Add hot/cold splitting test job to jit-runtime-experimental

eng/pipelines/common/templates/runtimes/run-test-job.yml

@@ -572,6 +572,7 @@ jobs:
           - jitosr_stress
           - jitosr_pgo
           - jitosr_stress_random
+          - jit_stress_splitting
           - jitpartialcompilation
           - jitpartialcompilation_osr
           - jitpartialcompilation_osr_pgo

src/coreclr/jit/compiler.h

@@ -7966,6 +7966,10 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
     void unwindReserveFuncHelper(FuncInfoDsc* func, bool isHotCode);
     void unwindEmitFuncHelper(FuncInfoDsc* func, void* pHotCode, void* pColdCode, bool isHotCode);
 
+#ifdef DEBUG
+    void fakeUnwindEmitFuncHelper(FuncInfoDsc* func, void* pHotCode);
+#endif // DEBUG
+
 #endif // TARGET_AMD64 || (TARGET_X86 && FEATURE_EH_FUNCLETS)
 
     UNATIVE_OFFSET unwindGetCurrentOffset(FuncInfoDsc* func);

src/coreclr/jit/ee_il_dll.cpp

@@ -1125,14 +1125,13 @@ void Compiler::eeDispLineInfos()
 void Compiler::eeAllocMem(AllocMemArgs* args)
 {
 #ifdef DEBUG
-    // Fake splitting implementation: hot section = hot code + 4K buffer + cold code
-    const UNATIVE_OFFSET hotSizeRequest      = args->hotCodeSize;
-    const UNATIVE_OFFSET coldSizeRequest     = args->coldCodeSize;
-    const UNATIVE_OFFSET fakeSplittingBuffer = 4096;
+    const UNATIVE_OFFSET hotSizeRequest  = args->hotCodeSize;
+    const UNATIVE_OFFSET coldSizeRequest = args->coldCodeSize;
 
+    // Fake splitting implementation: place hot/cold code in contiguous section
     if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
     {
-        args->hotCodeSize  = hotSizeRequest + fakeSplittingBuffer + coldSizeRequest;
+        args->hotCodeSize  = hotSizeRequest + coldSizeRequest;
         args->coldCodeSize = 0;
     }
 #endif
@@ -1143,8 +1142,8 @@ void Compiler::eeAllocMem(AllocMemArgs* args)
     if (JitConfig.JitFakeProcedureSplitting() && (coldSizeRequest > 0))
     {
         // Fix up hot/cold code pointers
-        args->coldCodeBlock   = ((BYTE*)args->hotCodeBlock) + hotSizeRequest + fakeSplittingBuffer;
-        args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest + fakeSplittingBuffer;
+        args->coldCodeBlock   = ((BYTE*)args->hotCodeBlock) + hotSizeRequest;
+        args->coldCodeBlockRW = ((BYTE*)args->hotCodeBlockRW) + hotSizeRequest;
 
         // Reset args' hot/cold code sizes in case caller reads them later
         args->hotCodeSize  = hotSizeRequest;
@@ -1161,13 +1160,6 @@ void Compiler::eeReserveUnwindInfo(bool isFunclet, bool isColdCode, ULONG unwind
         printf("reserveUnwindInfo(isFunclet=%s, isColdCode=%s, unwindSize=0x%x)\n", isFunclet ? "true" : "false",
                isColdCode ? "true" : "false", unwindSize);
     }
-
-    // Fake splitting currently does not handle unwind info for cold code
-    if (isColdCode && JitConfig.JitFakeProcedureSplitting())
-    {
-        JITDUMP("reserveUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
-        return;
-    }
 #endif // DEBUG
 
     if (info.compMatchedVM)
@@ -1207,13 +1199,6 @@ void Compiler::eeAllocUnwindInfo(BYTE*          pHotCode,
         }
         printf(")\n");
     }
-
-    // Fake splitting currently does not handle unwind info for cold code
-    if (pColdCode && JitConfig.JitFakeProcedureSplitting())
-    {
-        JITDUMP("allocUnwindInfo for cold code with JitFakeProcedureSplitting enabled: ignoring cold unwind info\n");
-        return;
-    }
 #endif // DEBUG
 
     if (info.compMatchedVM)

src/coreclr/jit/emit.cpp

@@ -6637,10 +6637,13 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,
             {
                 // The allocated chunk is bigger than used, fill in unused space in it.
                 unsigned unusedSize = allocatedHotCodeSize - emitCurCodeOffs(cp);
+                BYTE*    cpRW       = cp + writeableOffset;
                 for (unsigned i = 0; i < unusedSize; ++i)
                 {
-                    *cp++ = DEFAULT_CODE_BUFFER_INIT;
+                    *cpRW++ = DEFAULT_CODE_BUFFER_INIT;
                 }
+
+                cp = cpRW - writeableOffset;
                 assert(allocatedHotCodeSize == emitCurCodeOffs(cp));
             }
         }

src/coreclr/jit/jitconfigvalues.h

@@ -196,11 +196,6 @@ CONFIG_INTEGER(JitDumpInlinePhases, W("JitDumpInlinePhases"), 1) // Dump inline
 CONFIG_METHODSET(JitEHDump, W("JitEHDump")) // Dump the EH table for the method, as reported to the VM
 CONFIG_METHODSET(JitExclude, W("JitExclude"))
 CONFIG_INTEGER(JitFakeProcedureSplitting, W("JitFakeProcedureSplitting"), 0) // Do code splitting independent of VM.
-                                                                             // For now, this disables unwind info for
-                                                                             // cold sections, breaking stack walks.
-                                                                             // Set COMPlus_GCgen0size=1000000 to avoid
-                                                                             // running the GC, which requires
-                                                                             // stack-walking.
 CONFIG_METHODSET(JitForceProcedureSplitting, W("JitForceProcedureSplitting"))
 CONFIG_METHODSET(JitGCDump, W("JitGCDump"))
 CONFIG_METHODSET(JitDebugDump, W("JitDebugDump"))

src/coreclr/jit/unwindamd64.cpp

@@ -656,11 +656,21 @@ void Compiler::unwindReserve()
 //
 void Compiler::unwindReserveFunc(FuncInfoDsc* func)
 {
-    unwindReserveFuncHelper(func, true);
-
-    if (fgFirstColdBlock != nullptr)
+#ifdef DEBUG
+    if (JitConfig.JitFakeProcedureSplitting() && (fgFirstColdBlock != nullptr))
     {
-        unwindReserveFuncHelper(func, false);
+        assert(func->funKind == FUNC_ROOT); // No fake-splitting of funclets.
+        unwindReserveFuncHelper(func, true);
+    }
+    else
+#endif // DEBUG
+    {
+        unwindReserveFuncHelper(func, true);
+
+        if (fgFirstColdBlock != nullptr)
+        {
+            unwindReserveFuncHelper(func, false);
+        }
     }
 }
 
@@ -880,12 +890,43 @@ void Compiler::unwindEmitFunc(FuncInfoDsc* func, void* pHotCode, void* pColdCode
     static_assert_no_msg(FUNC_HANDLER == (FuncKind)CORJIT_FUNC_HANDLER);
     static_assert_no_msg(FUNC_FILTER == (FuncKind)CORJIT_FUNC_FILTER);
 
-    unwindEmitFuncHelper(func, pHotCode, pColdCode, true);
+#ifdef DEBUG
+    if (JitConfig.JitFakeProcedureSplitting() && (pColdCode != nullptr))
+    {
+        fakeUnwindEmitFuncHelper(func, pHotCode);
+    }
+    else
+#endif // DEBUG
+    {
+        unwindEmitFuncHelper(func, pHotCode, pColdCode, true);
+
+        if (pColdCode != nullptr)
+        {
+            unwindEmitFuncHelper(func, pHotCode, pColdCode, false);
+        }
+    }
+}
+
+#ifdef DEBUG
+void Compiler::fakeUnwindEmitFuncHelper(FuncInfoDsc* func, void* pHotCode)
+{
+    assert(fgFirstColdBlock != nullptr);
+    assert(func->funKind == FUNC_ROOT); // No fake-splitting of funclets.
 
-    if (pColdCode != nullptr)
+    const UNATIVE_OFFSET startOffset     = 0;
+    const UNATIVE_OFFSET endOffset       = info.compNativeCodeSize;
+    const DWORD          unwindCodeBytes = sizeof(func->unwindCodes) - func->unwindCodeSlot;
+    BYTE*                pUnwindBlock    = &func->unwindCodes[func->unwindCodeSlot];
+
+    if (opts.dspUnwind)
     {
-        unwindEmitFuncHelper(func, pHotCode, pColdCode, false);
+        DumpUnwindInfo(true, startOffset, endOffset, (const UNWIND_INFO* const)pUnwindBlock);
     }
+
+    // Pass pColdCode = nullptr; VM allocs unwind info for combined hot/cold section
+    eeAllocUnwindInfo((BYTE*)pHotCode, nullptr, startOffset, endOffset, unwindCodeBytes, pUnwindBlock,
+                      (CorJitFuncKind)func->funKind);
 }
+#endif // DEBUG
 
 #endif // TARGET_AMD64

src/coreclr/jit/unwindx86.cpp

@@ -113,11 +113,21 @@ void Compiler::unwindEmit(void* pHotCode, void* pColdCode)
 //
 void Compiler::unwindReserveFunc(FuncInfoDsc* func)
 {
-    unwindReserveFuncHelper(func, true);
-
-    if (fgFirstColdBlock != nullptr)
+#ifdef DEBUG
+    if (JitConfig.JitFakeProcedureSplitting() && (fgFirstColdBlock != nullptr))
     {
-        unwindReserveFuncHelper(func, false);
+        assert(func->funKind == FUNC_ROOT); // No fake-splitting of funclets.
+        unwindReserveFuncHelper(func, true);
+    }
+    else
+#endif // DEBUG
+    {
+        unwindReserveFuncHelper(func, true);
+
+        if (fgFirstColdBlock != nullptr)
+        {
+            unwindReserveFuncHelper(func, false);
+        }
     }
 }
 
@@ -154,11 +164,20 @@ void Compiler::unwindEmitFunc(FuncInfoDsc* func, void* pHotCode, void* pColdCode
     static_assert_no_msg(FUNC_HANDLER == (FuncKind)CORJIT_FUNC_HANDLER);
     static_assert_no_msg(FUNC_FILTER == (FuncKind)CORJIT_FUNC_FILTER);
 
-    unwindEmitFuncHelper(func, pHotCode, pColdCode, true);
-
-    if (pColdCode != nullptr)
+#ifdef DEBUG
+    if (JitConfig.JitFakeProcedureSplitting() && (pColdCode != nullptr))
+    {
+        fakeUnwindEmitFuncHelper(func, pHotCode);
+    }
+    else
+#endif // DEBUG
     {
-        unwindEmitFuncHelper(func, pHotCode, pColdCode, false);
+        unwindEmitFuncHelper(func, pHotCode, pColdCode, true);
+
+        if (pColdCode != nullptr)
+        {
+            unwindEmitFuncHelper(func, pHotCode, pColdCode, false);
+        }
     }
 }
 
@@ -256,4 +275,23 @@ void Compiler::unwindEmitFuncHelper(FuncInfoDsc* func, void* pHotCode, void* pCo
     eeAllocUnwindInfo((BYTE*)pHotCode, (BYTE*)pColdCode, startOffset, endOffset, sizeof(UNWIND_INFO),
                       (BYTE*)&unwindInfo, (CorJitFuncKind)func->funKind);
 }
+
+#ifdef DEBUG
+void Compiler::fakeUnwindEmitFuncHelper(FuncInfoDsc* func, void* pHotCode)
+{
+    assert(fgFirstColdBlock != nullptr);
+    assert(func->funKind == FUNC_ROOT); // No fake-splitting of funclets.
+
+    const UNATIVE_OFFSET startOffset = 0;
+    const UNATIVE_OFFSET endOffset   = info.compNativeCodeSize;
+
+    UNWIND_INFO unwindInfo;
+    unwindInfo.FunctionLength = (ULONG)(endOffset);
+
+    // Pass pColdCode = nullptr; VM allocs unwind info for combined hot/cold section
+    eeAllocUnwindInfo((BYTE*)pHotCode, nullptr, startOffset, endOffset, sizeof(UNWIND_INFO), (BYTE*)&unwindInfo,
+                      (CorJitFuncKind)func->funKind);
+}
+#endif // DEBUG
+
 #endif // FEATURE_EH_FUNCLETS

src/tests/Common/testenvironment.proj

@@ -42,7 +42,9 @@
       COMPlus_HeapVerify;
       COMPlus_JITMinOpts;
       COMPlus_JitELTHookEnabled;
+      COMPlus_JitFakeProcedureSplitting;
       COMPlus_JitStress;
+      COMPlus_JitStressProcedureSplitting;
       COMPlus_JitStressRegs;
       COMPlus_TailcallStress;
       COMPlus_ReadyToRun;
@@ -188,6 +190,7 @@
     <TestEnvironment Include="jitosr" TC_OnStackReplacement="1" TC_QuickJitForLoops="1" TieredCompilation="1" />
     <TestEnvironment Include="jitosr_stress" TC_OnStackReplacement="1" TC_QuickJitForLoops="1" TC_OnStackReplacement_InitialCounter="1" OSR_HitLimit="1" TieredCompilation="1" />
     <TestEnvironment Include="jitosr_stress_random" TC_OnStackReplacement="1" TC_QuickJitForLoops="1" TC_OnStackReplacement_InitialCounter="1" OSR_HitLimit="2" TieredCompilation="1" JitRandomOnStackReplacement="15"/>
+    <TestEnvironment Include="jit_stress_splitting" JitFakeProcedureSplitting="1" JitStressProcedureSplitting="1" />
     <TestEnvironment Include="jitosr_pgo" TC_OnStackReplacement="1" TC_QuickJitForLoops="1" TieredCompilation="1" TieredPGO="1" />
     <TestEnvironment Include="jitpartialcompilation" TC_PartialCompilation="1" TC_QuickJitForLoops="1" TieredCompilation="1" />
     <TestEnvironment Include="jitpartialcompilation_pgo" TC_PartialCompilation="1" TC_QuickJitForLoops="1" TieredCompilation="1" TieredPGO="1" />