; LLVM IR from IsaacAsante/HackerRank :: C Programming/Students Marks Sum (students marks sum)

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

10:                                               ; preds = %36, %3
  %11 = load i32, ptr %9, align 4, !tbaa !9
  %12 = load i32, ptr %5, align 4, !tbaa !9
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  br label %39

15:                                               ; preds = %10
  %16 = load i32, ptr %9, align 4, !tbaa !9
  %17 = srem i32 %16, 2
  %18 = icmp ne i32 %17, 0
  br i1 %18, label %19, label %27

19:                                               ; preds = %15
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  %21 = load i32, ptr %9, align 4, !tbaa !9
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds i32, ptr %20, i64 %22
  %24 = load i32, ptr %23, align 4, !tbaa !9
  %25 = load i32, ptr %8, align 4, !tbaa !9
  %26 = add nsw i32 %25, %24
  store i32 %26, ptr %8, align 4, !tbaa !9
  br label %35

27:                                               ; preds = %15
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = load i32, ptr %9, align 4, !tbaa !9
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds i32, ptr %28, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !9
  %33 = load i32, ptr %7, align 4, !tbaa !9
  %34 = add nsw i32 %33, %32
  store i32 %34, ptr %7, align 4, !tbaa !9
  br label %35

35:                                               ; preds = %27, %19
  br label %36

36:                                               ; preds = %35
  %37 = load i32, ptr %9, align 4, !tbaa !9
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %9, align 4, !tbaa !9
  br label %10, !llvm.loop !12

39:                                               ; preds = %14
  %40 = load i8, ptr %6, align 1, !tbaa !11
  %41 = sext i8 %40 to i32
  %42 = icmp eq i32 %41, 98
  br i1 %42, label %43, label %45

43:                                               ; preds = %39
  %44 = load i32, ptr %7, align 4, !tbaa !9
  br label %47

45:                                               ; preds = %39
  %46 = load i32, ptr %8, align 4, !tbaa !9
  br label %47

47:                                               ; preds = %45, %43
  %48 = phi i32 [ %44, %43 ], [ %46, %45 ]
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  ret i32 %48
}

; 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 i32 @marks_summation(ptr nocapture noundef readonly %0, i32 noundef %1, i8 noundef signext %2) local_unnamed_addr #0 {
  %4 = icmp sgt i32 %1, 0
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %3
  %wide.trip.count = zext nneg i32 %1 to i64
  %min.iters.check = icmp ult i32 %1, 8
  br i1 %min.iters.check, label %.lr.ph.preheader27, label %vector.ph

.lr.ph.preheader27:                               ; preds = %middle.block, %.lr.ph.preheader
  %indvars.iv.ph = phi i64 [ 0, %.lr.ph.preheader ], [ %n.vec, %middle.block ]
  %.01216.ph = phi i32 [ 0, %.lr.ph.preheader ], [ %20, %middle.block ]
  %.01315.ph = phi i32 [ 0, %.lr.ph.preheader ], [ %21, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %wide.trip.count, 2147483640
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.ind = phi <4 x i64> [ <i64 0, i64 1, i64 2, i64 3>, %vector.ph ], [ %vec.ind.next, %vector.body ]
  %vec.phi = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %17, %vector.body ]
  %vec.phi21 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %18, %vector.body ]
  %vec.phi22 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %13, %vector.body ]
  %vec.phi23 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %14, %vector.body ]
  %5 = and <4 x i64> %vec.ind, <i64 1, i64 1, i64 1, i64 1>
  %6 = and <4 x i64> %vec.ind, <i64 1, i64 1, i64 1, i64 1>
  %7 = icmp eq <4 x i64> %5, zeroinitializer
  %8 = icmp eq <4 x i64> %6, zeroinitializer
  %9 = getelementptr inbounds i32, ptr %0, i64 %index
  %10 = getelementptr inbounds i8, ptr %9, i64 16
  %wide.load = load <4 x i32>, ptr %9, align 4, !tbaa !5
  %wide.load24 = load <4 x i32>, ptr %10, align 4, !tbaa !5
  %11 = select <4 x i1> %7, <4 x i32> %wide.load, <4 x i32> zeroinitializer
  %12 = select <4 x i1> %8, <4 x i32> %wide.load24, <4 x i32> zeroinitializer
  %13 = add <4 x i32> %vec.phi22, %11
  %14 = add <4 x i32> %vec.phi23, %12
  %15 = select <4 x i1> %7, <4 x i32> zeroinitializer, <4 x i32> %wide.load
  %16 = select <4 x i1> %8, <4 x i32> zeroinitializer, <4 x i32> %wide.load24
  %17 = add <4 x i32> %vec.phi, %15
  %18 = add <4 x i32> %vec.phi21, %16
  %index.next = add nuw i64 %index, 8
  %vec.ind.next = add <4 x i64> %vec.ind, <i64 8, i64 8, i64 8, i64 8>
  %19 = icmp eq i64 %index.next, %n.vec
  br i1 %19, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %bin.rdx = add <4 x i32> %18, %17
  %20 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %bin.rdx)
  %bin.rdx25 = add <4 x i32> %14, %13
  %21 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %bin.rdx25)
  %cmp.n = icmp eq i64 %n.vec, %wide.trip.count
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader27

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %3
  %.013.lcssa = phi i32 [ 0, %3 ], [ %21, %middle.block ], [ %.114, %.lr.ph ]
  %.012.lcssa = phi i32 [ 0, %3 ], [ %20, %middle.block ], [ %.1, %.lr.ph ]
  %22 = icmp eq i8 %2, 98
  %23 = select i1 %22, i32 %.013.lcssa, i32 %.012.lcssa
  ret i32 %23

.lr.ph:                                           ; preds = %.lr.ph.preheader27, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ %indvars.iv.ph, %.lr.ph.preheader27 ]
  %.01216 = phi i32 [ %.1, %.lr.ph ], [ %.01216.ph, %.lr.ph.preheader27 ]
  %.01315 = phi i32 [ %.114, %.lr.ph ], [ %.01315.ph, %.lr.ph.preheader27 ]
  %24 = and i64 %indvars.iv, 1
  %.not = icmp eq i64 %24, 0
  %25 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %26 = load i32, ptr %25, align 4, !tbaa !5
  %27 = select i1 %.not, i32 %26, i32 0
  %.114 = add nsw i32 %.01315, %27
  %28 = select i1 %.not, i32 0, i32 %26
  %.1 = add nsw i32 %.01216, %28
  %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 !13
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.vector.reduce.add.v4i32(<4 x i32>) #1

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" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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, !11, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10, !12, !11}


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