; LLVM IR from ubaldot/defrecs :: stm32f4x/ADC_Readings/Drivers/CMSIS/DSP/Source/StatisticsFunctions (q31)

; 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 void @arm_max_no_idx_q31(ptr noundef %0, i32 noundef %1, ptr noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store ptr %2, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #2
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = getelementptr inbounds i32, ptr %10, i32 1
  store ptr %11, ptr %4, align 8, !tbaa !5
  %12 = load i32, ptr %10, align 4, !tbaa !9
  store i32 %12, ptr %8, align 4, !tbaa !9
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = sub i32 %13, 1
  store i32 %14, ptr %9, align 4, !tbaa !9
  br label %15

15:                                               ; preds = %27, %3
  %16 = load i32, ptr %9, align 4, !tbaa !9
  %17 = icmp ugt i32 %16, 0
  br i1 %17, label %18, label %30

18:                                               ; preds = %15
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = getelementptr inbounds i32, ptr %19, i32 1
  store ptr %20, ptr %4, align 8, !tbaa !5
  %21 = load i32, ptr %19, align 4, !tbaa !9
  store i32 %21, ptr %7, align 4, !tbaa !9
  %22 = load i32, ptr %8, align 4, !tbaa !9
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = icmp slt i32 %22, %23
  br i1 %24, label %25, label %27

25:                                               ; preds = %18
  %26 = load i32, ptr %7, align 4, !tbaa !9
  store i32 %26, ptr %8, align 4, !tbaa !9
  br label %27

27:                                               ; preds = %25, %18
  %28 = load i32, ptr %9, align 4, !tbaa !9
  %29 = add i32 %28, -1
  store i32 %29, ptr %9, align 4, !tbaa !9
  br label %15, !llvm.loop !11

30:                                               ; preds = %15
  %31 = load i32, ptr %8, align 4, !tbaa !9
  %32 = load ptr, ptr %6, align 8, !tbaa !5
  store i32 %31, ptr %32, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  ret void
}

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

; 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 }

!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"

; Function Attrs: nofree norecurse nosync nounwind memory(read, argmem: readwrite, inaccessiblemem: none) uwtable
define dso_local void @arm_max_no_idx_q31(ptr nocapture noundef readonly %0, i32 noundef %1, ptr nocapture noundef writeonly %2) local_unnamed_addr #0 {
  %4 = load i32, ptr %0, align 4, !tbaa !5
  %.012 = add i32 %1, -1
  %.not13 = icmp eq i32 %.012, 0
  br i1 %.not13, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %3
  %5 = zext i32 %.012 to i64
  %min.iters.check = icmp ult i32 %.012, 8
  br i1 %min.iters.check, label %.lr.ph.preheader22, label %vector.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %5, 4294967288
  %.cast = trunc nuw i64 %n.vec to i32
  %ind.end = sub i32 %.012, %.cast
  %6 = shl nuw nsw i64 %n.vec, 2
  %ind.end17 = getelementptr i8, ptr %0, i64 %6
  %minmax.ident.splatinsert = insertelement <4 x i32> poison, i32 %4, i64 0
  %minmax.ident.splat = shufflevector <4 x i32> %minmax.ident.splatinsert, <4 x i32> poison, <4 x i32> zeroinitializer
  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> [ %minmax.ident.splat, %vector.ph ], [ %9, %vector.body ]
  %vec.phi19 = phi <4 x i32> [ %minmax.ident.splat, %vector.ph ], [ %10, %vector.body ]
  %offset.idx = shl i64 %index, 2
  %next.gep = getelementptr i8, ptr %0, i64 %offset.idx
  %7 = getelementptr inbounds i8, ptr %next.gep, i64 4
  %8 = getelementptr inbounds i8, ptr %next.gep, i64 20
  %wide.load = load <4 x i32>, ptr %7, align 4, !tbaa !5
  %wide.load21 = load <4 x i32>, ptr %8, align 4, !tbaa !5
  %9 = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %vec.phi, <4 x i32> %wide.load)
  %10 = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %vec.phi19, <4 x i32> %wide.load21)
  %index.next = add nuw i64 %index, 8
  %11 = icmp eq i64 %index.next, %n.vec
  br i1 %11, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %rdx.minmax = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %9, <4 x i32> %10)
  %12 = tail call i32 @llvm.vector.reduce.smax.v4i32(<4 x i32> %rdx.minmax)
  %cmp.n = icmp eq i64 %n.vec, %5
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader22

.lr.ph.preheader22:                               ; preds = %middle.block, %.lr.ph.preheader
  %.016.ph = phi i32 [ %.012, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  %.0915.ph = phi i32 [ %4, %.lr.ph.preheader ], [ %12, %middle.block ]
  %.pn14.ph = phi ptr [ %0, %.lr.ph.preheader ], [ %ind.end17, %middle.block ]
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader22, %.lr.ph
  %.016 = phi i32 [ %.0, %.lr.ph ], [ %.016.ph, %.lr.ph.preheader22 ]
  %.0915 = phi i32 [ %spec.select, %.lr.ph ], [ %.0915.ph, %.lr.ph.preheader22 ]
  %.pn14 = phi ptr [ %.010, %.lr.ph ], [ %.pn14.ph, %.lr.ph.preheader22 ]
  %.010 = getelementptr inbounds i8, ptr %.pn14, i64 4
  %13 = load i32, ptr %.010, align 4, !tbaa !5
  %spec.select = tail call i32 @llvm.smax.i32(i32 %.0915, i32 %13)
  %.0 = add i32 %.016, -1
  %.not = icmp eq i32 %.0, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %3
  %.09.lcssa = phi i32 [ %4, %3 ], [ %12, %middle.block ], [ %spec.select, %.lr.ph ]
  store i32 %.09.lcssa, ptr %2, align 4, !tbaa !5
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare <4 x i32> @llvm.smax.v4i32(<4 x i32>, <4 x i32>) #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.vector.reduce.smax.v4i32(<4 x i32>) #1

attributes #0 = { nofree norecurse nosync nounwind memory(read, argmem: readwrite, inaccessiblemem: none) 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, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10, !12, !11}


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