Index: llvm/lib/Transforms/IPO/HotColdSplitting.cpp
===================================================================
--- llvm/lib/Transforms/IPO/HotColdSplitting.cpp
+++ llvm/lib/Transforms/IPO/HotColdSplitting.cpp
@@ -44,6 +44,7 @@
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/IR/ProfDataUtils.h"
 #include "llvm/IR/User.h"
 #include "llvm/IR/Value.h"
 #include "llvm/Support/CommandLine.h"
@@ -102,11 +103,35 @@
   return !(isa<ReturnInst>(I) || isa<IndirectBrInst>(I));
 }
 
-bool unlikelyExecuted(BasicBlock &BB) {
+void analyzeProfMetadata(BasicBlock &BB, SmallPtrSetImpl<BasicBlock *> &AnnotatedColdBlocks) {
+  // TODO: Handle branches with > 2 successors.
+  BranchInst *CondBr = dyn_cast<BranchInst>(BB.getTerminator());
+  if (!CondBr)
+    return;
+
+  uint64_t TrueWeight, FalseWeight;
+  if (!extractBranchWeights(*CondBr, TrueWeight, FalseWeight))
+    return;
+
+  if (TrueWeight + FalseWeight == 0)
+    return;
+
+  if (BranchProbability(TrueWeight, TrueWeight + FalseWeight) <= BranchProbability(1, 1000))
+    AnnotatedColdBlocks.insert(CondBr->getSuccessor(0));
+
+  if (BranchProbability(FalseWeight, TrueWeight + FalseWeight) <= BranchProbability(1, 1000))
+    AnnotatedColdBlocks.insert(CondBr->getSuccessor(1));
+}
+
+bool unlikelyExecuted(BasicBlock &BB, SmallPtrSetImpl<BasicBlock *> &AnnotatedColdBlocks) {
   // Exception handling blocks are unlikely executed.
   if (BB.isEHPad() || isa<ResumeInst>(BB.getTerminator()))
     return true;
 
+  analyzeProfMetadata(BB, AnnotatedColdBlocks);
+  if (AnnotatedColdBlocks.count(&BB))
+    return true;
+
   // The block is cold if it calls/invokes a cold function. However, do not
   // mark sanitizer traps as cold.
   for (Instruction &I : BB)
@@ -564,6 +589,7 @@
 
   // The set of cold blocks.
   SmallPtrSet<BasicBlock *, 4> ColdBlocks;
+  SmallPtrSet<BasicBlock *, 4> AnnotatedColdBlocks;
 
   // The worklist of non-intersecting regions left to outline.
   SmallVector<OutliningRegion, 2> OutliningWorklist;
@@ -595,7 +621,7 @@
       continue;
 
     bool Cold = (BFI && PSI->isColdBlock(BB, BFI)) ||
-                (EnableStaticAnalysis && unlikelyExecuted(*BB));
+                (EnableStaticAnalysis && unlikelyExecuted(*BB, AnnotatedColdBlocks));
     if (!Cold)
       continue;
 
Index: llvm/test/Transforms/HotColdSplit/split-static-profile.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/HotColdSplit/split-static-profile.ll
@@ -0,0 +1,61 @@
+; RUN: opt -S -passes=hotcoldsplit < %s 2>&1  | FileCheck %s
+
+;Check that the unlikely branch is outlined.
+;int cold(const char*);
+;int hot(const char*);
+
+;void foo(int a, int b) {
+;  if (a == b) [[unlikely]] {
+;    cold("same");
+;    cold("same");
+;  } else {
+;    hot("different");
+;  }
+;}
+
+; CHECK: internal void @_Z3fooii.cold.1() #[[ATTR0:[0-9]+]]
+; CHECK-NEXT: newFuncRoot
+; CHECK: tail call noundef i32 @_Z4coldPKc
+; CHECK: tail call noundef i32 @_Z4coldPKc
+; attributes #[[ATTR0]] = { cold minsize }
+
+source_filename = "/app/example.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@.str = private unnamed_addr constant [5 x i8] c"same\00", align 1
+@.str.1 = private unnamed_addr constant [10 x i8] c"different\00", align 1
+
+define dso_local void @_Z3fooii(i32 noundef %a, i32 noundef %b) local_unnamed_addr {
+entry:
+  %cmp = icmp eq i32 %a, %b
+  br i1 %cmp, label %if.then, label %if.else, !prof !6
+
+if.then:
+  %call = tail call noundef i32 @_Z4coldPKc(ptr noundef nonnull @.str)
+  %call1 = tail call noundef i32 @_Z4coldPKc(ptr noundef nonnull @.str)
+  br label %if.end
+
+if.else:
+  %call2 = tail call noundef i32 @_Z3hotPKc(ptr noundef nonnull @.str.1)
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+declare noundef i32 @_Z4coldPKc(ptr noundef) local_unnamed_addr #1
+
+declare noundef i32 @_Z3hotPKc(ptr noundef) local_unnamed_addr #1
+
+!llvm.linker.options = !{}
+!llvm.module.flags = !{!0, !1, !2, !3, !4}
+!llvm.ident = !{!5}
+
+!0 = !{i32 7, !"Dwarf Version", i32 4}
+!1 = !{i32 1, !"wchar_size", i32 4}
+!2 = !{i32 8, !"PIC Level", i32 2}
+!3 = !{i32 7, !"PIE Level", i32 2}
+!4 = !{i32 7, !"uwtable", i32 2}
+!5 = !{!"clang version 18.0.0 (https://github.com/llvm/llvm-project.git 733edde00582c2a4a6266a4cd2bed7015f4246ce)"}
+!6 = !{!"branch_weights", i32 1, i32 2000}