user: What is the c source code of the assembly code below?

```asm
<iswt2>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x58,%rsp
  mov    %rdi,0x20(%rsp)
  mov    %rsi,0x28(%rsp)
  mov    %rdx,0x30(%rsp)
  mov    %rcx,0x38(%rsp)
  mov    %r8d,%ebx
  mov    %r9d,%r15d
  mov    0xb0(%rsp),%r13
  mov    0xb8(%rsp),%r14d
  mov    %r8d,%eax
  imul   %r9d,%eax
  lea    0x0(,%rax,8),%ebp
  mov    %ebp,0x4c(%rsp)
  mov    %ebp,%edi
  call   <malloc@plt>
  mov    %rax,0x8(%rsp)
  mov    %ebp,%edi
  call   <malloc@plt>
  mov    %rax,0x10(%rsp)
  test   %r15d,%r15d
  jle    L36
  movslq %ebx,%rax
  shl    $0x3,%rax
  mov    %rax,0x40(%rsp)
  mov    $0x0,%ebp
  mov    $0x0,%r12d
  mov    %r15d,0x18(%rsp)
  mov    0xc0(%rsp),%r15d
L6:
  mov    0x8(%rsp),%rax
  lea    (%rax,%rbp,1),%rcx
  mov    0x28(%rsp),%rax
  lea    (%rax,%rbp,1),%rsi
  mov    0x20(%rsp),%rax
  lea    (%rax,%rbp,1),%rdi
  sub    $0x8,%rsp
  push   %r15
  push   %r14
  push   %r13
  mov    0xc8(%rsp),%r9
  mov    %ebx,%r8d
  mov    %ebx,%edx
  call   <iswt_conv_step@plt>
  add    $0x18,%rsp
  mov    0x18(%rsp),%rax
  lea    (%rax,%rbp,1),%rcx
  mov    0x40(%rsp),%rax
  lea    (%rax,%rbp,1),%rsi
  mov    0x38(%rsp),%rax
  lea    (%rax,%rbp,1),%rdi
  push   %r15
  push   %r14
  push   %r13
  mov    0xc8(%rsp),%r9
  mov    %ebx,%r8d
  mov    %ebx,%edx
  call   <iswt_conv_step@plt>
  add    $0x1,%r12d
  add    0x60(%rsp),%rbp
  add    $0x20,%rsp
  cmp    %r12d,0x18(%rsp)
  jne    L6
  mov    0x18(%rsp),%r15d
L36:
  mov    0x4c(%rsp),%r12d
  mov    %r12d,%edi
  call   <malloc@plt>
  mov    %r15d,%r9d
  mov    %ebx,%r8d
  mov    %rax,0x18(%rsp)
  mov    %rax,%rcx
  mov    %ebx,%edx
  mov    %r15d,%esi
  mov    0x8(%rsp),%rbp
  mov    %rbp,%rdi
  call   <matrix_tran@plt>
  mov    %rbp,%rdi
  call   <free@plt>
  mov    %r12d,%edi
  call   <malloc@plt>
  mov    %r15d,%r9d
  mov    %ebx,%r8d
  mov    %rax,0x20(%rsp)
  mov    %rax,%rcx
  mov    %ebx,%edx
  mov    %r15d,%esi
  mov    0x10(%rsp),%rbp
  mov    %rbp,%rdi
  call   <matrix_tran@plt>
  mov    %rbp,%rdi
  call   <free@plt>
  mov    %r12d,%edi
  call   <malloc@plt>
  mov    %rax,0x28(%rsp)
  test   %ebx,%ebx
  jle    L21
  movslq %r15d,%rbp
  lea    0x0(,%rbp,8),%rsi
  mov    %rsi,0x10(%rsp)
  mov    0x18(%rsp),%rbp
  mov    0x20(%rsp),%rdx
  mov    $0x0,%r12d
  mov    %ebx,0x8(%rsp)
  mov    %rax,%rbx
  mov    %r13,0xb0(%rsp)
  mov    %r15d,%r13d
  mov    %rdx,%r15
L34:
  sub    $0x8,%rsp
  mov    0xc8(%rsp),%eax
  push   %rax
  push   %r14
  push   0xc8(%rsp)
  mov    0xc8(%rsp),%r9
  mov    %r13d,%r8d
  mov    %rbx,%rcx
  mov    %r13d,%edx
  mov    %r15,%rsi
  mov    %rbp,%rdi
  call   <iswt_conv_step@plt>
  add    $0x1,%r12d
  mov    0x30(%rsp),%rax
  add    %rax,%rbp
  add    %rax,%r15
  add    %rax,%rbx
  add    $0x20,%rsp
  cmp    %r12d,0x8(%rsp)
  jne    L34
  mov    0x8(%rsp),%ebx
  mov    %r13d,%r15d
L21:
  mov    0x18(%rsp),%rdi
  call   <free@plt>
  mov    0x20(%rsp),%rdi
  call   <free@plt>
  mov    %r15d,%r9d
  mov    %ebx,%r8d
  mov    0x90(%rsp),%rcx
  mov    %r15d,%edx
  mov    %ebx,%esi
  mov    0x28(%rsp),%rbx
  mov    %rbx,%rdi
  call   <matrix_tran@plt>
  mov    %rbx,%rdi
  call   <free@plt>
  add    $0x58,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void iswt2(double *matrixInApprox, double *matrixInColDetail, double *matrixInRowDetail, double *matrixInDetail, int matrixInRow, int matrixInCol, double *matrixOut, int matrixOutRow, int matrixOutCol, double *filterLow, double *filterHi, int filterLength, int step) {
  int row, col;
  double *matrixOutApproxPre, *matrixOutDetailPre;
  double *matrixOutPre;
  double *pMatrixOutApproxPre, *pMatrixOutDetailPre;
  matrixOutApproxPre = malloc(matrixInRow * matrixInCol * sizeof(double));
  matrixOutDetailPre = malloc(matrixInRow * matrixInCol * sizeof(double));
  for (col = 0; col < matrixInCol; col++) {
    iswt_conv_step(matrixInApprox + col * matrixInRow, matrixInColDetail + col * matrixInRow, matrixInRow, matrixOutApproxPre + col * matrixInRow, matrixInRow, filterLow, filterHi, filterLength, step);
    iswt_conv_step(matrixInRowDetail + col * matrixInRow, matrixInDetail + col * matrixInRow, matrixInRow, matrixOutDetailPre + col * matrixInRow, matrixInRow, filterLow, filterHi, filterLength, step);
  }
  pMatrixOutApproxPre = malloc(matrixInRow * matrixInCol * sizeof(double));
  matrix_tran(matrixOutApproxPre, matrixInCol, matrixInRow, pMatrixOutApproxPre, matrixInRow, matrixInCol);
  free(matrixOutApproxPre);
  pMatrixOutDetailPre = malloc(matrixInRow * matrixInCol * sizeof(double));
  matrix_tran(matrixOutDetailPre, matrixInCol, matrixInRow, pMatrixOutDetailPre, matrixInRow, matrixInCol);
  free(matrixOutDetailPre);
  matrixOutPre = malloc(matrixInRow * matrixInCol * sizeof(double));
  for (row = 0; row < matrixInRow; row++) {
    iswt_conv_step(pMatrixOutApproxPre + row * matrixInCol, pMatrixOutDetailPre + row * matrixInCol, matrixInCol, matrixOutPre + row * matrixInCol, matrixInCol, filterLow, filterHi, filterLength, step);
  }
  free(pMatrixOutApproxPre);
  free(pMatrixOutDetailPre);
  matrix_tran(matrixOutPre, matrixInRow, matrixInCol, matrixOut, matrixInRow, matrixInCol);
  free(matrixOutPre);
  return;
}
```