#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int strlen(char *);
int trimEnd(char *line, char end) {
  int newLine = line[strlen(line) - 1] == end;
  if (newLine) {
    line[strlen(line) - 1] = '\0';
  } else {
    return -1;
  }
  return 0;
}


x86 assembly (clang, -O0):
<trimEnd>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %sil,%al
mov    %rdi,-0x10(%rbp)
mov    %al,-0x11(%rbp)
mov    -0x10(%rbp),%rax
mov    %rax,-0x20(%rbp)
mov    -0x10(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x20(%rbp),%rax
sub    $0x1,%ecx
movslq %ecx,%rcx
movsbl (%rax,%rcx,1),%eax
movsbl -0x11(%rbp),%ecx
cmp    %ecx,%eax
sete   %al
and    $0x1,%al
movzbl %al,%eax
mov    %eax,-0x18(%rbp)
cmpl   $0x0,-0x18(%rbp)
je     1184 <trimEnd+0x74>
mov    -0x10(%rbp),%rax
mov    %rax,-0x28(%rbp)
mov    -0x10(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x28(%rbp),%rax
sub    $0x1,%ecx
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
jmp    1190 <trimEnd+0x80>
movl   $0xffffffff,-0x4(%rbp)
jmp    1197 <trimEnd+0x87>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<trimEnd>:
push   %rbp
push   %rbx
push   %rax
mov    %esi,%ebp
mov    %rdi,%rbx
call   1030 <strlen@plt>
movslq %eax,%rcx
mov    $0xffffffff,%eax
cmp    %bpl,-0x1(%rcx,%rbx,1)
jne    113d <trimEnd+0x2d>
mov    %rbx,%rdi
call   1030 <strlen@plt>
cltq
movb   $0x0,-0x1(%rax,%rbx,1)
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %rbp
ret

LLVM IR (-O0):
define i32 @trimEnd(i8* %0, i8 signext %1) {
%3 = alloca i32
%4 = alloca i8*
%5 = alloca i8
%6 = alloca i32
store i8* %0, i8** %4
store i8 %1, i8* %5
%7 = load i8*, i8** %4
%8 = load i8*, i8** %4
%9 = call i32 @strlen(i8* %8)
%10 = sub nsw i32 %9, 1
%11 = sext i32 %10 to i64
%12 = getelementptr inbounds i8, i8* %7, i64 %11
%13 = load i8, i8* %12
%14 = sext i8 %13 to i32
%15 = load i8, i8* %5
%16 = sext i8 %15 to i32
%17 = icmp eq i32 %14, %16
%18 = zext i1 %17 to i32
store i32 %18, i32* %6
%19 = load i32, i32* %6
%20 = icmp ne i32 %19, 0
br i1 %20, label %21, label %28
21: ; preds = %2
%22 = load i8*, i8** %4
%23 = load i8*, i8** %4
%24 = call i32 @strlen(i8* %23)
%25 = sub nsw i32 %24, 1
%26 = sext i32 %25 to i64
%27 = getelementptr inbounds i8, i8* %22, i64 %26
store i8 0, i8* %27
br label %29
28: ; preds = %2
store i32 -1, i32* %3
br label %30
29: ; preds = %21
store i32 0, i32* %3
br label %30
30: ; preds = %29, %28
%31 = load i32, i32* %3
ret i32 %31
}

LLVM IR (-O2):
define i32 @trimEnd(i8* %0, i8 signext %1) {
%3 = tail call i32 @strlen(i8* %0)
%4 = add nsw i32 %3, -1
%5 = sext i32 %4 to i64
%6 = getelementptr inbounds i8, i8* %0, i64 %5
%7 = load i8, i8* %6
%8 = icmp eq i8 %7, %1
br i1 %8, label %9, label %14
9: ; preds = %2
%10 = tail call i32 @strlen(i8* %0)
%11 = add nsw i32 %10, -1
%12 = sext i32 %11 to i64
%13 = getelementptr inbounds i8, i8* %0, i64 %12
store i8 0, i8* %13
br label %14
14: ; preds = %2, %9
%15 = phi i32 [ 0, %9 ], [ -1, %2 ]
ret i32 %15
}