; LLVM IR from hanzohasashi33/Competetive_programming :: hackerrank/problem_solving (simplearraysum)

; 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 @summation(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  %6 = load i32, ptr %5, align 4, !tbaa !9
  %7 = icmp eq i32 %6, 0
  br i1 %7, label %8, label %12

8:                                                ; preds = %2
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  %10 = getelementptr inbounds i32, ptr %9, i64 0
  %11 = load i32, ptr %10, align 4, !tbaa !9
  store i32 %11, ptr %3, align 4
  br label %23

12:                                               ; preds = %2
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = load i32, ptr %5, align 4, !tbaa !9
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds i32, ptr %13, i64 %15
  %17 = load i32, ptr %16, align 4, !tbaa !9
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = load i32, ptr %5, align 4, !tbaa !9
  %20 = sub nsw i32 %19, 1
  %21 = call i32 @summation(ptr noundef %18, i32 noundef %20)
  %22 = add nsw i32 %17, %21
  store i32 %22, ptr %3, align 4
  br label %23

23:                                               ; preds = %12, %8
  %24 = load i32, ptr %3, align 4
  ret i32 %24
}

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, !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}


; 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 @summation(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %1, 0
  br i1 %3, label %tailrecurse._crit_edge, label %tailrecurse.preheader

tailrecurse.preheader:                            ; preds = %2
  %4 = sext i32 %1 to i64
  %min.iters.check = icmp ult i32 %1, 8
  br i1 %min.iters.check, label %tailrecurse.preheader14, label %vector.ph

tailrecurse.preheader14:                          ; preds = %middle.block, %tailrecurse.preheader
  %indvars.iv.ph = phi i64 [ %4, %tailrecurse.preheader ], [ %ind.end, %middle.block ]
  %accumulator.tr8.ph = phi i32 [ 0, %tailrecurse.preheader ], [ %11, %middle.block ]
  br label %tailrecurse

vector.ph:                                        ; preds = %tailrecurse.preheader
  %n.vec = and i64 %4, -8
  %ind.end = and i64 %4, 7
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.phi = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %8, %vector.body ]
  %vec.phi11 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %9, %vector.body ]
  %offset.idx = sub i64 %4, %index
  %5 = getelementptr inbounds i32, ptr %0, i64 %offset.idx
  %6 = getelementptr inbounds i8, ptr %5, i64 -12
  %7 = getelementptr inbounds i8, ptr %5, i64 -28
  %wide.load = load <4 x i32>, ptr %6, align 4, !tbaa !5
  %reverse = shufflevector <4 x i32> %wide.load, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
  %wide.load12 = load <4 x i32>, ptr %7, align 4, !tbaa !5
  %reverse13 = shufflevector <4 x i32> %wide.load12, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
  %8 = add <4 x i32> %reverse, %vec.phi
  %9 = add <4 x i32> %reverse13, %vec.phi11
  %index.next = add nuw i64 %index, 8
  %10 = icmp eq i64 %index.next, %n.vec
  br i1 %10, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %bin.rdx = add <4 x i32> %9, %8
  %11 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %bin.rdx)
  %cmp.n = icmp eq i64 %n.vec, %4
  br i1 %cmp.n, label %tailrecurse._crit_edge, label %tailrecurse.preheader14

tailrecurse._crit_edge:                           ; preds = %tailrecurse, %middle.block, %2
  %accumulator.tr.lcssa = phi i32 [ 0, %2 ], [ %11, %middle.block ], [ %15, %tailrecurse ]
  %12 = load i32, ptr %0, align 4, !tbaa !5
  %accumulator.ret.tr = add nsw i32 %12, %accumulator.tr.lcssa
  ret i32 %accumulator.ret.tr

tailrecurse:                                      ; preds = %tailrecurse.preheader14, %tailrecurse
  %indvars.iv = phi i64 [ %indvars.iv.next, %tailrecurse ], [ %indvars.iv.ph, %tailrecurse.preheader14 ]
  %accumulator.tr8 = phi i32 [ %15, %tailrecurse ], [ %accumulator.tr8.ph, %tailrecurse.preheader14 ]
  %13 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %15 = add nsw i32 %14, %accumulator.tr8
  %16 = icmp eq i64 %indvars.iv.next, 0
  br i1 %16, label %tailrecurse._crit_edge, label %tailrecurse, !llvm.loop !12
}

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


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