; LLVM IR from mirohs/gc :: util (last_index_of_char)

; 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.String = type { ptr, 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 @last_index_of_char(ptr %0, i64 %1, i8 noundef signext %2) #1 {
  %4 = alloca i32, align 4
  %5 = alloca %struct.String, align 8
  %6 = alloca i8, align 1
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = getelementptr inbounds { ptr, i64 }, ptr %5, i32 0, i32 0
  store ptr %0, ptr %9, align 8
  %10 = getelementptr inbounds { ptr, i64 }, ptr %5, i32 0, i32 1
  store i64 %1, ptr %10, align 8
  store i8 %2, ptr %6, align 1, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %11 = getelementptr inbounds %struct.String, ptr %5, i32 0, i32 1
  %12 = load i32, ptr %11, align 8, !tbaa !8
  %13 = sub nsw i32 %12, 1
  store i32 %13, ptr %7, align 4, !tbaa !12
  br label %14

14:                                               ; preds = %32, %3
  %15 = load i32, ptr %7, align 4, !tbaa !12
  %16 = icmp sge i32 %15, 0
  br i1 %16, label %18, label %17

17:                                               ; preds = %14
  store i32 2, ptr %8, align 4
  br label %35

18:                                               ; preds = %14
  %19 = getelementptr inbounds %struct.String, ptr %5, i32 0, i32 0
  %20 = load ptr, ptr %19, align 8, !tbaa !13
  %21 = load i32, ptr %7, align 4, !tbaa !12
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds i8, ptr %20, i64 %22
  %24 = load i8, ptr %23, align 1, !tbaa !5
  %25 = sext i8 %24 to i32
  %26 = load i8, ptr %6, align 1, !tbaa !5
  %27 = sext i8 %26 to i32
  %28 = icmp eq i32 %25, %27
  br i1 %28, label %29, label %31

29:                                               ; preds = %18
  %30 = load i32, ptr %7, align 4, !tbaa !12
  store i32 %30, ptr %4, align 4
  store i32 1, ptr %8, align 4
  br label %35

31:                                               ; preds = %18
  br label %32

32:                                               ; preds = %31
  %33 = load i32, ptr %7, align 4, !tbaa !12
  %34 = add nsw i32 %33, -1
  store i32 %34, ptr %7, align 4, !tbaa !12
  br label %14, !llvm.loop !14

35:                                               ; preds = %29, %17
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  %36 = load i32, ptr %8, align 4
  switch i32 %36, label %40 [
    i32 2, label %37
    i32 1, label %38
  ]

37:                                               ; preds = %35
  store i32 -1, ptr %4, align 4
  br label %38

38:                                               ; preds = %37, %35
  %39 = load i32, ptr %4, align 4
  ret i32 %39

40:                                               ; preds = %35
  unreachable
}

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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = !{!9, !11, i64 8}
!9 = !{!"String", !10, i64 0, !11, i64 8, !11, i64 12}
!10 = !{!"any pointer", !6, i64 0}
!11 = !{!"int", !6, i64 0}
!12 = !{!11, !11, i64 0}
!13 = !{!9, !10, 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 norecurse nosync nounwind memory(argmem: read) uwtable
define dso_local range(i32 -2147483648, 2147483647) i32 @last_index_of_char(ptr nocapture readonly %0, i64 %1, i8 noundef signext %2) local_unnamed_addr #0 {
  %4 = and i64 %1, 4294967295
  br label %5

5:                                                ; preds = %8, %3
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ %4, %3 ]
  %6 = trunc nuw i64 %indvars.iv to i32
  %7 = icmp slt i32 %6, 1
  br i1 %7, label %.split.loop.exit10, label %8

8:                                                ; preds = %5
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %9 = and i64 %indvars.iv.next, 4294967295
  %10 = getelementptr inbounds i8, ptr %0, i64 %9
  %11 = load i8, ptr %10, align 1, !tbaa !5
  %12 = icmp eq i8 %11, %2
  br i1 %12, label %.split.loop.exit, label %5, !llvm.loop !8

.split.loop.exit:                                 ; preds = %8
  %indvars.le = trunc i64 %indvars.iv.next to i32
  br label %.split.loop.exit10

.split.loop.exit10:                               ; preds = %5, %.split.loop.exit
  %spec.select = phi i32 [ %indvars.le, %.split.loop.exit ], [ -1, %5 ]
  ret i32 %spec.select
}

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, !6, i64 0}
!6 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass