; LLVM IR from InsightSoftwareConsortium/ITK :: Modules/ThirdParty/MINC/src/libminc/nifti (nifti1_io)

; 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: nounwind uwtable
define dso_local void @nifti_swap_2bytes(i64 noundef %0, ptr noundef %1) #1 {
  %3 = alloca i64, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i64, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca i8, align 1
  store i64 %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %9 = load ptr, ptr %4, align 8, !tbaa !9
  store ptr %9, ptr %6, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.start.p0(i64 1, ptr %8) #2
  store i64 0, ptr %5, align 8, !tbaa !5
  br label %10

10:                                               ; preds = %26, %2
  %11 = load i64, ptr %5, align 8, !tbaa !5
  %12 = load i64, ptr %3, align 8, !tbaa !5
  %13 = icmp ult i64 %11, %12
  br i1 %13, label %14, label %29

14:                                               ; preds = %10
  %15 = load ptr, ptr %6, align 8, !tbaa !9
  %16 = getelementptr inbounds i8, ptr %15, i64 1
  store ptr %16, ptr %7, align 8, !tbaa !9
  %17 = load ptr, ptr %6, align 8, !tbaa !9
  %18 = load i8, ptr %17, align 1, !tbaa !11
  store i8 %18, ptr %8, align 1, !tbaa !11
  %19 = load ptr, ptr %7, align 8, !tbaa !9
  %20 = load i8, ptr %19, align 1, !tbaa !11
  %21 = load ptr, ptr %6, align 8, !tbaa !9
  store i8 %20, ptr %21, align 1, !tbaa !11
  %22 = load i8, ptr %8, align 1, !tbaa !11
  %23 = load ptr, ptr %7, align 8, !tbaa !9
  store i8 %22, ptr %23, align 1, !tbaa !11
  %24 = load ptr, ptr %6, align 8, !tbaa !9
  %25 = getelementptr inbounds i8, ptr %24, i64 2
  store ptr %25, ptr %6, align 8, !tbaa !9
  br label %26

26:                                               ; preds = %14
  %27 = load i64, ptr %5, align 8, !tbaa !5
  %28 = add i64 %27, 1
  store i64 %28, ptr %5, align 8, !tbaa !5
  br label %10, !llvm.loop !12

29:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 1, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #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 = !{!"long", !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 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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(readwrite, inaccessiblemem: none) uwtable
define dso_local void @nifti_swap_2bytes(i64 noundef %0, ptr nocapture noundef %1) local_unnamed_addr #0 {
  %.not = icmp eq i64 %0, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %xtraiter = and i64 %0, 3
  %3 = icmp ult i64 %0, 4
  br i1 %3, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i64 %0, -4
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.01011 = phi ptr [ %1, %.lr.ph.preheader.new ], [ %19, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.3, %.lr.ph ]
  %4 = getelementptr inbounds i8, ptr %.01011, i64 1
  %5 = load i8, ptr %.01011, align 1, !tbaa !5
  %6 = load i8, ptr %4, align 1, !tbaa !5
  store i8 %6, ptr %.01011, align 1, !tbaa !5
  store i8 %5, ptr %4, align 1, !tbaa !5
  %7 = getelementptr inbounds i8, ptr %.01011, i64 2
  %8 = getelementptr inbounds i8, ptr %.01011, i64 3
  %9 = load i8, ptr %7, align 1, !tbaa !5
  %10 = load i8, ptr %8, align 1, !tbaa !5
  store i8 %10, ptr %7, align 1, !tbaa !5
  store i8 %9, ptr %8, align 1, !tbaa !5
  %11 = getelementptr inbounds i8, ptr %.01011, i64 4
  %12 = getelementptr inbounds i8, ptr %.01011, i64 5
  %13 = load i8, ptr %11, align 1, !tbaa !5
  %14 = load i8, ptr %12, align 1, !tbaa !5
  store i8 %14, ptr %11, align 1, !tbaa !5
  store i8 %13, ptr %12, align 1, !tbaa !5
  %15 = getelementptr inbounds i8, ptr %.01011, i64 6
  %16 = getelementptr inbounds i8, ptr %.01011, i64 7
  %17 = load i8, ptr %15, align 1, !tbaa !5
  %18 = load i8, ptr %16, align 1, !tbaa !5
  store i8 %18, ptr %15, align 1, !tbaa !5
  store i8 %17, ptr %16, align 1, !tbaa !5
  %19 = getelementptr inbounds i8, ptr %.01011, i64 8
  %niter.next.3 = add i64 %niter, 4
  %niter.ncmp.3 = icmp eq i64 %niter.next.3, %unroll_iter
  br i1 %niter.ncmp.3, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !8

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.01011.unr = phi ptr [ %1, %.lr.ph.preheader ], [ %19, %.lr.ph ]
  %lcmp.mod.not = icmp eq i64 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil
  %.01011.epil = phi ptr [ %23, %.lr.ph.epil ], [ %.01011.unr, %._crit_edge.loopexit.unr-lcssa ]
  %epil.iter = phi i64 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %._crit_edge.loopexit.unr-lcssa ]
  %20 = getelementptr inbounds i8, ptr %.01011.epil, i64 1
  %21 = load i8, ptr %.01011.epil, align 1, !tbaa !5
  %22 = load i8, ptr %20, align 1, !tbaa !5
  store i8 %22, ptr %.01011.epil, align 1, !tbaa !5
  store i8 %21, ptr %20, align 1, !tbaa !5
  %23 = getelementptr inbounds i8, ptr %.01011.epil, i64 2
  %epil.iter.next = add i64 %epil.iter, 1
  %epil.iter.cmp.not = icmp eq i64 %epil.iter.next, %xtraiter
  br i1 %epil.iter.cmp.not, label %._crit_edge, label %.lr.ph.epil, !llvm.loop !10

._crit_edge:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil, %2
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(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" }

!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"}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.unroll.disable"}


; Effective O3 passes: CorrelatedValuePropagationPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass