JIT: Support for devirtualizing array interface methods (#108153)

Update JIT and runtime to devirtualize interface calls on arrays over non-shared element types. Shared types are not (yet) handled. Add intrinsic and inlining attributes to key methods in the BCL. This allows the JIT to devirtualize and inline enumerator creation and devirtualize and inline all methods that access the enumerator. And this in turn allows the enumerator to be stack allocated in some simple cases. However, the enumerator fields are not (yet) physically promoted, because of an optimization in the BCL to return a static empty array enumerator. So the object being accessed later is ambiguous. Alse ensure that since GDV resolves the virtual call twice, and expects to get similar results both times, things work for the array case by keeping track of the initial devirtualization inputs. Progress towards #62457.
dotnet · Oct 2, 2024 · 6906730 · 6906730
1 parent 8611665
commit 6906730
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Showing 32 changed files with 597 additions and 216 deletions.
diff --git a/src/coreclr/System.Private.CoreLib/src/System/Array.CoreCLR.cs b/src/coreclr/System.Private.CoreLib/src/System/Array.CoreCLR.cs
@@ -740,6 +740,8 @@ private SZArrayHelper()
             Debug.Fail("Hey! How'd I get here?");
         }
 
+        [Intrinsic]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal IEnumerator<T> GetEnumerator<T>()
         {
             // ! Warning: "this" is an array, not an SZArrayHelper. See comments above

diff --git a/src/coreclr/inc/corinfo.h b/src/coreclr/inc/corinfo.h
@@ -1510,18 +1510,21 @@ struct CORINFO_DEVIRTUALIZATION_INFO
     // [Out] results of resolveVirtualMethod.
     // - devirtualizedMethod is set to MethodDesc of devirt'ed method iff we were able to devirtualize.
     //      invariant is `resolveVirtualMethod(...) == (devirtualizedMethod != nullptr)`.
-    // - requiresInstMethodTableArg is set to TRUE if the devirtualized method requires a type handle arg.
     // - exactContext is set to wrapped CORINFO_CLASS_HANDLE of devirt'ed method table.
     // - details on the computation done by the jit host
     // - If pResolvedTokenDevirtualizedMethod is not set to NULL and targeting an R2R image
     //   use it as the parameter to getCallInfo
+    // - requiresInstMethodTableArg is set to TRUE if the devirtualized method requires a type handle arg.
+    // - wasArrayInterfaceDevirt is set TRUE for array interface method devirtualization
+    //     (in which case the method handle and context will be a generic method)
     //
     CORINFO_METHOD_HANDLE           devirtualizedMethod;
-    bool                            requiresInstMethodTableArg;
     CORINFO_CONTEXT_HANDLE          exactContext;
     CORINFO_DEVIRTUALIZATION_DETAIL detail;
     CORINFO_RESOLVED_TOKEN          resolvedTokenDevirtualizedMethod;
     CORINFO_RESOLVED_TOKEN          resolvedTokenDevirtualizedUnboxedMethod;
+    bool                            requiresInstMethodTableArg;
+    bool                            wasArrayInterfaceDevirt;
 };
 
 //----------------------------------------------------------------------------
@@ -2123,6 +2126,12 @@ class ICorStaticInfo
             CORINFO_CLASS_HANDLE elemType
             ) = 0;
 
+    // Given T, return the type of the SZArrayHelper enumerator
+    // Returns null if the type can't be determined exactly.
+    virtual CORINFO_CLASS_HANDLE getSZArrayHelperEnumeratorClass(
+            CORINFO_CLASS_HANDLE elemType
+            ) = 0;
+
     // Given resolved token that corresponds to an intrinsic classified to
     // get a raw handle (NI_System_Activator_AllocatorOf etc.), fetch the
     // handle associated with the token. If this is not possible at

diff --git a/src/coreclr/inc/icorjitinfoimpl_generated.h b/src/coreclr/inc/icorjitinfoimpl_generated.h
@@ -105,6 +105,9 @@ CORINFO_CLASS_HANDLE getDefaultComparerClass(
 CORINFO_CLASS_HANDLE getDefaultEqualityComparerClass(
           CORINFO_CLASS_HANDLE elemType) override;
 
+CORINFO_CLASS_HANDLE getSZArrayHelperEnumeratorClass(
+          CORINFO_CLASS_HANDLE elemType) override;
+
 void expandRawHandleIntrinsic(
           CORINFO_RESOLVED_TOKEN* pResolvedToken,
           CORINFO_METHOD_HANDLE callerHandle,

diff --git a/src/coreclr/inc/jiteeversionguid.h b/src/coreclr/inc/jiteeversionguid.h
@@ -43,11 +43,11 @@ typedef const GUID *LPCGUID;
 #define GUID_DEFINED
 #endif // !GUID_DEFINED
 
-constexpr GUID JITEEVersionIdentifier = { /* b75a5475-ff22-4078-9551-2024ce03d383 */
-    0xb75a5475,
-    0xff22,
-    0x4078,
-    {0x95, 0x51, 0x20, 0x24, 0xce, 0x03, 0xd3, 0x83}
+constexpr GUID JITEEVersionIdentifier = { /* 9b8ef809-94d4-41b6-9d4c-dd61379abbe0 */
+    0x9b8ef809,
+    0x94d4,
+    0x41b6,
+    {0x9d, 0x4c, 0xdd, 0x61, 0x37, 0x9a, 0xbb, 0xe0}
   };
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////

diff --git a/src/coreclr/jit/ICorJitInfo_names_generated.h b/src/coreclr/jit/ICorJitInfo_names_generated.h
@@ -24,6 +24,7 @@ DEF_CLR_API(resolveVirtualMethod)
 DEF_CLR_API(getUnboxedEntry)
 DEF_CLR_API(getDefaultComparerClass)
 DEF_CLR_API(getDefaultEqualityComparerClass)
+DEF_CLR_API(getSZArrayHelperEnumeratorClass)
 DEF_CLR_API(expandRawHandleIntrinsic)
 DEF_CLR_API(isIntrinsicType)
 DEF_CLR_API(getUnmanagedCallConv)

diff --git a/src/coreclr/jit/ICorJitInfo_wrapper_generated.hpp b/src/coreclr/jit/ICorJitInfo_wrapper_generated.hpp
@@ -209,6 +209,15 @@ CORINFO_CLASS_HANDLE WrapICorJitInfo::getDefaultEqualityComparerClass(
     return temp;
 }
 
+CORINFO_CLASS_HANDLE WrapICorJitInfo::getSZArrayHelperEnumeratorClass(
+          CORINFO_CLASS_HANDLE elemType)
+{
+    API_ENTER(getSZArrayHelperEnumeratorClass);
+    CORINFO_CLASS_HANDLE temp = wrapHnd->getSZArrayHelperEnumeratorClass(elemType);
+    API_LEAVE(getSZArrayHelperEnumeratorClass);
+    return temp;
+}
+
 void WrapICorJitInfo::expandRawHandleIntrinsic(
           CORINFO_RESOLVED_TOKEN* pResolvedToken,
           CORINFO_METHOD_HANDLE callerHandle,

diff --git a/src/coreclr/jit/compiler.h b/src/coreclr/jit/compiler.h
@@ -7573,7 +7573,9 @@ class Compiler
                                              CORINFO_CONTEXT_HANDLE contextHandle,
                                              unsigned               methodAttr,
                                              unsigned               classAttr,
-                                             unsigned               likelihood);
+                                             unsigned               likelihood,
+                                             bool                   arrayInterface,
+                                             CORINFO_CONTEXT_HANDLE originalContextHandle);
 
     int getGDVMaxTypeChecks()
     {

diff --git a/src/coreclr/jit/fginline.cpp b/src/coreclr/jit/fginline.cpp
@@ -69,7 +69,7 @@ bool Compiler::IsDisallowedRecursiveInline(InlineContext* ancestor, InlineInfo*
 {
     // We disallow inlining the exact same instantiation.
     if ((ancestor->GetCallee() == inlineInfo->fncHandle) &&
-        (ancestor->GetRuntimeContext() == inlineInfo->inlineCandidateInfo->exactContextHnd))
+        (ancestor->GetRuntimeContext() == inlineInfo->inlineCandidateInfo->exactContextHandle))
     {
         JITDUMP("Call site is trivially recursive\n");
         return true;
@@ -80,7 +80,7 @@ bool Compiler::IsDisallowedRecursiveInline(InlineContext* ancestor, InlineInfo*
     // involved this can quickly consume a large amount of resources, so try to
     // verify that we aren't inlining recursively with complex contexts.
     if (info.compCompHnd->haveSameMethodDefinition(inlineInfo->fncHandle, ancestor->GetCallee()) &&
-        ContextComplexityExceeds(inlineInfo->inlineCandidateInfo->exactContextHnd, 64))
+        ContextComplexityExceeds(inlineInfo->inlineCandidateInfo->exactContextHandle, 64))
     {
         JITDUMP("Call site is recursive with a complex generic context\n");
         return true;
@@ -1300,7 +1300,7 @@ void Compiler::fgInvokeInlineeCompiler(GenTreeCall* call, InlineResult* inlineRe
                     ->NewContext(pParam->inlineInfo->inlineCandidateInfo->inlinersContext, pParam->inlineInfo->iciStmt,
                                               pParam->inlineInfo->iciCall);
             pParam->inlineInfo->argCnt                   = pParam->inlineCandidateInfo->methInfo.args.totalILArgs();
-            pParam->inlineInfo->tokenLookupContextHandle = pParam->inlineCandidateInfo->exactContextHnd;
+            pParam->inlineInfo->tokenLookupContextHandle = pParam->inlineCandidateInfo->exactContextHandle;
 
             JITLOG_THIS(pParam->pThis,
                                      (LL_INFO100000, "INLINER: inlineInfo.tokenLookupContextHandle for %s set to 0x%p:\n",
@@ -2042,7 +2042,7 @@ Statement* Compiler::fgInlinePrependStatements(InlineInfo* inlineInfo)
 
     if (inlineInfo->inlineCandidateInfo->initClassResult & CORINFO_INITCLASS_USE_HELPER)
     {
-        CORINFO_CLASS_HANDLE exactClass = eeGetClassFromContext(inlineInfo->inlineCandidateInfo->exactContextHnd);
+        CORINFO_CLASS_HANDLE exactClass = eeGetClassFromContext(inlineInfo->inlineCandidateInfo->exactContextHandle);
 
         tree    = fgGetSharedCCtor(exactClass);
         newStmt = gtNewStmt(tree, callDI);

diff --git a/src/coreclr/jit/gentree.cpp b/src/coreclr/jit/gentree.cpp
@@ -12981,9 +12981,10 @@ void Compiler::gtDispTree(GenTree*                    tree,
                 {
                     inlineInfo = call->GetSingleInlineCandidateInfo();
                 }
-                if ((inlineInfo != nullptr) && (inlineInfo->exactContextHnd != nullptr))
+
+                if ((inlineInfo != nullptr) && (inlineInfo->exactContextHandle != nullptr))
                 {
-                    printf(" (exactContextHnd=0x%p)", dspPtr(inlineInfo->exactContextHnd));
+                    printf(" (exactContextHandle=0x%p)", dspPtr(inlineInfo->exactContextHandle));
                 }
             }
 
@@ -19048,7 +19049,7 @@ CORINFO_CLASS_HANDLE Compiler::gtGetClassHandle(GenTree* tree, bool* pIsExact, b
                 // of the inlinee.
                 if (eeIsSharedInst(objClass))
                 {
-                    CORINFO_CONTEXT_HANDLE context = inlInfo->exactContextHnd;
+                    CORINFO_CONTEXT_HANDLE context = inlInfo->exactContextHandle;
 
                     if (context != nullptr)
                     {