void cftfx41(int n, float *a) {
  void cftf161(float *a);
  void cftf162(float *a);
  void cftf081(float *a);
  void cftf082(float *a);
  if (n == 128) {
    cftf161(a);
    cftf162(&a[32]);
    cftf161(&a[64]);
    cftf161(&a[96]);
  } else {
    cftf081(a);
    cftf082(&a[16]);
    cftf081(&a[32]);
    cftf081(&a[48]);
  }
}


x86 assembly (clang, -O0):
<cftfx41>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
cmpl   $0x80,-0x4(%rbp)
jne    119a <cftfx41+0x5a>
mov    -0x10(%rbp),%rdi
call   1030 <cftf161@plt>
mov    -0x10(%rbp),%rdi
add    $0x80,%rdi
call   1050 <cftf162@plt>
mov    -0x10(%rbp),%rdi
add    $0x100,%rdi
call   1030 <cftf161@plt>
mov    -0x10(%rbp),%rdi
add    $0x180,%rdi
call   1030 <cftf161@plt>
jmp    11d0 <cftfx41+0x90>
mov    -0x10(%rbp),%rdi
call   1040 <cftf081@plt>
mov    -0x10(%rbp),%rdi
add    $0x40,%rdi
call   1060 <cftf082@plt>
mov    -0x10(%rbp),%rdi
add    $0x80,%rdi
call   1040 <cftf081@plt>
mov    -0x10(%rbp),%rdi
add    $0xc0,%rdi
call   1040 <cftf081@plt>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<cftfx41>:
push   %rbx
mov    %rsi,%rbx
cmp    $0x80,%edi
jne    117c <cftfx41+0x3c>
mov    %rbx,%rdi
call   1030 <cftf161@plt>
lea    0x80(%rbx),%rdi
call   1050 <cftf162@plt>
lea    0x100(%rbx),%rdi
call   1030 <cftf161@plt>
add    $0x180,%rbx
mov    %rbx,%rdi
pop    %rbx
jmp    1030 <cftf161@plt>
mov    %rbx,%rdi
call   1040 <cftf081@plt>
lea    0x40(%rbx),%rdi
call   1060 <cftf082@plt>
lea    0x80(%rbx),%rdi
call   1040 <cftf081@plt>
add    $0xc0,%rbx
mov    %rbx,%rdi
pop    %rbx
jmp    1040 <cftf081@plt>

LLVM IR (-O0):
define void @cftfx41(i32 %0, float* %1) {
%3 = alloca i32
%4 = alloca float*
store i32 %0, i32* %3
store float* %1, float** %4
%5 = load i32, i32* %3
%6 = icmp eq i32 %5, 128
br i1 %6, label %7, label %15
7: ; preds = %2
%8 = load float*, float** %4
%9 = load float*, float** %4
%10 = getelementptr inbounds float, float* %9, i64 32
%11 = load float*, float** %4
%12 = getelementptr inbounds float, float* %11, i64 64
%13 = load float*, float** %4
%14 = getelementptr inbounds float, float* %13, i64 96
br label %23
15: ; preds = %2
%16 = load float*, float** %4
%17 = load float*, float** %4
%18 = getelementptr inbounds float, float* %17, i64 16
%19 = load float*, float** %4
%20 = getelementptr inbounds float, float* %19, i64 32
%21 = load float*, float** %4
%22 = getelementptr inbounds float, float* %21, i64 48
br label %23
23: ; preds = %15, %7
ret void
}

LLVM IR (-O2):
define void @cftfx41(i32 %0, float* %1) {
%3 = icmp eq i32 %0, 128
br i1 %3, label %4, label %8
4: ; preds = %2
tail call void @cftf161(float* %1)
%5 = getelementptr inbounds float, float* %1, i64 32
tail call void @cftf162(float* %5)
%6 = getelementptr inbounds float, float* %1, i64 64
tail call void @cftf161(float* %6)
%7 = getelementptr inbounds float, float* %1, i64 96
tail call void @cftf161(float* %7)
br label %12
8: ; preds = %2
tail call void @cftf081(float* %1)
%9 = getelementptr inbounds float, float* %1, i64 16
tail call void @cftf082(float* %9)
%10 = getelementptr inbounds float, float* %1, i64 32
tail call void @cftf081(float* %10)
%11 = getelementptr inbounds float, float* %1, i64 48
tail call void @cftf081(float* %11)
br label %12
12: ; preds = %8, %4
ret void
}