void ecl2fk5(dtheta, dphi, epoch) double *dtheta;
double *dphi;
double epoch;
{
  int i, j;
  double rtheta, rphi, v1[3], v2[3];
  double t, eps0, r;
  double rmat[9];
  void v2s3(), s2v3(), fk5prec(), rotmat();
  rtheta = degrad(*dtheta);
  rphi = degrad(*dphi);
  r = 1.0;
  s2v3(rtheta, rphi, r, v1);
  t = (epoch - 2000.0) * 0.01;
  eps0 = secrad((84381.448 + (-46.8150 + (-0.00059 + 0.001813 * t) * t) * t));
  rotmat(1, eps0, 0.0, 0.0, rmat);
  for (i = 0; i < 3; i++) {
    v2[i] = 0;
    for (j = 0; j < 3; j++)
      v2[i] = v2[i] + (rmat[3 * j + i] * v1[j]);
  }
  v2s3(v2, &rtheta, &rphi, &r);
  *dtheta = raddeg(rtheta);
  *dphi = raddeg(rphi);
  if (epoch != 2000.0)
    fk5prec(epoch, 2000.0, dtheta, dphi);
}


x86 assembly (clang, -O0):
<ecl2fk5>:
push   %rbp
mov    %rsp,%rbp
sub    $0xd0,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movsd  %xmm0,-0x18(%rbp)
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x28(%rbp)
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  0xe70(%rip),%xmm0
movsd  %xmm0,-0x88(%rbp)
ff
movsd  -0x28(%rbp),%xmm0
movsd  -0x30(%rbp),%xmm1
movsd  -0x88(%rbp),%xmm2
ff
lea    -0x50(%rbp),%rdi
mov    $0x3,%al
call   1070 <s2v3@plt>
movsd  -0x18(%rbp),%xmm0
movsd  0xe36(%rip),%xmm1
subsd  %xmm1,%xmm0
movsd  0xe22(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x78(%rbp)
movsd  -0x78(%rbp),%xmm0
movsd  0xdfc(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xdf8(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  -0x78(%rbp),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xdd3(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  -0x78(%rbp),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xdb6(%rip),%xmm1
addsd  %xmm1,%xmm0
mov    $0x1,%al
call   1080 <secrad@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x80(%rbp)
movsd  -0x80(%rbp),%xmm0
lea    -0xd0(%rbp),%rsi
mov    $0x1,%edi
xorps  %xmm2,%xmm2
movaps %xmm2,%xmm1
mov    $0x3,%al
call   1040 <rotmat@plt>
movl   $0x0,-0x1c(%rbp)
cmpl   $0x3,-0x1c(%rbp)
jge    1304 <ecl2fk5+0x194>
movslq -0x1c(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,-0x70(%rbp,%rax,8)
movl   $0x0,-0x20(%rbp)
cmpl   $0x3,-0x20(%rbp)
jge    12f1 <ecl2fk5+0x181>
movslq -0x1c(%rbp),%rax
movsd  -0x70(%rbp,%rax,8),%xmm1
imul   $0x3,-0x20(%rbp),%eax
add    -0x1c(%rbp),%eax
cltq
movsd  -0xd0(%rbp,%rax,8),%xmm0
ff ff
movslq -0x20(%rbp),%rax
movsd  -0x50(%rbp,%rax,8),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movslq -0x1c(%rbp),%rax
movsd  %xmm0,-0x70(%rbp,%rax,8)
mov    -0x20(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x20(%rbp)
jmp    12a1 <ecl2fk5+0x131>
jmp    12f6 <ecl2fk5+0x186>
mov    -0x1c(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1c(%rbp)
jmp    1283 <ecl2fk5+0x113>
lea    -0x70(%rbp),%rdi
lea    -0x28(%rbp),%rsi
lea    -0x30(%rbp),%rdx
lea    -0x88(%rbp),%rcx
mov    $0x0,%al
call   1090 <v2s3@plt>
movsd  -0x28(%rbp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
cvtsi2sd %eax,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,(%rax)
movsd  -0x30(%rbp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
cvtsi2sd %eax,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,(%rax)
movsd  -0x18(%rbp),%xmm0
movsd  0xccd(%rip),%xmm1
ucomisd %xmm1,%xmm0
jne    1370 <ecl2fk5+0x200>
jp     1370 <ecl2fk5+0x200>
jmp    138c <ecl2fk5+0x21c>
movsd  -0x18(%rbp),%xmm0
mov    -0x8(%rbp),%rdi
mov    -0x10(%rbp),%rsi
movsd  0xca3(%rip),%xmm1
mov    $0x2,%al
call   1030 <fk5prec@plt>
add    $0xd0,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<ecl2fk5>:
push   %r14
push   %rbx
sub    $0xb8,%rsp
movsd  %xmm0,0x8(%rsp)
mov    %rsi,%r14
mov    %rdi,%rbx
movsd  (%rdi),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,0x20(%rsp)
movsd  %xmm0,0x18(%rsp)
movsd  (%r14),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
cvtsi2sd %eax,%xmm1
movsd  %xmm1,0x10(%rsp)
movabs $0x3ff0000000000000,%rax
mov    %rax,0x28(%rsp)
movsd  0xe2f(%rip),%xmm2
lea    0x30(%rsp),%rdi
movsd  0x20(%rsp),%xmm0
mov    $0x3,%al
call   1070 <s2v3@plt>
movsd  0xe1d(%rip),%xmm1
addsd  0x8(%rsp),%xmm1
mulsd  0xe17(%rip),%xmm1
movsd  0xe17(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xe13(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xe0f(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xe0b(%rip),%xmm0
mov    $0x1,%al
call   1080 <secrad@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
lea    0x70(%rsp),%rsi
xorpd  %xmm1,%xmm1
xorps  %xmm2,%xmm2
mov    $0x1,%edi
mov    $0x3,%al
call   1040 <rotmat@plt>
movsd  0x30(%rsp),%xmm2
movsd  0x38(%rsp),%xmm0
movsd  0x40(%rsp),%xmm1
movapd %xmm2,%xmm3
unpcklpd %xmm2,%xmm3
mulpd  0x70(%rsp),%xmm3
xorpd  %xmm4,%xmm4
addpd  %xmm3,%xmm4
movupd 0x88(%rsp),%xmm3
movapd %xmm0,%xmm5
unpcklpd %xmm0,%xmm5
mulpd  %xmm3,%xmm5
addpd  %xmm4,%xmm5
movapd %xmm1,%xmm3
unpcklpd %xmm1,%xmm3
mulpd  0xa0(%rsp),%xmm3
addpd  %xmm5,%xmm3
movapd %xmm3,0x50(%rsp)
mulsd  0x80(%rsp),%xmm2
addsd  0xd88(%rip),%xmm2
mulsd  0x98(%rsp),%xmm0
addsd  %xmm2,%xmm0
mulsd  0xb0(%rsp),%xmm1
addsd  %xmm0,%xmm1
movsd  %xmm1,0x60(%rsp)
lea    0x50(%rsp),%rdi
lea    0x18(%rsp),%rsi
lea    0x10(%rsp),%rdx
lea    0x28(%rsp),%rcx
xor    %eax,%eax
call   1090 <v2s3@plt>
movsd  0x18(%rsp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,(%rbx)
movsd  0x10(%rsp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,(%r14)
movsd  0x8(%rsp),%xmm0
ucomisd 0xd06(%rip),%xmm0
jne    1336 <ecl2fk5+0x1c6>
jnp    134b <ecl2fk5+0x1db>
movsd  0xcfa(%rip),%xmm1
mov    %rbx,%rdi
mov    %r14,%rsi
mov    $0x2,%al
call   1030 <fk5prec@plt>
add    $0xb8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
define void @ecl2fk5(double* %0, double* %1, double %2) {
%4 = alloca double*
%5 = alloca double*
%6 = alloca double
%7 = alloca i32
%8 = alloca i32
%9 = alloca double
%10 = alloca double
%11 = alloca [3 x double]
%12 = alloca [3 x double]
%13 = alloca double
%14 = alloca double
%15 = alloca double
%16 = alloca [9 x double]
store double* %0, double** %4
store double* %1, double** %5
store double %2, double* %6
%17 = load double*, double** %4
%18 = load double, double* %17
%19 = call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %18)
%20 = sitofp i32 %19 to double
store double %20, double* %9
%21 = load double*, double** %5
%22 = load double, double* %21
%23 = call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %22)
%24 = sitofp i32 %23 to double
store double %24, double* %10
store double 1.000000e+00, double* %15
%25 = load double, double* %9
%26 = load double, double* %10
%27 = load double, double* %15
%28 = getelementptr inbounds [3 x double], [3 x double]* %11, i64 0, i64 0
%29 = load double, double* %6
%30 = fsub double %29, 2.000000e+03
%31 = fmul double %30, 1.000000e-02
store double %31, double* %13
%32 = load double, double* %13
%33 = call double @llvm.fmuladd.f64(double 1.813000e-03, double %32, double -5.900000e-04)
%34 = load double, double* %13
%35 = call double @llvm.fmuladd.f64(double %33, double %34, double -4.681500e+01)
%36 = load double, double* %13
%37 = call double @llvm.fmuladd.f64(double %35, double %36, double 0x40F499D72B020C4A)
%38 = call i32 (double, ...) bitcast (i32 (...)* @secrad to i32 (double, ...)*)(double %37)
%39 = sitofp i32 %38 to double
store double %39, double* %14
%40 = load double, double* %14
%41 = getelementptr inbounds [9 x double], [9 x double]* %16, i64 0, i64 0
store i32 0, i32* %7
br label %42
42: ; preds = %76, %3
%43 = load i32, i32* %7
%44 = icmp slt i32 %43, 3
br i1 %44, label %45, label %79
45: ; preds = %42
%46 = load i32, i32* %7
%47 = sext i32 %46 to i64
%48 = getelementptr inbounds [3 x double], [3 x double]* %12, i64 0, i64 %47
store double 0.000000e+00, double* %48
store i32 0, i32* %8
br label %49
49: ; preds = %72, %45
%50 = load i32, i32* %8
%51 = icmp slt i32 %50, 3
br i1 %51, label %52, label %75
52: ; preds = %49
%53 = load i32, i32* %7
%54 = sext i32 %53 to i64
%55 = getelementptr inbounds [3 x double], [3 x double]* %12, i64 0, i64 %54
%56 = load double, double* %55
%57 = load i32, i32* %8
%58 = mul nsw i32 3, %57
%59 = load i32, i32* %7
%60 = add nsw i32 %58, %59
%61 = sext i32 %60 to i64
%62 = getelementptr inbounds [9 x double], [9 x double]* %16, i64 0, i64 %61
%63 = load double, double* %62
%64 = load i32, i32* %8
%65 = sext i32 %64 to i64
%66 = getelementptr inbounds [3 x double], [3 x double]* %11, i64 0, i64 %65
%67 = load double, double* %66
%68 = call double @llvm.fmuladd.f64(double %63, double %67, double %56)
%69 = load i32, i32* %7
%70 = sext i32 %69 to i64
%71 = getelementptr inbounds [3 x double], [3 x double]* %12, i64 0, i64 %70
store double %68, double* %71
br label %72
72: ; preds = %52
%73 = load i32, i32* %8
%74 = add nsw i32 %73, 1
store i32 %74, i32* %8
br label %49
75: ; preds = %49
br label %76
76: ; preds = %75
%77 = load i32, i32* %7
%78 = add nsw i32 %77, 1
store i32 %78, i32* %7
br label %42
79: ; preds = %42
%80 = getelementptr inbounds [3 x double], [3 x double]* %12, i64 0, i64 0
%81 = load double, double* %9
%82 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %81)
%83 = sitofp i32 %82 to double
%84 = load double*, double** %4
store double %83, double* %84
%85 = load double, double* %10
%86 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %85)
%87 = sitofp i32 %86 to double
%88 = load double*, double** %5
store double %87, double* %88
%89 = load double, double* %6
%90 = fcmp une double %89, 2.000000e+03
br i1 %90, label %91, label %95
91: ; preds = %79
%92 = load double, double* %6
%93 = load double*, double** %4
%94 = load double*, double** %5
br label %95
95: ; preds = %91, %79
ret void
}

LLVM IR (-O2):
define void @ecl2fk5(double* %0, double* %1, double %2) {
%4 = alloca double
%5 = alloca double
%6 = alloca [3 x double]
%7 = alloca [3 x double]
%8 = alloca double
%9 = alloca [9 x double]
%10 = bitcast double* %4 to i8*
%11 = bitcast double* %5 to i8*
%12 = bitcast [3 x double]* %6 to i8*
%13 = bitcast [3 x double]* %7 to i8*
%14 = bitcast double* %8 to i8*
%15 = bitcast [9 x double]* %9 to i8*
%16 = load double, double* %0
%17 = tail call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %16)
%18 = sitofp i32 %17 to double
store double %18, double* %4
%19 = load double, double* %1
%20 = tail call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %19)
%21 = sitofp i32 %20 to double
store double %21, double* %5
store double 1.000000e+00, double* %8
%22 = getelementptr inbounds [3 x double], [3 x double]* %6, i64 0, i64 0
%23 = fadd double %2, -2.000000e+03
%24 = fmul double %23, 1.000000e-02
%25 = call double @llvm.fmuladd.f64(double %24, double 1.813000e-03, double -5.900000e-04)
%26 = call double @llvm.fmuladd.f64(double %25, double %24, double -4.681500e+01)
%27 = call double @llvm.fmuladd.f64(double %26, double %24, double 0x40F499D72B020C4A)
%28 = call i32 (double, ...) bitcast (i32 (...)* @secrad to i32 (double, ...)*)(double %27)
%29 = sitofp i32 %28 to double
%30 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 0
%31 = getelementptr inbounds [3 x double], [3 x double]* %7, i64 0, i64 0
%32 = load double, double* %22
%33 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 3
%34 = getelementptr inbounds [3 x double], [3 x double]* %6, i64 0, i64 1
%35 = load double, double* %34
%36 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 6
%37 = getelementptr inbounds [3 x double], [3 x double]* %6, i64 0, i64 2
%38 = load double, double* %37
%39 = bitcast [9 x double]* %9 to <2 x double>*
%40 = load <2 x double>, <2 x double>* %39
%41 = insertelement <2 x double> poison, double %32, i64 0
%42 = shufflevector <2 x double> %41, <2 x double> poison, <2 x i32> zeroinitializer
%43 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %40, <2 x double> %42, <2 x double> zeroinitializer)
%44 = bitcast double* %33 to <2 x double>*
%45 = load <2 x double>, <2 x double>* %44
%46 = insertelement <2 x double> poison, double %35, i64 0
%47 = shufflevector <2 x double> %46, <2 x double> poison, <2 x i32> zeroinitializer
%48 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %45, <2 x double> %47, <2 x double> %43)
%49 = bitcast double* %36 to <2 x double>*
%50 = load <2 x double>, <2 x double>* %49
%51 = insertelement <2 x double> poison, double %38, i64 0
%52 = shufflevector <2 x double> %51, <2 x double> poison, <2 x i32> zeroinitializer
%53 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %50, <2 x double> %52, <2 x double> %48)
%54 = bitcast [3 x double]* %7 to <2 x double>*
store <2 x double> %53, <2 x double>* %54
%55 = getelementptr inbounds [3 x double], [3 x double]* %7, i64 0, i64 2
%56 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 2
%57 = load double, double* %56
%58 = call double @llvm.fmuladd.f64(double %57, double %32, double 0.000000e+00)
%59 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 5
%60 = load double, double* %59
%61 = call double @llvm.fmuladd.f64(double %60, double %35, double %58)
%62 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 8
%63 = load double, double* %62
%64 = call double @llvm.fmuladd.f64(double %63, double %38, double %61)
store double %64, double* %55
%65 = load double, double* %4
%66 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %65)
%67 = sitofp i32 %66 to double
store double %67, double* %0
%68 = load double, double* %5
%69 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %68)
%70 = sitofp i32 %69 to double
store double %70, double* %1
%71 = fcmp une double %2, 2.000000e+03
br i1 %71, label %72, label %73
72: ; preds = %3
br label %73
73: ; preds = %72, %3
ret void
}