#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 /*<<< orphan*/ printf(char *, float);
int /*<<< orphan*/ scanf(char *, ...);
int main() {
  int n;
  float total = 0.0f;
  scanf("%d", &n);
  while (n--) {
    float q, y;
    scanf("%f %f", &q, &y);
    total += q * y;
  }
  printf("%.3f\n", total);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
xorps  %xmm0,%xmm0
movss  %xmm0,-0xc(%rbp)
lea    0xec2(%rip),%rdi
lea    -0x8(%rbp),%rsi
mov    $0x0,%al
call   1040 <scanf@plt>
mov    -0x8(%rbp),%eax
mov    %eax,%ecx
add    $0xffffffff,%ecx
mov    %ecx,-0x8(%rbp)
cmp    $0x0,%eax
je     1194 <main+0x74>
lea    0xe9f(%rip),%rdi
lea    -0x10(%rbp),%rsi
lea    -0x14(%rbp),%rdx
mov    $0x0,%al
call   1040 <scanf@plt>
movss  -0x10(%rbp),%xmm0
movss  -0x14(%rbp),%xmm2
movss  -0xc(%rbp),%xmm1
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0xc(%rbp)
jmp    1149 <main+0x29>
movss  -0xc(%rbp),%xmm0
lea    0xe69(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %rbx
sub    $0x10,%rsp
lea    0xed0(%rip),%rdi
lea    0x4(%rsp),%rsi
xor    %eax,%eax
call   1040 <scanf@plt>
xorps  %xmm0,%xmm0
subl   $0x1,0x4(%rsp)
jb     119b <main+0x7b>
xorps  %xmm0,%xmm0
lea    0xeb3(%rip),%r14
lea    0xc(%rsp),%r15
lea    0x8(%rsp),%rbx
nopw   0x0(%rax,%rax,1)
movss  %xmm0,(%rsp)
mov    %r14,%rdi
mov    %r15,%rsi
mov    %rbx,%rdx
xor    %eax,%eax
call   1040 <scanf@plt>
movss  0xc(%rsp),%xmm0
mulss  0x8(%rsp),%xmm0
movss  (%rsp),%xmm1
addss  %xmm0,%xmm1
movss  %xmm1,(%rsp)
movss  (%rsp),%xmm0
subl   $0x1,0x4(%rsp)
jae    1160 <main+0x40>
lea    0xe67(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%d\00"
@.str.1 = [6 x i8] c"%f %f\00"
@.str.2 = [6 x i8] c"%.3f\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca float
%4 = alloca float
%5 = alloca float
store i32 0, i32* %1
store float 0.000000e+00, float* %3
%6 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %2)
br label %7
7: ; preds = %11, %0
%8 = load i32, i32* %2
%9 = add nsw i32 %8, -1
store i32 %9, i32* %2
%10 = icmp ne i32 %8, 0
br i1 %10, label %11, label %17
11: ; preds = %7
%12 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), float* %4, float* %5)
%13 = load float, float* %4
%14 = load float, float* %5
%15 = load float, float* %3
%16 = call float @llvm.fmuladd.f32(float %13, float %14, float %15)
store float %16, float* %3
br label %7
17: ; preds = %7
%18 = load float, float* %3
%19 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.2, i64 0, i64 0), float %18)
ret i32 0
}

LLVM IR (-O2):
@.str = [3 x i8] c"%d\00"
@.str.1 = [6 x i8] c"%f %f\00"
@.str.2 = [6 x i8] c"%.3f\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca float
%3 = alloca float
%4 = bitcast i32* %1 to i8*
%5 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %1)
%6 = load i32, i32* %1
%7 = add nsw i32 %6, -1
store i32 %7, i32* %1
%8 = icmp eq i32 %6, 0
br i1 %8, label %21, label %9
9: ; preds = %0
%10 = bitcast float* %2 to i8*
%11 = bitcast float* %3 to i8*
br label %12
12: ; preds = %9, %12
%13 = phi float [ 0.000000e+00, %9 ], [ %17, %12 ]
%14 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), float* %2, float* %3)
%15 = load float, float* %2
%16 = load float, float* %3
%17 = call float @llvm.fmuladd.f32(float %15, float %16, float %13)
%18 = load i32, i32* %1
%19 = add nsw i32 %18, -1
store i32 %19, i32* %1
%20 = icmp eq i32 %18, 0
br i1 %20, label %21, label %12
21: ; preds = %12, %0
%22 = phi float [ 0.000000e+00, %0 ], [ %17, %12 ]
%23 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.2, i64 0, i64 0), float %22)
ret i32 0
}