; LLVM IR from 6leetcode/6leetcode :: questions/LCCI/面试题 17.01. Add Without Plus (c)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

; Function Attrs: nounwind uwtable
define dso_local i32 @add(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  %8 = load i32, ptr %4, align 4, !tbaa !5
  %9 = icmp eq i32 %8, 0
  br i1 %9, label %10, label %12

10:                                               ; preds = %2
  %11 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %11, ptr %3, align 4
  br label %34

12:                                               ; preds = %2
  %13 = load i32, ptr %5, align 4, !tbaa !5
  %14 = icmp eq i32 %13, 0
  br i1 %14, label %15, label %17

15:                                               ; preds = %12
  %16 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %16, ptr %3, align 4
  br label %34

17:                                               ; preds = %12
  br label %18

18:                                               ; preds = %17
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %19

19:                                               ; preds = %22, %18
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = icmp ne i32 %20, 0
  br i1 %21, label %22, label %32

22:                                               ; preds = %19
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = xor i32 %23, %24
  store i32 %25, ptr %6, align 4, !tbaa !5
  %26 = load i32, ptr %4, align 4, !tbaa !5
  %27 = load i32, ptr %5, align 4, !tbaa !5
  %28 = and i32 %26, %27
  %29 = shl i32 %28, 1
  store i32 %29, ptr %7, align 4, !tbaa !5
  %30 = load i32, ptr %6, align 4, !tbaa !5
  store i32 %30, ptr %4, align 4, !tbaa !5
  %31 = load i32, ptr %7, align 4, !tbaa !5
  store i32 %31, ptr %5, align 4, !tbaa !5
  br label %19, !llvm.loop !9

32:                                               ; preds = %19
  %33 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %33, ptr %3, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %34

34:                                               ; preds = %32, %15, %10
  %35 = load i32, ptr %3, align 4
  ret i32 %35
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

; Function Attrs: nofree norecurse nosync nounwind memory(none) uwtable
define dso_local i32 @add(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %0, 0
  br i1 %3, label %.loopexit, label %4

4:                                                ; preds = %2
  %5 = icmp eq i32 %1, 0
  br i1 %5, label %.loopexit, label %.preheader

.preheader:                                       ; preds = %4, %.preheader
  %.018 = phi i32 [ %8, %.preheader ], [ %1, %4 ]
  %.01317 = phi i32 [ %6, %.preheader ], [ %0, %4 ]
  %6 = xor i32 %.018, %.01317
  %7 = and i32 %.018, %.01317
  %8 = shl i32 %7, 1
  %.not = icmp eq i32 %8, 0
  br i1 %.not, label %.loopexit, label %.preheader, !llvm.loop !5

.loopexit:                                        ; preds = %.preheader, %4, %2
  %.014 = phi i32 [ %1, %2 ], [ %0, %4 ], [ %6, %.preheader ]
  ret i32 %.014
}

attributes #0 = { nofree norecurse nosync nounwind memory(none) uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass