[llvm] [nfc][PGO]Factor out profile scaling into a standalone helper function (PR #83780)
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llvm-commits at lists.llvm.org
Mon Mar 4 09:02:34 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms
@llvm/pr-subscribers-llvm-ir
Author: Mingming Liu (minglotus-6)
<details>
<summary>Changes</summary>
- Put the helper function in `ProfDataUtil.h/cpp`, which is already a dependency of `Instructions.cpp`
- The helper function could be re-used to update profiles of `InvokeInst` (in a follow-up pull request)
---
Full diff: https://github.com/llvm/llvm-project/pull/83780.diff
4 Files Affected:
- (modified) llvm/include/llvm/IR/ProfDataUtils.h (+3)
- (modified) llvm/lib/IR/Instructions.cpp (+1-45)
- (modified) llvm/lib/IR/ProfDataUtils.cpp (+48)
- (added) llvm/test/Transforms/Inline/update_value_profile.ll (+82)
``````````diff
diff --git a/llvm/include/llvm/IR/ProfDataUtils.h b/llvm/include/llvm/IR/ProfDataUtils.h
index 255fa2ff1c7906..c0897408986fb3 100644
--- a/llvm/include/llvm/IR/ProfDataUtils.h
+++ b/llvm/include/llvm/IR/ProfDataUtils.h
@@ -108,5 +108,8 @@ bool extractProfTotalWeight(const Instruction &I, uint64_t &TotalWeights);
/// a `prof` metadata reference to instruction `I`.
void setBranchWeights(Instruction &I, ArrayRef<uint32_t> Weights);
+/// Scaling the profile data attached to 'I' using the ratio of S/T.
+void scaleProfData(Instruction &I, uint64_t S, uint64_t T);
+
} // namespace llvm
#endif
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
index 42cdcad78228f6..9ae71acd523c36 100644
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -825,15 +825,6 @@ CallInst *CallInst::Create(CallInst *CI, ArrayRef<OperandBundleDef> OpB,
// of S/T. The meaning of "branch_weights" meta data for call instruction is
// transfered to represent call count.
void CallInst::updateProfWeight(uint64_t S, uint64_t T) {
- auto *ProfileData = getMetadata(LLVMContext::MD_prof);
- if (ProfileData == nullptr)
- return;
-
- auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
- if (!ProfDataName || (!ProfDataName->getString().equals("branch_weights") &&
- !ProfDataName->getString().equals("VP")))
- return;
-
if (T == 0) {
LLVM_DEBUG(dbgs() << "Attempting to update profile weights will result in "
"div by 0. Ignoring. Likely the function "
@@ -842,42 +833,7 @@ void CallInst::updateProfWeight(uint64_t S, uint64_t T) {
"with non-zero prof info.");
return;
}
-
- MDBuilder MDB(getContext());
- SmallVector<Metadata *, 3> Vals;
- Vals.push_back(ProfileData->getOperand(0));
- APInt APS(128, S), APT(128, T);
- if (ProfDataName->getString().equals("branch_weights") &&
- ProfileData->getNumOperands() > 0) {
- // Using APInt::div may be expensive, but most cases should fit 64 bits.
- APInt Val(128, mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(1))
- ->getValue()
- .getZExtValue());
- Val *= APS;
- Vals.push_back(MDB.createConstant(
- ConstantInt::get(Type::getInt32Ty(getContext()),
- Val.udiv(APT).getLimitedValue(UINT32_MAX))));
- } else if (ProfDataName->getString().equals("VP"))
- for (unsigned i = 1; i < ProfileData->getNumOperands(); i += 2) {
- // The first value is the key of the value profile, which will not change.
- Vals.push_back(ProfileData->getOperand(i));
- uint64_t Count =
- mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i + 1))
- ->getValue()
- .getZExtValue();
- // Don't scale the magic number.
- if (Count == NOMORE_ICP_MAGICNUM) {
- Vals.push_back(ProfileData->getOperand(i + 1));
- continue;
- }
- // Using APInt::div may be expensive, but most cases should fit 64 bits.
- APInt Val(128, Count);
- Val *= APS;
- Vals.push_back(MDB.createConstant(
- ConstantInt::get(Type::getInt64Ty(getContext()),
- Val.udiv(APT).getLimitedValue())));
- }
- setMetadata(LLVMContext::MD_prof, MDNode::get(getContext(), Vals));
+ scaleProfData(*this, S, T);
}
//===----------------------------------------------------------------------===//
diff --git a/llvm/lib/IR/ProfDataUtils.cpp b/llvm/lib/IR/ProfDataUtils.cpp
index b1a10d0ce5a522..dc86f4204b1a1d 100644
--- a/llvm/lib/IR/ProfDataUtils.cpp
+++ b/llvm/lib/IR/ProfDataUtils.cpp
@@ -190,4 +190,52 @@ void setBranchWeights(Instruction &I, ArrayRef<uint32_t> Weights) {
I.setMetadata(LLVMContext::MD_prof, BranchWeights);
}
+void scaleProfData(Instruction &I, uint64_t S, uint64_t T) {
+ assert(T != 0 && "Caller should guarantee");
+ auto *ProfileData = I.getMetadata(LLVMContext::MD_prof);
+ if (ProfileData == nullptr)
+ return;
+
+ auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
+ if (!ProfDataName || (!ProfDataName->getString().equals("branch_weights") &&
+ !ProfDataName->getString().equals("VP")))
+ return;
+
+ LLVMContext &C = I.getContext();
+
+ MDBuilder MDB(C);
+ SmallVector<Metadata *, 3> Vals;
+ Vals.push_back(ProfileData->getOperand(0));
+ APInt APS(128, S), APT(128, T);
+ if (ProfDataName->getString().equals("branch_weights") &&
+ ProfileData->getNumOperands() > 0) {
+ // Using APInt::div may be expensive, but most cases should fit 64 bits.
+ APInt Val(128, mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(1))
+ ->getValue()
+ .getZExtValue());
+ Val *= APS;
+ Vals.push_back(MDB.createConstant(ConstantInt::get(
+ Type::getInt32Ty(C), Val.udiv(APT).getLimitedValue(UINT32_MAX))));
+ } else if (ProfDataName->getString().equals("VP"))
+ for (unsigned i = 1; i < ProfileData->getNumOperands(); i += 2) {
+ // The first value is the key of the value profile, which will not change.
+ Vals.push_back(ProfileData->getOperand(i));
+ uint64_t Count =
+ mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i + 1))
+ ->getValue()
+ .getZExtValue();
+ // Don't scale the magic number.
+ if (Count == NOMORE_ICP_MAGICNUM) {
+ Vals.push_back(ProfileData->getOperand(i + 1));
+ continue;
+ }
+ // Using APInt::div may be expensive, but most cases should fit 64 bits.
+ APInt Val(128, Count);
+ Val *= APS;
+ Vals.push_back(MDB.createConstant(ConstantInt::get(
+ Type::getInt64Ty(C), Val.udiv(APT).getLimitedValue())));
+ }
+ I.setMetadata(LLVMContext::MD_prof, MDNode::get(C, Vals));
+}
+
} // namespace llvm
diff --git a/llvm/test/Transforms/Inline/update_value_profile.ll b/llvm/test/Transforms/Inline/update_value_profile.ll
new file mode 100644
index 00000000000000..7fa8c28f89f7ce
--- /dev/null
+++ b/llvm/test/Transforms/Inline/update_value_profile.ll
@@ -0,0 +1,82 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes='require<profile-summary>,cgscc(inline)' -inline-threshold=100 -S | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; When 'callee' is inlined into caller1 and caller2, the indirect call value
+; profiles of the inlined copy should be scaled based on callers' profiles,
+; and the indirect call value profiles in 'callee' should be updated.
+define i32 @callee(ptr %0, i32 %1) !prof !20 {
+; CHECK-LABEL: define i32 @callee(
+; CHECK-SAME: ptr [[TMP0:%.*]], i32 [[TMP1:%.*]]) !prof [[PROF0:![0-9]+]] {
+; CHECK-NEXT: [[TMP3:%.*]] = load ptr, ptr [[TMP0]], align 8
+; CHECK-NEXT: [[TMP4:%.*]] = getelementptr inbounds i8, ptr [[TMP3]], i64 8
+; CHECK-NEXT: [[TMP5:%.*]] = load ptr, ptr [[TMP4]], align 8
+; CHECK-NEXT: [[TMP6:%.*]] = tail call i32 [[TMP5]](ptr [[TMP0]], i32 [[TMP1]]), !prof [[PROF1:![0-9]+]]
+; CHECK-NEXT: ret i32 [[TMP6]]
+;
+ %3 = load ptr, ptr %0
+ %5 = getelementptr inbounds i8, ptr %3, i64 8
+ %6 = load ptr, ptr %5
+ %7 = tail call i32 %6(ptr %0, i32 %1), !prof !17
+ ret i32 %7
+}
+
+define i32 @caller1(i32 %0) !prof !18 {
+; CHECK-LABEL: define i32 @caller1(
+; CHECK-SAME: i32 [[TMP0:%.*]]) !prof [[PROF2:![0-9]+]] {
+; CHECK-NEXT: [[TMP2:%.*]] = tail call ptr @_Z10createTypei(i32 [[TMP0]])
+; CHECK-NEXT: [[TMP3:%.*]] = load ptr, ptr [[TMP2]], align 8
+; CHECK-NEXT: [[TMP4:%.*]] = getelementptr inbounds i8, ptr [[TMP3]], i64 8
+; CHECK-NEXT: [[TMP5:%.*]] = load ptr, ptr [[TMP4]], align 8
+; CHECK-NEXT: [[TMP6:%.*]] = tail call i32 [[TMP5]](ptr [[TMP2]], i32 [[TMP0]]), !prof [[PROF3:![0-9]+]]
+; CHECK-NEXT: ret i32 [[TMP6]]
+;
+ %2 = tail call ptr @_Z10createTypei(i32 %0)
+ %3 = tail call i32 @callee(ptr %2, i32 %0)
+ ret i32 %3
+}
+
+define i32 @caller2(i32 %0) !prof !19 {
+; CHECK-LABEL: define i32 @caller2(
+; CHECK-SAME: i32 [[TMP0:%.*]]) !prof [[PROF4:![0-9]+]] {
+; CHECK-NEXT: [[TMP2:%.*]] = tail call ptr @_Z10createTypei(i32 [[TMP0]])
+; CHECK-NEXT: [[TMP3:%.*]] = load ptr, ptr [[TMP2]], align 8
+; CHECK-NEXT: [[TMP4:%.*]] = getelementptr inbounds i8, ptr [[TMP3]], i64 8
+; CHECK-NEXT: [[TMP5:%.*]] = load ptr, ptr [[TMP4]], align 8
+; CHECK-NEXT: [[TMP6:%.*]] = tail call i32 [[TMP5]](ptr [[TMP2]], i32 [[TMP0]]), !prof [[PROF5:![0-9]+]]
+; CHECK-NEXT: ret i32 [[TMP6]]
+;
+ %2 = tail call ptr @_Z10createTypei(i32 %0)
+ %3 = tail call i32 @callee(ptr %2, i32 %0)
+ ret i32 %3
+}
+
+declare ptr @_Z10createTypei(i32)
+
+!1 = !{i32 1, !"ProfileSummary", !2}
+!2 = !{!3, !4, !5, !6, !7, !8, !9, !10}
+!3 = !{!"ProfileFormat", !"InstrProf"}
+!4 = !{!"TotalCount", i64 10000}
+!5 = !{!"MaxCount", i64 10}
+!6 = !{!"MaxInternalCount", i64 1}
+!7 = !{!"MaxFunctionCount", i64 1000}
+!8 = !{!"NumCounts", i64 3}
+!9 = !{!"NumFunctions", i64 3}
+!10 = !{!"DetailedSummary", !11}
+!11 = !{!12, !13, !14}
+!12 = !{i32 10000, i64 100, i32 1}
+!13 = !{i32 999000, i64 100, i32 1}
+!14 = !{i32 999999, i64 1, i32 2}
+!17 = !{!"VP", i32 0, i64 1600, i64 15186643663281959480, i64 1000, i64 15101948577241817854, i64 600}
+!18 = !{!"function_entry_count", i64 1000}
+!19 = !{!"function_entry_count", i64 600}
+!20 = !{!"function_entry_count", i64 1700}
+;.
+; CHECK: [[PROF0]] = !{!"function_entry_count", i64 100}
+; CHECK: [[PROF1]] = !{!"VP", i32 0, i64 94, i64 -3260100410427592136, i64 58, i64 -3344795496467733762, i64 35}
+; CHECK: [[PROF2]] = !{!"function_entry_count", i64 1000}
+; CHECK: [[PROF3]] = !{!"VP", i32 0, i64 941, i64 -3260100410427592136, i64 588, i64 -3344795496467733762, i64 352}
+; CHECK: [[PROF4]] = !{!"function_entry_count", i64 600}
+; CHECK: [[PROF5]] = !{!"VP", i32 0, i64 564, i64 -3260100410427592136, i64 352, i64 -3344795496467733762, i64 211}
+;.
``````````
</details>
https://github.com/llvm/llvm-project/pull/83780
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