; LLVM IR from modlfo/AudioEngine :: AudioEngine/JuceLibraryCode/modules/juce_audio_formats/codecs/flac/libFLAC/crc_9c19bb46_FLAC (crc16)

; 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"

@FLAC__crc16_table = external dso_local constant [256 x i32], align 16

; 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 @FLAC__crc16(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !9
  br label %6

6:                                                ; preds = %10, %2
  %7 = load i32, ptr %4, align 4, !tbaa !9
  %8 = add i32 %7, -1
  store i32 %8, ptr %4, align 4, !tbaa !9
  %9 = icmp ne i32 %7, 0
  br i1 %9, label %10, label %25

10:                                               ; preds = %6
  %11 = load i32, ptr %5, align 4, !tbaa !9
  %12 = shl i32 %11, 8
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = lshr i32 %13, 8
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds i8, ptr %15, i32 1
  store ptr %16, ptr %3, align 8, !tbaa !5
  %17 = load i8, ptr %15, align 1, !tbaa !11
  %18 = zext i8 %17 to i32
  %19 = xor i32 %14, %18
  %20 = zext i32 %19 to i64
  %21 = getelementptr inbounds [256 x i32], ptr @FLAC__crc16_table, i64 0, i64 %20
  %22 = load i32, ptr %21, align 4, !tbaa !9
  %23 = xor i32 %12, %22
  %24 = and i32 %23, 65535
  store i32 %24, ptr %5, align 4, !tbaa !9
  br label %6, !llvm.loop !12

25:                                               ; preds = %6
  %26 = load i32, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %26
}

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 = !{!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"

@FLAC__crc16_table = external dso_local local_unnamed_addr constant [256 x i32], align 16

; Function Attrs: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local range(i32 0, 65536) i32 @FLAC__crc16(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not6 = icmp eq i32 %1, 0
  br i1 %.not6, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %xtraiter = and i32 %1, 1
  %3 = icmp eq i32 %1, 1
  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 i32 %1, -2
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.09 = phi i32 [ 0, %.lr.ph.preheader.new ], [ %25, %.lr.ph ]
  %.057 = phi ptr [ %0, %.lr.ph.preheader.new ], [ %17, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %4 = shl nuw nsw i32 %.09, 8
  %5 = lshr i32 %.09, 8
  %6 = getelementptr inbounds i8, ptr %.057, i64 1
  %7 = load i8, ptr %.057, align 1, !tbaa !5
  %8 = zext i8 %7 to i32
  %9 = xor i32 %5, %8
  %10 = zext nneg i32 %9 to i64
  %11 = getelementptr inbounds [256 x i32], ptr @FLAC__crc16_table, i64 0, i64 %10
  %12 = load i32, ptr %11, align 4, !tbaa !8
  %13 = xor i32 %12, %4
  %14 = and i32 %13, 65535
  %15 = shl nuw nsw i32 %14, 8
  %16 = lshr i32 %14, 8
  %17 = getelementptr inbounds i8, ptr %.057, i64 2
  %18 = load i8, ptr %6, align 1, !tbaa !5
  %19 = zext i8 %18 to i32
  %20 = xor i32 %16, %19
  %21 = zext nneg i32 %20 to i64
  %22 = getelementptr inbounds [256 x i32], ptr @FLAC__crc16_table, i64 0, i64 %21
  %23 = load i32, ptr %22, align 4, !tbaa !8
  %24 = xor i32 %23, %15
  %25 = and i32 %24, 65535
  %niter.next.1 = add i32 %niter, 2
  %niter.ncmp.1 = icmp eq i32 %niter.next.1, %unroll_iter
  br i1 %niter.ncmp.1, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !10

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i32 [ poison, %.lr.ph.preheader ], [ %25, %.lr.ph ]
  %.09.unr = phi i32 [ 0, %.lr.ph.preheader ], [ %25, %.lr.ph ]
  %.057.unr = phi ptr [ %0, %.lr.ph.preheader ], [ %17, %.lr.ph ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa
  %26 = shl nuw nsw i32 %.09.unr, 8
  %27 = lshr i32 %.09.unr, 8
  %28 = load i8, ptr %.057.unr, align 1, !tbaa !5
  %29 = zext i8 %28 to i32
  %30 = xor i32 %27, %29
  %31 = zext nneg i32 %30 to i64
  %32 = getelementptr inbounds [256 x i32], ptr @FLAC__crc16_table, i64 0, i64 %31
  %33 = load i32, ptr %32, align 4, !tbaa !8
  %34 = xor i32 %33, %26
  %35 = and i32 %34, 65535
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.0.lcssa = phi i32 [ 0, %2 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %35, %.lr.ph.epil ]
  ret i32 %.0.lcssa
}

attributes #0 = { nofree norecurse nosync nounwind memory(read, 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 = !{!9, !9, i64 0}
!9 = !{!"int", !6, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass