; LLVM IR from At-EC/At-RTOS :: source (k_malloc)

; 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"

%struct.free_head = type { ptr, i32 }

@g_free_list_head = external hidden global %struct.free_head, align 8

; 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 @k_free_size() #1 {
  %1 = alloca i32, align 4
  %2 = alloca ptr, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #2
  store i32 0, ptr %1, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #2
  %3 = load ptr, ptr @g_free_list_head, align 8, !tbaa !9
  store ptr %3, ptr %2, align 8, !tbaa !12
  br label %4

4:                                                ; preds = %7, %0
  %5 = load ptr, ptr %2, align 8, !tbaa !12
  %6 = icmp ne ptr %5, null
  br i1 %6, label %7, label %16

7:                                                ; preds = %4
  %8 = load ptr, ptr %2, align 8, !tbaa !12
  %9 = getelementptr inbounds %struct.free_head, ptr %8, i32 0, i32 1
  %10 = load i32, ptr %9, align 8, !tbaa !13
  %11 = load i32, ptr %1, align 4, !tbaa !5
  %12 = add i32 %11, %10
  store i32 %12, ptr %1, align 4, !tbaa !5
  %13 = load ptr, ptr %2, align 8, !tbaa !12
  %14 = getelementptr inbounds %struct.free_head, ptr %13, i32 0, i32 0
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  store ptr %15, ptr %2, align 8, !tbaa !12
  br label %4, !llvm.loop !14

16:                                               ; preds = %4
  %17 = load i32, ptr %1, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #2
  ret i32 %17
}

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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !11, i64 0}
!10 = !{!"free_head", !11, i64 0, !6, i64 8}
!11 = !{!"any pointer", !7, i64 0}
!12 = !{!11, !11, i64 0}
!13 = !{!10, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

%struct.free_head = type { ptr, i32 }

@g_free_list_head = external hidden local_unnamed_addr global %struct.free_head, align 8

; Function Attrs: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local i32 @k_free_size() local_unnamed_addr #0 {
  %.05 = load ptr, ptr @g_free_list_head, align 8, !tbaa !5
  %.not6 = icmp eq ptr %.05, null
  br i1 %.not6, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.08 = phi ptr [ %.0, %.lr.ph ], [ %.05, %0 ]
  %.047 = phi i32 [ %3, %.lr.ph ], [ 0, %0 ]
  %1 = getelementptr inbounds i8, ptr %.08, i64 8
  %2 = load i32, ptr %1, align 8, !tbaa !11
  %3 = add i32 %2, %.047
  %.0 = load ptr, ptr %.08, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph, %0
  %.04.lcssa = phi i32 [ 0, %0 ], [ %3, %.lr.ph ]
  ret i32 %.04.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, !7, i64 0}
!6 = !{!"free_head", !7, i64 0, !10, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"int", !8, i64 0}
!11 = !{!6, !10, i64 8}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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