; LLVM IR from AllenDowney/ExercisesInC :: exercises/ex07 (hash)

; 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 i32 @hash_string(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %6, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, 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 %7

7:                                                ; preds = %15, %1
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = load i32, ptr %5, align 4, !tbaa !9
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds i8, ptr %8, i64 %10
  %12 = load i8, ptr %11, align 1, !tbaa !11
  %13 = sext i8 %12 to i32
  %14 = icmp ne i32 %13, 0
  br i1 %14, label %15, label %26

15:                                               ; preds = %7
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = load i32, ptr %5, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds i8, ptr %16, i64 %18
  %20 = load i8, ptr %19, align 1, !tbaa !11
  %21 = sext i8 %20 to i32
  %22 = load i32, ptr %4, align 4, !tbaa !9
  %23 = add nsw i32 %22, %21
  store i32 %23, ptr %4, align 4, !tbaa !9
  %24 = load i32, ptr %5, align 4, !tbaa !9
  %25 = add nsw i32 %24, 1
  store i32 %25, ptr %5, align 4, !tbaa !9
  br label %7, !llvm.loop !12

26:                                               ; preds = %7
  %27 = load i32, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret i32 %27
}

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"

; Function Attrs: nofree norecurse nosync nounwind memory(argmem: read) uwtable
define dso_local i32 @hash_string(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = load i8, ptr %0, align 1, !tbaa !5
  %.not9 = icmp eq i8 %2, 0
  br i1 %.not9, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %1 ]
  %3 = phi i8 [ %7, %.lr.ph ], [ %2, %1 ]
  %.0710 = phi i32 [ %5, %.lr.ph ], [ 0, %1 ]
  %4 = sext i8 %3 to i32
  %5 = add nsw i32 %.0710, %4
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %6 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv.next
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %.not = icmp eq i8 %7, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.07.lcssa = phi i32 [ 0, %1 ], [ %5, %.lr.ph ]
  ret i32 %.07.lcssa
}

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: read) 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"}


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