#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*/ __ogg_fdrfftb(int, double *, double *, int *);
void dcsqb1(int n, double *x, double *w, double *xh, int *ifac) {
  int modn, i, k, kc;
  int np2, ns2;
  double xim1;
  ns2 = (n + 1) >> 1;
  np2 = n;
  for (i = 2; i < n; i += 2) {
    xim1 = x[i - 1] + x[i];
    x[i] -= x[i - 1];
    x[i - 1] = xim1;
  }
  x[0] += x[0];
  modn = n % 2;
  if (modn == 0)
    x[n - 1] += x[n - 1];
  __ogg_fdrfftb(n, x, xh, ifac);
  kc = np2;
  for (k = 1; k < ns2; k++) {
    kc--;
    xh[k] = w[k - 1] * x[kc] + w[kc - 1] * x[k];
    xh[kc] = w[k - 1] * x[k] - w[kc - 1] * x[kc];
  }
  if (modn == 0)
    x[ns2] = w[ns2 - 1] * (x[ns2] + x[ns2]);
  kc = np2;
  for (k = 1; k < ns2; k++) {
    kc--;
    x[k] = xh[k] + xh[kc];
    x[kc] = xh[k] - xh[kc];
  }
  x[0] += x[0];
}


x86 assembly (clang, -O0):
<dcsqb1>:
push   %rbp
mov    %rsp,%rbp
sub    $0x50,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    %rcx,-0x20(%rbp)
mov    %r8,-0x28(%rbp)
mov    -0x4(%rbp),%eax
add    $0x1,%eax
sar    $0x1,%eax
mov    %eax,-0x40(%rbp)
mov    -0x4(%rbp),%eax
mov    %eax,-0x3c(%rbp)
movl   $0x2,-0x30(%rbp)
mov    -0x30(%rbp),%eax
cmp    -0x4(%rbp),%eax
jge    11c1 <dcsqb1+0xb1>
mov    -0x10(%rbp),%rax
mov    -0x30(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x30(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x48(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x30(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm1
mov    -0x10(%rbp),%rax
movslq -0x30(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,(%rax,%rcx,8)
movsd  -0x48(%rbp),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x30(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x30(%rbp),%eax
add    $0x2,%eax
mov    %eax,-0x30(%rbp)
jmp    1144 <dcsqb1+0x34>
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm0
mov    -0x10(%rbp),%rax
addsd  (%rax),%xmm0
movsd  %xmm0,(%rax)
mov    -0x4(%rbp),%eax
mov    $0x2,%ecx
cltd
idiv   %ecx
mov    %edx,-0x2c(%rbp)
cmpl   $0x0,-0x2c(%rbp)
jne    1216 <dcsqb1+0x106>
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
addsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x4(%rbp),%edi
mov    -0x10(%rbp),%rsi
mov    -0x20(%rbp),%rdx
mov    -0x28(%rbp),%rcx
call   1030 <__ogg_fdrfftb@plt>
mov    -0x3c(%rbp),%eax
mov    %eax,-0x38(%rbp)
movl   $0x1,-0x34(%rbp)
mov    -0x34(%rbp),%eax
cmp    -0x40(%rbp),%eax
jge    1317 <dcsqb1+0x207>
mov    -0x38(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,-0x38(%rbp)
mov    -0x18(%rbp),%rax
mov    -0x34(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x38(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm2
mov    -0x18(%rbp),%rax
mov    -0x38(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm1
mov    -0x10(%rbp),%rax
movslq -0x34(%rbp),%rcx
mulsd  (%rax,%rcx,8),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x20(%rbp),%rax
movslq -0x34(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x18(%rbp),%rax
mov    -0x34(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x34(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm2
mov    -0x18(%rbp),%rax
mov    -0x38(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm1
mov    -0x10(%rbp),%rax
movslq -0x38(%rbp),%rcx
mulsd  (%rax,%rcx,8),%xmm1
movq   %xmm1,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x20(%rbp),%rax
movslq -0x38(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x34(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x34(%rbp)
jmp    1237 <dcsqb1+0x127>
cmpl   $0x0,-0x2c(%rbp)
jne    135e <dcsqb1+0x24e>
mov    -0x18(%rbp),%rax
mov    -0x40(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x40(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm1
mov    -0x10(%rbp),%rax
movslq -0x40(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm1
mulsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movslq -0x40(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x3c(%rbp),%eax
mov    %eax,-0x38(%rbp)
movl   $0x1,-0x34(%rbp)
mov    -0x34(%rbp),%eax
cmp    -0x40(%rbp),%eax
jge    13dc <dcsqb1+0x2cc>
mov    -0x38(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,-0x38(%rbp)
mov    -0x20(%rbp),%rax
movslq -0x34(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x20(%rbp),%rax
movslq -0x38(%rbp),%rcx
addsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x34(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x20(%rbp),%rax
movslq -0x34(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x20(%rbp),%rax
movslq -0x38(%rbp),%rcx
subsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
movslq -0x38(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x34(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x34(%rbp)
jmp    136b <dcsqb1+0x25b>
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm0
mov    -0x10(%rbp),%rax
addsd  (%rax),%xmm0
movsd  %xmm0,(%rax)
add    $0x50,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<dcsqb1>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
push   %rax
mov    %rcx,%r14
mov    %rdx,%r12
mov    %rsi,%rbx
mov    %edi,%r13d
cmp    $0x3,%edi
jl     128b <dcsqb1+0x17b>
cmp    $0x5,%r13
mov    $0x4,%eax
cmovae %r13,%rax
add    $0xfffffffffffffffd,%rax
mov    $0x2,%ecx
cmp    $0x2,%rax
jb     1260 <dcsqb1+0x150>
shr    %rax
add    $0x1,%rax
movabs $0x7ffffffffffffffe,%rcx
ff ff 7f
and    %rax,%rcx
lea    -0x2(%rcx),%rdx
mov    %rdx,%rbp
shr    %rbp
add    $0x1,%rbp
test   %rdx,%rdx
je     1463 <dcsqb1+0x353>
mov    %rbp,%rsi
and    $0xfffffffffffffffe,%rsi
mov    $0x1,%edx
nopw   0x0(%rax,%rax,1)
movupd (%rbx,%rdx,8),%xmm0
movupd 0x10(%rbx,%rdx,8),%xmm1
movupd 0x20(%rbx,%rdx,8),%xmm2
movupd 0x30(%rbx,%rdx,8),%xmm3
movapd %xmm0,%xmm4
unpcklpd %xmm1,%xmm4
unpckhpd %xmm1,%xmm0
movapd %xmm4,%xmm1
addpd  %xmm0,%xmm1
subpd  %xmm4,%xmm0
movapd %xmm1,%xmm4
unpckhpd %xmm0,%xmm4
unpcklpd %xmm0,%xmm1
movupd %xmm1,(%rbx,%rdx,8)
movupd %xmm4,0x10(%rbx,%rdx,8)
movapd %xmm2,%xmm0
unpcklpd %xmm3,%xmm0
unpckhpd %xmm3,%xmm2
movapd %xmm0,%xmm1
addpd  %xmm2,%xmm1
subpd  %xmm0,%xmm2
movapd %xmm1,%xmm0
unpckhpd %xmm2,%xmm0
unpcklpd %xmm2,%xmm1
movupd %xmm1,0x20(%rbx,%rdx,8)
movupd %xmm0,0x30(%rbx,%rdx,8)
add    $0x8,%rdx
add    $0xfffffffffffffffe,%rsi
jne    1190 <dcsqb1+0x80>
test   $0x1,%bpl
je     1250 <dcsqb1+0x140>
movupd (%rbx,%rdx,8),%xmm0
movupd 0x10(%rbx,%rdx,8),%xmm1
movapd %xmm0,%xmm2
unpcklpd %xmm1,%xmm2
unpckhpd %xmm1,%xmm0
movapd %xmm2,%xmm1
addpd  %xmm0,%xmm1
subpd  %xmm2,%xmm0
movapd %xmm1,%xmm2
unpckhpd %xmm0,%xmm2
unpcklpd %xmm0,%xmm1
movupd %xmm1,(%rbx,%rdx,8)
movupd %xmm2,0x10(%rbx,%rdx,8)
cmp    %rcx,%rax
je     128b <dcsqb1+0x17b>
add    %rax,%rax
or     $0x2,%rax
mov    %rax,%rcx
nop
movsd  -0x8(%rbx,%rcx,8),%xmm0
movsd  (%rbx,%rcx,8),%xmm1
movapd %xmm0,%xmm2
addsd  %xmm1,%xmm2
subsd  %xmm0,%xmm1
movsd  %xmm1,(%rbx,%rcx,8)
movsd  %xmm2,-0x8(%rbx,%rcx,8)
add    $0x2,%rcx
cmp    %r13,%rcx
jb     1260 <dcsqb1+0x150>
lea    0x1(%rdi),%r15d
movsd  (%rbx),%xmm0
addsd  %xmm0,%xmm0
movsd  %xmm0,(%rbx)
test   $0x1,%dil
jne    12b4 <dcsqb1+0x1a4>
movslq %edi,%rax
movsd  -0x8(%rbx,%rax,8),%xmm0
addsd  %xmm0,%xmm0
movsd  %xmm0,-0x8(%rbx,%rax,8)
sar    %r15d
mov    %rbx,%rsi
mov    %r14,%rdx
mov    %r8,%rcx
mov    %rdi,%rbp
call   1030 <__ogg_fdrfftb@plt>
mov    %rbp,%r9
cmp    $0x3,%r9d
jl     1350 <dcsqb1+0x240>
cmp    $0x3,%r15d
mov    $0x2,%esi
cmovge %r15d,%esi
lea    -0x10(%r12,%r13,8),%rax
lea    -0x8(%rbx,%r13,8),%rcx
lea    (%r14,%r13,8),%r8
add    $0xfffffffffffffff8,%r8
lea    -0x8(,%rsi,8),%rdx
ff
mov    $0x1,%edi
xor    %ebp,%ebp
nop
movsd  (%rax,%rbp,1),%xmm0
mulsd  (%rbx,%rdi,8),%xmm0
movsd  -0x8(%r12,%rdi,8),%xmm1
mulsd  (%rcx,%rbp,1),%xmm1
addsd  %xmm0,%xmm1
movsd  %xmm1,(%r14,%rdi,8)
movsd  (%rcx,%rbp,1),%xmm0
mulsd  (%rax,%rbp,1),%xmm0
movsd  -0x8(%r12,%rdi,8),%xmm1
mulsd  (%rbx,%rdi,8),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,(%r8,%rbp,1)
add    $0x1,%rdi
add    $0xfffffffffffffff8,%rbp
mov    %rdx,%rsi
add    %rbp,%rsi
jne    1300 <dcsqb1+0x1f0>
test   $0x1,%r9b
jne    136e <dcsqb1+0x25e>
movslq %r15d,%rax
movsd  (%rbx,%rax,8),%xmm0
addsd  %xmm0,%xmm0
mulsd  -0x8(%r12,%rax,8),%xmm0
movsd  %xmm0,(%rbx,%rax,8)
cmp    $0x3,%r9d
jl     1448 <dcsqb1+0x338>
cmp    $0x3,%r15d
mov    $0x2,%eax
cmovge %r15d,%eax
add    $0xffffffffffffffff,%rax
mov    $0x1,%ecx
cmp    $0x5,%r9d
jl     141e <dcsqb1+0x30e>
lea    (%rbx,%r13,8),%rcx
add    $0xfffffffffffffff8,%rcx
lea    (%r14,%r13,8),%rdx
add    $0xfffffffffffffff8,%rdx
mov    %rax,%rdi
and    $0xfffffffffffffffe,%rdi
neg    %rdi
mov    $0x10,%ebp
xor    %esi,%esi
nopl   0x0(%rax)
movsd  -0x8(%r14,%rbp,1),%xmm0
addsd  (%rdx,%rsi,8),%xmm0
movsd  %xmm0,-0x8(%rbx,%rbp,1)
movsd  -0x8(%r14,%rbp,1),%xmm0
subsd  (%rdx,%rsi,8),%xmm0
movsd  %xmm0,(%rcx,%rsi,8)
movsd  (%r14,%rbp,1),%xmm0
addsd  -0x8(%rdx,%rsi,8),%xmm0
movsd  %xmm0,(%rbx,%rbp,1)
movsd  (%r14,%rbp,1),%xmm0
subsd  -0x8(%rdx,%rsi,8),%xmm0
movsd  %xmm0,-0x8(%rcx,%rsi,8)
add    $0xfffffffffffffffe,%rsi
add    $0x10,%rbp
cmp    %rsi,%rdi
jne    13c0 <dcsqb1+0x2b0>
add    %rsi,%r13
mov    $0x1,%ecx
sub    %rsi,%rcx
test   $0x1,%al
je     1448 <dcsqb1+0x338>
movsd  (%r14,%rcx,8),%xmm0
addsd  -0x8(%r14,%r13,8),%xmm0
movsd  %xmm0,(%rbx,%rcx,8)
movsd  (%r14,%rcx,8),%xmm0
subsd  -0x8(%r14,%r13,8),%xmm0
movsd  %xmm0,-0x8(%rbx,%r13,8)
movsd  (%rbx),%xmm0
addsd  %xmm0,%xmm0
movsd  %xmm0,(%rbx)
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret
mov    $0x1,%edx
test   $0x1,%bpl
jne    1216 <dcsqb1+0x106>
jmp    1250 <dcsqb1+0x140>

LLVM IR (-O0):
define void @dcsqb1(i32 %0, double* %1, double* %2, double* %3, i32* %4) {
%6 = alloca i32
%7 = alloca double*
%8 = alloca double*
%9 = alloca double*
%10 = alloca i32*
%11 = alloca i32
%12 = alloca i32
%13 = alloca i32
%14 = alloca i32
%15 = alloca i32
%16 = alloca i32
%17 = alloca double
store i32 %0, i32* %6
store double* %1, double** %7
store double* %2, double** %8
store double* %3, double** %9
store i32* %4, i32** %10
%18 = load i32, i32* %6
%19 = add nsw i32 %18, 1
%20 = ashr i32 %19, 1
store i32 %20, i32* %16
%21 = load i32, i32* %6
store i32 %21, i32* %15
store i32 2, i32* %12
br label %22
22: ; preds = %57, %5
%23 = load i32, i32* %12
%24 = load i32, i32* %6
%25 = icmp slt i32 %23, %24
br i1 %25, label %26, label %60
26: ; preds = %22
%27 = load double*, double** %7
%28 = load i32, i32* %12
%29 = sub nsw i32 %28, 1
%30 = sext i32 %29 to i64
%31 = getelementptr inbounds double, double* %27, i64 %30
%32 = load double, double* %31
%33 = load double*, double** %7
%34 = load i32, i32* %12
%35 = sext i32 %34 to i64
%36 = getelementptr inbounds double, double* %33, i64 %35
%37 = load double, double* %36
%38 = fadd double %32, %37
store double %38, double* %17
%39 = load double*, double** %7
%40 = load i32, i32* %12
%41 = sub nsw i32 %40, 1
%42 = sext i32 %41 to i64
%43 = getelementptr inbounds double, double* %39, i64 %42
%44 = load double, double* %43
%45 = load double*, double** %7
%46 = load i32, i32* %12
%47 = sext i32 %46 to i64
%48 = getelementptr inbounds double, double* %45, i64 %47
%49 = load double, double* %48
%50 = fsub double %49, %44
store double %50, double* %48
%51 = load double, double* %17
%52 = load double*, double** %7
%53 = load i32, i32* %12
%54 = sub nsw i32 %53, 1
%55 = sext i32 %54 to i64
%56 = getelementptr inbounds double, double* %52, i64 %55
store double %51, double* %56
br label %57
57: ; preds = %26
%58 = load i32, i32* %12
%59 = add nsw i32 %58, 2
store i32 %59, i32* %12
br label %22
60: ; preds = %22
%61 = load double*, double** %7
%62 = getelementptr inbounds double, double* %61, i64 0
%63 = load double, double* %62
%64 = load double*, double** %7
%65 = getelementptr inbounds double, double* %64, i64 0
%66 = load double, double* %65
%67 = fadd double %66, %63
store double %67, double* %65
%68 = load i32, i32* %6
%69 = srem i32 %68, 2
store i32 %69, i32* %11
%70 = load i32, i32* %11
%71 = icmp eq i32 %70, 0
br i1 %71, label %72, label %86
72: ; preds = %60
%73 = load double*, double** %7
%74 = load i32, i32* %6
%75 = sub nsw i32 %74, 1
%76 = sext i32 %75 to i64
%77 = getelementptr inbounds double, double* %73, i64 %76
%78 = load double, double* %77
%79 = load double*, double** %7
%80 = load i32, i32* %6
%81 = sub nsw i32 %80, 1
%82 = sext i32 %81 to i64
%83 = getelementptr inbounds double, double* %79, i64 %82
%84 = load double, double* %83
%85 = fadd double %84, %78
store double %85, double* %83
br label %86
86: ; preds = %72, %60
%87 = load i32, i32* %6
%88 = load double*, double** %7
%89 = load double*, double** %9
%90 = load i32*, i32** %10
%91 = call i32 @__ogg_fdrfftb(i32 %87, double* %88, double* %89, i32* %90)
%92 = load i32, i32* %15
store i32 %92, i32* %14
store i32 1, i32* %13
br label %93
93: ; preds = %157, %86
%94 = load i32, i32* %13
%95 = load i32, i32* %16
%96 = icmp slt i32 %94, %95
br i1 %96, label %97, label %160
97: ; preds = %93
%98 = load i32, i32* %14
%99 = add nsw i32 %98, -1
store i32 %99, i32* %14
%100 = load double*, double** %8
%101 = load i32, i32* %13
%102 = sub nsw i32 %101, 1
%103 = sext i32 %102 to i64
%104 = getelementptr inbounds double, double* %100, i64 %103
%105 = load double, double* %104
%106 = load double*, double** %7
%107 = load i32, i32* %14
%108 = sext i32 %107 to i64
%109 = getelementptr inbounds double, double* %106, i64 %108
%110 = load double, double* %109
%111 = load double*, double** %8
%112 = load i32, i32* %14
%113 = sub nsw i32 %112, 1
%114 = sext i32 %113 to i64
%115 = getelementptr inbounds double, double* %111, i64 %114
%116 = load double, double* %115
%117 = load double*, double** %7
%118 = load i32, i32* %13
%119 = sext i32 %118 to i64
%120 = getelementptr inbounds double, double* %117, i64 %119
%121 = load double, double* %120
%122 = fmul double %116, %121
%123 = call double @llvm.fmuladd.f64(double %105, double %110, double %122)
%124 = load double*, double** %9
%125 = load i32, i32* %13
%126 = sext i32 %125 to i64
%127 = getelementptr inbounds double, double* %124, i64 %126
store double %123, double* %127
%128 = load double*, double** %8
%129 = load i32, i32* %13
%130 = sub nsw i32 %129, 1
%131 = sext i32 %130 to i64
%132 = getelementptr inbounds double, double* %128, i64 %131
%133 = load double, double* %132
%134 = load double*, double** %7
%135 = load i32, i32* %13
%136 = sext i32 %135 to i64
%137 = getelementptr inbounds double, double* %134, i64 %136
%138 = load double, double* %137
%139 = load double*, double** %8
%140 = load i32, i32* %14
%141 = sub nsw i32 %140, 1
%142 = sext i32 %141 to i64
%143 = getelementptr inbounds double, double* %139, i64 %142
%144 = load double, double* %143
%145 = load double*, double** %7
%146 = load i32, i32* %14
%147 = sext i32 %146 to i64
%148 = getelementptr inbounds double, double* %145, i64 %147
%149 = load double, double* %148
%150 = fmul double %144, %149
%151 = fneg double %150
%152 = call double @llvm.fmuladd.f64(double %133, double %138, double %151)
%153 = load double*, double** %9
%154 = load i32, i32* %14
%155 = sext i32 %154 to i64
%156 = getelementptr inbounds double, double* %153, i64 %155
store double %152, double* %156
br label %157
157: ; preds = %97
%158 = load i32, i32* %13
%159 = add nsw i32 %158, 1
store i32 %159, i32* %13
br label %93
160: ; preds = %93
%161 = load i32, i32* %11
%162 = icmp eq i32 %161, 0
br i1 %162, label %163, label %186
163: ; preds = %160
%164 = load double*, double** %8
%165 = load i32, i32* %16
%166 = sub nsw i32 %165, 1
%167 = sext i32 %166 to i64
%168 = getelementptr inbounds double, double* %164, i64 %167
%169 = load double, double* %168
%170 = load double*, double** %7
%171 = load i32, i32* %16
%172 = sext i32 %171 to i64
%173 = getelementptr inbounds double, double* %170, i64 %172
%174 = load double, double* %173
%175 = load double*, double** %7
%176 = load i32, i32* %16
%177 = sext i32 %176 to i64
%178 = getelementptr inbounds double, double* %175, i64 %177
%179 = load double, double* %178
%180 = fadd double %174, %179
%181 = fmul double %169, %180
%182 = load double*, double** %7
%183 = load i32, i32* %16
%184 = sext i32 %183 to i64
%185 = getelementptr inbounds double, double* %182, i64 %184
store double %181, double* %185
br label %186
186: ; preds = %163, %160
%187 = load i32, i32* %15
store i32 %187, i32* %14
store i32 1, i32* %13
br label %188
188: ; preds = %225, %186
%189 = load i32, i32* %13
%190 = load i32, i32* %16
%191 = icmp slt i32 %189, %190
br i1 %191, label %192, label %228
192: ; preds = %188
%193 = load i32, i32* %14
%194 = add nsw i32 %193, -1
store i32 %194, i32* %14
%195 = load double*, double** %9
%196 = load i32, i32* %13
%197 = sext i32 %196 to i64
%198 = getelementptr inbounds double, double* %195, i64 %197
%199 = load double, double* %198
%200 = load double*, double** %9
%201 = load i32, i32* %14
%202 = sext i32 %201 to i64
%203 = getelementptr inbounds double, double* %200, i64 %202
%204 = load double, double* %203
%205 = fadd double %199, %204
%206 = load double*, double** %7
%207 = load i32, i32* %13
%208 = sext i32 %207 to i64
%209 = getelementptr inbounds double, double* %206, i64 %208
store double %205, double* %209
%210 = load double*, double** %9
%211 = load i32, i32* %13
%212 = sext i32 %211 to i64
%213 = getelementptr inbounds double, double* %210, i64 %212
%214 = load double, double* %213
%215 = load double*, double** %9
%216 = load i32, i32* %14
%217 = sext i32 %216 to i64
%218 = getelementptr inbounds double, double* %215, i64 %217
%219 = load double, double* %218
%220 = fsub double %214, %219
%221 = load double*, double** %7
%222 = load i32, i32* %14
%223 = sext i32 %222 to i64
%224 = getelementptr inbounds double, double* %221, i64 %223
store double %220, double* %224
br label %225
225: ; preds = %192
%226 = load i32, i32* %13
%227 = add nsw i32 %226, 1
store i32 %227, i32* %13
br label %188
228: ; preds = %188
%229 = load double*, double** %7
%230 = getelementptr inbounds double, double* %229, i64 0
%231 = load double, double* %230
%232 = load double*, double** %7
%233 = getelementptr inbounds double, double* %232, i64 0
%234 = load double, double* %233
%235 = fadd double %234, %231
store double %235, double* %233
ret void
}

LLVM IR (-O2):
define void @dcsqb1(i32 %0, double* %1, double* nocapture %2, double* %3, i32* %4) {
%6 = add nsw i32 %0, 1
%7 = ashr i32 %6, 1
%8 = icmp sgt i32 %0, 2
br i1 %8, label %9, label %86
9: ; preds = %5
%10 = zext i32 %0 to i64
%11 = call i64 @llvm.umax.i64(i64 %10, i64 4)
%12 = add nsw i64 %11, -3
%13 = lshr i64 %12, 1
%14 = add nuw nsw i64 %13, 1
%15 = icmp ult i64 %12, 2
br i1 %15, label %73, label %16
16: ; preds = %9
%17 = and i64 %14, 9223372036854775806
%18 = shl nuw i64 %14, 1
%19 = or i64 %18, 2
%20 = add nsw i64 %17, -2
%21 = lshr exact i64 %20, 1
%22 = add nuw i64 %21, 1
%23 = and i64 %22, 1
%24 = icmp eq i64 %20, 0
br i1 %24, label %58, label %25
25: ; preds = %16
%26 = and i64 %22, -2
br label %27
27: ; preds = %27, %25
%28 = phi i64 [ 0, %25 ], [ %52, %27 ]
%29 = phi i64 [ 0, %25 ], [ %53, %27 ]
%30 = shl i64 %28, 1
%31 = or i64 %30, 1
%32 = getelementptr inbounds double, double* %1, i64 %31
%33 = bitcast double* %32 to <4 x double>*
%34 = load <4 x double>, <4 x double>* %33
%35 = shufflevector <4 x double> %34, <4 x double> poison, <2 x i32> <i32 0, i32 2>
%36 = shufflevector <4 x double> %34, <4 x double> poison, <2 x i32> <i32 1, i32 3>
%37 = fadd <2 x double> %35, %36
%38 = fsub <2 x double> %36, %35
%39 = bitcast double* %32 to <4 x double>*
%40 = shufflevector <2 x double> %37, <2 x double> %38, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
store <4 x double> %40, <4 x double>* %39
%41 = shl i64 %28, 1
%42 = or i64 %41, 5
%43 = getelementptr inbounds double, double* %1, i64 %42
%44 = bitcast double* %43 to <4 x double>*
%45 = load <4 x double>, <4 x double>* %44
%46 = shufflevector <4 x double> %45, <4 x double> poison, <2 x i32> <i32 0, i32 2>
%47 = shufflevector <4 x double> %45, <4 x double> poison, <2 x i32> <i32 1, i32 3>
%48 = fadd <2 x double> %46, %47
%49 = fsub <2 x double> %47, %46
%50 = bitcast double* %43 to <4 x double>*
%51 = shufflevector <2 x double> %48, <2 x double> %49, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
store <4 x double> %51, <4 x double>* %50
%52 = add nuw i64 %28, 4
%53 = add nuw i64 %29, 2
%54 = icmp eq i64 %53, %26
br i1 %54, label %55, label %27
55: ; preds = %27
%56 = shl i64 %52, 1
%57 = or i64 %56, 1
br label %58
58: ; preds = %55, %16
%59 = phi i64 [ 1, %16 ], [ %57, %55 ]
%60 = icmp eq i64 %23, 0
br i1 %60, label %71, label %61
61: ; preds = %58
%62 = getelementptr inbounds double, double* %1, i64 %59
%63 = bitcast double* %62 to <4 x double>*
%64 = load <4 x double>, <4 x double>* %63
%65 = shufflevector <4 x double> %64, <4 x double> poison, <2 x i32> <i32 0, i32 2>
%66 = shufflevector <4 x double> %64, <4 x double> poison, <2 x i32> <i32 1, i32 3>
%67 = fadd <2 x double> %65, %66
%68 = fsub <2 x double> %66, %65
%69 = bitcast double* %62 to <4 x double>*
%70 = shufflevector <2 x double> %67, <2 x double> %68, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
store <4 x double> %70, <4 x double>* %69
br label %71
71: ; preds = %58, %61
%72 = icmp eq i64 %14, %17
br i1 %72, label %86, label %73
73: ; preds = %9, %71
%74 = phi i64 [ 2, %9 ], [ %19, %71 ]
br label %75
75: ; preds = %73, %75
%76 = phi i64 [ %84, %75 ], [ %74, %73 ]
%77 = add nsw i64 %76, -1
%78 = getelementptr inbounds double, double* %1, i64 %77
%79 = load double, double* %78
%80 = getelementptr inbounds double, double* %1, i64 %76
%81 = load double, double* %80
%82 = fadd double %79, %81
%83 = fsub double %81, %79
store double %83, double* %80
store double %82, double* %78
%84 = add nuw nsw i64 %76, 2
%85 = icmp ult i64 %84, %10
br i1 %85, label %75, label %86
86: ; preds = %75, %71, %5
%87 = load double, double* %1
%88 = fadd double %87, %87
store double %88, double* %1
%89 = and i32 %0, 1
%90 = icmp eq i32 %89, 0
br i1 %90, label %91, label %97
91: ; preds = %86
%92 = add nsw i32 %0, -1
%93 = sext i32 %92 to i64
%94 = getelementptr inbounds double, double* %1, i64 %93
%95 = load double, double* %94
%96 = fadd double %95, %95
store double %96, double* %94
br label %97
97: ; preds = %91, %86
%98 = tail call i32 @__ogg_fdrfftb(i32 %0, double* %1, double* %3, i32* %4)
br i1 %8, label %99, label %130
99: ; preds = %97
%100 = zext i32 %0 to i64
%101 = call i32 @llvm.smax.i32(i32 %7, i32 2)
%102 = zext i32 %101 to i64
br label %103
103: ; preds = %99, %103
%104 = phi i64 [ %100, %99 ], [ %106, %103 ]
%105 = phi i64 [ 1, %99 ], [ %128, %103 ]
%106 = add nsw i64 %104, -1
%107 = add nsw i64 %105, -1
%108 = getelementptr inbounds double, double* %2, i64 %107
%109 = load double, double* %108
%110 = getelementptr inbounds double, double* %1, i64 %106
%111 = load double, double* %110
%112 = add nsw i64 %104, -2
%113 = getelementptr inbounds double, double* %2, i64 %112
%114 = load double, double* %113
%115 = getelementptr inbounds double, double* %1, i64 %105
%116 = load double, double* %115
%117 = fmul double %114, %116
%118 = tail call double @llvm.fmuladd.f64(double %109, double %111, double %117)
%119 = getelementptr inbounds double, double* %3, i64 %105
store double %118, double* %119
%120 = load double, double* %108
%121 = load double, double* %115
%122 = load double, double* %113
%123 = load double, double* %110
%124 = fneg double %122
%125 = fmul double %123, %124
%126 = tail call double @llvm.fmuladd.f64(double %120, double %121, double %125)
%127 = getelementptr inbounds double, double* %3, i64 %106
store double %126, double* %127
%128 = add nuw nsw i64 %105, 1
%129 = icmp eq i64 %128, %102
br i1 %129, label %130, label %103
130: ; preds = %103, %97
br i1 %90, label %131, label %141
131: ; preds = %130
%132 = add nsw i32 %7, -1
%133 = sext i32 %132 to i64
%134 = getelementptr inbounds double, double* %2, i64 %133
%135 = load double, double* %134
%136 = sext i32 %7 to i64
%137 = getelementptr inbounds double, double* %1, i64 %136
%138 = load double, double* %137
%139 = fadd double %138, %138
%140 = fmul double %135, %139
store double %140, double* %137
br label %141
141: ; preds = %131, %130
br i1 %8, label %142, label %197
142: ; preds = %141
%143 = zext i32 %0 to i64
%144 = call i32 @llvm.smax.i32(i32 %7, i32 2)
%145 = zext i32 %144 to i64
%146 = add nsw i64 %145, -1
%147 = and i64 %146, 1
%148 = icmp slt i32 %0, 5
br i1 %148, label %181, label %149
149: ; preds = %142
%150 = and i64 %146, -2
br label %151
151: ; preds = %151, %149
%152 = phi i64 [ %143, %149 ], [ %167, %151 ]
%153 = phi i64 [ 1, %149 ], [ %178, %151 ]
%154 = phi i64 [ 0, %149 ], [ %179, %151 ]
%155 = add nsw i64 %152, -1
%156 = getelementptr inbounds double, double* %3, i64 %153
%157 = load double, double* %156
%158 = getelementptr inbounds double, double* %3, i64 %155
%159 = load double, double* %158
%160 = fadd double %157, %159
%161 = getelementptr inbounds double, double* %1, i64 %153
store double %160, double* %161
%162 = load double, double* %156
%163 = load double, double* %158
%164 = fsub double %162, %163
%165 = getelementptr inbounds double, double* %1, i64 %155
store double %164, double* %165
%166 = add nuw nsw i64 %153, 1
%167 = add nsw i64 %152, -2
%168 = getelementptr inbounds double, double* %3, i64 %166
%169 = load double, double* %168
%170 = getelementptr inbounds double, double* %3, i64 %167
%171 = load double, double* %170
%172 = fadd double %169, %171
%173 = getelementptr inbounds double, double* %1, i64 %166
store double %172, double* %173
%174 = load double, double* %168
%175 = load double, double* %170
%176 = fsub double %174, %175
%177 = getelementptr inbounds double, double* %1, i64 %167
store double %176, double* %177
%178 = add nuw nsw i64 %153, 2
%179 = add i64 %154, 2
%180 = icmp eq i64 %179, %150
br i1 %180, label %181, label %151
181: ; preds = %151, %142
%182 = phi i64 [ %143, %142 ], [ %167, %151 ]
%183 = phi i64 [ 1, %142 ], [ %178, %151 ]
%184 = icmp eq i64 %147, 0
br i1 %184, label %197, label %185
185: ; preds = %181
%186 = add nsw i64 %182, -1
%187 = getelementptr inbounds double, double* %3, i64 %183
%188 = load double, double* %187
%189 = getelementptr inbounds double, double* %3, i64 %186
%190 = load double, double* %189
%191 = fadd double %188, %190
%192 = getelementptr inbounds double, double* %1, i64 %183
store double %191, double* %192
%193 = load double, double* %187
%194 = load double, double* %189
%195 = fsub double %193, %194
%196 = getelementptr inbounds double, double* %1, i64 %186
store double %195, double* %196
br label %197
197: ; preds = %185, %181, %141
%198 = load double, double* %1
%199 = fadd double %198, %198
store double %199, double* %1
ret void
}