Don't inline calls inside rarely used (cold) basic blocks

EgorBo · Sep 7, 2020 · 5e02b19 · 5e02b19
1 parent b3bc0a7
commit 5e02b19
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Showing 2 changed files with 15 additions and 0 deletions.
diff --git a/src/coreclr/src/jit/importer.cpp b/src/coreclr/src/jit/importer.cpp
@@ -20117,6 +20117,20 @@ void Compiler::impMarkInlineCandidateHelper(GenTreeCall*           call,
 
     if (!(methAttr & CORINFO_FLG_FORCEINLINE))
     {
+
+        if (compCurBB->isRunRarely())
+        {
+#ifdef DEBUG
+            if (verbose)
+            {
+                printf("\nWill not inline calls in cold basic blocks\n");
+            }
+#endif
+
+            inlineResult.NoteFatal(InlineObservation::CALLSITE_IS_WITHIN_COLD_BLOCK);
+            return;
+        }
+
         /* Don't bother inline blocks that are in the filter region */
         if (bbInCatchHandlerILRange(compCurBB))
         {

diff --git a/src/coreclr/src/jit/inline.def b/src/coreclr/src/jit/inline.def
@@ -137,6 +137,7 @@ INLINE_OBSERVATION(IS_TOO_DEEP,               bool,   "too deep",
 INLINE_OBSERVATION(IS_VIRTUAL,                bool,   "virtual",                              FATAL,       CALLSITE)
 INLINE_OBSERVATION(IS_VM_NOINLINE,            bool,   "noinline per VM",                      FATAL,       CALLSITE)
 INLINE_OBSERVATION(IS_WITHIN_CATCH,           bool,   "within catch region",                  FATAL,       CALLSITE)
+INLINE_OBSERVATION(IS_WITHIN_COLD_BLOCK,      bool,   "within cold block",                    FATAL,       CALLSITE)
 INLINE_OBSERVATION(IS_WITHIN_FILTER,          bool,   "within filter region",                 FATAL,       CALLSITE)
 INLINE_OBSERVATION(LDARGA_NOT_LOCAL_VAR,      bool,   "ldarga not on local var",              FATAL,       CALLSITE)
 INLINE_OBSERVATION(LDFLD_NEEDS_HELPER,        bool,   "ldfld needs helper",                   FATAL,       CALLSITE)