; LLVM IR from AllenDowney/ExercisesInC :: exercises/ex04 (bigbadint)

; 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"

@.str.4 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.17 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local ptr @reverse_string(ptr noundef) #0

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

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #2

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

declare i32 @printf(ptr noundef, ...) #3

; Function Attrs: nounwind uwtable
define dso_local void @test_reverse_string_again() #0 {
  %1 = alloca ptr, align 8
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #5
  %4 = call noalias ptr @malloc(i64 noundef 400) #6
  store ptr %4, ptr %1, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  store i32 0, ptr %2, align 4, !tbaa !9
  br label %5

5:                                                ; preds = %16, %0
  %6 = load i32, ptr %2, align 4, !tbaa !9
  %7 = icmp slt i32 %6, 400
  br i1 %7, label %9, label %8

8:                                                ; preds = %5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  br label %19

9:                                                ; preds = %5
  %10 = load i32, ptr %2, align 4, !tbaa !9
  %11 = trunc i32 %10 to i8
  %12 = load ptr, ptr %1, align 8, !tbaa !5
  %13 = load i32, ptr %2, align 4, !tbaa !9
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds i8, ptr %12, i64 %14
  store i8 %11, ptr %15, align 1, !tbaa !11
  br label %16

16:                                               ; preds = %9
  %17 = load i32, ptr %2, align 4, !tbaa !9
  %18 = add nsw i32 %17, 1
  store i32 %18, ptr %2, align 4, !tbaa !9
  br label %5, !llvm.loop !12

19:                                               ; preds = %8
  %20 = load ptr, ptr %1, align 8, !tbaa !5
  call void @free(ptr noundef %20) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #5
  %21 = call ptr @reverse_string(ptr noundef @.str.4)
  store ptr %21, ptr %3, align 8, !tbaa !5
  %22 = load ptr, ptr %3, align 8, !tbaa !5
  %23 = call i32 (ptr, ...) @printf(ptr noundef @.str.17, ptr noundef %22)
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #5
  ret void
}

; Function Attrs: nounwind
declare void @free(ptr noundef) #4

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 allocsize(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 #3 = { "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 #4 = { nounwind "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 #5 = { nounwind }
attributes #6 = { nounwind allocsize(0) }

!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"

@.str.4 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.17 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local ptr @reverse_string(ptr noundef) local_unnamed_addr #0

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local void @test_reverse_string_again() local_unnamed_addr #0 {
  %1 = tail call ptr @reverse_string(ptr noundef nonnull @.str.4)
  %2 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.17, ptr noundef %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 = { nofree nounwind "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,LoopRotatePass,SROAPass,SimplifyCFGPass,TailCallElimPass