; LLVM IR from codemistic/Data-Structures-and-Algorithms :: Arrays (08_Improving_Linear_search)

; 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"

%struct.Array = type { [20 x i32], i32, i32 }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind uwtable
declare dso_local void @swap(ptr noundef, ptr noundef) #1

; Function Attrs: nounwind uwtable
define dso_local i32 @LinearSearch(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %34, %2
  %9 = load i32, ptr %6, align 4, !tbaa !9
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.Array, ptr %10, i32 0, i32 1
  %12 = load i32, ptr %11, align 4, !tbaa !11
  %13 = icmp slt i32 %9, %12
  br i1 %13, label %14, label %37

14:                                               ; preds = %8
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.Array, ptr %16, i32 0, i32 0
  %18 = load i32, ptr %6, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [20 x i32], ptr %17, i64 0, i64 %19
  %21 = load i32, ptr %20, align 4, !tbaa !9
  %22 = icmp eq i32 %15, %21
  br i1 %22, label %23, label %33

23:                                               ; preds = %14
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.Array, ptr %24, i32 0, i32 0
  %26 = load i32, ptr %6, align 4, !tbaa !9
  %27 = sext i32 %26 to i64
  %28 = getelementptr inbounds [20 x i32], ptr %25, i64 0, i64 %27
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.Array, ptr %29, i32 0, i32 0
  %31 = getelementptr inbounds [20 x i32], ptr %30, i64 0, i64 0
  call void @swap(ptr noundef %28, ptr noundef %31)
  %32 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %32, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %38

33:                                               ; preds = %14
  br label %34

34:                                               ; preds = %33
  %35 = load i32, ptr %6, align 4, !tbaa !9
  %36 = add nsw i32 %35, 1
  store i32 %36, ptr %6, align 4, !tbaa !9
  br label %8, !llvm.loop !13

37:                                               ; preds = %8
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %38

38:                                               ; preds = %37, %23
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  %39 = load i32, ptr %3, align 4
  ret i32 %39
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!12, !10, i64 80}
!12 = !{!"Array", !7, i64 0, !10, i64 80, !10, i64 84}
!13 = distinct !{!13, !14}
!14 = !{!"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: nounwind uwtable
declare dso_local void @swap(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local i32 @LinearSearch(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = getelementptr inbounds i8, ptr %0, i64 80
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph.preheader, label %.loopexit

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = zext nneg i32 %4 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %12
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %12 ]
  %6 = getelementptr inbounds [20 x i32], ptr %0, i64 0, i64 %indvars.iv
  %7 = load i32, ptr %6, align 4, !tbaa !10
  %8 = icmp eq i32 %7, %1
  br i1 %8, label %9, label %12

9:                                                ; preds = %.lr.ph
  %10 = getelementptr inbounds [20 x i32], ptr %0, i64 0, i64 %indvars.iv
  %11 = trunc nuw nsw i64 %indvars.iv to i32
  tail call void @swap(ptr noundef nonnull %10, ptr noundef nonnull %0)
  br label %.loopexit

12:                                               ; preds = %.lr.ph
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %.loopexit, label %.lr.ph, !llvm.loop !11

.loopexit:                                        ; preds = %12, %2, %9
  %.010 = phi i32 [ %11, %9 ], [ -1, %2 ], [ -1, %12 ]
  ret i32 %.010
}

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" }

!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, !9, i64 80}
!6 = !{!"Array", !7, i64 0, !9, i64 80, !9, i64 84}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!"int", !7, i64 0}
!10 = !{!9, !9, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass