[llvm] acfd0a3 - [llvm-profgen] Update callsite body samples by summing up all call target samples.
Hongtao Yu via llvm-commits
llvm-commits at lists.llvm.org
Mon May 16 09:13:43 PDT 2022
Author: Hongtao Yu
Date: 2022-05-16T09:13:37-07:00
New Revision: acfd0a345619c9293ac8fa5f690fa78b27a10814
URL: https://github.com/llvm/llvm-project/commit/acfd0a345619c9293ac8fa5f690fa78b27a10814
DIFF: https://github.com/llvm/llvm-project/commit/acfd0a345619c9293ac8fa5f690fa78b27a10814.diff
LOG: [llvm-profgen] Update callsite body samples by summing up all call target samples.
Current profile generation caculcates callsite body samples and call target samples separately. The former is done based on LBR range samples while the latter is done based on branch samples. Note that there's a subtle difference. LBR ranges is formed from two consecutive branch samples. Therefore the last entry in a LBR record will not be counted towards body samples while there's still a chance for it to be counted towards call targets if it is a function call. I'm making sense of the call body samples by updating it to the aggregation of call targets.
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D122609
Added:
llvm/test/tools/llvm-profgen/update-samples.test
Modified:
llvm/include/llvm/ProfileData/SampleProf.h
llvm/test/tools/llvm-profgen/inline-noprobe2.test
llvm/test/tools/llvm-profgen/noinline-noprobe.test
llvm/tools/llvm-profgen/ProfileGenerator.cpp
llvm/tools/llvm-profgen/ProfileGenerator.h
Removed:
################################################################################
diff --git a/llvm/include/llvm/ProfileData/SampleProf.h b/llvm/include/llvm/ProfileData/SampleProf.h
index a39a4d8c5658e..8d8813ecf8c13 100644
--- a/llvm/include/llvm/ProfileData/SampleProf.h
+++ b/llvm/include/llvm/ProfileData/SampleProf.h
@@ -387,6 +387,13 @@ class SampleRecord {
return SortCallTargets(CallTargets);
}
+ uint64_t getCallTargetSum() const {
+ uint64_t Sum = 0;
+ for (const auto &I : CallTargets)
+ Sum += I.second;
+ return Sum;
+ }
+
/// Sort call targets in descending order of call frequency.
static const SortedCallTargetSet SortCallTargets(const CallTargetMap &Targets) {
SortedCallTargetSet SortedTargets;
@@ -779,6 +786,19 @@ class FunctionSamples {
return BodySamples[LineLocation(Index, 0)].merge(S, Weight);
}
+ // Accumulate all call target samples to update the body samples.
+ void updateCallsiteSamples() {
+ for (auto &I : BodySamples) {
+ uint64_t TargetSamples = I.second.getCallTargetSum();
+ // It's possible that the body sample count can be greater than the call
+ // target sum. E.g, if some call targets are external targets, they won't
+ // be considered valid call targets, but the body sample count which is
+ // from lbr ranges can actually include them.
+ if (TargetSamples > I.second.getSamples())
+ I.second.addSamples(TargetSamples - I.second.getSamples());
+ }
+ }
+
// Accumulate all body samples to set total samples.
void updateTotalSamples() {
setTotalSamples(0);
diff --git a/llvm/test/tools/llvm-profgen/inline-noprobe2.test b/llvm/test/tools/llvm-profgen/inline-noprobe2.test
index 4d41243278dd5..97c96f0336606 100644
--- a/llvm/test/tools/llvm-profgen/inline-noprobe2.test
+++ b/llvm/test/tools/llvm-profgen/inline-noprobe2.test
@@ -59,7 +59,7 @@
;CHECK: 6.1: 17
;CHECK: 6.3: 17
;CHECK: 7: 0
-;CHECK: 8: 0 quick_sort:1
+;CHECK: 8: 1 quick_sort:1
;CHECK: 9: 0
;CHECK: 11: 0
;CHECK: 14: 0
@@ -97,7 +97,7 @@
;CHECK: quick_sort:903:25
;CHECK: 1: 24
;CHECK: 2: 12 partition_pivot_last:7 partition_pivot_first:5
-;CHECK: 3: 11 quick_sort:12
+;CHECK: 3: 12 quick_sort:12
;CHECK: 4: 12 quick_sort:12
;CHECK: 6: 24
;CHECK: 65507: 12
diff --git a/llvm/test/tools/llvm-profgen/noinline-noprobe.test b/llvm/test/tools/llvm-profgen/noinline-noprobe.test
index f5bbc295462c0..19a58780ca636 100644
--- a/llvm/test/tools/llvm-profgen/noinline-noprobe.test
+++ b/llvm/test/tools/llvm-profgen/noinline-noprobe.test
@@ -11,7 +11,7 @@
;CHECK: 0: 0
;CHECK: 1: 0
;CHECK: 2: 19
-;CHECK: 3: 19 bar:21
+;CHECK: 3: 21 bar:21
;CHECK: 4: 0
;CHECK: 5: 0
;CHECK: bar:926:21
diff --git a/llvm/test/tools/llvm-profgen/update-samples.test b/llvm/test/tools/llvm-profgen/update-samples.test
new file mode 100644
index 0000000000000..d3ae425d860a3
--- /dev/null
+++ b/llvm/test/tools/llvm-profgen/update-samples.test
@@ -0,0 +1,45 @@
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noprobe.perfscript --binary=%S/Inputs/noprobe.perfbin --output=%t1
+; RUN: FileCheck %s --input-file %t1 --check-prefix=CALLSITE
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noprobe.perfscript --binary=%S/Inputs/noprobe.perfbin --output=%t2 --update-total-samples=1
+; RUN: FileCheck %s --input-file %t2 --check-prefix=TOTAL
+
+
+;CALLSITE: foo:1241:0
+;CALLSITE: 0: 0
+;CALLSITE: 1: 0
+;CALLSITE: 2: 19
+;CALLSITE: 3: 21 bar:21
+;CALLSITE: 4: 0
+;CALLSITE: 5: 0
+
+;TOTAL: foo:40:0
+;TOTAL: 0: 0
+;TOTAL: 1: 0
+;TOTAL: 2: 19
+;TOTAL: 3: 21 bar:21
+;TOTAL: 4: 0
+;TOTAL: 5: 0
+
+
+; original code:
+; clang -O3 -g -fdebug-info-for-profiling test.c -fno-inline -o a.out
+#include <stdio.h>
+
+int bar(int x, int y) {
+ if (x % 3) {
+ return x - y;
+ }
+ return x + y;
+}
+
+void foo() {
+ int s, i = 0;
+ while (i++ < 4000 * 4000)
+ if (i % 91) s = bar(i, s); else s += 30;
+ printf("sum is %d\n", s);
+}
+
+int main() {
+ foo();
+ return 0;
+}
diff --git a/llvm/tools/llvm-profgen/ProfileGenerator.cpp b/llvm/tools/llvm-profgen/ProfileGenerator.cpp
index be5a581b63e02..65b2395159222 100644
--- a/llvm/tools/llvm-profgen/ProfileGenerator.cpp
+++ b/llvm/tools/llvm-profgen/ProfileGenerator.cpp
@@ -381,15 +381,26 @@ void ProfileGeneratorBase::updateBodySamplesforFunctionProfile(
}
void ProfileGeneratorBase::updateTotalSamples() {
- if (!UpdateTotalSamples)
- return;
-
for (auto &Item : ProfileMap) {
FunctionSamples &FunctionProfile = Item.second;
FunctionProfile.updateTotalSamples();
}
}
+void ProfileGeneratorBase::updateCallsiteSamples() {
+ for (auto &Item : ProfileMap) {
+ FunctionSamples &FunctionProfile = Item.second;
+ FunctionProfile.updateCallsiteSamples();
+ }
+}
+
+void ProfileGeneratorBase::updateFunctionSamples() {
+ updateCallsiteSamples();
+
+ if (UpdateTotalSamples)
+ updateTotalSamples();
+}
+
void ProfileGeneratorBase::collectProfiledFunctions() {
std::unordered_set<const BinaryFunction *> ProfiledFunctions;
if (SampleCounters) {
@@ -491,7 +502,7 @@ void ProfileGenerator::generateLineNumBasedProfile() {
// Fill in boundary sample counts as well as call site samples for calls
populateBoundarySamplesForAllFunctions(SC.BranchCounter);
- updateTotalSamples();
+ updateFunctionSamples();
}
void ProfileGenerator::generateProbeBasedProfile() {
@@ -505,7 +516,7 @@ void ProfileGenerator::generateProbeBasedProfile() {
// Fill in boundary sample counts as well as call site samples for calls
populateBoundarySamplesWithProbesForAllFunctions(SC.BranchCounter);
- updateTotalSamples();
+ updateFunctionSamples();
}
void ProfileGenerator::populateBodySamplesWithProbesForAllFunctions(
@@ -785,7 +796,7 @@ void CSProfileGenerator::generateLineNumBasedProfile() {
// body sample.
populateInferredFunctionSamples();
- updateTotalSamples();
+ updateFunctionSamples();
}
void CSProfileGenerator::populateBodySamplesForFunction(
diff --git a/llvm/tools/llvm-profgen/ProfileGenerator.h b/llvm/tools/llvm-profgen/ProfileGenerator.h
index 410b08fb2e044..a6a9a10baadcb 100644
--- a/llvm/tools/llvm-profgen/ProfileGenerator.h
+++ b/llvm/tools/llvm-profgen/ProfileGenerator.h
@@ -100,8 +100,13 @@ class ProfileGeneratorBase {
void updateBodySamplesforFunctionProfile(FunctionSamples &FunctionProfile,
const SampleContextFrame &LeafLoc,
uint64_t Count);
+
+ void updateFunctionSamples();
+
void updateTotalSamples();
+ void updateCallsiteSamples();
+
StringRef getCalleeNameForOffset(uint64_t TargetOffset);
void computeSummaryAndThreshold();
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