8272873: C2: Inlining should not depend on absolute call site counts

Reviewed-by: kvn, vlivanov, dlong
openjdk · Aug 26, 2021 · 673ce7e · 673ce7e · openjdk-notifier · Aug 26, 2021
1 parent 7212561
commit 673ce7e
Show file tree

Hide file tree

Showing 10 changed files with 5 additions and 17 deletions.
diff --git a/src/hotspot/cpu/aarch64/globals_aarch64.hpp b/src/hotspot/cpu/aarch64/globals_aarch64.hpp
@@ -39,7 +39,6 @@ define_pd_global(bool, UncommonNullCast,         true);  // Uncommon-trap NULLs
 define_pd_global(uintx, CodeCacheSegmentSize,    64 COMPILER1_AND_COMPILER2_PRESENT(+64)); // Tiered compilation has large code-entry alignment.
 define_pd_global(intx, CodeEntryAlignment,       64);
 define_pd_global(intx, OptoLoopAlignment,        16);
-define_pd_global(intx, InlineFrequencyCount,     100);
 
 #define DEFAULT_STACK_YELLOW_PAGES (2)
 #define DEFAULT_STACK_RED_PAGES (1)

diff --git a/src/hotspot/cpu/arm/globals_arm.hpp b/src/hotspot/cpu/arm/globals_arm.hpp
@@ -53,7 +53,6 @@ define_pd_global(intx,  StackRedPages,            DEFAULT_STACK_RED_PAGES);
 define_pd_global(intx,  StackShadowPages,         DEFAULT_STACK_SHADOW_PAGES);
 define_pd_global(intx,  StackReservedPages,       DEFAULT_STACK_RESERVED_PAGES);
 
-define_pd_global(intx,  InlineFrequencyCount,     50);
 #if  defined(COMPILER1) || defined(COMPILER2)
 define_pd_global(intx,  InlineSmallCode,          1500);
 #endif

diff --git a/src/hotspot/cpu/ppc/globals_ppc.hpp b/src/hotspot/cpu/ppc/globals_ppc.hpp
@@ -58,7 +58,6 @@ define_pd_global(intx, StackReservedPages,    DEFAULT_STACK_RESERVED_PAGES);
 define_pd_global(uintx, CodeCacheSegmentSize,  128);
 define_pd_global(intx,  CodeEntryAlignment,    128);
 define_pd_global(intx,  OptoLoopAlignment,     16);
-define_pd_global(intx,  InlineFrequencyCount,  100);
 define_pd_global(intx,  InlineSmallCode,       1500);
 
 // Flags for template interpreter.

diff --git a/src/hotspot/cpu/s390/globals_s390.hpp b/src/hotspot/cpu/s390/globals_s390.hpp
@@ -43,7 +43,6 @@ define_pd_global(uintx, CodeCacheSegmentSize,        256);
 // code size significantly by padding nops between IVC and second UEP.
 define_pd_global(intx,  CodeEntryAlignment,          64);
 define_pd_global(intx,  OptoLoopAlignment,           2);
-define_pd_global(intx,  InlineFrequencyCount,        100);
 define_pd_global(intx,  InlineSmallCode,             2000);
 
 #define DEFAULT_STACK_YELLOW_PAGES   (2)

diff --git a/src/hotspot/cpu/x86/globals_x86.hpp b/src/hotspot/cpu/x86/globals_x86.hpp
@@ -49,7 +49,6 @@ define_pd_global(intx, CodeEntryAlignment,       32);
 define_pd_global(intx, CodeEntryAlignment,       16);
 #endif // COMPILER2_OR_JVMCI
 define_pd_global(intx, OptoLoopAlignment,        16);
-define_pd_global(intx, InlineFrequencyCount,     100);
 define_pd_global(intx, InlineSmallCode,          1000);
 
 #define DEFAULT_STACK_YELLOW_PAGES (NOT_WINDOWS(2) WINDOWS_ONLY(3))

diff --git a/src/hotspot/cpu/zero/globals_zero.hpp b/src/hotspot/cpu/zero/globals_zero.hpp
@@ -39,7 +39,6 @@ define_pd_global(bool,  UncommonNullCast,     true);
 define_pd_global(uintx, CodeCacheSegmentSize, 64 COMPILER1_AND_COMPILER2_PRESENT(+64)); // Tiered compilation has large code-entry alignment.
 define_pd_global(intx,  CodeEntryAlignment,   32);
 define_pd_global(intx,  OptoLoopAlignment,    16);
-define_pd_global(intx,  InlineFrequencyCount, 100);
 define_pd_global(intx,  InlineSmallCode,      1000);
 
 // not used, but must satisfy following constraints:

diff --git a/src/hotspot/share/opto/bytecodeInfo.cpp b/src/hotspot/share/opto/bytecodeInfo.cpp
@@ -156,18 +156,17 @@ bool InlineTree::should_inline(ciMethod* callee_method, ciMethod* caller_method,
   int invoke_count     = method()->interpreter_invocation_count();
 
   assert(invoke_count != 0, "require invocation count greater than zero");
-  int freq = call_site_count / invoke_count;
+  double freq = (double)call_site_count / (double)invoke_count;
 
   // bump the max size if the call is frequent
   if ((freq >= InlineFrequencyRatio) ||
-      (call_site_count >= InlineFrequencyCount) ||
       is_unboxing_method(callee_method, C) ||
       is_init_with_ea(callee_method, caller_method, C)) {
 
     max_inline_size = C->freq_inline_size();
     if (size <= max_inline_size && TraceFrequencyInlining) {
       CompileTask::print_inline_indent(inline_level());
-      tty->print_cr("Inlined frequent method (freq=%d count=%d):", freq, call_site_count);
+      tty->print_cr("Inlined frequent method (freq=%lf):", freq);
       CompileTask::print_inline_indent(inline_level());
       callee_method->print();
       tty->cr();

diff --git a/src/hotspot/share/runtime/arguments.cpp b/src/hotspot/share/runtime/arguments.cpp
@@ -534,6 +534,7 @@ static SpecialFlag const special_jvm_flags[] = {
 
   // -------------- Obsolete Flags - sorted by expired_in --------------
   { "CriticalJNINatives",           JDK_Version::jdk(16), JDK_Version::jdk(18), JDK_Version::jdk(19) },
+  { "InlineFrequencyCount",         JDK_Version::undefined(), JDK_Version::jdk(18), JDK_Version::jdk(19) },
   { "G1RSetRegionEntries",          JDK_Version::undefined(), JDK_Version::jdk(18), JDK_Version::jdk(19) },
   { "G1RSetSparseRegionEntries",    JDK_Version::undefined(), JDK_Version::jdk(18), JDK_Version::jdk(19) },
   { "AlwaysLockClassLoader",        JDK_Version::jdk(17), JDK_Version::jdk(18), JDK_Version::jdk(19) },

diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
@@ -1400,14 +1400,8 @@ const intx ObjectAlignmentInBytes = 8;
   product(intx, SpecTrapLimitExtraEntries,  3, EXPERIMENTAL,                \
           "Extra method data trap entries for speculation")                 \
                                                                             \
-  develop(intx, InlineFrequencyRatio,    20,                                \
+  product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC,                   \
           "Ratio of call site execution to caller method invocation")       \
-          range(0, max_jint)                                                \
-                                                                            \
-  product_pd(intx, InlineFrequencyCount, DIAGNOSTIC,                        \
-          "Count of call site execution necessary to trigger frequent "     \
-          "inlining")                                                       \
-          range(0, max_jint)                                                \
                                                                             \
   develop(intx, InlineThrowCount,    50,                                    \
           "Force inlining of interpreted methods that throw this often")    \

diff --git a/test/lib-test/jdk/test/whitebox/vm_flags/IntxTest.java b/test/lib-test/jdk/test/whitebox/vm_flags/IntxTest.java
@@ -36,7 +36,7 @@
 import jdk.test.lib.Platform;
 public class IntxTest {
     private static final String FLAG_NAME = "OnStackReplacePercentage";
-    private static final String FLAG_DEBUG_NAME = "InlineFrequencyCount";
+    private static final String FLAG_DEBUG_NAME = "BciProfileWidth";
     private static final long COMPILE_THRESHOLD = VmFlagTest.WHITE_BOX.getIntxVMFlag("CompileThreshold");
     private static final Long[] TESTS = {0L, 100L, (long)(Integer.MAX_VALUE>>3)*100L};