Refactor indirect call promotion profitability analysis (NFC)
Summary:
Refactored the profitability analysis out of the IC promotion pass and
into lib/Analysis so that it can be accessed by the summary index
builder in a follow-on patch to enable IC promotion in ThinLTO (D21932).
Reviewers: davidxl, xur
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22182
llvm-svn: 275216
diff --git a/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp b/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp
index 92847c5..c9bc7db 100644
--- a/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp
+++ b/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp
@@ -13,11 +13,12 @@
//
//===----------------------------------------------------------------------===//
-#include "IndirectCallSiteVisitor.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/CFG.h"
+#include "llvm/Analysis/IndirectCallPromotionAnalysis.h"
+#include "llvm/Analysis/IndirectCallSiteVisitor.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/IRBuilder.h"
@@ -49,28 +50,6 @@
static cl::opt<bool> DisableICP("disable-icp", cl::init(false), cl::Hidden,
cl::desc("Disable indirect call promotion"));
-// The minimum call count for the direct-call target to be considered as the
-// promotion candidate.
-static cl::opt<unsigned>
- ICPCountThreshold("icp-count-threshold", cl::Hidden, cl::ZeroOrMore,
- cl::init(1000),
- cl::desc("The minimum count to the direct call target "
- "for the promotion"));
-
-// The percent threshold for the direct-call target (this call site vs the
-// total call count) for it to be considered as the promotion target.
-static cl::opt<unsigned>
- ICPPercentThreshold("icp-percent-threshold", cl::init(33), cl::Hidden,
- cl::ZeroOrMore,
- cl::desc("The percentage threshold for the promotion"));
-
-// Set the maximum number of targets to promote for a single indirect-call
-// callsite.
-static cl::opt<unsigned>
- MaxNumPromotions("icp-max-prom", cl::init(2), cl::Hidden, cl::ZeroOrMore,
- cl::desc("Max number of promotions for a single indirect "
- "call callsite"));
-
// Set the cutoff value for the promotion. If the value is other than 0, we
// stop the transformation once the total number of promotions equals the cutoff
// value.
@@ -91,6 +70,7 @@
static cl::opt<bool> ICPLTOMode("icp-lto", cl::init(false), cl::Hidden,
cl::desc("Run indirect-call promotion in LTO "
"mode"));
+
// If the option is set to true, only call instructions will be considered for
// transformation -- invoke instructions will be ignored.
static cl::opt<bool>
@@ -157,14 +137,6 @@
// defines.
InstrProfSymtab *Symtab;
- // Allocate space to read the profile annotation.
- std::unique_ptr<InstrProfValueData[]> ValueDataArray;
-
- // Count is the call count for the direct-call target and
- // TotalCount is the call count for the indirect-call callsite.
- // Return true we should promote this indirect-call target.
- bool isPromotionProfitable(uint64_t Count, uint64_t TotalCount);
-
enum TargetStatus {
OK, // Should be able to promote.
NotAvailableInModule, // Cannot find the target in current module.
@@ -185,10 +157,13 @@
};
// Check if the indirect-call call site should be promoted. Return the number
- // of promotions.
+ // of promotions. Inst is the candidate indirect call, ValueDataRef
+ // contains the array of value profile data for profiled targets,
+ // TotalCount is the total profiled count of call executions, and
+ // NumCandidates is the number of candidate entries in ValueDataRef.
std::vector<PromotionCandidate> getPromotionCandidatesForCallSite(
Instruction *Inst, const ArrayRef<InstrProfValueData> &ValueDataRef,
- uint64_t TotalCount);
+ uint64_t TotalCount, uint32_t NumCandidates);
// Main function that transforms Inst (either a indirect-call instruction, or
// an invoke instruction , to a conditional call to F. This is like:
@@ -232,21 +207,11 @@
public:
ICallPromotionFunc(Function &Func, Module *Modu, InstrProfSymtab *Symtab)
: F(Func), M(Modu), Symtab(Symtab) {
- ValueDataArray = llvm::make_unique<InstrProfValueData[]>(MaxNumPromotions);
}
bool processFunction();
};
} // end anonymous namespace
-bool ICallPromotionFunc::isPromotionProfitable(uint64_t Count,
- uint64_t TotalCount) {
- if (Count < ICPCountThreshold)
- return false;
-
- unsigned Percentage = (Count * 100) / TotalCount;
- return (Percentage >= ICPPercentThreshold);
-}
-
ICallPromotionFunc::TargetStatus
ICallPromotionFunc::isPromotionLegal(Instruction *Inst, uint64_t Target,
Function *&TargetFunction) {
@@ -291,19 +256,20 @@
std::vector<ICallPromotionFunc::PromotionCandidate>
ICallPromotionFunc::getPromotionCandidatesForCallSite(
Instruction *Inst, const ArrayRef<InstrProfValueData> &ValueDataRef,
- uint64_t TotalCount) {
+ uint64_t TotalCount, uint32_t NumCandidates) {
uint32_t NumVals = ValueDataRef.size();
std::vector<PromotionCandidate> Ret;
DEBUG(dbgs() << " \nWork on callsite #" << NumOfPGOICallsites << *Inst
- << " Num_targets: " << NumVals << "\n");
+ << " Num_targets: " << NumVals
+ << " Num_candidates: " << NumCandidates << "\n");
NumOfPGOICallsites++;
if (ICPCSSkip != 0 && NumOfPGOICallsites <= ICPCSSkip) {
DEBUG(dbgs() << " Skip: User options.\n");
return Ret;
}
- for (uint32_t I = 0; I < MaxNumPromotions && I < NumVals; I++) {
+ for (uint32_t I = 0; I < NumCandidates; I++) {
uint64_t Count = ValueDataRef[I].Count;
assert(Count <= TotalCount);
uint64_t Target = ValueDataRef[I].Value;
@@ -322,10 +288,6 @@
DEBUG(dbgs() << " Not promote: Cutoff reached.\n");
break;
}
- if (!isPromotionProfitable(Count, TotalCount)) {
- DEBUG(dbgs() << " Not promote: Cold target.\n");
- break;
- }
Function *TargetFunction = nullptr;
TargetStatus Status = isPromotionLegal(Inst, Target, TargetFunction);
if (Status != OK) {
@@ -633,18 +595,16 @@
// annotation to perform indirect-call promotion.
bool ICallPromotionFunc::processFunction() {
bool Changed = false;
+ ICallPromotionAnalysis ICallAnalysis;
for (auto &I : findIndirectCallSites(F)) {
- uint32_t NumVals;
+ uint32_t NumVals, NumCandidates;
uint64_t TotalCount;
- bool Res =
- getValueProfDataFromInst(*I, IPVK_IndirectCallTarget, MaxNumPromotions,
- ValueDataArray.get(), NumVals, TotalCount);
- if (!Res)
+ auto ICallProfDataRef = ICallAnalysis.getPromotionCandidatesForInstruction(
+ I, NumVals, TotalCount, NumCandidates);
+ if (!NumCandidates)
continue;
- ArrayRef<InstrProfValueData> ValueDataArrayRef(ValueDataArray.get(),
- NumVals);
- auto PromotionCandidates =
- getPromotionCandidatesForCallSite(I, ValueDataArrayRef, TotalCount);
+ auto PromotionCandidates = getPromotionCandidatesForCallSite(
+ I, ICallProfDataRef, TotalCount, NumCandidates);
uint32_t NumPromoted = tryToPromote(I, PromotionCandidates, TotalCount);
if (NumPromoted == 0)
continue;
@@ -656,8 +616,8 @@
if (TotalCount == 0 || NumPromoted == NumVals)
continue;
// Otherwise we need update with the un-promoted records back.
- annotateValueSite(*M, *I, ValueDataArrayRef.slice(NumPromoted), TotalCount,
- IPVK_IndirectCallTarget, MaxNumPromotions);
+ annotateValueSite(*M, *I, ICallProfDataRef.slice(NumPromoted), TotalCount,
+ IPVK_IndirectCallTarget, NumCandidates);
}
return Changed;
}