#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 */
typedef scalar_t__ ssize_t;

/* Variables and functions */
scalar_t__ EINTR;
scalar_t__ errno;
int /*<<< orphan*/ perror_exit(char *);
scalar_t__ read(int, void *, size_t);
ssize_t xread(int fd, void *buf, size_t count) {
  ssize_t retval;
  do {
    retval = read(fd, buf, count);
  } while ((retval < 0) && (errno == EINTR));
  if (retval < 0)
    perror_exit("read");
  return retval;
}


x86 assembly (clang, -O0):
<xread>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    -0x4(%rbp),%edi
mov    -0x10(%rbp),%rsi
mov    -0x18(%rbp),%rdx
call   1030 <read@plt>
mov    %rax,-0x20(%rbp)
xor    %eax,%eax
cmpq   $0x0,-0x20(%rbp)
mov    %al,-0x21(%rbp)
jge    1171 <xread+0x51>
mov    0x2e82(%rip),%rax
mov    (%rax),%rax
mov    0x2e70(%rip),%rcx
cmp    (%rcx),%rax
sete   %al
mov    %al,-0x21(%rbp)
mov    -0x21(%rbp),%al
test   $0x1,%al
jne    1133 <xread+0x13>
cmpq   $0x0,-0x20(%rbp)
jge    1193 <xread+0x73>
lea    0xe72(%rip),%rdi
call   1040 <perror_exit@plt>
mov    -0x20(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<xread>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
push   %rax
mov    %rdx,%r14
mov    %rsi,%r15
mov    %edi,%ebp
mov    0x2ea6(%rip),%r12
mov    0x2e97(%rip),%r13
cs nopw 0x0(%rax,%rax,1)
nopl   0x0(%rax,%rax,1)
mov    %ebp,%edi
mov    %r15,%rsi
mov    %r14,%rdx
call   1030 <read@plt>
mov    %rax,%rbx
test   %rax,%rax
jns    116f <xread+0x4f>
mov    0x0(%r13),%rax
cmp    %rax,(%r12)
je     1150 <xread+0x30>
test   %rbx,%rbx
jns    1180 <xread+0x60>
lea    0xe85(%rip),%rdi
call   1040 <perror_exit@plt>
mov    %rbx,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
@errno = global i64 0
@EINTR = global i64 0
@.str = [5 x i8] c"read\00"
define i64 @xread(i32 %0, i8* %1, i64 %2) {
%4 = alloca i32
%5 = alloca i8*
%6 = alloca i64
%7 = alloca i64
store i32 %0, i32* %4
store i8* %1, i8** %5
store i64 %2, i64* %6
br label %8
8: ; preds = %20, %3
%9 = load i32, i32* %4
%10 = load i8*, i8** %5
%11 = load i64, i64* %6
%12 = call i64 @read(i32 %9, i8* %10, i64 %11)
store i64 %12, i64* %7
br label %13
13: ; preds = %8
%14 = load i64, i64* %7
%15 = icmp slt i64 %14, 0
br i1 %15, label %16, label %20
16: ; preds = %13
%17 = load i64, i64* @errno
%18 = load i64, i64* @EINTR
%19 = icmp eq i64 %17, %18
br label %20
20: ; preds = %16, %13
%21 = phi i1 [ false, %13 ], [ %19, %16 ]
br i1 %21, label %8, label %22
22: ; preds = %20
%23 = load i64, i64* %7
%24 = icmp slt i64 %23, 0
br i1 %24, label %25, label %27
25: ; preds = %22
%26 = call i32 @perror_exit(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0))
br label %27
27: ; preds = %25, %22
%28 = load i64, i64* %7
ret i64 %28
}

LLVM IR (-O2):
@errno = global i64 0
@EINTR = global i64 0
@.str = [5 x i8] c"read\00"
define i64 @xread(i32 %0, i8* nocapture %1, i64 %2) {
br label %4
4: ; preds = %4, %3
%5 = tail call i64 @read(i32 %0, i8* %1, i64 %2)
%6 = icmp slt i64 %5, 0
%7 = load i64, i64* @errno
%8 = load i64, i64* @EINTR
%9 = icmp eq i64 %7, %8
%10 = select i1 %6, i1 %9, i1 false
br i1 %10, label %4, label %11
11: ; preds = %4
br i1 %6, label %12, label %14
12: ; preds = %11
%13 = tail call i32 @perror_exit(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0))
br label %14
14: ; preds = %12, %11
ret i64 %5
}