#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 */
scalar_t__ islower(char);
int strlen(char *);
char toupper(char);
void str_toupper(char *str) {
  int i, slen;
  slen = strlen(str);
  for (i = 0; i < slen; i++) {
    if (islower(str[i])) {
      str[i] = toupper(str[i]);
    }
  }
}


x86 assembly (clang, -O0):
<str_toupper>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rdi
call   1050 <strlen@plt>
mov    %eax,-0x10(%rbp)
movl   $0x0,-0xc(%rbp)
mov    -0xc(%rbp),%eax
cmp    -0x10(%rbp),%eax
jge    11a7 <str_toupper+0x77>
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movsbl (%rax,%rcx,1),%edi
call   1030 <islower@plt>
cmp    $0x0,%rax
je     1194 <str_toupper+0x64>
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movsbl (%rax,%rcx,1),%edi
call   1040 <toupper@plt>
mov    %al,%dl
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
mov    %dl,(%rax,%rcx,1)
jmp    1199 <str_toupper+0x69>
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    114f <str_toupper+0x1f>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<str_toupper>:
push   %r15
push   %r14
push   %rbx
mov    %rdi,%r15
call   1050 <strlen@plt>
test   %eax,%eax
jle    1178 <str_toupper+0x48>
mov    %eax,%r14d
xor    %ebx,%ebx
jmp    1159 <str_toupper+0x29>
nopl   0x0(%rax,%rax,1)
add    $0x1,%rbx
cmp    %rbx,%r14
je     1178 <str_toupper+0x48>
movsbl (%r15,%rbx,1),%edi
call   1030 <islower@plt>
test   %rax,%rax
je     1150 <str_toupper+0x20>
movsbl (%r15,%rbx,1),%edi
call   1040 <toupper@plt>
mov    %al,(%r15,%rbx,1)
jmp    1150 <str_toupper+0x20>
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define void @str_toupper(i8* %0) {
%2 = alloca i8*
%3 = alloca i32
%4 = alloca i32
store i8* %0, i8** %2
%5 = load i8*, i8** %2
%6 = call i32 @strlen(i8* %5)
store i32 %6, i32* %4
store i32 0, i32* %3
br label %7
7: ; preds = %31, %1
%8 = load i32, i32* %3
%9 = load i32, i32* %4
%10 = icmp slt i32 %8, %9
br i1 %10, label %11, label %34
11: ; preds = %7
%12 = load i8*, i8** %2
%13 = load i32, i32* %3
%14 = sext i32 %13 to i64
%15 = getelementptr inbounds i8, i8* %12, i64 %14
%16 = load i8, i8* %15
%17 = call i64 @islower(i8 signext %16)
%18 = icmp ne i64 %17, 0
br i1 %18, label %19, label %30
19: ; preds = %11
%20 = load i8*, i8** %2
%21 = load i32, i32* %3
%22 = sext i32 %21 to i64
%23 = getelementptr inbounds i8, i8* %20, i64 %22
%24 = load i8, i8* %23
%25 = call signext i8 @toupper(i8 signext %24)
%26 = load i8*, i8** %2
%27 = load i32, i32* %3
%28 = sext i32 %27 to i64
%29 = getelementptr inbounds i8, i8* %26, i64 %28
store i8 %25, i8* %29
br label %30
30: ; preds = %19, %11
br label %31
31: ; preds = %30
%32 = load i32, i32* %3
%33 = add nsw i32 %32, 1
store i32 %33, i32* %3
br label %7
34: ; preds = %7
ret void
}

LLVM IR (-O2):
define void @str_toupper(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = icmp sgt i32 %2, 0
br i1 %3, label %4, label %18
4: ; preds = %1
%5 = zext i32 %2 to i64
br label %6
6: ; preds = %4, %15
%7 = phi i64 [ 0, %4 ], [ %16, %15 ]
%8 = getelementptr inbounds i8, i8* %0, i64 %7
%9 = load i8, i8* %8
%10 = tail call i64 @islower(i8 signext %9)
%11 = icmp eq i64 %10, 0
br i1 %11, label %15, label %12
12: ; preds = %6
%13 = load i8, i8* %8
%14 = tail call signext i8 @toupper(i8 signext %13)
store i8 %14, i8* %8
br label %15
15: ; preds = %6, %12
%16 = add nuw nsw i64 %7, 1
%17 = icmp eq i64 %16, %5
br i1 %17, label %18, label %6
18: ; preds = %15, %1
ret void
}