diff --git a/llvm/include/llvm/Transforms/Utils/SizeOpts.h b/llvm/include/llvm/Transforms/Utils/SizeOpts.h
--- a/llvm/include/llvm/Transforms/Utils/SizeOpts.h
+++ b/llvm/include/llvm/Transforms/Utils/SizeOpts.h
@@ -21,6 +21,7 @@
 
 extern cl::opt<bool> EnablePGSO;
 extern cl::opt<bool> PGSOLargeWorkingSetSizeOnly;
+extern cl::opt<bool> PGSOIRPassOrTestOnly;
 extern cl::opt<bool> PGSOColdCodeOnly;
 extern cl::opt<bool> ForcePGSO;
 extern cl::opt<int> PgsoCutoffInstrProf;
@@ -34,8 +35,9 @@
 class ProfileSummaryInfo;
 
 enum class PGSOQueryType {
-  IRPass,  // A query call from an IR-level transform pass.
-  Other,   // Others.
+  IRPass, // A query call from an IR-level transform pass.
+  Test,   // A query call from a unit test.
+  Other,  // Others.
 };
 
 template<typename AdapterT, typename FuncT, typename BFIT>
@@ -48,6 +50,11 @@
     return true;
   if (!EnablePGSO)
     return false;
+  // Temporarily enable size optimizations only for the IR pass or test query
+  // sites for gradual commit/rollout. This is to be removed later.
+  if (PGSOIRPassOrTestOnly && !(QueryType == PGSOQueryType::IRPass ||
+                                QueryType == PGSOQueryType::Test))
+    return false;
   if (PGSOColdCodeOnly ||
       (PGSOLargeWorkingSetSizeOnly && !PSI->hasLargeWorkingSetSize())) {
     // Even if the working set size isn't large, size-optimize cold code.
@@ -68,6 +75,11 @@
     return true;
   if (!EnablePGSO)
     return false;
+  // Temporarily enable size optimizations only for the IR pass or test query
+  // sites for gradual commit/rollout. This is to be removed later.
+  if (PGSOIRPassOrTestOnly && !(QueryType == PGSOQueryType::IRPass ||
+                                QueryType == PGSOQueryType::Test))
+    return false;
   if (PGSOColdCodeOnly ||
       (PGSOLargeWorkingSetSizeOnly && !PSI->hasLargeWorkingSetSize())) {
     // Even if the working set size isn't large, size-optimize cold code.
diff --git a/llvm/lib/Transforms/Utils/SizeOpts.cpp b/llvm/lib/Transforms/Utils/SizeOpts.cpp
--- a/llvm/lib/Transforms/Utils/SizeOpts.cpp
+++ b/llvm/lib/Transforms/Utils/SizeOpts.cpp
@@ -28,6 +28,11 @@
     cl::desc("Apply the profile guided size optimizations only "
              "to cold code."));
 
+cl::opt<bool> PGSOIRPassOrTestOnly(
+    "pgso-ir-pass-or-test-only", cl::Hidden, cl::init(true),
+    cl::desc("Apply the profile guided size optimizations only"
+             "to the IR passes or tests."));
+
 cl::opt<bool> ForcePGSO(
     "force-pgso", cl::Hidden, cl::init(false),
     cl::desc("Force the (profiled-guided) size optimizations. "));
diff --git a/llvm/unittests/Target/X86/MachineSizeOptsTest.cpp b/llvm/unittests/Target/X86/MachineSizeOptsTest.cpp
--- a/llvm/unittests/Target/X86/MachineSizeOptsTest.cpp
+++ b/llvm/unittests/Target/X86/MachineSizeOptsTest.cpp
@@ -113,13 +113,13 @@
   ASSERT_TRUE(iter == BB0.succ_end());
   MachineBasicBlock *BB3 = *BB1->succ_begin();
   ASSERT_TRUE(BB3 == *BB2->succ_begin());
-  EXPECT_FALSE(shouldOptimizeForSize(F, &PSI, MBFI_F));
-  EXPECT_TRUE(shouldOptimizeForSize(G, &PSI, MBFI_G));
-  EXPECT_FALSE(shouldOptimizeForSize(H, &PSI, MBFI_H));
-  EXPECT_FALSE(shouldOptimizeForSize(&BB0, &PSI, MBFI_F));
-  EXPECT_FALSE(shouldOptimizeForSize(BB1, &PSI, MBFI_F));
-  EXPECT_TRUE(shouldOptimizeForSize(BB2, &PSI, MBFI_F));
-  EXPECT_FALSE(shouldOptimizeForSize(BB3, &PSI, MBFI_F));
+  EXPECT_FALSE(shouldOptimizeForSize(F, &PSI, MBFI_F, PGSOQueryType::Test));
+  EXPECT_TRUE(shouldOptimizeForSize(G, &PSI, MBFI_G, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(H, &PSI, MBFI_H, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(&BB0, &PSI, MBFI_F, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(BB1, &PSI, MBFI_F, PGSOQueryType::Test));
+  EXPECT_TRUE(shouldOptimizeForSize(BB2, &PSI, MBFI_F, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(BB3, &PSI, MBFI_F, PGSOQueryType::Test));
 }
 
 const char* MachineSizeOptsTest::MIRString = R"MIR(
diff --git a/llvm/unittests/Transforms/Utils/SizeOptsTest.cpp b/llvm/unittests/Transforms/Utils/SizeOptsTest.cpp
--- a/llvm/unittests/Transforms/Utils/SizeOptsTest.cpp
+++ b/llvm/unittests/Transforms/Utils/SizeOptsTest.cpp
@@ -68,13 +68,13 @@
   BasicBlock *BB3 = BB1->getSingleSuccessor();
 
   EXPECT_TRUE(PSI.hasProfileSummary());
-  EXPECT_FALSE(shouldOptimizeForSize(F, &PSI, BFI_F));
-  EXPECT_TRUE(shouldOptimizeForSize(G, &PSI, BFI_G));
-  EXPECT_FALSE(shouldOptimizeForSize(H, &PSI, BFI_H));
-  EXPECT_FALSE(shouldOptimizeForSize(&BB0, &PSI, BFI_F));
-  EXPECT_FALSE(shouldOptimizeForSize(BB1, &PSI, BFI_F));
-  EXPECT_TRUE(shouldOptimizeForSize(BB2, &PSI, BFI_F));
-  EXPECT_FALSE(shouldOptimizeForSize(BB3, &PSI, BFI_F));
+  EXPECT_FALSE(shouldOptimizeForSize(F, &PSI, BFI_F, PGSOQueryType::Test));
+  EXPECT_TRUE(shouldOptimizeForSize(G, &PSI, BFI_G, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(H, &PSI, BFI_H, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(&BB0, &PSI, BFI_F, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(BB1, &PSI, BFI_F, PGSOQueryType::Test));
+  EXPECT_TRUE(shouldOptimizeForSize(BB2, &PSI, BFI_F, PGSOQueryType::Test));
+  EXPECT_FALSE(shouldOptimizeForSize(BB3, &PSI, BFI_F, PGSOQueryType::Test));
 }
 
 const char* SizeOptsTest::IRString = R"IR(