Multiple GDV: ignore non-inlineable candidates

src/coreclr/jit/gentree.cpp

@@ -2194,7 +2194,12 @@ void GenTreeCall::SetSingleInlineCandidateInfo(InlineCandidateInfo* candidateInf
 InlineCandidateInfo* GenTreeCall::GetGDVCandidateInfo(uint8_t index)
 {
     assert(index < gtInlineInfoCount);
-    return &gtInlineCandidateInfo[index];
+    if (gtInlineInfoCount > 1)
+    {
+        // In this case we should access it through gtInlineCandidateInfoList
+        return gtInlineCandidateInfoList->at(index);
+    }
+    return gtInlineCandidateInfo;
 }
 
 //-------------------------------------------------------------------------
@@ -2212,22 +2217,56 @@ void GenTreeCall::AddGDVCandidateInfo(Compiler* comp, InlineCandidateInfo* candi
 
     if (gtInlineInfoCount == 0)
     {
+        // Most calls are monomorphic, so we don't need to allocate a vector
         gtInlineCandidateInfo = candidateInfo;
     }
     else if (gtInlineInfoCount == 1)
     {
-        gtInlineCandidateInfo =
-            new (comp, CMK_Inlining) InlineCandidateInfo[MAX_GDV_TYPE_CHECKS]{*gtInlineCandidateInfo, *candidateInfo};
+        // Upgrade gtInlineCandidateInfo to gtInlineCandidateInfoList (vector)
+        CompAllocator        allocator      = comp->getAllocator(CMK_Inlining);
+        InlineCandidateInfo* firstCandidate = gtInlineCandidateInfo;
+        gtInlineCandidateInfoList           = new (allocator) jitstd::vector<InlineCandidateInfo*>(allocator);
+        gtInlineCandidateInfoList->push_back(firstCandidate);
+        gtInlineCandidateInfoList->push_back(candidateInfo);
     }
     else
     {
-        gtInlineCandidateInfo[gtInlineInfoCount] = *candidateInfo;
+        gtInlineCandidateInfoList->push_back(candidateInfo);
     }
-
     gtCallMoreFlags |= GTF_CALL_M_GUARDED_DEVIRT;
     gtInlineInfoCount++;
 }
 
+//-------------------------------------------------------------------------
+// RemoveGDVCandidateInfo: Remove a guarded devirtualization (GDV) candidate info
+//     by its index. Index must not be greater than gtInlineInfoCount
+//     the call will be marked as "has no inline candidates" if the last candidate is removed
+//
+// Arguments:
+//     comp    - Compiler instance
+//     index   - GDV candidate to remove
+//
+void GenTreeCall::RemoveGDVCandidateInfo(Compiler* comp, uint8_t index)
+{
+    assert(index < gtInlineInfoCount);
+
+    if (gtInlineInfoCount == 1)
+    {
+        // No longer have any inline candidates
+        ClearInlineInfo();
+        assert(gtInlineInfoCount == 0);
+        return;
+    }
+    gtInlineCandidateInfoList->erase(gtInlineCandidateInfoList->begin() + index);
+    gtInlineInfoCount--;
+
+    // Downgrade gtInlineCandidateInfoList to gtInlineCandidateInfo
+    if (gtInlineInfoCount == 1)
+    {
+        gtInlineCandidateInfo = gtInlineCandidateInfoList->at(0);
+    }
+}
+
 //-------------------------------------------------------------------------
 // HasSideEffects:
 //    Returns true if this call has any side effects. All non-helpers are considered to have side-effects. Only helpers

src/coreclr/jit/gentree.h

@@ -5447,6 +5447,8 @@ struct GenTreeCall final : public GenTree
 
     void AddGDVCandidateInfo(Compiler* comp, InlineCandidateInfo* candidateInfo);
 
+    void RemoveGDVCandidateInfo(Compiler* comp, uint8_t index);
+
     void ClearInlineInfo()
     {
         SetSingleInlineCandidateInfo(nullptr);
@@ -5542,8 +5544,12 @@ struct GenTreeCall final : public GenTree
     union {
         // only used for CALLI unmanaged calls (CT_INDIRECT)
         GenTree* gtCallCookie;
+
         // gtInlineCandidateInfo is only used when inlining methods
-        InlineCandidateInfo*                 gtInlineCandidateInfo;
+        InlineCandidateInfo* gtInlineCandidateInfo;
+        // gtInlineCandidateInfoList is used when we have more than one GDV candidate
+        jitstd::vector<InlineCandidateInfo*>* gtInlineCandidateInfoList;
+
         HandleHistogramProfileCandidateInfo* gtHandleHistogramProfileCandidateInfo;
         LateDevirtualizationInfo*            gtLateDevirtualizationInfo;
         CORINFO_GENERIC_HANDLE compileTimeHelperArgumentHandle; // Used to track type handle argument of dynamic helpers

src/coreclr/jit/importercalls.cpp

@@ -6212,29 +6212,22 @@ void Compiler::impMarkInlineCandidate(GenTree*               callNode,
 
     if (call->IsGuardedDevirtualizationCandidate())
     {
-        const uint8_t candidatesCount = call->GetInlineCandidatesCount();
-        assert(candidatesCount > 0);
-        for (uint8_t candidateId = 0; candidateId < candidatesCount; candidateId++)
+        assert(call->GetInlineCandidatesCount() > 0);
+        for (uint8_t candidateId = 0; candidateId < call->GetInlineCandidatesCount(); candidateId++)
         {
             InlineResult inlineResult(this, call, nullptr, "impMarkInlineCandidate", true);
 
             // Do the actual evaluation
             impMarkInlineCandidateHelper(call, candidateId, exactContextHnd, exactContextNeedsRuntimeLookup, callInfo,
                                          ilOffset, &inlineResult);
 
+            // Ignore non-inlineable candidates
+            // TODO: Consider keeping them to just devirtualize without inlining, at least for interface
+            // calls on NativeAOT, but that requires more changes elsewhere too.
             if (!inlineResult.IsCandidate())
             {
-                if (candidatesCount > 1)
-                {
-                    // TODO: we should not give up if one of the candidates fails to inline while others succeed.
-                    //
-                    JITDUMP(
-                        "We had multiple inline candidates but have to give up on them since one of them didn't pass"
-                        "inline checks")
-                    call->ClearInlineInfo();
-                    call->ClearGuardedDevirtualizationCandidate();
-                }
-                break;
+                call->RemoveGDVCandidateInfo(this, candidateId);
+                candidateId--;
             }
         }
     }