void cred(a) int a;
{
  int x = 0;
  printf("%c  ", groo(a, 8));
  for (; x < 16; x++)
    printf("%c", (char)a * 16 + x);
  printf("\n");
}


x86 assembly (clang, -O0):
<cred>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %edi,-0x4(%rbp)
movl   $0x0,-0x8(%rbp)
mov    -0x4(%rbp),%edi
mov    $0x8,%esi
mov    $0x0,%al
call   1030 <groo@plt>
mov    %eax,%esi
lea    0xeb6(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
cmpl   $0x10,-0x8(%rbp)
jge    1183 <cred+0x63>
mov    -0x4(%rbp),%eax
movsbl %al,%esi
shl    $0x4,%esi
add    -0x8(%rbp),%esi
lea    0xe97(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    1151 <cred+0x31>
lea    0xe7e(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<cred>:
push   %rbx
mov    %edi,%ebx
mov    $0x8,%esi
xor    %eax,%eax
call   1040 <groo@plt>
lea    0xeba(%rip),%rdi
mov    %eax,%esi
xor    %eax,%eax
call   1050 <printf@plt>
movsbl %bl,%ebx
shl    $0x4,%ebx
mov    %ebx,%edi
call   1030 <putchar@plt>
lea    0x1(%rbx),%edi
call   1030 <putchar@plt>
lea    0x2(%rbx),%edi
call   1030 <putchar@plt>
lea    0x3(%rbx),%edi
call   1030 <putchar@plt>
lea    0x4(%rbx),%edi
call   1030 <putchar@plt>
lea    0x5(%rbx),%edi
call   1030 <putchar@plt>
lea    0x6(%rbx),%edi
call   1030 <putchar@plt>
lea    0x7(%rbx),%edi
call   1030 <putchar@plt>
lea    0x8(%rbx),%edi
call   1030 <putchar@plt>
lea    0x9(%rbx),%edi
call   1030 <putchar@plt>
lea    0xa(%rbx),%edi
call   1030 <putchar@plt>
lea    0xb(%rbx),%edi
call   1030 <putchar@plt>
lea    0xc(%rbx),%edi
call   1030 <putchar@plt>
lea    0xd(%rbx),%edi
call   1030 <putchar@plt>
lea    0xe(%rbx),%edi
call   1030 <putchar@plt>
or     $0xf,%ebx
mov    %ebx,%edi
call   1030 <putchar@plt>
mov    $0xa,%edi
pop    %rbx
jmp    1030 <putchar@plt>

LLVM IR (-O0):
@.str = [5 x i8] c"%c \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [2 x i8] c"\0A\00"
define void @cred(i32 %0) {
%2 = alloca i32
%3 = alloca i32
store i32 %0, i32* %2
store i32 0, i32* %3
%4 = load i32, i32* %2
%5 = call i32 (i32, i32, ...) bitcast (i32 (...)* @groo to i32 (i32, i32, ...)*)(i32 %4, i32 8)
%6 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %5)
br label %7
7: ; preds = %18, %1
%8 = load i32, i32* %3
%9 = icmp slt i32 %8, 16
br i1 %9, label %10, label %21
10: ; preds = %7
%11 = load i32, i32* %2
%12 = trunc i32 %11 to i8
%13 = sext i8 %12 to i32
%14 = mul nsw i32 %13, 16
%15 = load i32, i32* %3
%16 = add nsw i32 %14, %15
%17 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32 %16)
br label %18
18: ; preds = %10
%19 = load i32, i32* %3
%20 = add nsw i32 %19, 1
store i32 %20, i32* %3
br label %7
21: ; preds = %7
%22 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.2, i64 0, i64 0))
ret void
}

LLVM IR (-O2):
@.str = [5 x i8] c"%c \00"
define void @cred(i32 %0) {
%2 = tail call i32 (i32, i32, ...) bitcast (i32 (...)* @groo to i32 (i32, i32, ...)*)(i32 %0, i32 8)
%3 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %2)
%4 = shl i32 %0, 24
%5 = ashr exact i32 %4, 20
%6 = tail call i32 @putchar(i32 %5)
%7 = or i32 %5, 1
%8 = tail call i32 @putchar(i32 %7)
%9 = or i32 %5, 2
%10 = tail call i32 @putchar(i32 %9)
%11 = or i32 %5, 3
%12 = tail call i32 @putchar(i32 %11)
%13 = or i32 %5, 4
%14 = tail call i32 @putchar(i32 %13)
%15 = or i32 %5, 5
%16 = tail call i32 @putchar(i32 %15)
%17 = or i32 %5, 6
%18 = tail call i32 @putchar(i32 %17)
%19 = or i32 %5, 7
%20 = tail call i32 @putchar(i32 %19)
%21 = or i32 %5, 8
%22 = tail call i32 @putchar(i32 %21)
%23 = or i32 %5, 9
%24 = tail call i32 @putchar(i32 %23)
%25 = or i32 %5, 10
%26 = tail call i32 @putchar(i32 %25)
%27 = or i32 %5, 11
%28 = tail call i32 @putchar(i32 %27)
%29 = or i32 %5, 12
%30 = tail call i32 @putchar(i32 %29)
%31 = or i32 %5, 13
%32 = tail call i32 @putchar(i32 %31)
%33 = or i32 %5, 14
%34 = tail call i32 @putchar(i32 %33)
%35 = or i32 %5, 15
%36 = tail call i32 @putchar(i32 %35)
%37 = tail call i32 @putchar(i32 10)
ret void
}