#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 *);
void StrSpaceToHyphen(char modString[]) {
  int i = 0;
  for (i = 0; i < strlen(modString); ++i) {
    if (modString[i] == ' ') {
      modString[i] = ' ';
    }
  }
  return;
}


x86 assembly (clang, -O0):
<StrSpaceToHyphen>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
movl   $0x0,-0xc(%rbp)
movl   $0x0,-0xc(%rbp)
mov    -0xc(%rbp),%eax
mov    %eax,-0x10(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x10(%rbp),%eax
cmp    %ecx,%eax
jge    117a <StrSpaceToHyphen+0x6a>
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movsbl (%rax,%rcx,1),%eax
cmp    $0x20,%eax
jne    1167 <StrSpaceToHyphen+0x57>
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movb   $0x20,(%rax,%rcx,1)
jmp    116c <StrSpaceToHyphen+0x5c>
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    112a <StrSpaceToHyphen+0x1a>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<StrSpaceToHyphen>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%r14
call   1030 <strlen@plt>
test   %eax,%eax
jle    1151 <StrSpaceToHyphen+0x41>
xor    %ebx,%ebx
jmp    1143 <StrSpaceToHyphen+0x33>
cs nopw 0x0(%rax,%rax,1)
xchg   %ax,%ax
add    $0x1,%rbx
mov    %r14,%rdi
call   1030 <strlen@plt>
cltq
cmp    %rax,%rbx
jge    1151 <StrSpaceToHyphen+0x41>
cmpb   $0x20,(%r14,%rbx,1)
jne    1130 <StrSpaceToHyphen+0x20>
movb   $0x20,(%r14,%rbx,1)
jmp    1130 <StrSpaceToHyphen+0x20>
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret

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

LLVM IR (-O2):
define void @StrSpaceToHyphen(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = icmp sgt i32 %2, 0
br i1 %3, label %4, label %15
4: ; preds = %1, %10
%5 = phi i64 [ %11, %10 ], [ 0, %1 ]
%6 = getelementptr inbounds i8, i8* %0, i64 %5
%7 = load i8, i8* %6
%8 = icmp eq i8 %7, 32
br i1 %8, label %9, label %10
9: ; preds = %4
store i8 32, i8* %6
br label %10
10: ; preds = %4, %9
%11 = add nuw nsw i64 %5, 1
%12 = tail call i32 @strlen(i8* %0)
%13 = sext i32 %12 to i64
%14 = icmp slt i64 %11, %13
br i1 %14, label %4, label %15
15: ; preds = %10, %1
ret void
}