[Preview 4] Disable tier 0 JIT (quick JIT) by default, rename config option (#23599)

Disable tier 0 JIT (quick JIT) by default, rename config option

- Tier 0 JIT is being called quick JIT in config options, renamed DisableTier0Jit to StartupTierQuickJit
- Disabled quick JIT by default, the current plan is to do that for preview 4
  - Concerns were that code produced by quick JIT may be slow, may allocate more, may use more stack space, and may be much larger than optimized code, and there there may be many cases where these things lead to regressions when the span of time between startup and steady-state is important
  - The thought was that with quick JIT disabled, tiering overhead from call counting and backgorund jitting with optimizations would be less, and perf during any point in time would be closer to 2.x releases
  - This mostly loses the startup perf gains from tiering. It may also be slightly slower compared with tiering off due to some overhead. When quick JIT is disabled for the startup tier, made a change to disable tiered compilation for methods in modules that are not R2R'ed since they will not be tiered currently anyway. The overhead and regression in R2R'ed modules will be looked into separately to see if it can be reduced.

Fixes https://github.com/dotnet/coreclr/issues/22998
Fixes https://github.com/dotnet/coreclr/issues/19751

1 files changed, 11 insertions, 11 deletions

diff --git a/src/vm/eeconfig.h b/src/vm/eeconfig.h
index dc6725fb44..3a22adc74a 100644
--- a/src/vm/eeconfig.h
+++ b/src/vm/eeconfig.h
@@ -281,12 +281,12 @@ public:
     
     // Tiered Compilation config
 #if defined(FEATURE_TIERED_COMPILATION)
-    bool          TieredCompilation(void)           const {LIMITED_METHOD_CONTRACT;  return fTieredCompilation; }
-    bool          TieredCompilation_DisableTier0Jit() const { LIMITED_METHOD_CONTRACT; return fTieredCompilation_DisableTier0Jit; }
-    bool          TieredCompilation_CallCounting()  const {LIMITED_METHOD_CONTRACT;  return fTieredCompilation_CallCounting; }
-    bool          TieredCompilation_OptimizeTier0() const {LIMITED_METHOD_CONTRACT; return fTieredCompilation_OptimizeTier0; }
-    DWORD         TieredCompilation_Tier1CallCountThreshold() const { LIMITED_METHOD_CONTRACT; return tieredCompilation_tier1CallCountThreshold; }
-    DWORD         TieredCompilation_Tier1CallCountingDelayMs() const { LIMITED_METHOD_CONTRACT; return tieredCompilation_tier1CallCountingDelayMs; }
+    bool          TieredCompilation(void)           const { LIMITED_METHOD_CONTRACT;  return fTieredCompilation; }
+    bool          TieredCompilation_QuickJit() const { LIMITED_METHOD_CONTRACT; return fTieredCompilation_QuickJit; }
+    bool          TieredCompilation_StartupTier_CallCounting()  const { LIMITED_METHOD_CONTRACT; return fTieredCompilation_StartupTier_CallCounting; }
+    bool          TieredCompilation_StartupTier_OptimizeCode() const { LIMITED_METHOD_CONTRACT; return fTieredCompilation_StartupTier_OptimizeCode; }
+    DWORD         TieredCompilation_StartupTier_CallCountThreshold() const { LIMITED_METHOD_CONTRACT; return tieredCompilation_StartupTier_CallCountThreshold; }
+    DWORD         TieredCompilation_StartupTier_CallCountingDelayMs() const { LIMITED_METHOD_CONTRACT; return tieredCompilation_StartupTier_CallCountingDelayMs; }
 #endif
 
 #ifndef CROSSGEN_COMPILE
@@ -1013,11 +1013,11 @@ private: //----------------------------------------------------------------
 
 #if defined(FEATURE_TIERED_COMPILATION)
     bool fTieredCompilation;
-    bool fTieredCompilation_DisableTier0Jit;
-    bool fTieredCompilation_CallCounting;
-    bool fTieredCompilation_OptimizeTier0;
-    DWORD tieredCompilation_tier1CallCountThreshold;
-    DWORD tieredCompilation_tier1CallCountingDelayMs;
+    bool fTieredCompilation_QuickJit;
+    bool fTieredCompilation_StartupTier_CallCounting;
+    bool fTieredCompilation_StartupTier_OptimizeCode;
+    DWORD tieredCompilation_StartupTier_CallCountThreshold;
+    DWORD tieredCompilation_StartupTier_CallCountingDelayMs;
 #endif
 
 #ifndef CROSSGEN_COMPILE