; LLVM IR from codemistic/Data-Structures-and-Algorithms :: Arrays (07_Linearsearch)

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

7:                                                ; preds = %23, %2
  %8 = load i32, ptr %5, align 4, !tbaa !5
  %9 = getelementptr inbounds %struct.Array, ptr %0, i32 0, i32 1
  %10 = load i32, ptr %9, align 8, !tbaa !9
  %11 = icmp slt i32 %8, %10
  br i1 %11, label %12, label %26

12:                                               ; preds = %7
  %13 = load i32, ptr %4, align 4, !tbaa !5
  %14 = getelementptr inbounds %struct.Array, ptr %0, i32 0, i32 0
  %15 = load i32, ptr %5, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds [20 x i32], ptr %14, i64 0, i64 %16
  %18 = load i32, ptr %17, align 4, !tbaa !5
  %19 = icmp eq i32 %13, %18
  br i1 %19, label %20, label %22

20:                                               ; preds = %12
  %21 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %21, ptr %3, align 4
  store i32 1, ptr %6, align 4
  br label %27

22:                                               ; preds = %12
  br label %23

23:                                               ; preds = %22
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = add nsw i32 %24, 1
  store i32 %25, ptr %5, align 4, !tbaa !5
  br label %7, !llvm.loop !11

26:                                               ; preds = %7
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %6, align 4
  br label %27

27:                                               ; preds = %26, %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  %28 = load i32, ptr %3, align 4
  ret i32 %28
}

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

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

; Function Attrs: nofree norecurse nosync nounwind memory(argmem: read) uwtable
define dso_local i32 @LinearSearch(ptr nocapture noundef readonly byval(%struct.Array) align 8 %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = getelementptr inbounds i8, ptr %0, i64 80
  %4 = load i32, ptr %3, align 8, !tbaa !5
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

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

.lr.ph:                                           ; preds = %.lr.ph.preheader, %9
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %9 ]
  %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 %._crit_edge.loopexit.split.loop.exit11, label %9

9:                                                ; 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 %._crit_edge, label %.lr.ph, !llvm.loop !11

._crit_edge.loopexit.split.loop.exit11:           ; preds = %.lr.ph
  %10 = trunc nuw nsw i64 %indvars.iv to i32
  br label %._crit_edge

._crit_edge:                                      ; preds = %9, %._crit_edge.loopexit.split.loop.exit11, %2
  %.06 = phi i32 [ -1, %2 ], [ %10, %._crit_edge.loopexit.split.loop.exit11 ], [ -1, %9 ]
  ret i32 %.06
}

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, !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: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass