#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ cft1st(int, double *, double *);
int /*<<< orphan*/ cftmdl(int, int, double *, double *);
void cftfsub(int n, double *a, double *w) {
  int j, j1, j2, j3, l;
  double x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
  l = 2;
  if (n >= 16) {
    cft1st(n, a, w);
    l = 16;
    while ((l << 3) <= n) {
      cftmdl(n, l, a, w);
      l <<= 3;
    }
  }
  if ((l << 1) < n) {
    for (j = 0; j < l; j += 2) {
      j1 = j + l;
      j2 = j1 + l;
      j3 = j2 + l;
      x0r = a[j] + a[j1];
      x0i = a[j + 1] + a[j1 + 1];
      x1r = a[j] - a[j1];
      x1i = a[j + 1] - a[j1 + 1];
      x2r = a[j2] + a[j3];
      x2i = a[j2 + 1] + a[j3 + 1];
      x3r = a[j2] - a[j3];
      x3i = a[j2 + 1] - a[j3 + 1];
      a[j] = x0r + x2r;
      a[j + 1] = x0i + x2i;
      a[j2] = x0r - x2r;
      a[j2 + 1] = x0i - x2i;
      a[j1] = x1r - x3i;
      a[j1 + 1] = x1i + x3r;
      a[j3] = x1r + x3i;
      a[j3 + 1] = x1i - x3r;
    }
  } else if ((l << 1) == n) {
    for (j = 0; j < l; j += 2) {
      j1 = j + l;
      x0r = a[j] - a[j1];
      x0i = a[j + 1] - a[j1 + 1];
      a[j] += a[j1];
      a[j + 1] += a[j1 + 1];
      a[j1] = x0r;
      a[j1 + 1] = x0i;
    }
  }
}


x86 assembly (clang, -O0):
<cftfsub>:
push   %rbp
mov    %rsp,%rbp
sub    $0x70,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
movl   $0x2,-0x2c(%rbp)
cmpl   $0x10,-0x4(%rbp)
jl     1190 <cftfsub+0x70>
mov    -0x4(%rbp),%edi
mov    -0x10(%rbp),%rsi
mov    -0x18(%rbp),%rdx
call   1030 <cft1st@plt>
movl   $0x10,-0x2c(%rbp)
mov    -0x2c(%rbp),%eax
shl    $0x3,%eax
cmp    -0x4(%rbp),%eax
jg     118b <cftfsub+0x6b>
mov    -0x4(%rbp),%edi
mov    -0x2c(%rbp),%esi
mov    -0x10(%rbp),%rdx
mov    -0x18(%rbp),%rcx
call   1040 <cftmdl@plt>
mov    -0x2c(%rbp),%eax
shl    $0x3,%eax
mov    %eax,-0x2c(%rbp)
jmp    115b <cftfsub+0x3b>
jmp    1190 <cftfsub+0x70>
mov    -0x2c(%rbp),%eax
shl    $0x1,%eax
cmp    -0x4(%rbp),%eax
jge    13cc <cftfsub+0x2ac>
movl   $0x0,-0x1c(%rbp)
mov    -0x1c(%rbp),%eax
cmp    -0x2c(%rbp),%eax
jge    13c7 <cftfsub+0x2a7>
mov    -0x1c(%rbp),%eax
add    -0x2c(%rbp),%eax
mov    %eax,-0x20(%rbp)
mov    -0x20(%rbp),%eax
add    -0x2c(%rbp),%eax
mov    %eax,-0x24(%rbp)
mov    -0x24(%rbp),%eax
add    -0x2c(%rbp),%eax
mov    %eax,-0x28(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x1c(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x20(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x38(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x1c(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x40(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x1c(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x20(%rbp),%rcx
subsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x48(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x1c(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
subsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x50(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x24(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x28(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x58(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x24(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x28(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x60(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x24(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x28(%rbp),%rcx
subsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x68(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x24(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x28(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
subsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x70(%rbp)
movsd  -0x38(%rbp),%xmm0
addsd  -0x58(%rbp),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x1c(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x40(%rbp),%xmm0
addsd  -0x60(%rbp),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x1c(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x38(%rbp),%xmm0
subsd  -0x58(%rbp),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x24(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x40(%rbp),%xmm0
subsd  -0x60(%rbp),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x24(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x48(%rbp),%xmm0
subsd  -0x70(%rbp),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x20(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x50(%rbp),%xmm0
addsd  -0x68(%rbp),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x48(%rbp),%xmm0
addsd  -0x70(%rbp),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x28(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x50(%rbp),%xmm0
subsd  -0x68(%rbp),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x28(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x1c(%rbp),%eax
add    $0x2,%eax
mov    %eax,-0x1c(%rbp)
jmp    11a6 <cftfsub+0x86>
jmp    14c8 <cftfsub+0x3a8>
mov    -0x2c(%rbp),%eax
shl    $0x1,%eax
cmp    -0x4(%rbp),%eax
jne    14c3 <cftfsub+0x3a3>
movl   $0x0,-0x1c(%rbp)
mov    -0x1c(%rbp),%eax
cmp    -0x2c(%rbp),%eax
jge    14be <cftfsub+0x39e>
mov    -0x1c(%rbp),%eax
add    -0x2c(%rbp),%eax
mov    %eax,-0x20(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x1c(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x20(%rbp),%rcx
subsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x38(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x1c(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
subsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x40(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x20(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x1c(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x1c(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x38(%rbp),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x20(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x40(%rbp),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x1c(%rbp),%eax
add    $0x2,%eax
mov    %eax,-0x1c(%rbp)
jmp    13e2 <cftfsub+0x2c2>
jmp    14c3 <cftfsub+0x3a3>
jmp    14c8 <cftfsub+0x3a8>
add    $0x70,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<cftfsub>:
push   %rbp
push   %r15
push   %r14
push   %rbx
push   %rax
mov    %rsi,%rbx
mov    %edi,%r15d
mov    $0x2,%ebp
cmp    $0x10,%edi
jl     117e <cftfsub+0x5e>
mov    %rdx,%r14
mov    %r15d,%edi
mov    %rbx,%rsi
call   1030 <cft1st@plt>
mov    $0x10,%ebp
cmp    $0x80,%r15d
jb     117e <cftfsub+0x5e>
mov    $0x10,%esi
mov    $0x80,%eax
nopl   (%rax)
mov    %eax,%ebp
mov    %r15d,%edi
mov    %rbx,%rdx
mov    %r14,%rcx
call   1040 <cftmdl@plt>
lea    0x0(,%rbp,8),%eax
mov    %ebp,%esi
cmp    %r15d,%eax
jle    1160 <cftfsub+0x40>
lea    0x0(%rbp,%rbp,1),%r9d
cmp    %r15d,%r9d
jge    12a2 <cftfsub+0x182>
test   %ebp,%ebp
jle    131d <cftfsub+0x1fd>
movabs $0x200000000,%r8
mov    %ebp,%r10d
or     $0x1,%r9
mov    %r10,%rdi
shl    $0x20,%rdi
lea    (%rbx,%r10,8),%r11
lea    (%rdi,%rdi,2),%rcx
lea    (%r10,%r10,2),%rax
lea    (%rbx,%rax,8),%r14
mov    %r10,%r15
shl    $0x4,%r15
add    %rbx,%r15
xor    %eax,%eax
nopl   0x0(%rax,%rax,1)
movsd  (%r11,%rax,8),%xmm2
movupd (%rbx,%rax,8),%xmm0
mov    %rdi,%rsi
sar    $0x1d,%rsi
or     $0x8,%rsi
movsd  (%rbx,%rsi,1),%xmm3
movapd %xmm0,%xmm1
subsd  %xmm2,%xmm1
unpcklpd %xmm3,%xmm2
addpd  %xmm0,%xmm2
unpckhpd %xmm0,%xmm0
subsd  %xmm3,%xmm0
movsd  (%r15,%rax,8),%xmm3
movsd  (%r14,%rax,8),%xmm4
lea    (%r9,%rax,1),%ebp
movslq %ebp,%rdx
movsd  (%rbx,%rdx,8),%xmm5
mov    %rcx,%rbp
sar    $0x1d,%rbp
or     $0x8,%rbp
movsd  (%rbx,%rbp,1),%xmm6
movapd %xmm3,%xmm7
unpcklpd %xmm5,%xmm7
subsd  %xmm4,%xmm3
unpcklpd %xmm6,%xmm4
addpd  %xmm7,%xmm4
subsd  %xmm6,%xmm5
movapd %xmm2,%xmm6
addpd  %xmm4,%xmm6
movupd %xmm6,(%rbx,%rax,8)
subpd  %xmm4,%xmm2
movlpd %xmm2,(%r15,%rax,8)
movhpd %xmm2,(%rbx,%rdx,8)
movapd %xmm1,%xmm2
subsd  %xmm5,%xmm2
movsd  %xmm2,(%r11,%rax,8)
movapd %xmm0,%xmm2
addsd  %xmm3,%xmm2
movsd  %xmm2,(%rbx,%rsi,1)
addsd  %xmm1,%xmm5
movsd  %xmm5,(%r14,%rax,8)
subsd  %xmm3,%xmm0
movsd  %xmm0,(%rbx,%rbp,1)
add    $0x2,%rax
add    %r8,%rdi
add    %r8,%rcx
cmp    %r10,%rax
jb     11d0 <cftfsub+0xb0>
jmp    131d <cftfsub+0x1fd>
jne    131d <cftfsub+0x1fd>
test   %ebp,%ebp
jle    131d <cftfsub+0x1fd>
movabs $0x200000000,%rax
mov    %ebp,%ebp
mov    %rbp,%rcx
shl    $0x20,%rcx
lea    (%rbx,%rbp,8),%rsi
xor    %edi,%edi
cs nopw 0x0(%rax,%rax,1)
nopl   0x0(%rax,%rax,1)
movsd  (%rsi,%rdi,8),%xmm0
movupd (%rbx,%rdi,8),%xmm1
movapd %xmm1,%xmm2
subsd  %xmm0,%xmm2
mov    %rcx,%rdx
sar    $0x1d,%rdx
or     $0x8,%rdx
movsd  (%rbx,%rdx,1),%xmm3
unpcklpd %xmm3,%xmm0
addpd  %xmm1,%xmm0
unpckhpd %xmm1,%xmm1
subsd  %xmm3,%xmm1
movupd %xmm0,(%rbx,%rdi,8)
movsd  %xmm2,(%rsi,%rdi,8)
movsd  %xmm1,(%rbx,%rdx,1)
add    $0x2,%rdi
add    %rax,%rcx
cmp    %rbp,%rdi
jb     12d0 <cftfsub+0x1b0>
add    $0x8,%rsp
pop    %rbx
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
define void @cftfsub(i32 %0, double* %1, double* %2) {
%4 = alloca i32
%5 = alloca double*
%6 = alloca double*
%7 = alloca i32
%8 = alloca i32
%9 = alloca i32
%10 = alloca i32
%11 = alloca i32
%12 = alloca double
%13 = alloca double
%14 = alloca double
%15 = alloca double
%16 = alloca double
%17 = alloca double
%18 = alloca double
%19 = alloca double
store i32 %0, i32* %4
store double* %1, double** %5
store double* %2, double** %6
store i32 2, i32* %11
%20 = load i32, i32* %4
%21 = icmp sge i32 %20, 16
br i1 %21, label %22, label %41
22: ; preds = %3
%23 = load i32, i32* %4
%24 = load double*, double** %5
%25 = load double*, double** %6
%26 = call i32 @cft1st(i32 %23, double* %24, double* %25)
store i32 16, i32* %11
br label %27
27: ; preds = %32, %22
%28 = load i32, i32* %11
%29 = shl i32 %28, 3
%30 = load i32, i32* %4
%31 = icmp sle i32 %29, %30
br i1 %31, label %32, label %40
32: ; preds = %27
%33 = load i32, i32* %4
%34 = load i32, i32* %11
%35 = load double*, double** %5
%36 = load double*, double** %6
%37 = call i32 @cftmdl(i32 %33, i32 %34, double* %35, double* %36)
%38 = load i32, i32* %11
%39 = shl i32 %38, 3
store i32 %39, i32* %11
br label %27
40: ; preds = %27
br label %41
41: ; preds = %40, %3
%42 = load i32, i32* %11
%43 = shl i32 %42, 1
%44 = load i32, i32* %4
%45 = icmp slt i32 %43, %44
br i1 %45, label %46, label %221
46: ; preds = %41
store i32 0, i32* %7
br label %47
47: ; preds = %217, %46
%48 = load i32, i32* %7
%49 = load i32, i32* %11
%50 = icmp slt i32 %48, %49
br i1 %50, label %51, label %220
51: ; preds = %47
%52 = load i32, i32* %7
%53 = load i32, i32* %11
%54 = add nsw i32 %52, %53
store i32 %54, i32* %8
%55 = load i32, i32* %8
%56 = load i32, i32* %11
%57 = add nsw i32 %55, %56
store i32 %57, i32* %9
%58 = load i32, i32* %9
%59 = load i32, i32* %11
%60 = add nsw i32 %58, %59
store i32 %60, i32* %10
%61 = load double*, double** %5
%62 = load i32, i32* %7
%63 = sext i32 %62 to i64
%64 = getelementptr inbounds double, double* %61, i64 %63
%65 = load double, double* %64
%66 = load double*, double** %5
%67 = load i32, i32* %8
%68 = sext i32 %67 to i64
%69 = getelementptr inbounds double, double* %66, i64 %68
%70 = load double, double* %69
%71 = fadd double %65, %70
store double %71, double* %12
%72 = load double*, double** %5
%73 = load i32, i32* %7
%74 = add nsw i32 %73, 1
%75 = sext i32 %74 to i64
%76 = getelementptr inbounds double, double* %72, i64 %75
%77 = load double, double* %76
%78 = load double*, double** %5
%79 = load i32, i32* %8
%80 = add nsw i32 %79, 1
%81 = sext i32 %80 to i64
%82 = getelementptr inbounds double, double* %78, i64 %81
%83 = load double, double* %82
%84 = fadd double %77, %83
store double %84, double* %13
%85 = load double*, double** %5
%86 = load i32, i32* %7
%87 = sext i32 %86 to i64
%88 = getelementptr inbounds double, double* %85, i64 %87
%89 = load double, double* %88
%90 = load double*, double** %5
%91 = load i32, i32* %8
%92 = sext i32 %91 to i64
%93 = getelementptr inbounds double, double* %90, i64 %92
%94 = load double, double* %93
%95 = fsub double %89, %94
store double %95, double* %14
%96 = load double*, double** %5
%97 = load i32, i32* %7
%98 = add nsw i32 %97, 1
%99 = sext i32 %98 to i64
%100 = getelementptr inbounds double, double* %96, i64 %99
%101 = load double, double* %100
%102 = load double*, double** %5
%103 = load i32, i32* %8
%104 = add nsw i32 %103, 1
%105 = sext i32 %104 to i64
%106 = getelementptr inbounds double, double* %102, i64 %105
%107 = load double, double* %106
%108 = fsub double %101, %107
store double %108, double* %15
%109 = load double*, double** %5
%110 = load i32, i32* %9
%111 = sext i32 %110 to i64
%112 = getelementptr inbounds double, double* %109, i64 %111
%113 = load double, double* %112
%114 = load double*, double** %5
%115 = load i32, i32* %10
%116 = sext i32 %115 to i64
%117 = getelementptr inbounds double, double* %114, i64 %116
%118 = load double, double* %117
%119 = fadd double %113, %118
store double %119, double* %16
%120 = load double*, double** %5
%121 = load i32, i32* %9
%122 = add nsw i32 %121, 1
%123 = sext i32 %122 to i64
%124 = getelementptr inbounds double, double* %120, i64 %123
%125 = load double, double* %124
%126 = load double*, double** %5
%127 = load i32, i32* %10
%128 = add nsw i32 %127, 1
%129 = sext i32 %128 to i64
%130 = getelementptr inbounds double, double* %126, i64 %129
%131 = load double, double* %130
%132 = fadd double %125, %131
store double %132, double* %17
%133 = load double*, double** %5
%134 = load i32, i32* %9
%135 = sext i32 %134 to i64
%136 = getelementptr inbounds double, double* %133, i64 %135
%137 = load double, double* %136
%138 = load double*, double** %5
%139 = load i32, i32* %10
%140 = sext i32 %139 to i64
%141 = getelementptr inbounds double, double* %138, i64 %140
%142 = load double, double* %141
%143 = fsub double %137, %142
store double %143, double* %18
%144 = load double*, double** %5
%145 = load i32, i32* %9
%146 = add nsw i32 %145, 1
%147 = sext i32 %146 to i64
%148 = getelementptr inbounds double, double* %144, i64 %147
%149 = load double, double* %148
%150 = load double*, double** %5
%151 = load i32, i32* %10
%152 = add nsw i32 %151, 1
%153 = sext i32 %152 to i64
%154 = getelementptr inbounds double, double* %150, i64 %153
%155 = load double, double* %154
%156 = fsub double %149, %155
store double %156, double* %19
%157 = load double, double* %12
%158 = load double, double* %16
%159 = fadd double %157, %158
%160 = load double*, double** %5
%161 = load i32, i32* %7
%162 = sext i32 %161 to i64
%163 = getelementptr inbounds double, double* %160, i64 %162
store double %159, double* %163
%164 = load double, double* %13
%165 = load double, double* %17
%166 = fadd double %164, %165
%167 = load double*, double** %5
%168 = load i32, i32* %7
%169 = add nsw i32 %168, 1
%170 = sext i32 %169 to i64
%171 = getelementptr inbounds double, double* %167, i64 %170
store double %166, double* %171
%172 = load double, double* %12
%173 = load double, double* %16
%174 = fsub double %172, %173
%175 = load double*, double** %5
%176 = load i32, i32* %9
%177 = sext i32 %176 to i64
%178 = getelementptr inbounds double, double* %175, i64 %177
store double %174, double* %178
%179 = load double, double* %13
%180 = load double, double* %17
%181 = fsub double %179, %180
%182 = load double*, double** %5
%183 = load i32, i32* %9
%184 = add nsw i32 %183, 1
%185 = sext i32 %184 to i64
%186 = getelementptr inbounds double, double* %182, i64 %185
store double %181, double* %186
%187 = load double, double* %14
%188 = load double, double* %19
%189 = fsub double %187, %188
%190 = load double*, double** %5
%191 = load i32, i32* %8
%192 = sext i32 %191 to i64
%193 = getelementptr inbounds double, double* %190, i64 %192
store double %189, double* %193
%194 = load double, double* %15
%195 = load double, double* %18
%196 = fadd double %194, %195
%197 = load double*, double** %5
%198 = load i32, i32* %8
%199 = add nsw i32 %198, 1
%200 = sext i32 %199 to i64
%201 = getelementptr inbounds double, double* %197, i64 %200
store double %196, double* %201
%202 = load double, double* %14
%203 = load double, double* %19
%204 = fadd double %202, %203
%205 = load double*, double** %5
%206 = load i32, i32* %10
%207 = sext i32 %206 to i64
%208 = getelementptr inbounds double, double* %205, i64 %207
store double %204, double* %208
%209 = load double, double* %15
%210 = load double, double* %18
%211 = fsub double %209, %210
%212 = load double*, double** %5
%213 = load i32, i32* %10
%214 = add nsw i32 %213, 1
%215 = sext i32 %214 to i64
%216 = getelementptr inbounds double, double* %212, i64 %215
store double %211, double* %216
br label %217
217: ; preds = %51
%218 = load i32, i32* %7
%219 = add nsw i32 %218, 2
store i32 %219, i32* %7
br label %47
220: ; preds = %47
br label %299
221: ; preds = %41
%222 = load i32, i32* %11
%223 = shl i32 %222, 1
%224 = load i32, i32* %4
%225 = icmp eq i32 %223, %224
br i1 %225, label %226, label %298
226: ; preds = %221
store i32 0, i32* %7
br label %227
227: ; preds = %294, %226
%228 = load i32, i32* %7
%229 = load i32, i32* %11
%230 = icmp slt i32 %228, %229
br i1 %230, label %231, label %297
231: ; preds = %227
%232 = load i32, i32* %7
%233 = load i32, i32* %11
%234 = add nsw i32 %232, %233
store i32 %234, i32* %8
%235 = load double*, double** %5
%236 = load i32, i32* %7
%237 = sext i32 %236 to i64
%238 = getelementptr inbounds double, double* %235, i64 %237
%239 = load double, double* %238
%240 = load double*, double** %5
%241 = load i32, i32* %8
%242 = sext i32 %241 to i64
%243 = getelementptr inbounds double, double* %240, i64 %242
%244 = load double, double* %243
%245 = fsub double %239, %244
store double %245, double* %12
%246 = load double*, double** %5
%247 = load i32, i32* %7
%248 = add nsw i32 %247, 1
%249 = sext i32 %248 to i64
%250 = getelementptr inbounds double, double* %246, i64 %249
%251 = load double, double* %250
%252 = load double*, double** %5
%253 = load i32, i32* %8
%254 = add nsw i32 %253, 1
%255 = sext i32 %254 to i64
%256 = getelementptr inbounds double, double* %252, i64 %255
%257 = load double, double* %256
%258 = fsub double %251, %257
store double %258, double* %13
%259 = load double*, double** %5
%260 = load i32, i32* %8
%261 = sext i32 %260 to i64
%262 = getelementptr inbounds double, double* %259, i64 %261
%263 = load double, double* %262
%264 = load double*, double** %5
%265 = load i32, i32* %7
%266 = sext i32 %265 to i64
%267 = getelementptr inbounds double, double* %264, i64 %266
%268 = load double, double* %267
%269 = fadd double %268, %263
store double %269, double* %267
%270 = load double*, double** %5
%271 = load i32, i32* %8
%272 = add nsw i32 %271, 1
%273 = sext i32 %272 to i64
%274 = getelementptr inbounds double, double* %270, i64 %273
%275 = load double, double* %274
%276 = load double*, double** %5
%277 = load i32, i32* %7
%278 = add nsw i32 %277, 1
%279 = sext i32 %278 to i64
%280 = getelementptr inbounds double, double* %276, i64 %279
%281 = load double, double* %280
%282 = fadd double %281, %275
store double %282, double* %280
%283 = load double, double* %12
%284 = load double*, double** %5
%285 = load i32, i32* %8
%286 = sext i32 %285 to i64
%287 = getelementptr inbounds double, double* %284, i64 %286
store double %283, double* %287
%288 = load double, double* %13
%289 = load double*, double** %5
%290 = load i32, i32* %8
%291 = add nsw i32 %290, 1
%292 = sext i32 %291 to i64
%293 = getelementptr inbounds double, double* %289, i64 %292
store double %288, double* %293
br label %294
294: ; preds = %231
%295 = load i32, i32* %7
%296 = add nsw i32 %295, 2
store i32 %296, i32* %7
br label %227
297: ; preds = %227
br label %298
298: ; preds = %297, %221
br label %299
299: ; preds = %298, %220
ret void
}

LLVM IR (-O2):
define void @cftfsub(i32 %0, double* %1, double* %2) {
%4 = icmp sgt i32 %0, 15
br i1 %4, label %5, label %14
5: ; preds = %3
%6 = tail call i32 @cft1st(i32 %0, double* %1, double* %2)
%7 = icmp ult i32 %0, 128
br i1 %7, label %14, label %8
8: ; preds = %5, %8
%9 = phi i32 [ %12, %8 ], [ 128, %5 ]
%10 = phi i32 [ %9, %8 ], [ 16, %5 ]
%11 = tail call i32 @cftmdl(i32 %0, i32 %10, double* %1, double* %2)
%12 = shl i32 %9, 3
%13 = icmp sgt i32 %12, %0
br i1 %13, label %14, label %8
14: ; preds = %8, %5, %3
%15 = phi i32 [ 2, %3 ], [ 16, %5 ], [ %9, %8 ]
%16 = shl i32 %15, 1
%17 = icmp slt i32 %16, %0
br i1 %17, label %18, label %79
18: ; preds = %14
%19 = icmp sgt i32 %15, 0
br i1 %19, label %20, label %108
20: ; preds = %18
%21 = zext i32 %15 to i64
%22 = shl i32 %15, 1
br label %23
23: ; preds = %20, %23
%24 = phi i64 [ 0, %20 ], [ %77, %23 ]
%25 = trunc i64 %24 to i32
%26 = add nuw nsw i64 %24, %21
%27 = add nuw nsw i64 %26, %21
%28 = add i32 %22, %25
%29 = add nuw nsw i64 %27, %21
%30 = getelementptr inbounds double, double* %1, i64 %24
%31 = getelementptr inbounds double, double* %1, i64 %26
%32 = load double, double* %31
%33 = bitcast double* %30 to <2 x double>*
%34 = load <2 x double>, <2 x double>* %33
%35 = shl i64 %26, 32
%36 = ashr exact i64 %35, 32
%37 = or i64 %36, 1
%38 = getelementptr inbounds double, double* %1, i64 %37
%39 = load double, double* %38
%40 = insertelement <2 x double> poison, double %32, i64 0
%41 = insertelement <2 x double> %40, double %39, i64 1
%42 = fadd <2 x double> %34, %41
%43 = extractelement <2 x double> %34, i64 0
%44 = fsub double %43, %32
%45 = extractelement <2 x double> %34, i64 1
%46 = fsub double %45, %39
%47 = getelementptr inbounds double, double* %1, i64 %27
%48 = load double, double* %47
%49 = getelementptr inbounds double, double* %1, i64 %29
%50 = load double, double* %49
%51 = or i32 %28, 1
%52 = sext i32 %51 to i64
%53 = getelementptr inbounds double, double* %1, i64 %52
%54 = load double, double* %53
%55 = shl i64 %29, 32
%56 = ashr exact i64 %55, 32
%57 = or i64 %56, 1
%58 = getelementptr inbounds double, double* %1, i64 %57
%59 = load double, double* %58
%60 = insertelement <2 x double> poison, double %48, i64 0
%61 = insertelement <2 x double> %60, double %54, i64 1
%62 = insertelement <2 x double> poison, double %50, i64 0
%63 = insertelement <2 x double> %62, double %59, i64 1
%64 = fadd <2 x double> %61, %63
%65 = fsub double %48, %50
%66 = fsub double %54, %59
%67 = fadd <2 x double> %42, %64
%68 = bitcast double* %30 to <2 x double>*
store <2 x double> %67, <2 x double>* %68
%69 = fsub <2 x double> %42, %64
%70 = extractelement <2 x double> %69, i64 0
store double %70, double* %47
%71 = fsub <2 x double> %42, %64
%72 = extractelement <2 x double> %71, i64 1
store double %72, double* %53
%73 = fsub double %44, %66
store double %73, double* %31
%74 = fadd double %46, %65
store double %74, double* %38
%75 = fadd double %44, %66
store double %75, double* %49
%76 = fsub double %46, %65
store double %76, double* %58
%77 = add nuw nsw i64 %24, 2
%78 = icmp ult i64 %77, %21
br i1 %78, label %23, label %108
79: ; preds = %14
%80 = icmp eq i32 %16, %0
%81 = icmp sgt i32 %15, 0
%82 = and i1 %80, %81
br i1 %82, label %83, label %108
83: ; preds = %79
%84 = zext i32 %15 to i64
br label %85
85: ; preds = %83, %85
%86 = phi i64 [ 0, %83 ], [ %106, %85 ]
%87 = add nuw nsw i64 %86, %84
%88 = getelementptr inbounds double, double* %1, i64 %86
%89 = getelementptr inbounds double, double* %1, i64 %87
%90 = load double, double* %89
%91 = bitcast double* %88 to <2 x double>*
%92 = load <2 x double>, <2 x double>* %91
%93 = extractelement <2 x double> %92, i64 0
%94 = fsub double %93, %90
%95 = shl i64 %87, 32
%96 = ashr exact i64 %95, 32
%97 = or i64 %96, 1
%98 = getelementptr inbounds double, double* %1, i64 %97
%99 = load double, double* %98
%100 = extractelement <2 x double> %92, i64 1
%101 = fsub double %100, %99
%102 = insertelement <2 x double> poison, double %90, i64 0
%103 = insertelement <2 x double> %102, double %99, i64 1
%104 = fadd <2 x double> %92, %103
%105 = bitcast double* %88 to <2 x double>*
store <2 x double> %104, <2 x double>* %105
store double %94, double* %89
store double %101, double* %98
%106 = add nuw nsw i64 %86, 2
%107 = icmp ult i64 %106, %84
br i1 %107, label %85, label %108
108: ; preds = %85, %23, %18, %79
ret void
}