %6
%21 = load double, double* %2
ret double %21
}

LLVM IR (-O2):
define double @rate_Hepp(double %0) {
%2 = fcmp oeq double %0, 0.000000e+00
br i1 %2, label %13, label %3
3: ; preds = %1
%4 = tail call double @sqrt(double %0)
%5 = fmul double %4, 3.480000e-26
%6 = fdiv double %0, 1.000000e+03
%7 = tail call double @pow(double %6, double -2.000000e-01)
%8 = fmul double %5, %7
%9 = fdiv double %0, 1.000000e+06
%10 = tail call double @pow(double %9, double 0x3FE6666666666666)
%11 = fadd double %10, 1.000000e+00
%12 = fdiv double %8, %11
br label %13
13: ; preds = %1, %3
%14 = phi double [ %12, %3 ], [ 0.000000e+00, %1 ]
ret double %14
}