void syn_percep_zero(float *xx, float *ak, float *awk1, float *awk2, float *y,
                     int N, int ord, char *stack) {
  int i;
  float *mem = ((((stack)) +=
                 ((sizeof(float)) - (int)((stack))) & ((sizeof(float)) - 1)),
                (stack) += ((ord) * sizeof(float)),
                (float *)((stack) - ((ord) * sizeof(float))));
  for (i = 0; i < ord; i++)
    mem[i] = 0;
  filter_mem2(xx, awk1, ak, y, N, ord, mem);
  for (i = 0; i < ord; i++)
    mem[i] = 0;
  iir_mem2(y, awk2, y, N, ord, mem);
}


x86 assembly (clang, -O0):
<syn_percep_zero>:
push   %rbp
mov    %rsp,%rbp
sub    $0x40,%rsp
mov    0x18(%rbp),%rax
mov    0x10(%rbp),%eax
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    %rcx,-0x20(%rbp)
mov    %r8,-0x28(%rbp)
mov    %r9d,-0x2c(%rbp)
mov    0x18(%rbp),%rax
movslq %eax,%rcx
mov    $0x4,%eax
sub    %rcx,%rax
and    $0x3,%rax
add    0x18(%rbp),%rax
mov    %rax,0x18(%rbp)
movslq 0x10(%rbp),%rax
shl    $0x2,%rax
add    0x18(%rbp),%rax
mov    %rax,0x18(%rbp)
mov    0x18(%rbp),%rax
movslq 0x10(%rbp),%rdx
shl    $0x2,%rdx
xor    %ecx,%ecx
sub    %rdx,%rcx
add    %rcx,%rax
mov    %rax,-0x38(%rbp)
movl   $0x0,-0x30(%rbp)
mov    -0x30(%rbp),%eax
cmp    0x10(%rbp),%eax
jge    11bb <syn_percep_zero+0x9b>
mov    -0x38(%rbp),%rax
movslq -0x30(%rbp),%rcx
xorps  %xmm0,%xmm0
movss  %xmm0,(%rax,%rcx,4)
mov    -0x30(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x30(%rbp)
jmp    1191 <syn_percep_zero+0x71>
mov    -0x8(%rbp),%rdi
mov    -0x18(%rbp),%rsi
mov    -0x10(%rbp),%rdx
mov    -0x28(%rbp),%rcx
mov    -0x2c(%rbp),%r8d
mov    0x10(%rbp),%r9d
mov    -0x38(%rbp),%rax
mov    %rax,(%rsp)
mov    $0x0,%al
call   1040 <filter_mem2@plt>
movl   $0x0,-0x30(%rbp)
mov    -0x30(%rbp),%eax
cmp    0x10(%rbp),%eax
jge    1213 <syn_percep_zero+0xf3>
mov    -0x38(%rbp),%rax
movslq -0x30(%rbp),%rcx
xorps  %xmm0,%xmm0
movss  %xmm0,(%rax,%rcx,4)
mov    -0x30(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x30(%rbp)
jmp    11e9 <syn_percep_zero+0xc9>
mov    -0x28(%rbp),%rdi
mov    -0x20(%rbp),%rsi
mov    -0x28(%rbp),%rdx
mov    -0x2c(%rbp),%ecx
mov    0x10(%rbp),%r8d
mov    -0x38(%rbp),%r9
mov    $0x0,%al
call   1030 <iir_mem2@plt>
add    $0x40,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<syn_percep_zero>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0x28,%rsp
mov    %r9d,%r15d
mov    %r8,%r12
mov    %rcx,%r14
mov    %rdx,%r13
mov    %rsi,%rdx
mov    0x60(%rsp),%ebp
mov    0x68(%rsp),%rax
mov    %eax,%ebx
neg    %ebx
and    $0x3,%ebx
add    %rax,%rbx
test   %ebp,%ebp
jle    11c2 <syn_percep_zero+0x92>
mov    %r14,0x20(%rsp)
mov    %ebp,%r14d
shl    $0x2,%r14
mov    %rdi,0x18(%rsp)
mov    %rbx,%rdi
xor    %esi,%esi
mov    %r15d,0x14(%rsp)
mov    %rdx,%r15
mov    %r14,%rdx
call   1030 <memset@plt>
mov    %rbx,(%rsp)
mov    0x18(%rsp),%rdi
mov    %r13,%rsi
mov    %r15,%rdx
mov    0x14(%rsp),%r15d
mov    %r12,%rcx
mov    %r15d,%r8d
mov    %ebp,%r9d
xor    %eax,%eax
call   1050 <filter_mem2@plt>
mov    %rbx,%rdi
xor    %esi,%esi
mov    %r14,%rdx
mov    0x20(%rsp),%r14
call   1030 <memset@plt>
jmp    11d9 <syn_percep_zero+0xa9>
mov    %rbx,(%rsp)
mov    %r13,%rsi
mov    %r12,%rcx
mov    %r15d,%r8d
mov    %ebp,%r9d
xor    %eax,%eax
call   1050 <filter_mem2@plt>
mov    %r12,%rdi
mov    %r14,%rsi
mov    %r12,%rdx
mov    %r15d,%ecx
mov    %ebp,%r8d
mov    %rbx,%r9
xor    %eax,%eax
add    $0x28,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
jmp    1040 <iir_mem2@plt>

LLVM IR (-O0):
define void @syn_percep_zero(float* %0, float* %1, float* %2, float* %3, float* %4, i32 %5, i32 %6, i8* %7) {
%9 = alloca float*
%10 = alloca float*
%11 = alloca float*
%12 = alloca float*
%13 = alloca float*
%14 = alloca i32
%15 = alloca i32
%16 = alloca i8*
%17 = alloca i32
%18 = alloca float*
store float* %0, float** %9
store float* %1, float** %10
store float* %2, float** %11
store float* %3, float** %12
store float* %4, float** %13
store i32 %5, i32* %14
store i32 %6, i32* %15
store i8* %7, i8** %16
%19 = load i8*, i8** %16
%20 = ptrtoint i8* %19 to i32
%21 = sext i32 %20 to i64
%22 = sub i64 4, %21
%23 = and i64 %22, 3
%24 = load i8*, i8** %16
%25 = getelementptr inbounds i8, i8* %24, i64 %23
store i8* %25, i8** %16
%26 = load i32, i32* %15
%27 = sext i32 %26 to i64
%28 = mul i64 %27, 4
%29 = load i8*, i8** %16
%30 = getelementptr inbounds i8, i8* %29, i64 %28
store i8* %30, i8** %16
%31 = load i8*, i8** %16
%32 = load i32, i32* %15
%33 = sext i32 %32 to i64
%34 = mul i64 %33, 4
%35 = sub i64 0, %34
%36 = getelementptr inbounds i8, i8* %31, i64 %35
%37 = bitcast i8* %36 to float*
store float* %37, float** %18
store i32 0, i32* %17
br label %38
38: ; preds = %47, %8
%39 = load i32, i32* %17
%40 = load i32, i32* %15
%41 = icmp slt i32 %39, %40
br i1 %41, label %42, label %50
42: ; preds = %38
%43 = load float*, float** %18
%44 = load i32, i32* %17
%45 = sext i32 %44 to i64
%46 = getelementptr inbounds float, float* %43, i64 %45
store float 0.000000e+00, float* %46
br label %47
47: ; preds = %42
%48 = load i32, i32* %17
%49 = add nsw i32 %48, 1
store i32 %49, i32* %17
br label %38
50: ; preds = %38
%51 = load float*, float** %9
%52 = load float*, float** %11
%53 = load float*, float** %10
%54 = load float*, float** %13
%55 = load i32, i32* %14
%56 = load i32, i32* %15
%57 = load float*, float** %18
%58 = call i32 (float*, float*, float*, float*, i32, i32, float*, ...) bitcast (i32 (...)* @filter_mem2 to i32 (float*, float*, float*, float*, i32, i32, float*, ...)*)(float* %51, float* %52, float* %53, float* %54, i32 %55, i32 %56, float* %57)
store i32 0, i32* %17
br label %59
59: ; preds = %68, %50
%60 = load i32, i32* %17
%61 = load i32, i32* %15
%62 = icmp slt i32 %60, %61
br i1 %62, label %63, label %71
63: ; preds = %59
%64 = load float*, float** %18
%65 = load i32, i32* %17
%66 = sext i32 %65 to i64
%67 = getelementptr inbounds float, float* %64, i64 %66
store float 0.000000e+00, float* %67
br label %68
68: ; preds = %63
%69 = load i32, i32* %17
%70 = add nsw i32 %69, 1
store i32 %70, i32* %17
br label %59
71: ; preds = %59
%72 = load float*, float** %13
%73 = load float*, float** %12
%74 = load float*, float** %13
%75 = load i32, i32* %14
%76 = load i32, i32* %15
%77 = load float*, float** %18
%78 = call i32 (float*, float*, float*, i32, i32, float*, ...) bitcast (i32 (...)* @iir_mem2 to i32 (float*, float*, float*, i32, i32, float*, ...)*)(float* %72, float* %73, float* %74, i32 %75, i32 %76, float* %77)
ret void
}

LLVM IR (-O2):
define void @syn_percep_zero(float* %0, float* %1, float* %2, float* %3, float* %4, i32 %5, i32 %6, i8* %7) {
%9 = ptrtoint i8* %7 to i64
%10 = sub i64 0, %9
%11 = and i64 %10, 3
%12 = getelementptr i8, i8* %7, i64 %11
%13 = sext i32 %6 to i64
%14 = shl nsw i64 %13, 2
%15 = getelementptr inbounds i8, i8* %12, i64 %14
%16 = sub nsw i64 0, %14
%17 = getelementptr inbounds i8, i8* %15, i64 %16
%18 = bitcast i8* %17 to float*
%19 = icmp sgt i32 %6, 0
br i1 %19, label %22, label %20
20: ; preds = %8
%21 = tail call i32 (float*, float*, float*, float*, i32, i32, float*, ...) bitcast (i32 (...)* @filter_mem2 to i32 (float*, float*, float*, float*, i32, i32, float*, ...)*)(float* %0, float* %2, float* %1, float* %4, i32 %5, i32 %6, float* %18)
br label %28
22: ; preds = %8
%23 = zext i32 %6 to i64
%24 = shl nuw nsw i64 %23, 2
%25 = tail call i32 (float*, float*, float*, float*, i32, i32, float*, ...) bitcast (i32 (...)* @filter_mem2 to i32 (float*, float*, float*, float*, i32, i32, float*, ...)*)(float* %0, float* %2, float* %1, float* %4, i32 %5, i32 %6, float* %18)
%26 = zext i32 %6 to i64
%27 = shl nuw nsw i64 %26, 2
br label %28
28: ; preds = %20, %22
%29 = tail call i32 (float*, float*, float*, i32, i32, float*, ...) bitcast (i32 (...)* @iir_mem2 to i32 (float*, float*, float*, i32, i32, float*, ...)*)(float* %4, float* %3, float* %4, i32 %5, i32 %6, float* %18)
ret void
}