int iodc_io_call(ep_address, arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7,
                 arg8, arg9, arg10, arg11)
int ep_address, arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9,
    arg10, arg11;
{
  int (*iodc_entry_point)();
  iodc_entry_point = (int (*)())ep_address;
  return ((*iodc_entry_point)(arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7,
                              arg8, arg9, arg10, arg11));
}


x86 assembly (clang, -O0):
<iodc_io_call>:
push   %rbp
mov    %rsp,%rbp
push   %r15
push   %r14
push   %r12
push   %rbx
sub    $0x50,%rsp
mov    0x40(%rbp),%eax
mov    0x38(%rbp),%eax
mov    0x30(%rbp),%eax
mov    0x28(%rbp),%eax
mov    0x20(%rbp),%eax
mov    0x18(%rbp),%eax
mov    0x10(%rbp),%eax
mov    %edi,-0x24(%rbp)
mov    %esi,-0x28(%rbp)
mov    %edx,-0x2c(%rbp)
mov    %ecx,-0x30(%rbp)
mov    %r8d,-0x34(%rbp)
mov    %r9d,-0x38(%rbp)
movslq -0x24(%rbp),%rax
mov    %rax,-0x40(%rbp)
mov    -0x40(%rbp),%r10
mov    -0x28(%rbp),%edi
mov    -0x2c(%rbp),%esi
mov    -0x30(%rbp),%edx
mov    -0x34(%rbp),%ecx
mov    -0x38(%rbp),%r8d
mov    0x10(%rbp),%r9d
mov    0x18(%rbp),%r12d
mov    0x20(%rbp),%r15d
mov    0x28(%rbp),%r14d
mov    0x30(%rbp),%ebx
mov    0x38(%rbp),%r11d
mov    0x40(%rbp),%eax
mov    %r12d,(%rsp)
mov    %r15d,0x8(%rsp)
mov    %r14d,0x10(%rsp)
mov    %ebx,0x18(%rsp)
mov    %r11d,0x20(%rsp)
mov    %eax,0x28(%rsp)
mov    $0x0,%al
call   *%r10
add    $0x50,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
pop    %rbp
ret

x86 assembly (clang, -O2):
<iodc_io_call>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
mov    %r9d,%eax
mov    0x30(%rsp),%r9d
mov    0x38(%rsp),%r10d
mov    0x40(%rsp),%r11d
mov    0x48(%rsp),%r14d
mov    0x50(%rsp),%r15d
mov    0x58(%rsp),%r12d
mov    0x60(%rsp),%r13d
movslq %edi,%rbx
mov    %esi,%edi
mov    %edx,%esi
mov    %ecx,%edx
mov    %r8d,%ecx
mov    %eax,%r8d
xor    %eax,%eax
push   %r13
push   %r12
push   %r15
push   %r14
push   %r11
push   %r10
call   *%rbx
add    $0x30,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define i32 @iodc_io_call(i32 %0, i32 %1, i32 %2, i32 %3, i32 %4, i32 %5, i32 %6, i32 %7, i32 %8, i32 %9, i32 %10, i32 %11, i32 %12) {
%14 = alloca i32
%15 = alloca i32
%16 = alloca i32
%17 = alloca i32
%18 = alloca i32
%19 = alloca i32
%20 = alloca i32
%21 = alloca i32
%22 = alloca i32
%23 = alloca i32
%24 = alloca i32
%25 = alloca i32
%26 = alloca i32
%27 = alloca i32 (...)*
store i32 %0, i32* %14
store i32 %1, i32* %15
store i32 %2, i32* %16
store i32 %3, i32* %17
store i32 %4, i32* %18
store i32 %5, i32* %19
store i32 %6, i32* %20
store i32 %7, i32* %21
store i32 %8, i32* %22
store i32 %9, i32* %23
store i32 %10, i32* %24
store i32 %11, i32* %25
store i32 %12, i32* %26
%28 = load i32, i32* %14
%29 = sext i32 %28 to i64
%30 = inttoptr i64 %29 to i32 (...)*
store i32 (...)* %30, i32 (...)** %27
%31 = load i32 (...)*, i32 (...)** %27
%32 = load i32, i32* %15
%33 = load i32, i32* %16
%34 = load i32, i32* %17
%35 = load i32, i32* %18
%36 = load i32, i32* %19
%37 = load i32, i32* %20
%38 = load i32, i32* %21
%39 = load i32, i32* %22
%40 = load i32, i32* %23
%41 = load i32, i32* %24
%42 = load i32, i32* %25
%43 = load i32, i32* %26
%44 = bitcast i32 (...)* %31 to i32 (i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, ...)*
%45 = call i32 (i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, ...) %44(i32 %32, i32 %33, i32 %34, i32 %35, i32 %36, i32 %37, i32 %38, i32 %39, i32 %40, i32 %41, i32 %42, i32 %43)
ret i32 %45
}

LLVM IR (-O2):
define i32 @iodc_io_call(i32 %0, i32 %1, i32 %2, i32 %3, i32 %4, i32 %5, i32 %6, i32 %7, i32 %8, i32 %9, i32 %10, i32 %11, i32 %12) {
%14 = sext i32 %0 to i64
%15 = inttoptr i64 %14 to i32 (i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, ...)*
%16 = tail call i32 (i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, ...) %15(i32 %1, i32 %2, i32 %3, i32 %4, i32 %5, i32 %6, i32 %7, i32 %8, i32 %9, i32 %10, i32 %11, i32 %12)
ret i32 %16
}