; LLVM IR from gzc/CLRS :: C32-String-Matching (FA)

; 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: nounwind uwtable
define dso_local i32 @suffix(ptr noundef %0, i32 noundef %1, i32 noundef %2, i8 noundef signext %3) #0 {
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i8, align 1
  %10 = alloca i32, align 4
  %11 = alloca i32, align 4
  store ptr %0, ptr %6, align 8, !tbaa !5
  store i32 %1, ptr %7, align 4, !tbaa !9
  store i32 %2, ptr %8, align 4, !tbaa !9
  store i8 %3, ptr %9, align 1, !tbaa !11
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #2
  %12 = load ptr, ptr %6, align 8, !tbaa !5
  %13 = load i32, ptr %7, align 4, !tbaa !9
  %14 = sub nsw i32 %13, 1
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds i8, ptr %12, i64 %15
  %17 = load i8, ptr %16, align 1, !tbaa !11
  %18 = sext i8 %17 to i32
  %19 = load i8, ptr %9, align 1, !tbaa !11
  %20 = sext i8 %19 to i32
  %21 = icmp ne i32 %18, %20
  br i1 %21, label %22, label %23

22:                                               ; preds = %4
  store i32 0, ptr %5, align 4
  store i32 1, ptr %11, align 4
  br label %54

23:                                               ; preds = %4
  store i32 0, ptr %10, align 4, !tbaa !9
  br label %24

24:                                               ; preds = %50, %23
  %25 = load i32, ptr %10, align 4, !tbaa !9
  %26 = load i32, ptr %7, align 4, !tbaa !9
  %27 = sub nsw i32 %26, 1
  %28 = icmp slt i32 %25, %27
  br i1 %28, label %29, label %53

29:                                               ; preds = %24
  %30 = load ptr, ptr %6, align 8, !tbaa !5
  %31 = load i32, ptr %10, align 4, !tbaa !9
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds i8, ptr %30, i64 %32
  %34 = load i8, ptr %33, align 1, !tbaa !11
  %35 = sext i8 %34 to i32
  %36 = load ptr, ptr %6, align 8, !tbaa !5
  %37 = load i32, ptr %8, align 4, !tbaa !9
  %38 = load i32, ptr %7, align 4, !tbaa !9
  %39 = sub nsw i32 %37, %38
  %40 = load i32, ptr %10, align 4, !tbaa !9
  %41 = add nsw i32 %39, %40
  %42 = add nsw i32 %41, 1
  %43 = sext i32 %42 to i64
  %44 = getelementptr inbounds i8, ptr %36, i64 %43
  %45 = load i8, ptr %44, align 1, !tbaa !11
  %46 = sext i8 %45 to i32
  %47 = icmp ne i32 %35, %46
  br i1 %47, label %48, label %49

48:                                               ; preds = %29
  store i32 0, ptr %5, align 4
  store i32 1, ptr %11, align 4
  br label %54

49:                                               ; preds = %29
  br label %50

50:                                               ; preds = %49
  %51 = load i32, ptr %10, align 4, !tbaa !9
  %52 = add nsw i32 %51, 1
  store i32 %52, ptr %10, align 4, !tbaa !9
  br label %24, !llvm.loop !12

53:                                               ; preds = %24
  store i32 1, ptr %5, align 4
  store i32 1, ptr %11, align 4
  br label %54

54:                                               ; preds = %53, %48, %22
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #2
  %55 = load i32, ptr %5, align 4
  ret i32 %55
}

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

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

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 }

!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 range(i32 0, 2) i32 @suffix(ptr nocapture noundef readonly %0, i32 noundef %1, i32 noundef %2, i8 noundef signext %3) local_unnamed_addr #0 {
  %5 = add nsw i32 %1, -1
  %6 = sext i32 %5 to i64
  %7 = getelementptr inbounds i8, ptr %0, i64 %6
  %8 = load i8, ptr %7, align 1, !tbaa !5
  %.not = icmp eq i8 %8, %3
  br i1 %.not, label %.preheader, label %.loopexit

.preheader:                                       ; preds = %4
  %9 = icmp sgt i32 %1, 1
  br i1 %9, label %.lr.ph, label %.loopexit

.lr.ph:                                           ; preds = %.preheader
  %invariant.gep = getelementptr i8, ptr %0, i64 1
  %10 = sub i32 %2, %1
  %11 = sext i32 %10 to i64
  %wide.trip.count = zext nneg i32 %5 to i64
  %invariant.gep18 = getelementptr i8, ptr %invariant.gep, i64 %11
  br label %13

12:                                               ; preds = %13
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %.loopexit, label %13, !llvm.loop !8

13:                                               ; preds = %.lr.ph, %12
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %12 ]
  %14 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %15 = load i8, ptr %14, align 1, !tbaa !5
  %gep19 = getelementptr i8, ptr %invariant.gep18, i64 %indvars.iv
  %16 = load i8, ptr %gep19, align 1, !tbaa !5
  %.not13 = icmp eq i8 %15, %16
  br i1 %.not13, label %12, label %.loopexit

.loopexit:                                        ; preds = %13, %12, %.preheader, %4
  %.012 = phi i32 [ 0, %4 ], [ 1, %.preheader ], [ 0, %13 ], [ 1, %12 ]
  ret i32 %.012
}

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: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass