[CSSPGO] Even flow distribution

Differential Revision: https://reviews.llvm.org/D118640
This commit is contained in:
spupyrev 2022-01-31 09:59:45 -08:00
parent 396865576f
commit f2ade65fb2
5 changed files with 508 additions and 34 deletions

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@ -15,15 +15,27 @@
#include "llvm/Transforms/Utils/SampleProfileInference.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include <queue>
#include <set>
#include <stack>
using namespace llvm;
#define DEBUG_TYPE "sample-profile-inference"
namespace {
static cl::opt<bool> SampleProfileEvenCountDistribution(
"sample-profile-even-count-distribution", cl::init(true), cl::Hidden,
cl::ZeroOrMore,
cl::desc("Try to evenly distribute counts when there are multiple equally "
"likely options."));
static cl::opt<unsigned> SampleProfileMaxDfsCalls(
"sample-profile-max-dfs-calls", cl::init(10), cl::Hidden, cl::ZeroOrMore,
cl::desc("Maximum number of dfs iterations for even count distribution."));
/// A value indicating an infinite flow/capacity/weight of a block/edge.
/// Not using numeric_limits<int64_t>::max(), as the values can be summed up
/// during the execution.
@ -52,16 +64,16 @@ public:
Nodes = std::vector<Node>(NodeCount);
Edges = std::vector<std::vector<Edge>>(NodeCount, std::vector<Edge>());
if (SampleProfileEvenCountDistribution)
AugmentingEdges =
std::vector<std::vector<Edge *>>(NodeCount, std::vector<Edge *>());
}
// Run the algorithm.
int64_t run() {
// Find an augmenting path and update the flow along the path
size_t AugmentationIters = 0;
while (findAugmentingPath()) {
augmentFlowAlongPath();
AugmentationIters++;
}
// Iteratively find an augmentation path/dag in the network and send the
// flow along its edges
size_t AugmentationIters = applyFlowAugmentation();
// Compute the total flow and its cost
int64_t TotalCost = 0;
@ -79,6 +91,7 @@ public:
<< " iterations with " << TotalFlow << " total flow"
<< " of " << TotalCost << " cost\n");
(void)TotalFlow;
(void)AugmentationIters;
return TotalCost;
}
@ -148,6 +161,55 @@ public:
static constexpr int64_t AuxCostUnlikely = ((int64_t)1) << 30;
private:
/// Iteratively find an augmentation path/dag in the network and send the
/// flow along its edges. The method returns the number of applied iterations.
size_t applyFlowAugmentation() {
size_t AugmentationIters = 0;
while (findAugmentingPath()) {
uint64_t PathCapacity = computeAugmentingPathCapacity();
while (PathCapacity > 0) {
bool Progress = false;
if (SampleProfileEvenCountDistribution) {
// Identify node/edge candidates for augmentation
identifyShortestEdges(PathCapacity);
// Find an augmenting DAG
auto AugmentingOrder = findAugmentingDAG();
// Apply the DAG augmentation
Progress = augmentFlowAlongDAG(AugmentingOrder);
PathCapacity = computeAugmentingPathCapacity();
}
if (!Progress) {
augmentFlowAlongPath(PathCapacity);
PathCapacity = 0;
}
AugmentationIters++;
}
}
return AugmentationIters;
}
/// Compute the capacity of the cannonical augmenting path. If the path is
/// saturated (that is, no flow can be sent along the path), then return 0.
uint64_t computeAugmentingPathCapacity() {
uint64_t PathCapacity = INF;
uint64_t Now = Target;
while (Now != Source) {
uint64_t Pred = Nodes[Now].ParentNode;
auto &Edge = Edges[Pred][Nodes[Now].ParentEdgeIndex];
assert(Edge.Capacity >= Edge.Flow && "incorrect edge flow");
uint64_t EdgeCapacity = uint64_t(Edge.Capacity - Edge.Flow);
PathCapacity = std::min(PathCapacity, EdgeCapacity);
Now = Pred;
}
return PathCapacity;
}
/// Check for existence of an augmenting path with a positive capacity.
bool findAugmentingPath() {
// Initialize data structures
@ -180,7 +242,7 @@ private:
// from Source to Target; it follows from inequalities
// Dist[Source, Target] >= Dist[Source, V] + Dist[V, Target]
// >= Dist[Source, V]
if (Nodes[Target].Distance == 0)
if (!SampleProfileEvenCountDistribution && Nodes[Target].Distance == 0)
break;
if (Nodes[Src].Distance > Nodes[Target].Distance)
continue;
@ -210,21 +272,9 @@ private:
}
/// Update the current flow along the augmenting path.
void augmentFlowAlongPath() {
// Find path capacity
int64_t PathCapacity = INF;
uint64_t Now = Target;
while (Now != Source) {
uint64_t Pred = Nodes[Now].ParentNode;
auto &Edge = Edges[Pred][Nodes[Now].ParentEdgeIndex];
PathCapacity = std::min(PathCapacity, Edge.Capacity - Edge.Flow);
Now = Pred;
}
void augmentFlowAlongPath(uint64_t PathCapacity) {
assert(PathCapacity > 0 && "found an incorrect augmenting path");
// Update the flow along the path
Now = Target;
uint64_t Now = Target;
while (Now != Source) {
uint64_t Pred = Nodes[Now].ParentNode;
auto &Edge = Edges[Pred][Nodes[Now].ParentEdgeIndex];
@ -237,6 +287,220 @@ private:
}
}
/// Find an Augmenting DAG order using a modified version of DFS in which we
/// can visit a node multiple times. In the DFS search, when scanning each
/// edge out of a node, continue search at Edge.Dst endpoint if it has not
/// been discovered yet and its NumCalls < MaxDfsCalls. The algorithm
/// runs in O(MaxDfsCalls * |Edges| + |Nodes|) time.
/// It returns an Augmenting Order (Taken nodes in decreasing Finish time)
/// that starts with Source and ends with Target.
std::vector<uint64_t> findAugmentingDAG() {
// We use a stack based implemenation of DFS to avoid recursion.
// Defining DFS data structures:
// A pair (NodeIdx, EdgeIdx) at the top of the Stack denotes that
// - we are currently visiting Nodes[NodeIdx] and
// - the next edge to scan is Edges[NodeIdx][EdgeIdx]
typedef std::pair<uint64_t, uint64_t> StackItemType;
std::stack<StackItemType> Stack;
std::vector<uint64_t> AugmentingOrder;
// Phase 0: Initialize Node attributes and Time for DFS run
for (auto &Node : Nodes) {
Node.Discovery = 0;
Node.Finish = 0;
Node.NumCalls = 0;
Node.Taken = false;
}
uint64_t Time = 0;
// Mark Target as Taken
// Taken attribute will be propagated backwards from Target towards Source
Nodes[Target].Taken = true;
// Phase 1: Start DFS traversal from Source
Stack.emplace(Source, 0);
Nodes[Source].Discovery = ++Time;
while (!Stack.empty()) {
auto NodeIdx = Stack.top().first;
auto EdgeIdx = Stack.top().second;
// If we haven't scanned all edges out of NodeIdx, continue scanning
if (EdgeIdx < Edges[NodeIdx].size()) {
auto &Edge = Edges[NodeIdx][EdgeIdx];
auto &Dst = Nodes[Edge.Dst];
Stack.top().second++;
if (Edge.OnShortestPath) {
// If we haven't seen Edge.Dst so far, continue DFS search there
if (Dst.Discovery == 0 && Dst.NumCalls < SampleProfileMaxDfsCalls) {
Dst.Discovery = ++Time;
Stack.emplace(Edge.Dst, 0);
Dst.NumCalls++;
} else if (Dst.Taken && Dst.Finish != 0) {
// Else, if Edge.Dst already have a path to Target, so that NodeIdx
Nodes[NodeIdx].Taken = true;
}
}
} else {
// If we are done scanning all edge out of NodeIdx
Stack.pop();
// If we haven't found a path from NodeIdx to Target, forget about it
if (!Nodes[NodeIdx].Taken) {
Nodes[NodeIdx].Discovery = 0;
} else {
// If we have found a path from NodeIdx to Target, then finish NodeIdx
// and propagate Taken flag to DFS parent unless at the Source
Nodes[NodeIdx].Finish = ++Time;
// NodeIdx == Source if and only if the stack is empty
if (NodeIdx != Source) {
assert(!Stack.empty() && "empty stack while running dfs");
Nodes[Stack.top().first].Taken = true;
}
AugmentingOrder.push_back(NodeIdx);
}
}
}
// Nodes are collected decreasing Finish time, so the order is reversed
std::reverse(AugmentingOrder.begin(), AugmentingOrder.end());
// Phase 2: Extract all forward (DAG) edges and fill in AugmentingEdges
for (size_t Src : AugmentingOrder) {
AugmentingEdges[Src].clear();
for (auto &Edge : Edges[Src]) {
uint64_t Dst = Edge.Dst;
if (Edge.OnShortestPath && Nodes[Src].Taken && Nodes[Dst].Taken &&
Nodes[Dst].Finish < Nodes[Src].Finish) {
AugmentingEdges[Src].push_back(&Edge);
}
}
assert((Src == Target || !AugmentingEdges[Src].empty()) &&
"incorrectly constructed augmenting edges");
}
return AugmentingOrder;
}
/// Update the current flow along the given (acyclic) subgraph specified by
/// the vertex order, AugmentingOrder. The objective is to send as much flow
/// as possible while evenly distributing flow among successors of each node.
/// After the update at least one edge is saturated.
bool augmentFlowAlongDAG(const std::vector<uint64_t> &AugmentingOrder) {
// Phase 0: Initialization
for (uint64_t Src : AugmentingOrder) {
Nodes[Src].FracFlow = 0;
Nodes[Src].IntFlow = 0;
for (auto &Edge : AugmentingEdges[Src]) {
Edge->AugmentedFlow = 0;
}
}
// Phase 1: Send a unit of fractional flow along the DAG
uint64_t MaxFlowAmount = INF;
Nodes[Source].FracFlow = 1.0;
for (uint64_t Src : AugmentingOrder) {
assert((Src == Target || Nodes[Src].FracFlow > 0.0) &&
"incorrectly computed fractional flow");
// Distribute flow evenly among successors of Src
uint64_t Degree = AugmentingEdges[Src].size();
for (auto &Edge : AugmentingEdges[Src]) {
double EdgeFlow = Nodes[Src].FracFlow / Degree;
Nodes[Edge->Dst].FracFlow += EdgeFlow;
if (Edge->Capacity == INF)
continue;
uint64_t MaxIntFlow = double(Edge->Capacity - Edge->Flow) / EdgeFlow;
MaxFlowAmount = std::min(MaxFlowAmount, MaxIntFlow);
}
}
// Stop early if we cannot send any (integral) flow from Source to Target
if (MaxFlowAmount == 0)
return false;
// Phase 2: Send an integral flow of MaxFlowAmount
Nodes[Source].IntFlow = MaxFlowAmount;
for (uint64_t Src : AugmentingOrder) {
if (Src == Target)
break;
// Distribute flow evenly among successors of Src, rounding up to make
// sure all flow is sent
uint64_t Degree = AugmentingEdges[Src].size();
// We are guaranteeed that Node[Src].IntFlow <= SuccFlow * Degree
uint64_t SuccFlow = (Nodes[Src].IntFlow + Degree - 1) / Degree;
for (auto &Edge : AugmentingEdges[Src]) {
uint64_t Dst = Edge->Dst;
uint64_t EdgeFlow = std::min(Nodes[Src].IntFlow, SuccFlow);
EdgeFlow = std::min(EdgeFlow, uint64_t(Edge->Capacity - Edge->Flow));
Nodes[Dst].IntFlow += EdgeFlow;
Nodes[Src].IntFlow -= EdgeFlow;
Edge->AugmentedFlow += EdgeFlow;
}
}
assert(Nodes[Target].IntFlow <= MaxFlowAmount);
Nodes[Target].IntFlow = 0;
// Phase 3: Send excess flow back traversing the nodes backwards.
// Because of rounding, not all flow can be sent along the edges of Src.
// Hence, sending the remaining flow back to maintain flow conservation
for (size_t Idx = AugmentingOrder.size() - 1; Idx > 0; Idx--) {
uint64_t Src = AugmentingOrder[Idx - 1];
// Try to send excess flow back along each edge.
// Make sure we only send back flow we just augmented (AugmentedFlow).
for (auto &Edge : AugmentingEdges[Src]) {
uint64_t Dst = Edge->Dst;
if (Nodes[Dst].IntFlow == 0)
continue;
uint64_t EdgeFlow = std::min(Nodes[Dst].IntFlow, Edge->AugmentedFlow);
Nodes[Dst].IntFlow -= EdgeFlow;
Nodes[Src].IntFlow += EdgeFlow;
Edge->AugmentedFlow -= EdgeFlow;
}
}
// Phase 4: Update flow values along all edges
bool HasSaturatedEdges = false;
for (uint64_t Src : AugmentingOrder) {
// Verify that we have sent all the excess flow from the node
assert(Src == Source || Nodes[Src].IntFlow == 0);
for (auto &Edge : AugmentingEdges[Src]) {
assert(uint64_t(Edge->Capacity - Edge->Flow) >= Edge->AugmentedFlow);
// Update flow values along the edge and its reverse copy
auto &RevEdge = Edges[Edge->Dst][Edge->RevEdgeIndex];
Edge->Flow += Edge->AugmentedFlow;
RevEdge.Flow -= Edge->AugmentedFlow;
if (Edge->Capacity == Edge->Flow && Edge->AugmentedFlow > 0)
HasSaturatedEdges = true;
}
}
// The augmentation is successful iff at least one edge becomes saturated
return HasSaturatedEdges;
}
/// Identify candidate (shortest) edges for augmentation.
void identifyShortestEdges(uint64_t PathCapacity) {
assert(PathCapacity > 0 && "found an incorrect augmenting DAG");
// To make sure the augmentation DAG contains only edges with large residual
// capacity, we prune all edges whose capacity is below a fraction of
// the capacity of the augmented path.
// (All edges of the path itself are always in the DAG)
uint64_t MinCapacity = std::max(PathCapacity / 2, uint64_t(1));
// Decide which edges are on a shortest path from Source to Target
for (size_t Src = 0; Src < Nodes.size(); Src++) {
// An edge cannot be augmenting if the endpoint has large distance
if (Nodes[Src].Distance > Nodes[Target].Distance)
continue;
for (auto &Edge : Edges[Src]) {
uint64_t Dst = Edge.Dst;
Edge.OnShortestPath =
Src != Target && Dst != Source &&
Nodes[Dst].Distance <= Nodes[Target].Distance &&
Nodes[Dst].Distance == Nodes[Src].Distance + Edge.Cost &&
Edge.Capacity > Edge.Flow &&
uint64_t(Edge.Capacity - Edge.Flow) >= MinCapacity;
}
}
}
/// A node in a flow network.
struct Node {
/// The cost of the cheapest path from the source to the current node.
@ -247,7 +511,20 @@ private:
uint64_t ParentEdgeIndex;
/// An indicator of whether the current node is in a queue.
bool Taken;
/// Data fields utilized in DAG-augmentation:
/// Fractional flow.
double FracFlow;
/// Integral flow.
uint64_t IntFlow;
/// Discovery time.
uint64_t Discovery;
/// Finish time.
uint64_t Finish;
/// NumCalls.
uint64_t NumCalls;
};
/// An edge in a flow network.
struct Edge {
/// The cost of the edge.
@ -260,6 +537,12 @@ private:
uint64_t Dst;
/// The index of the reverse edge between Dst and the current node.
uint64_t RevEdgeIndex;
/// Data fields utilized in DAG-augmentation:
/// Whether the edge is currently on a shortest path from Source to Target.
bool OnShortestPath;
/// Extra flow along the edge.
uint64_t AugmentedFlow;
};
/// The set of network nodes.
@ -270,6 +553,8 @@ private:
uint64_t Source;
/// Target (sink) node of the flow.
uint64_t Target;
/// Augmenting edges.
std::vector<std::vector<Edge *>> AugmentingEdges;
};
/// A post-processing adjustment of control flow. It applies two steps by
@ -511,7 +796,7 @@ private:
std::vector<FlowBlock *> &KnownDstBlocks,
std::vector<FlowBlock *> &UnknownBlocks) {
// Run BFS from SrcBlock and make sure all paths are going through unknown
// blocks and end at a non-unknown DstBlock
// blocks and end at a known DstBlock
auto Visited = BitVector(NumBlocks(), false);
std::queue<uint64_t> Queue;

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@ -0,0 +1,16 @@
foo1:37078302:0
1: 1000
2: 0
3: 0
4: 1000
!CFGChecksum: 157181141624
foo2:37078302:0
3: 1000
!CFGChecksum: 208782362068
foo3:37078302:0
1: 1000
4: 1000
6: 1000
!CFGChecksum: 189901498683

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@ -1,19 +1,19 @@
; Make sure Import GUID list for ThinLTO properly set for CSSPGO
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list.prof -S | FileCheck %s
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list.prof -sample-profile-even-count-distribution=0 -S | FileCheck %s
; RUN: llvm-profdata merge --sample --extbinary %S/Inputs/csspgo-import-list.prof -o %t.prof
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%t.prof -S | FileCheck %s
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%t.prof -sample-profile-even-count-distribution=0 -S | FileCheck %s
; RUN: llvm-profdata show --sample -show-sec-info-only %t.prof | FileCheck %s --check-prefix=CHECK-ORDERED
; RUN: llvm-profdata merge --sample --extbinary --use-md5 %S/Inputs/csspgo-import-list.prof -o %t.md5
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%t.md5 -S | FileCheck %s
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%t.md5 -sample-profile-even-count-distribution=0 -S | FileCheck %s
; RUN: llvm-profdata show --sample -show-sec-info-only %t.md5 | FileCheck %s --check-prefix=CHECK-ORDERED
;; Validate that with replay in effect, we import call sites even if they are below the threshold
;; Baseline import decisions
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list.prof -profile-summary-hot-count=10000 -S | FileCheck %s --check-prefix=THRESHOLD
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list.prof -profile-summary-hot-count=10000 -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=THRESHOLD
;; With replay
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list.prof -sample-profile-inline-replay=%S/Inputs/csspgo-import-list-replay.txt -sample-profile-inline-replay-scope=Module -profile-summary-hot-count=10000 -S | FileCheck %s --check-prefix=THRESHOLD-REPLAY
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list.prof -sample-profile-inline-replay=%S/Inputs/csspgo-import-list-replay.txt -sample-profile-inline-replay-scope=Module -profile-summary-hot-count=10000 -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=THRESHOLD-REPLAY
;; With replay but no profile information for call to _Z5funcAi. We import _Z5funcAi because it's explicitly in the replay but don't go further to its callee (_Z3fibi) because we lack samples
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list-no-funca.prof -sample-profile-inline-replay=%S/Inputs/csspgo-import-list-replay.txt -sample-profile-inline-replay-scope=Module -profile-summary-hot-count=10000 -S | FileCheck %s --check-prefix=THRESHOLD-REPLAY-NO-FUNCA
; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -sample-profile-file=%S/Inputs/csspgo-import-list-no-funca.prof -sample-profile-inline-replay=%S/Inputs/csspgo-import-list-replay.txt -sample-profile-inline-replay-scope=Module -profile-summary-hot-count=10000 -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=THRESHOLD-REPLAY-NO-FUNCA
declare i32 @_Z5funcBi(i32 %x)
declare i32 @_Z5funcAi(i32 %x)

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@ -8,10 +8,10 @@
; main:3 @ _Z5funcAi
; main:3 @ _Z5funcAi:1 @ _Z8funcLeafi
; _Z5funcBi:1 @ _Z8funcLeafi
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/profile-context-tracker.prof -sample-profile-inline-size -sample-profile-prioritized-inline=0 -profile-sample-accurate -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%t -sample-profile-inline-size -sample-profile-prioritized-inline=0 -profile-sample-accurate -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/profile-context-tracker.prof -sample-profile-inline-size -sample-profile-cold-inline-threshold=200 -profile-sample-accurate -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%t -sample-profile-inline-size -sample-profile-cold-inline-threshold=200 -profile-sample-accurate -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/profile-context-tracker.prof -sample-profile-inline-size -sample-profile-prioritized-inline=0 -profile-sample-accurate -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%t -sample-profile-inline-size -sample-profile-prioritized-inline=0 -profile-sample-accurate -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/profile-context-tracker.prof -sample-profile-inline-size -sample-profile-cold-inline-threshold=200 -profile-sample-accurate -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=INLINE-ALL
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%t -sample-profile-inline-size -sample-profile-cold-inline-threshold=200 -profile-sample-accurate -sample-profile-even-count-distribution=0 -S | FileCheck %s --check-prefix=INLINE-ALL
;
; Test we inlined the following in top-down order and entry counts accurate reflects post-inline base profile
; _Z5funcAi:1 @ _Z8funcLeafi
@ -145,9 +145,9 @@ entry:
; INLINE-HOT-DAG-SAME: [[LEAF_PROF]] = !{!"function_entry_count", i64 0}
; INLINE-HOT-DAG: [[FUNCB_PROF]] = !{!"function_entry_count", i64 13}
; INLINE-NONE: [[MAIN_PROF]] = !{!"function_entry_count", i64 1}
; INLINE-NONE: [[MAIN_PROF]] = !{!"function_entry_count", i64 13}
; INLINE-NONE: [[FUNCA_PROF]] = !{!"function_entry_count", i64 24}
; INLINE-NONE-DAG-SAME: [[LEAF_PROF]] = !{!"function_entry_count", i64 22}
; INLINE-NONE-DAG-SAME: [[LEAF_PROF]] = !{!"function_entry_count", i64 21}
; INLINE-NONE-DAG: [[FUNCB_PROF]] = !{!"function_entry_count", i64 32}
declare i32 @_Z3fibi(i32)

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@ -0,0 +1,173 @@
; RUN: opt < %s -passes=pseudo-probe,sample-profile -sample-profile-use-profi -sample-profile-file=%S/Inputs/profile-inference-even-count-distribution.prof | opt -analyze -branch-prob -enable-new-pm=0 | FileCheck %s
; RUN: opt < %s -passes=pseudo-probe,sample-profile -sample-profile-use-profi -sample-profile-file=%S/Inputs/profile-inference-even-count-distribution.prof | opt -analyze -block-freq -enable-new-pm=0 | FileCheck %s --check-prefix=CHECK2
; The test verifies that counts are evenly distributed among branches with
; equal weights.
;
; +-----------+ +-----------+
; | b3 [0] | <-- | b1 [1000] |
; +-----------+ +-----------+
; | |
; | |
; | v
; | +-----------+
; | | b2 [0] |
; | +-----------+
; | |
; | |
; | v
; | +-----------+
; +-------------> | b4 [1000] |
; +-----------+
@yydebug = dso_local global i32 0, align 4
; Function Attrs: nounwind uwtable
define dso_local i32 @foo1(i32 %0, i32 %1) #0 {
b11:
call void @llvm.pseudoprobe(i64 7682762345278052905, i64 1, i32 0, i64 -1)
%cmp = icmp ne i32 %0, 0
br i1 %cmp, label %b12, label %b13
; CHECK: edge b11 -> b12 probability is 0x40000000 / 0x80000000 = 50.00%
; CHECK: edge b11 -> b13 probability is 0x40000000 / 0x80000000 = 50.00%
; CHECK2: - b11: float = {{.*}}, int = {{.*}}, count = 1000
b12:
call void @llvm.pseudoprobe(i64 7682762345278052905, i64 2, i32 0, i64 -1)
br label %b14
; CHECK2: - b12: float = {{.*}}, int = {{.*}}, count = 500
b13:
call void @llvm.pseudoprobe(i64 7682762345278052905, i64 3, i32 0, i64 -1)
br label %b14
; CHECK2: - b13: float = {{.*}}, int = {{.*}}, count = 500
b14:
call void @llvm.pseudoprobe(i64 7682762345278052905, i64 4, i32 0, i64 -1)
ret i32 %1
; CHECK2: - b14: float = {{.*}}, int = {{.*}}, count = 1000
}
; The test verifies that counts are evenly distributed when the entry basic
; block is dangling.
;
; +-----------+
; | b1 [?] | -+
; +-----------+ |
; | |
; | |
; v |
; +-----------+ |
; | b2 [?] | |
; +-----------+ |
; | |
; | |
; v |
; +-----------+ |
; | b3 [1000] | <+
; +-----------+
define dso_local i32 @foo2(i32 %0, i32 %1) #0 {
b21:
call void @llvm.pseudoprobe(i64 2494702099028631698, i64 1, i32 0, i64 -1)
%cmp = icmp ne i32 %0, 0
br i1 %cmp, label %b22, label %b23
; CHECK: edge b21 -> b22 probability is 0x40000000 / 0x80000000 = 50.00%
; CHECK: edge b21 -> b23 probability is 0x40000000 / 0x80000000 = 50.00%
; CHECK2: - b21: float = {{.*}}, int = {{.*}}, count = 1000
b22:
call void @llvm.pseudoprobe(i64 2494702099028631698, i64 2, i32 0, i64 -1)
br label %b23
; CHECK2: - b22: float = {{.*}}, int = {{.*}}, count = 500
b23:
call void @llvm.pseudoprobe(i64 2494702099028631698, i64 3, i32 0, i64 -1)
ret i32 %1
; CHECK2: - b23: float = {{.*}}, int = {{.*}}, count = 1000
}
; The test verifies even count distribution in the presence of multiple sinks.
;
; +-----------+
; | b1 [1000] |
; +-----------+
; |
; |
; v
; +-----------+
; | b2 [?] | -+
; +-----------+ |
; | |
; | |
; v |
; +--------+ +-----------+ |
; | b5 [?] | <-- | b3 [?] | |
; +--------+ +-----------+ |
; | | |
; | | |
; | v |
; | +-----------+ |
; | | b4 [1000] | <+
; | +-----------+
; | |
; | |
; | v
; | +-----------+
; +----------> | b6 [1000] |
; +-----------+
;
define dso_local i32 @foo3(i32 %0, i32 %1) #0 {
b31:
call void @llvm.pseudoprobe(i64 -7908226060800700466, i64 1, i32 0, i64 -1)
%cmp = icmp ne i32 %0, 0
br label %b32
; CHECK2: - b31: float = {{.*}}, int = {{.*}}, count = 1000
b32:
call void @llvm.pseudoprobe(i64 -7908226060800700466, i64 2, i32 0, i64 -1)
br i1 %cmp, label %b33, label %b34
; CHECK: edge b32 -> b33 probability is 0x40000000 / 0x80000000 = 50.00%
; CHECK: edge b32 -> b34 probability is 0x40000000 / 0x80000000 = 50.00%
; CHECK2: - b32: float = {{.*}}, int = {{.*}}, count = 1000
b33:
call void @llvm.pseudoprobe(i64 -7908226060800700466, i64 3, i32 0, i64 -1)
br i1 %cmp, label %b35, label %b34
; CHECK: edge b33 -> b35 probability is 0x00000000 / 0x80000000 = 0.00%
; CHECK: edge b33 -> b34 probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge]
; CHECK2: - b33: float = {{.*}}, int = {{.*}}, count = 500
b34:
call void @llvm.pseudoprobe(i64 -7908226060800700466, i64 4, i32 0, i64 -1)
br label %b36
; CHECK2: - b34: float = {{.*}}, int = {{.*}}, count = 1000
b35:
call void @llvm.pseudoprobe(i64 -7908226060800700466, i64 5, i32 0, i64 -1)
br label %b36
; CHECK2: - b35: float = {{.*}}, int = {{.*}}, count = 0
b36:
call void @llvm.pseudoprobe(i64 -7908226060800700466, i64 6, i32 0, i64 -1)
ret i32 %1
; CHECK2: - b36: float = {{.*}}, int = {{.*}}, count = 1000
}
; Function Attrs: inaccessiblememonly nounwind willreturn
declare void @llvm.pseudoprobe(i64, i64, i32, i64) #4
attributes #0 = { noinline nounwind uwtable "use-sample-profile" }
attributes #4 = { inaccessiblememonly nounwind willreturn }
!llvm.pseudo_probe_desc = !{!7, !8, !9, !10}
!7 = !{i64 7682762345278052905, i64 157181141624, !"foo1", null}
!8 = !{i64 2494702099028631698, i64 208782362068, !"foo2", null}
!9 = !{i64 -7908226060800700466, i64 189901498683, !"foo3", null}
!10 = !{i64 -6882312132165544686, i64 241030178952, !"foo4", null}