; LLVM IR from namantam1/x86-assembly :: leetcode (find_difference)

; 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 signext i8 @findTheDifference_c(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  %7 = load ptr, ptr %4, align 8, !tbaa !5
  %8 = load i32, ptr %5, align 4, !tbaa !9
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds i8, ptr %7, i64 %9
  %11 = load i8, ptr %10, align 1, !tbaa !11
  %12 = sext i8 %11 to i32
  store i32 %12, ptr %6, align 4, !tbaa !9
  br label %13

13:                                               ; preds = %21, %2
  %14 = load ptr, ptr %3, align 8, !tbaa !5
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds i8, ptr %14, i64 %16
  %18 = load i8, ptr %17, align 1, !tbaa !11
  %19 = sext i8 %18 to i32
  %20 = icmp ne i32 %19, 0
  br i1 %20, label %21, label %40

21:                                               ; preds = %13
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = load i32, ptr %5, align 4, !tbaa !9
  %24 = add nsw i32 %23, 1
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i8, ptr %22, i64 %25
  %27 = load i8, ptr %26, align 1, !tbaa !11
  %28 = sext i8 %27 to i32
  %29 = load ptr, ptr %3, align 8, !tbaa !5
  %30 = load i32, ptr %5, align 4, !tbaa !9
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds i8, ptr %29, i64 %31
  %33 = load i8, ptr %32, align 1, !tbaa !11
  %34 = sext i8 %33 to i32
  %35 = sub nsw i32 %28, %34
  %36 = load i32, ptr %6, align 4, !tbaa !9
  %37 = add nsw i32 %36, %35
  store i32 %37, ptr %6, align 4, !tbaa !9
  %38 = load i32, ptr %5, align 4, !tbaa !9
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %5, align 4, !tbaa !9
  br label %13, !llvm.loop !12

40:                                               ; preds = %13
  %41 = load i32, ptr %6, align 4, !tbaa !9
  %42 = trunc i32 %41 to i8
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i8 %42
}

; 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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(argmem: read) uwtable
define dso_local signext i8 @findTheDifference_c(ptr nocapture noundef readonly %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  %3 = load i8, ptr %1, align 1, !tbaa !5
  %4 = load i8, ptr %0, align 1, !tbaa !5
  %.not12 = icmp eq i8 %4, 0
  br i1 %.not12, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %2 ]
  %5 = phi i8 [ %11, %.lr.ph ], [ %4, %2 ]
  %.014 = phi i8 [ %9, %.lr.ph ], [ %3, %2 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %6 = getelementptr inbounds i8, ptr %1, i64 %indvars.iv.next
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = sub i8 %.014, %5
  %9 = add i8 %8, %7
  %10 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv.next
  %11 = load i8, ptr %10, align 1, !tbaa !5
  %.not = icmp eq i8 %11, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %.lr.ph, %2
  %.0.lcssa = phi i8 [ %3, %2 ], [ %9, %.lr.ph ]
  ret i8 %.0.lcssa
}

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: read) 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 = !{!6, !6, i64 0}
!6 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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