char *dimstr_c(int d) {
  char *retval;
  if (d == 0) {
    retval = "";
  } else if (d == 1) {
    retval = "[i1]";
  } else if (d == 2) {
    retval = "[i2][i1]";
  } else if (d == 3) {
    retval = "[i3][i2][i1]";
  } else if (d == 4) {
    retval = "[i4][i3][i2][i1]";
  } else if (d == 5) {
    retval = "[i5][i4][i3][i2][i1]";
  } else {
    retval = " REGISTRY ERROR TOO MANY DIMS ";
  }
  return (retval);
}


x86 assembly (clang, -O0):
<dimstr_c>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0x4(%rbp)
cmpl   $0x0,-0x4(%rbp)
jne    1121 <dimstr_c+0x21>
lea    0xf1b(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11c7 <dimstr_c+0xc7>
cmpl   $0x1,-0x4(%rbp)
jne    113b <dimstr_c+0x3b>
lea    0xede(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11c2 <dimstr_c+0xc2>
cmpl   $0x2,-0x4(%rbp)
jne    1155 <dimstr_c+0x55>
lea    0xec0(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11bd <dimstr_c+0xbd>
cmpl   $0x3,-0x4(%rbp)
jne    116f <dimstr_c+0x6f>
lea    0xea2(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11b8 <dimstr_c+0xb8>
cmpl   $0x4,-0x4(%rbp)
jne    1189 <dimstr_c+0x89>
lea    0xe84(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11b3 <dimstr_c+0xb3>
cmpl   $0x5,-0x4(%rbp)
jne    11a3 <dimstr_c+0xa3>
lea    0xe66(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11ae <dimstr_c+0xae>
lea    0xe6b(%rip),%rax
mov    %rax,-0x10(%rbp)
jmp    11b3 <dimstr_c+0xb3>
jmp    11b8 <dimstr_c+0xb8>
jmp    11bd <dimstr_c+0xbd>
jmp    11c2 <dimstr_c+0xc2>
jmp    11c7 <dimstr_c+0xc7>
mov    -0x10(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<dimstr_c>:
cmp    $0x5,%edi
ja     1117 <dimstr_c+0x17>
movslq %edi,%rax
lea    0xf25(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xef7(%rip),%rax
ret

LLVM IR (-O0):
@.str = [1 x i8] zeroinitializer
@.str.1 = [5 x i8] c"[i1]\00"
@.str.2 = [9 x i8] c"[i2][i1]\00"
@.str.3 = [13 x i8] c"[i3][i2][i1]\00"
@.str.4 = [17 x i8] c"[i4][i3][i2][i1]\00"
@.str.5 = [21 x i8] c"[i5][i4][i3][i2][i1]\00"
@.str.6 = [31 x i8] c" REGISTRY ERROR TOO MANY DIMS \00"
define i8* @dimstr_c(i32 %0) {
%2 = alloca i32
%3 = alloca i8*
store i32 %0, i32* %2
%4 = load i32, i32* %2
%5 = icmp eq i32 %4, 0
br i1 %5, label %6, label %7
6: ; preds = %1
store i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i64 0, i64 0), i8** %3
br label %33
7: ; preds = %1
%8 = load i32, i32* %2
%9 = icmp eq i32 %8, 1
br i1 %9, label %10, label %11
10: ; preds = %7
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0), i8** %3
br label %32
11: ; preds = %7
%12 = load i32, i32* %2
%13 = icmp eq i32 %12, 2
br i1 %13, label %14, label %15
14: ; preds = %11
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.2, i64 0, i64 0), i8** %3
br label %31
15: ; preds = %11
%16 = load i32, i32* %2
%17 = icmp eq i32 %16, 3
br i1 %17, label %18, label %19
18: ; preds = %15
store i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.3, i64 0, i64 0), i8** %3
br label %30
19: ; preds = %15
%20 = load i32, i32* %2
%21 = icmp eq i32 %20, 4
br i1 %21, label %22, label %23
22: ; preds = %19
store i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.4, i64 0, i64 0), i8** %3
br label %29
23: ; preds = %19
%24 = load i32, i32* %2
%25 = icmp eq i32 %24, 5
br i1 %25, label %26, label %27
26: ; preds = %23
store i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.5, i64 0, i64 0), i8** %3
br label %28
27: ; preds = %23
store i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.6, i64 0, i64 0), i8** %3
br label %28
28: ; preds = %27, %26
br label %29
29: ; preds = %28, %22
br label %30
30: ; preds = %29, %18
br label %31
31: ; preds = %30, %14
br label %32
32: ; preds = %31, %10
br label %33
33: ; preds = %32, %6
%34 = load i8*, i8** %3
ret i8* %34
}

LLVM IR (-O2):
@.str = [1 x i8] zeroinitializer
@.str.1 = [5 x i8] c"[i1]\00"
@.str.2 = [9 x i8] c"[i2][i1]\00"
@.str.3 = [13 x i8] c"[i3][i2][i1]\00"
@.str.4 = [17 x i8] c"[i4][i3][i2][i1]\00"
@.str.5 = [21 x i8] c"[i5][i4][i3][i2][i1]\00"
@.str.6 = [31 x i8] c" REGISTRY ERROR TOO MANY DIMS \00"
@reltable.dimstr_c = [6 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([1 x i8]* @.str to i64), i64 ptrtoint ([6 x i32]* @reltable.dimstr_c to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.1 to i64), i64 ptrtoint ([6 x i32]* @reltable.dimstr_c to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.2 to i64), i64 ptrtoint ([6 x i32]* @reltable.dimstr_c to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([13 x i8]* @.str.3 to i64), i64 ptrtoint ([6 x i32]* @reltable.dimstr_c to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([17 x i8]* @.str.4 to i64), i64 ptrtoint ([6 x i32]* @reltable.dimstr_c to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([21 x i8]* @.str.5 to i64), i64 ptrtoint ([6 x i32]* @reltable.dimstr_c to i64)) to i32)]
define i8* @dimstr_c(i32 %0) {
%2 = icmp ult i32 %0, 6
br i1 %2, label %3, label %7
3: ; preds = %1
%4 = sext i32 %0 to i64
%5 = shl i64 %4, 2
%6 = call i8* @llvm.load.relative.i64(i8* bitcast ([6 x i32]* @reltable.dimstr_c to i8*), i64 %5)
br label %7
7: ; preds = %1, %3
%8 = phi i8* [ %6, %3 ], [ getelementptr inbounds ([31 x i8], [31 x i8]* @.str.6, i64 0, i64 0), %1 ]
ret i8* %8
}