From 5aa7e0e8e5279864275421540e3bd071072afb25 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka@google.com>
Date: Mon, 10 Jun 2024 15:19:36 -0700
Subject: [PATCH] [NFCI][metadata][clang] Use
 create{Unlikely,Likely}BranchWeights (#89467)

It does not look like particular value is inportant.
Howere, there is a comment., but the current implementation
of `create{Unlikely,Likely}BranchWeights` use the same value.

Follow up to #89464
---
 clang/lib/CodeGen/CGExpr.cpp        | 5 ++---
 clang/lib/CodeGen/CGExprComplex.cpp | 3 +--
 clang/lib/CodeGen/CGObjCGNU.cpp     | 4 ++--
 clang/lib/CodeGen/CGObjCMac.cpp     | 2 +-
 4 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index d6478cc6835d82..48d8ca34788621 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -3571,9 +3571,8 @@ void CodeGenFunction::EmitCheck(
   llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
   llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
   // Give hint that we very much don't expect to execute the handler
-  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
   llvm::MDBuilder MDHelper(getLLVMContext());
-  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
+  llvm::MDNode *Node = MDHelper.createLikelyBranchWeights();
   Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
   EmitBlock(Handlers);
 
@@ -3641,7 +3640,7 @@ void CodeGenFunction::EmitCfiSlowPathCheck(
   llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
 
   llvm::MDBuilder MDHelper(getLLVMContext());
-  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
+  llvm::MDNode *Node = MDHelper.createLikelyBranchWeights();
   BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
 
   EmitBlock(CheckBB);
diff --git a/clang/lib/CodeGen/CGExprComplex.cpp b/clang/lib/CodeGen/CGExprComplex.cpp
index 9ef73e36f66f35..f19334489a0ba5 100644
--- a/clang/lib/CodeGen/CGExprComplex.cpp
+++ b/clang/lib/CodeGen/CGExprComplex.cpp
@@ -856,8 +856,7 @@ ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
       llvm::BasicBlock *OrigBB = Branch->getParent();
 
       // Give hint that we very much don't expect to see NaNs.
-      // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
-      llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
+      llvm::MDNode *BrWeight = MDHelper.createUnlikelyBranchWeights();
       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
 
       // Now test the imaginary part and create its branch.
diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
index 6540ac69f2d9b0..948b10954ebbed 100644
--- a/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -2069,7 +2069,7 @@ class CGObjCGNUstep2 : public CGObjCGNUstep {
 
         Builder.CreateCondBr(Builder.CreateICmpEQ(selfValue, Zero),
                              SelfIsNilBlock, ContBlock,
-                             MDHelper.createBranchWeights(1, 1 << 20));
+                             MDHelper.createUnlikelyBranchWeights());
 
         CGF.EmitBlock(SelfIsNilBlock);
 
@@ -2104,7 +2104,7 @@ class CGObjCGNUstep2 : public CGObjCGNUstep {
             CGF.createBasicBlock("objc_direct_method.class_initialized");
         Builder.CreateCondBr(Builder.CreateICmpEQ(isInitialized, Zeros[0]),
                              notInitializedBlock, initializedBlock,
-                             MDHelper.createBranchWeights(1, 1 << 20));
+                             MDHelper.createUnlikelyBranchWeights());
         CGF.EmitBlock(notInitializedBlock);
         Builder.SetInsertPoint(notInitializedBlock);
         CGF.EmitRuntimeCall(SentInitializeFn, selfValue);
diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index 042cd5d46da4b2..30f3911a8b03c2 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -4072,7 +4072,7 @@ void CGObjCCommonMac::GenerateDirectMethodPrologue(
 
     llvm::MDBuilder MDHelper(CGM.getLLVMContext());
     Builder.CreateCondBr(Builder.CreateICmpEQ(selfValue, Zero), SelfIsNilBlock,
-                         ContBlock, MDHelper.createBranchWeights(1, 1 << 20));
+                         ContBlock, MDHelper.createUnlikelyBranchWeights());
 
     CGF.EmitBlock(SelfIsNilBlock);