[llvm] r367703 - [NewPassManager] Resolve assertion in CGSCCPassManager when CallCounts change.
Alina Sbirlea via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 2 11:37:03 PDT 2019
Author: asbirlea
Date: Fri Aug 2 11:37:03 2019
New Revision: 367703
URL: http://llvm.org/viewvc/llvm-project?rev=367703&view=rev
Log:
[NewPassManager] Resolve assertion in CGSCCPassManager when CallCounts change.
Summary:
If the CallCounts change after an iteration of the DevirtSCCRepeatedPass, this is not reflected in the local CallCounts structure triggering the assertion checking the before/after sizes.
Since it is valid for the size to change and this only uses the CallCounts for the devirtualizing heuristic, keep a <Function*, CallCount> map instead, and make the devirtualizing decision using the counts for the functions that exist both before and after the pass.
Resolves PR42726.
Reviewers: chandlerc
Subscribers: mehdi_amini, jlebar, sanjoy.google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65621
Added:
llvm/trunk/test/Other/new-pm-pr42726-cgscc.ll
Modified:
llvm/trunk/include/llvm/Analysis/CGSCCPassManager.h
Modified: llvm/trunk/include/llvm/Analysis/CGSCCPassManager.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/CGSCCPassManager.h?rev=367703&r1=367702&r2=367703&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/CGSCCPassManager.h (original)
+++ llvm/trunk/include/llvm/Analysis/CGSCCPassManager.h Fri Aug 2 11:37:03 2019
@@ -88,6 +88,7 @@
#ifndef LLVM_ANALYSIS_CGSCCPASSMANAGER_H
#define LLVM_ANALYSIS_CGSCCPASSMANAGER_H
+#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/PriorityWorklist.h"
#include "llvm/ADT/STLExtras.h"
@@ -583,10 +584,12 @@ public:
SmallVectorImpl<WeakTrackingVH> &CallHandles) {
assert(CallHandles.empty() && "Must start with a clear set of handles.");
- SmallVector<CallCount, 4> CallCounts;
+ SmallDenseMap<Function *, CallCount> CallCounts;
+ CallCount CountLocal = {0, 0};
for (LazyCallGraph::Node &N : C) {
- CallCounts.push_back({0, 0});
- CallCount &Count = CallCounts.back();
+ CallCount &Count =
+ CallCounts.insert(std::make_pair(&N.getFunction(), CountLocal))
+ .first->second;
for (Instruction &I : instructions(N.getFunction()))
if (auto CS = CallSite(&I)) {
if (CS.getCalledFunction()) {
@@ -626,8 +629,6 @@ public:
// Check that we didn't miss any update scenario.
assert(!UR.InvalidatedSCCs.count(C) && "Processing an invalid SCC!");
assert(C->begin() != C->end() && "Cannot have an empty SCC!");
- assert((int)CallCounts.size() == C->size() &&
- "Cannot have changed the size of the SCC!");
// Check whether any of the handles were devirtualized.
auto IsDevirtualizedHandle = [&](WeakTrackingVH &CallH) {
@@ -642,7 +643,7 @@ public:
if (!F)
return false;
- LLVM_DEBUG(dbgs() << "Found devirutalized call from "
+ LLVM_DEBUG(dbgs() << "Found devirtualized call from "
<< CS.getParent()->getParent()->getName() << " to "
<< F->getName() << "\n");
@@ -664,12 +665,20 @@ public:
// manner of transformations such as DCE and other things, but seems to
// work well in practice.
if (!Devirt)
- for (int i = 0, Size = C->size(); i < Size; ++i)
- if (CallCounts[i].Indirect > NewCallCounts[i].Indirect &&
- CallCounts[i].Direct < NewCallCounts[i].Direct) {
- Devirt = true;
- break;
+ // Iterate over the keys in NewCallCounts, if Function also exists in
+ // CallCounts, make the check below.
+ for (auto &Pair : NewCallCounts) {
+ auto &CallCountNew = Pair.second;
+ auto CountIt = CallCounts.find(Pair.first);
+ if (CountIt != CallCounts.end()) {
+ const auto &CallCountOld = CountIt->second;
+ if (CallCountOld.Indirect > CallCountNew.Indirect &&
+ CallCountOld.Direct < CallCountNew.Direct) {
+ Devirt = true;
+ break;
+ }
}
+ }
if (!Devirt) {
PA.intersect(std::move(PassPA));
Added: llvm/trunk/test/Other/new-pm-pr42726-cgscc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Other/new-pm-pr42726-cgscc.ll?rev=367703&view=auto
==============================================================================
--- llvm/trunk/test/Other/new-pm-pr42726-cgscc.ll (added)
+++ llvm/trunk/test/Other/new-pm-pr42726-cgscc.ll Fri Aug 2 11:37:03 2019
@@ -0,0 +1,57 @@
+; RUN: opt -aa-pipeline=default -passes="default<O1>" %s -S | FileCheck %s
+; REQUIRES: asserts
+
+declare void @bar()
+declare void @baz(i32*)
+
+; CHECK-LABEL: @foo1()
+define void @foo1() {
+entry:
+ %tag = alloca i32, align 4
+ call void @baz(i32* %tag)
+ %tmp = load i32, i32* %tag, align 4
+ switch i32 %tmp, label %sw.bb799 [
+ i32 10, label %sw.bb239
+ ]
+
+sw.bb239:
+ call void @foo2()
+ br label %cleanup871
+
+sw.bb799:
+ call void @foo3(i32 undef)
+ br label %cleanup871
+
+cleanup871:
+ call void @bar()
+ unreachable
+}
+
+define void @foo2() {
+ call void @foo4()
+ unreachable
+}
+
+define void @foo3(i32 %ptr) {
+ call void @foo1()
+ unreachable
+}
+
+define void @foo4() {
+entry:
+ %tag = alloca i32, align 4
+ call void @baz(i32* %tag)
+ %tmp = load i32, i32* %tag, align 4
+ switch i32 %tmp, label %sw.bb442 [
+ i32 16, label %sw.bb352
+ ]
+
+sw.bb352:
+ call void @foo3(i32 undef)
+ unreachable
+
+sw.bb442:
+ call void @foo2()
+ unreachable
+}
+
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