#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 */
struct timeval {
  scalar_t__ tv_usec;
  scalar_t__ tv_sec;
};

/* Variables and functions */
struct timeval timeval_sub(struct timeval *a, struct timeval *b) {
  struct timeval result;
  result.tv_sec = a->tv_sec - b->tv_sec;
  result.tv_usec = a->tv_usec - b->tv_usec;
  if (a->tv_usec < b->tv_usec) {
    result.tv_sec -= 1;
    result.tv_usec += 1000000;
  }
  return result;
}


x86 assembly (clang, -O0):
<timeval_sub>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x18(%rbp)
mov    %rsi,-0x20(%rbp)
mov    -0x18(%rbp),%rax
mov    0x8(%rax),%rax
mov    -0x20(%rbp),%rcx
sub    0x8(%rcx),%rax
mov    %rax,-0x8(%rbp)
mov    -0x18(%rbp),%rax
mov    (%rax),%rax
mov    -0x20(%rbp),%rcx
sub    (%rcx),%rax
mov    %rax,-0x10(%rbp)
mov    -0x18(%rbp),%rax
mov    (%rax),%rax
mov    -0x20(%rbp),%rcx
cmp    (%rcx),%rax
jge    1160 <timeval_sub+0x60>
mov    -0x8(%rbp),%rax
sub    $0x1,%rax
mov    %rax,-0x8(%rbp)
mov    -0x10(%rbp),%rax
add    $0xf4240,%rax
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x8(%rbp),%rdx
pop    %rbp
ret

x86 assembly (clang, -O2):
<timeval_sub>:
mov    (%rdi),%rax
mov    0x8(%rdi),%rdx
mov    (%rsi),%r8
mov    %rax,%rdi
sub    %r8,%rdi
add    $0xf4240,%rdi
xor    %ecx,%ecx
sub    %r8,%rax
cmovl  %rdi,%rax
setl   %cl
sub    0x8(%rsi),%rdx
sub    %rcx,%rdx
ret

LLVM IR (-O0):
%struct.timeval = type { i64, i64 }
define { i64, i64 } @timeval_sub(%struct.timeval* %0, %struct.timeval* %1) {
%3 = alloca %struct.timeval
%4 = alloca %struct.timeval*
%5 = alloca %struct.timeval*
store %struct.timeval* %0, %struct.timeval** %4
store %struct.timeval* %1, %struct.timeval** %5
%6 = load %struct.timeval*, %struct.timeval** %4
%7 = getelementptr inbounds %struct.timeval, %struct.timeval* %6, i32 0, i32 1
%8 = load i64, i64* %7
%9 = load %struct.timeval*, %struct.timeval** %5
%10 = getelementptr inbounds %struct.timeval, %struct.timeval* %9, i32 0, i32 1
%11 = load i64, i64* %10
%12 = sub nsw i64 %8, %11
%13 = getelementptr inbounds %struct.timeval, %struct.timeval* %3, i32 0, i32 1
store i64 %12, i64* %13
%14 = load %struct.timeval*, %struct.timeval** %4
%15 = getelementptr inbounds %struct.timeval, %struct.timeval* %14, i32 0, i32 0
%16 = load i64, i64* %15
%17 = load %struct.timeval*, %struct.timeval** %5
%18 = getelementptr inbounds %struct.timeval, %struct.timeval* %17, i32 0, i32 0
%19 = load i64, i64* %18
%20 = sub nsw i64 %16, %19
%21 = getelementptr inbounds %struct.timeval, %struct.timeval* %3, i32 0, i32 0
store i64 %20, i64* %21
%22 = load %struct.timeval*, %struct.timeval** %4
%23 = getelementptr inbounds %struct.timeval, %struct.timeval* %22, i32 0, i32 0
%24 = load i64, i64* %23
%25 = load %struct.timeval*, %struct.timeval** %5
%26 = getelementptr inbounds %struct.timeval, %struct.timeval* %25, i32 0, i32 0
%27 = load i64, i64* %26
%28 = icmp slt i64 %24, %27
br i1 %28, label %29, label %36
29: ; preds = %2
%30 = getelementptr inbounds %struct.timeval, %struct.timeval* %3, i32 0, i32 1
%31 = load i64, i64* %30
%32 = sub nsw i64 %31, 1
store i64 %32, i64* %30
%33 = getelementptr inbounds %struct.timeval, %struct.timeval* %3, i32 0, i32 0
%34 = load i64, i64* %33
%35 = add nsw i64 %34, 1000000
store i64 %35, i64* %33
br label %36
36: ; preds = %29, %2
%37 = bitcast %struct.timeval* %3 to { i64, i64 }*
%38 = load { i64, i64 }, { i64, i64 }* %37
ret { i64, i64 } %38
}

LLVM IR (-O2):
%struct.timeval = type { i64, i64 }
define { i64, i64 } @timeval_sub(%struct.timeval* nocapture %0, %struct.timeval* nocapture %1) {
%3 = getelementptr inbounds %struct.timeval, %struct.timeval* %0, i64 0, i32 1
%4 = load i64, i64* %3
%5 = getelementptr inbounds %struct.timeval, %struct.timeval* %1, i64 0, i32 1
%6 = load i64, i64* %5
%7 = sub i64 %4, %6
%8 = getelementptr inbounds %struct.timeval, %struct.timeval* %0, i64 0, i32 0
%9 = load i64, i64* %8
%10 = getelementptr inbounds %struct.timeval, %struct.timeval* %1, i64 0, i32 0
%11 = load i64, i64* %10
%12 = sub nsw i64 %9, %11
%13 = icmp slt i64 %9, %11
%14 = add nsw i64 %12, 1000000
%15 = select i1 %13, i64 %14, i64 %12
%16 = sext i1 %13 to i64
%17 = add nsw i64 %7, %16
%18 = insertvalue { i64, i64 } poison, i64 %15, 0
%19 = insertvalue { i64, i64 } %18, i64 %17, 1
ret { i64, i64 } %19
}