; LLVM IR from bartobri/data-structures-c :: symbol-table/array-key-index (st)

; 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"

@st = external hidden global ptr, align 8
@M = external hidden global i32, align 4

; 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 void @STsort(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 0, ptr %3, align 4, !tbaa !9
  br label %4

4:                                                ; preds = %23, %1
  %5 = load i32, ptr %3, align 4, !tbaa !9
  %6 = load i32, ptr @M, align 4, !tbaa !9
  %7 = icmp slt i32 %5, %6
  br i1 %7, label %8, label %26

8:                                                ; preds = %4
  %9 = load ptr, ptr @st, align 8, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !9
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds ptr, ptr %9, i64 %11
  %13 = load ptr, ptr %12, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %15, label %22

15:                                               ; preds = %8
  %16 = load ptr, ptr %2, align 8, !tbaa !5
  %17 = load ptr, ptr @st, align 8, !tbaa !5
  %18 = load i32, ptr %3, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds ptr, ptr %17, i64 %19
  %21 = load ptr, ptr %20, align 8, !tbaa !5
  call void %16(ptr noundef %21)
  br label %22

22:                                               ; preds = %15, %8
  br label %23

23:                                               ; preds = %22
  %24 = load i32, ptr %3, align 4, !tbaa !9
  %25 = add nsw i32 %24, 1
  store i32 %25, ptr %3, align 4, !tbaa !9
  br label %4, !llvm.loop !11

26:                                               ; preds = %4
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret void
}

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 = !{!"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 = distinct !{!11, !12}
!12 = !{!"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"

@st = external hidden local_unnamed_addr global ptr, align 8
@M = external hidden local_unnamed_addr global i32, align 4

; Function Attrs: nounwind uwtable
define dso_local void @STsort(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @M, align 4, !tbaa !5
  %3 = icmp sgt i32 %2, 0
  br i1 %3, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %.pre7 = load ptr, ptr @st, align 8, !tbaa !9
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %9
  %4 = phi i32 [ %2, %.lr.ph.preheader ], [ %10, %9 ]
  %5 = phi ptr [ %.pre7, %.lr.ph.preheader ], [ %11, %9 ]
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %9 ]
  %6 = getelementptr inbounds ptr, ptr %5, i64 %indvars.iv
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %9, label %8

8:                                                ; preds = %.lr.ph
  tail call void %0(ptr noundef nonnull %7) #1
  %.pre = load ptr, ptr @st, align 8, !tbaa !9
  %.pre8 = load i32, ptr @M, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %.lr.ph, %8
  %10 = phi i32 [ %4, %.lr.ph ], [ %.pre8, %8 ]
  %11 = phi ptr [ %5, %.lr.ph ], [ %.pre, %8 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %12 = sext i32 %10 to i64
  %13 = icmp slt i64 %indvars.iv.next, %12
  br i1 %13, label %.lr.ph, label %._crit_edge, !llvm.loop !11

._crit_edge:                                      ; preds = %9, %1
  ret void
}

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 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass