; LLVM IR from gzc/CLRS :: C16-Greedy-Algorithms/huffman/BinaryStdIn.ll (ZN11BinaryStdIn7readIntEv)

; 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: mustprogress uwtable
declare dso_local noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528)) #1 align 2

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_ZN11BinaryStdIn7readIntEv(ptr noundef nonnull align 8 dereferenceable(528) %0) #1 align 2 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i8, align 1
  store ptr %0, ptr %2, align 8, !tbaa !5
  %6 = load ptr, ptr %2, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 0, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !9
  br label %7

7:                                                ; preds = %19, %1
  %8 = load i32, ptr %4, align 4, !tbaa !9
  %9 = icmp slt i32 %8, 4
  br i1 %9, label %11, label %10

10:                                               ; preds = %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %22

11:                                               ; preds = %7
  call void @llvm.lifetime.start.p0(i64 1, ptr %5) #2
  %12 = call noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528) %6)
  store i8 %12, ptr %5, align 1, !tbaa !11
  %13 = load i32, ptr %3, align 4, !tbaa !9
  %14 = shl i32 %13, 8
  store i32 %14, ptr %3, align 4, !tbaa !9
  %15 = load i8, ptr %5, align 1, !tbaa !11
  %16 = sext i8 %15 to i32
  %17 = load i32, ptr %3, align 4, !tbaa !9
  %18 = or i32 %17, %16
  store i32 %18, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 1, ptr %5) #2
  br label %19

19:                                               ; preds = %11
  %20 = load i32, ptr %4, align 4, !tbaa !9
  %21 = add nsw i32 %20, 1
  store i32 %21, ptr %4, align 4, !tbaa !9
  br label %7, !llvm.loop !12

22:                                               ; preds = %10
  %23 = load i32, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %23
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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++ 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"

; Function Attrs: mustprogress uwtable
declare dso_local noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_ZN11BinaryStdIn7readIntEv(ptr noundef nonnull align 8 dereferenceable(528) %0) local_unnamed_addr #0 align 2 {
  %2 = tail call noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528) %0)
  %3 = sext i8 %2 to i32
  %4 = tail call noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528) %0)
  %5 = sext i8 %4 to i32
  %6 = tail call noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528) %0)
  %7 = shl nsw i32 %3, 16
  %8 = shl nsw i32 %5, 8
  %9 = or i32 %7, %8
  %10 = sext i8 %6 to i32
  %11 = or i32 %9, %10
  %12 = tail call noundef signext i8 @_ZN11BinaryStdIn8readCharEv(ptr noundef nonnull align 8 dereferenceable(528) %0)
  %13 = shl nsw i32 %11, 8
  %14 = sext i8 %12 to i32
  %15 = or i32 %13, %14
  ret i32 %15
}

attributes #0 = { mustprogress 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)"}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LCSSAPass,LoopRotatePass,ReassociatePass,SCCPPass,SROAPass,SimplifyCFGPass,TailCallElimPass