; LLVM IR from zeux/meshoptimizer :: src (indexcodec)

; 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: 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: mustprogress nounwind uwtable
define dso_local i32 @meshopt_decodeIndexVersion(ptr noundef %0, i64 noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i64, align 8
  %6 = alloca i8, align 1
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i64 %1, ptr %5, align 8, !tbaa !9
  %9 = load i64, ptr %5, align 8, !tbaa !9
  %10 = icmp ult i64 %9, 1
  br i1 %10, label %11, label %12

11:                                               ; preds = %2
  store i32 -1, ptr %3, align 4
  br label %37

12:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 1, ptr %6) #2
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = getelementptr inbounds i8, ptr %13, i64 0
  %15 = load i8, ptr %14, align 1, !tbaa !11
  store i8 %15, ptr %6, align 1, !tbaa !11
  %16 = load i8, ptr %6, align 1, !tbaa !11
  %17 = zext i8 %16 to i32
  %18 = and i32 %17, 240
  %19 = icmp ne i32 %18, 224
  br i1 %19, label %20, label %26

20:                                               ; preds = %12
  %21 = load i8, ptr %6, align 1, !tbaa !11
  %22 = zext i8 %21 to i32
  %23 = and i32 %22, 240
  %24 = icmp ne i32 %23, 208
  br i1 %24, label %25, label %26

25:                                               ; preds = %20
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %36

26:                                               ; preds = %20, %12
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %27 = load i8, ptr %6, align 1, !tbaa !11
  %28 = zext i8 %27 to i32
  %29 = and i32 %28, 15
  store i32 %29, ptr %8, align 4, !tbaa !12
  %30 = load i32, ptr %8, align 4, !tbaa !12
  %31 = icmp sgt i32 %30, 1
  br i1 %31, label %32, label %33

32:                                               ; preds = %26
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %35

33:                                               ; preds = %26
  %34 = load i32, ptr %8, align 4, !tbaa !12
  store i32 %34, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %35

35:                                               ; preds = %33, %32
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  br label %36

36:                                               ; preds = %35, %25
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #2
  br label %37

37:                                               ; preds = %36, %11
  %38 = load i32, ptr %3, align 4
  ret i32 %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"long", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = !{!13, !13, i64 0}
!13 = !{!"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: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: read) uwtable
define dso_local range(i32 -1, 2) i32 @meshopt_decodeIndexVersion(ptr nocapture noundef readonly %0, i64 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i64 %1, 0
  br i1 %3, label %10, label %4

4:                                                ; preds = %2
  %5 = load i8, ptr %0, align 1, !tbaa !5
  %trunc = and i8 %5, -16
  switch i8 %trunc, label %10 [
    i8 -32, label %6
    i8 -48, label %6
  ]

6:                                                ; preds = %4, %4
  %7 = and i8 %5, 15
  %8 = zext nneg i8 %7 to i32
  %9 = icmp ugt i8 %7, 1
  %. = select i1 %9, i32 -1, i32 %8
  br label %10

10:                                               ; preds = %6, %4, %2
  %.2 = phi i32 [ -1, %2 ], [ %., %6 ], [ -1, %4 ]
  ret i32 %.2
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn 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, !6, i64 0}
!6 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass