; LLVM IR from huhuanming/leetcode :: C/LeetCode (reverseString)

; 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 ptr @reverseString(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca i64, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  store ptr null, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #4
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  %7 = call i64 @strlen(ptr noundef %6) #5
  store i64 %7, ptr %4, align 8, !tbaa !9
  %8 = load i64, ptr %4, align 8, !tbaa !9
  %9 = add i64 1, %8
  %10 = mul i64 8, %9
  %11 = call noalias ptr @malloc(i64 noundef %10) #6
  store ptr %11, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  store i32 0, ptr %5, align 4, !tbaa !11
  br label %12

12:                                               ; preds = %32, %1
  %13 = load i32, ptr %5, align 4, !tbaa !11
  %14 = sext i32 %13 to i64
  %15 = load i64, ptr %4, align 8, !tbaa !9
  %16 = icmp ult i64 %14, %15
  br i1 %16, label %18, label %17

17:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  br label %35

18:                                               ; preds = %12
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = load i64, ptr %4, align 8, !tbaa !9
  %21 = getelementptr inbounds i8, ptr %19, i64 %20
  %22 = load i32, ptr %5, align 4, !tbaa !11
  %23 = sext i32 %22 to i64
  %24 = sub i64 0, %23
  %25 = getelementptr inbounds i8, ptr %21, i64 %24
  %26 = getelementptr inbounds i8, ptr %25, i64 -1
  %27 = load i8, ptr %26, align 1, !tbaa !13
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = load i32, ptr %5, align 4, !tbaa !11
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds i8, ptr %28, i64 %30
  store i8 %27, ptr %31, align 1, !tbaa !13
  br label %32

32:                                               ; preds = %18
  %33 = load i32, ptr %5, align 4, !tbaa !11
  %34 = add nsw i32 %33, 1
  store i32 %34, ptr %5, align 4, !tbaa !11
  br label %12, !llvm.loop !14

35:                                               ; preds = %17
  %36 = load ptr, ptr %3, align 8, !tbaa !5
  %37 = load i64, ptr %4, align 8, !tbaa !9
  %38 = getelementptr inbounds i8, ptr %36, i64 %37
  store i8 0, ptr %38, align 1, !tbaa !13
  %39 = load ptr, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  ret ptr %39
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #2

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #3

; 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 willreturn memory(read) "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 #3 = { nounwind allocsize(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 #4 = { nounwind }
attributes #5 = { nounwind willreturn memory(read) }
attributes #6 = { nounwind allocsize(0) }

!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 = !{!"long", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"int", !7, i64 0}
!13 = !{!7, !7, i64 0}
!14 = distinct !{!14, !15}
!15 = !{!"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 nounwind memory(write, argmem: read, inaccessiblemem: readwrite) uwtable
define dso_local noalias noundef ptr @reverseString(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #3
  %3 = shl i64 %2, 3
  %4 = add i64 %3, 8
  %5 = tail call noalias ptr @malloc(i64 noundef %4) #4
  %.not = icmp eq i64 %2, 0
  br i1 %.not, label %._crit_edge, label %iter.check

iter.check:                                       ; preds = %1
  %6 = getelementptr inbounds i8, ptr %0, i64 %2
  %invariant.gep = getelementptr i8, ptr %6, i64 -1
  %min.iters.check = icmp ult i64 %2, 8
  br i1 %min.iters.check, label %vec.epilog.scalar.ph.preheader, label %vector.main.loop.iter.check

vector.main.loop.iter.check:                      ; preds = %iter.check
  %min.iters.check16 = icmp ult i64 %2, 32
  br i1 %min.iters.check16, label %vec.epilog.ph, label %vector.ph

vector.ph:                                        ; preds = %vector.main.loop.iter.check
  %n.vec = and i64 %2, -32
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %7 = sub nsw i64 0, %index
  %8 = getelementptr i8, ptr %invariant.gep, i64 %7
  %9 = getelementptr i8, ptr %8, i64 -15
  %10 = getelementptr i8, ptr %8, i64 -31
  %wide.load = load <16 x i8>, ptr %9, align 1, !tbaa !5
  %reverse = shufflevector <16 x i8> %wide.load, <16 x i8> poison, <16 x i32> <i32 15, i32 14, i32 13, i32 12, i32 11, i32 10, i32 9, i32 8, i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
  %wide.load17 = load <16 x i8>, ptr %10, align 1, !tbaa !5
  %reverse18 = shufflevector <16 x i8> %wide.load17, <16 x i8> poison, <16 x i32> <i32 15, i32 14, i32 13, i32 12, i32 11, i32 10, i32 9, i32 8, i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
  %11 = getelementptr inbounds i8, ptr %5, i64 %index
  %12 = getelementptr inbounds i8, ptr %11, i64 16
  store <16 x i8> %reverse, ptr %11, align 1, !tbaa !5
  store <16 x i8> %reverse18, ptr %12, align 1, !tbaa !5
  %index.next = add nuw i64 %index, 32
  %13 = icmp eq i64 %index.next, %n.vec
  br i1 %13, label %middle.block, label %vector.body, !llvm.loop !8

middle.block:                                     ; preds = %vector.body
  %cmp.n = icmp eq i64 %2, %n.vec
  br i1 %cmp.n, label %._crit_edge, label %vec.epilog.iter.check

vec.epilog.iter.check:                            ; preds = %middle.block
  %n.vec.remaining = and i64 %2, 24
  %min.epilog.iters.check = icmp eq i64 %n.vec.remaining, 0
  br i1 %min.epilog.iters.check, label %vec.epilog.scalar.ph.preheader, label %vec.epilog.ph

vec.epilog.scalar.ph.preheader:                   ; preds = %vec.epilog.middle.block, %iter.check, %vec.epilog.iter.check
  %indvars.iv.ph = phi i64 [ 0, %iter.check ], [ %n.vec, %vec.epilog.iter.check ], [ %n.vec20, %vec.epilog.middle.block ]
  br label %vec.epilog.scalar.ph

vec.epilog.ph:                                    ; preds = %vector.main.loop.iter.check, %vec.epilog.iter.check
  %vec.epilog.resume.val = phi i64 [ %n.vec, %vec.epilog.iter.check ], [ 0, %vector.main.loop.iter.check ]
  %n.vec20 = and i64 %2, -8
  %invariant.gep26 = getelementptr i8, ptr %invariant.gep, i64 -7
  br label %vec.epilog.vector.body

vec.epilog.vector.body:                           ; preds = %vec.epilog.vector.body, %vec.epilog.ph
  %index21 = phi i64 [ %vec.epilog.resume.val, %vec.epilog.ph ], [ %index.next24, %vec.epilog.vector.body ]
  %14 = sub nsw i64 0, %index21
  %gep27 = getelementptr i8, ptr %invariant.gep26, i64 %14
  %wide.load22 = load <8 x i8>, ptr %gep27, align 1, !tbaa !5
  %reverse23 = shufflevector <8 x i8> %wide.load22, <8 x i8> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
  %15 = getelementptr inbounds i8, ptr %5, i64 %index21
  store <8 x i8> %reverse23, ptr %15, align 1, !tbaa !5
  %index.next24 = add nuw i64 %index21, 8
  %16 = icmp eq i64 %index.next24, %n.vec20
  br i1 %16, label %vec.epilog.middle.block, label %vec.epilog.vector.body, !llvm.loop !12

vec.epilog.middle.block:                          ; preds = %vec.epilog.vector.body
  %cmp.n25 = icmp eq i64 %2, %n.vec20
  br i1 %cmp.n25, label %._crit_edge, label %vec.epilog.scalar.ph.preheader

._crit_edge:                                      ; preds = %vec.epilog.scalar.ph, %middle.block, %vec.epilog.middle.block, %1
  %17 = getelementptr inbounds i8, ptr %5, i64 %2
  store i8 0, ptr %17, align 1, !tbaa !5
  ret ptr %5

vec.epilog.scalar.ph:                             ; preds = %vec.epilog.scalar.ph.preheader, %vec.epilog.scalar.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %vec.epilog.scalar.ph ], [ %indvars.iv.ph, %vec.epilog.scalar.ph.preheader ]
  %18 = sub nsw i64 0, %indvars.iv
  %gep = getelementptr i8, ptr %invariant.gep, i64 %18
  %19 = load i8, ptr %gep, align 1, !tbaa !5
  %20 = getelementptr inbounds i8, ptr %5, i64 %indvars.iv
  store i8 %19, ptr %20, align 1, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %2
  br i1 %exitcond.not, label %._crit_edge, label %vec.epilog.scalar.ph, !llvm.loop !13
}

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #1

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #2

attributes #0 = { nofree nounwind memory(write, argmem: read, inaccessiblemem: readwrite) 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 = { mustprogress nofree nounwind willreturn memory(argmem: read) "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 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 #3 = { nounwind willreturn memory(read) }
attributes #4 = { nounwind allocsize(0) }

!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, !10, !11}
!9 = !{!"llvm.loop.mustprogress"}
!10 = !{!"llvm.loop.isvectorized", i32 1}
!11 = !{!"llvm.loop.unroll.runtime.disable"}
!12 = distinct !{!12, !9, !10, !11}
!13 = distinct !{!13, !9, !11, !10}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass