JIT: use root compiler instance for sufficient PGO observation

src/coreclr/jit/fginline.cpp

@@ -781,6 +781,17 @@ PhaseStatus Compiler::fgInline()
         Metrics.ProfileConsistentBeforeInline++;
     }
 
+    if (!fgHaveProfileWeights())
+    {
+        JITDUMP("INLINER: no pgo data\n");
+    }
+    else
+    {
+        JITDUMP("INLINER: pgo source is %s; pgo data is %sconsistent; %strusted; %ssufficient\n",
+                compGetPgoSourceName(), fgPgoConsistent ? "" : "not ", fgHaveTrustedProfileWeights() ? "" : "not ",
+                fgHaveSufficientProfileWeights() ? "" : "not ");
+    }
+
     noway_assert(fgFirstBB != nullptr);
 
     BasicBlock*                                 block = fgFirstBB;

src/coreclr/jit/inlinepolicy.cpp

@@ -1372,13 +1372,24 @@ void ExtendedDefaultPolicy::NoteInt(InlineObservation obs, int value)
             // TODO: Enable for PgoSource::Static as well if it's not the generic profile we bundle.
             if (m_HasProfileWeights && (m_RootCompiler->fgHaveTrustedProfileWeights()))
             {
+                JITDUMP("Callee and root has trusted profile\n");
                 maxCodeSize = static_cast<unsigned>(JitConfig.JitExtDefaultPolicyMaxILProf());
             }
+            else if (m_RootCompiler->fgHaveSufficientProfileWeights())
+            {
+                JITDUMP("Root has sufficient profile\n");
+                maxCodeSize = static_cast<unsigned>(JitConfig.JitExtDefaultPolicyMaxILRoot());
+            }
+            else
+            {
+                JITDUMP("Callee has %s profile\n", m_HasProfileWeights ? "untrusted" : "no");
+            }
 
             unsigned alwaysInlineSize = InlineStrategy::ALWAYS_INLINE_SIZE;
             if (m_InsideThrowBlock)
             {
                 // Inline only small code in BBJ_THROW blocks, e.g. <= 8 bytes of IL
+                JITDUMP("Call site in throw block\n");
                 alwaysInlineSize /= 2;
                 maxCodeSize = min(alwaysInlineSize + 1, maxCodeSize);
             }
@@ -1401,6 +1412,7 @@ void ExtendedDefaultPolicy::NoteInt(InlineObservation obs, int value)
             else
             {
                 // Callee too big, not a candidate
+                JITDUMP("Callee IL size %u exceeds maxCodeSize %u\n", m_CodeSize, maxCodeSize);
                 SetNever(InlineObservation::CALLEE_TOO_MUCH_IL);
             }
             break;
@@ -1425,6 +1437,7 @@ void ExtendedDefaultPolicy::NoteInt(InlineObservation obs, int value)
 
                 if ((unsigned)value > bbLimit)
                 {
+                    JITDUMP("Callee BB count %u exceeds bbLimit %u\n", value, bbLimit);
                     SetNever(InlineObservation::CALLEE_TOO_MANY_BASIC_BLOCKS);
                 }
             }

src/coreclr/jit/jitconfigvalues.h

@@ -658,6 +658,7 @@ CONFIG_STRING(JitInlineReplayFile, "JitInlineReplayFile")
 // relies on PGO if it exists and generally is more aggressive.
 RELEASE_CONFIG_INTEGER(JitExtDefaultPolicy, "JitExtDefaultPolicy", 1)
 RELEASE_CONFIG_INTEGER(JitExtDefaultPolicyMaxIL, "JitExtDefaultPolicyMaxIL", 0x80)
+RELEASE_CONFIG_INTEGER(JitExtDefaultPolicyMaxILRoot, "JitExtDefaultPolicyMaxILRoot", 0x100)
 RELEASE_CONFIG_INTEGER(JitExtDefaultPolicyMaxILProf, "JitExtDefaultPolicyMaxILProf", 0x400)
 RELEASE_CONFIG_INTEGER(JitExtDefaultPolicyMaxBB, "JitExtDefaultPolicyMaxBB", 7)