[llvm] r358225 - [PGO] Better handling of profile hash mismatch
Rong Xu via llvm-commits
llvm-commits at lists.llvm.org
Thu Apr 11 13:54:17 PDT 2019
Author: xur
Date: Thu Apr 11 13:54:17 2019
New Revision: 358225
URL: http://llvm.org/viewvc/llvm-project?rev=358225&view=rev
Log:
[PGO] Better handling of profile hash mismatch
We currently assume profile hash conflicts will be caught by an upfront
check and we assert for the cases that escape the check. The assumption
is not always true as there are chances of conflict. This patch prints
a warning and skips annotating the function for the escaped cases,.
Differential Revision: https://reviews.llvm.org/D60154
Added:
llvm/trunk/test/Transforms/PGOProfile/Inputs/select_hash_conflict.proftext
llvm/trunk/test/Transforms/PGOProfile/select_hash_conflict.ll
Modified:
llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
Modified: llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp?rev=358225&r1=358224&r2=358225&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp Thu Apr 11 13:54:17 2019
@@ -1006,8 +1006,8 @@ private:
// Is to use the context sensitive profile.
bool IsCS;
- // Find the Instrumented BB and set the value.
- void setInstrumentedCounts(const std::vector<uint64_t> &CountFromProfile);
+ // Find the Instrumented BB and set the value. Return false on error.
+ bool setInstrumentedCounts(const std::vector<uint64_t> &CountFromProfile);
// Set the edge counter value for the unknown edge -- there should be only
// one unknown edge.
@@ -1036,10 +1036,14 @@ private:
} // end anonymous namespace
// Visit all the edges and assign the count value for the instrumented
-// edges and the BB.
-void PGOUseFunc::setInstrumentedCounts(
+// edges and the BB. Return false on error.
+bool PGOUseFunc::setInstrumentedCounts(
const std::vector<uint64_t> &CountFromProfile) {
- assert(FuncInfo.getNumCounters() == CountFromProfile.size());
+ // The number of counters here should match the number of counters
+ // in profile. Return if they mismatch.
+ if (FuncInfo.getNumCounters() != CountFromProfile.size()) {
+ return false;
+ }
// Use a worklist as we will update the vector during the iteration.
std::vector<PGOUseEdge *> WorkList;
for (auto &E : FuncInfo.MST.AllEdges)
@@ -1071,6 +1075,7 @@ void PGOUseFunc::setInstrumentedCounts(
}
ProfileCountSize = CountFromProfile.size();
CountPosition = I;
+ return true;
}
// Set the count value for the unknown edge. There should be one and only one
@@ -1146,7 +1151,16 @@ bool PGOUseFunc::readCounters(IndexedIns
getBBInfo(nullptr).UnknownCountOutEdge = 2;
getBBInfo(nullptr).UnknownCountInEdge = 2;
- setInstrumentedCounts(CountFromProfile);
+ if (!setInstrumentedCounts(CountFromProfile)) {
+ LLVM_DEBUG(
+ dbgs() << "Inconsistent number of counts, skipping this function");
+ Ctx.diagnose(DiagnosticInfoPGOProfile(
+ M->getName().data(),
+ Twine("Inconsistent number of counts in ") + F.getName().str()
+ + Twine(": the profile may be stale or there is a function name collision."),
+ DS_Warning));
+ return false;
+ }
ProgramMaxCount = PGOReader->getMaximumFunctionCount(IsCS);
return true;
}
Added: llvm/trunk/test/Transforms/PGOProfile/Inputs/select_hash_conflict.proftext
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PGOProfile/Inputs/select_hash_conflict.proftext?rev=358225&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/PGOProfile/Inputs/select_hash_conflict.proftext (added)
+++ llvm/trunk/test/Transforms/PGOProfile/Inputs/select_hash_conflict.proftext Thu Apr 11 13:54:17 2019
@@ -0,0 +1,10 @@
+# IR level Instrumentation Flag
+:ir
+foo
+# Func Hash:
+12884901887
+# Num Counters:
+1
+# Counter Values:
+1
+
Added: llvm/trunk/test/Transforms/PGOProfile/select_hash_conflict.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PGOProfile/select_hash_conflict.ll?rev=358225&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/PGOProfile/select_hash_conflict.ll (added)
+++ llvm/trunk/test/Transforms/PGOProfile/select_hash_conflict.ll Thu Apr 11 13:54:17 2019
@@ -0,0 +1,97 @@
+; RUN: llvm-profdata merge %S/Inputs/select_hash_conflict.proftext -o %t.profdata
+; RUN: opt < %s -pgo-instr-use -pgo-test-profile-file=%t.profdata -pgo-instr-select=true -S | FileCheck %s
+; RUN: opt < %s -passes=pgo-instr-use -pgo-test-profile-file=%t.profdata -pgo-instr-select=true -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at a = common dso_local local_unnamed_addr global [16 x i32] zeroinitializer, align 16
+ at c0 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c1 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c2 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c3 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c4 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c5 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c6 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c7 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c8 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c9 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c10 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c11 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c12 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c13 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c14 = common dso_local local_unnamed_addr global i8 0, align 1
+ at c15 = common dso_local local_unnamed_addr global i8 0, align 1
+
+define i32 @foo(i32 %n) {
+entry:
+ %0 = load i8, i8* @c0, align 1
+ %tobool = icmp eq i8 %0, 0
+ %cond = select i1 %tobool, i32 2, i32 1
+ store i32 %cond, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 0), align 16
+ %1 = load i8, i8* @c1, align 1
+ %tobool2 = icmp eq i8 %1, 0
+ %cond3 = select i1 %tobool2, i32 2, i32 1
+ store i32 %cond3, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 1), align 4
+ %2 = load i8, i8* @c2, align 1
+ %tobool5 = icmp eq i8 %2, 0
+ %cond6 = select i1 %tobool5, i32 2, i32 1
+ store i32 %cond6, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 2), align 8
+ %3 = load i8, i8* @c3, align 1
+ %tobool8 = icmp eq i8 %3, 0
+ %cond9 = select i1 %tobool8, i32 2, i32 1
+ store i32 %cond9, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 3), align 4
+ %4 = load i8, i8* @c4, align 1
+ %tobool11 = icmp eq i8 %4, 0
+ %cond12 = select i1 %tobool11, i32 2, i32 1
+ store i32 %cond12, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 4), align 16
+ %5 = load i8, i8* @c5, align 1
+ %tobool14 = icmp eq i8 %5, 0
+ %cond15 = select i1 %tobool14, i32 2, i32 1
+ store i32 %cond15, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 5), align 4
+ %6 = load i8, i8* @c6, align 1
+ %tobool17 = icmp eq i8 %6, 0
+ %cond18 = select i1 %tobool17, i32 2, i32 1
+ store i32 %cond18, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 6), align 8
+ %7 = load i8, i8* @c7, align 1
+ %tobool20 = icmp eq i8 %7, 0
+ %cond21 = select i1 %tobool20, i32 2, i32 1
+ store i32 %cond21, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 7), align 4
+ %8 = load i8, i8* @c8, align 1
+ %tobool23 = icmp eq i8 %8, 0
+ %cond24 = select i1 %tobool23, i32 2, i32 1
+ store i32 %cond24, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 8), align 16
+ %9 = load i8, i8* @c9, align 1
+ %tobool26 = icmp eq i8 %9, 0
+ %cond27 = select i1 %tobool26, i32 2, i32 1
+ store i32 %cond27, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 9), align 4
+ %10 = load i8, i8* @c10, align 1
+ %tobool29 = icmp eq i8 %10, 0
+ %cond30 = select i1 %tobool29, i32 2, i32 1
+ store i32 %cond30, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 10), align 8
+ %11 = load i8, i8* @c11, align 1
+ %tobool32 = icmp eq i8 %11, 0
+ %cond33 = select i1 %tobool32, i32 2, i32 1
+ store i32 %cond33, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 11), align 4
+ %12 = load i8, i8* @c12, align 1
+ %tobool35 = icmp eq i8 %12, 0
+ %cond36 = select i1 %tobool35, i32 2, i32 1
+ store i32 %cond36, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 12), align 16
+ %13 = load i8, i8* @c13, align 1
+ %tobool38 = icmp eq i8 %13, 0
+ %cond39 = select i1 %tobool38, i32 2, i32 1
+ store i32 %cond39, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 13), align 4
+ %14 = load i8, i8* @c14, align 1
+ %tobool41 = icmp eq i8 %14, 0
+ %cond42 = select i1 %tobool41, i32 2, i32 1
+ store i32 %cond42, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 14), align 8
+ %15 = load i8, i8* @c15, align 1
+ %tobool44 = icmp eq i8 %15, 0
+ %cond45 = select i1 %tobool44, i32 2, i32 1
+ store i32 %cond45, i32* getelementptr inbounds ([16 x i32], [16 x i32]* @a, i64 0, i64 15), align 4
+ ret i32 %n
+}
+; CHECK-LABEL: define i32 @foo(i32 %n)
+; We should skip the profile.
+; CHECK-NOT: %{{.*}} = select i1 %{{.*}}, i32 2, i32 1, !prof
+
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