commit 7f8678ec4d2abec1f540fb441be60604bec86b6e
author Mathieu Chartier <mathieuc@google.com> Fri Aug 30 16:22:28 2019 -0700
committer Mathieu Chartier <mathieuc@google.com> Fri Sep 06 18:40:59 2019 +0000
tree e36b4d32dfc47fcebadf0ee5c7e4d1e3d51412a6
parent 84e5bb990d48263849bab132d80d753495bc7204

Revert^2 "Prevent overflow for AOT hotness counters"

Fixed bug where sbc usage was incorrect. sbc does -1 + carry.

Test: test/run-test --always-clean --runtime-option -Xcheck:jni --64 674-hotness-compiled
Test: test/run-test --always-clean --runtime-option -Xcheck:jni 674-hotness-compiled
Bug: 139883463

This reverts commit 7ab07777b08db86dda2891f3e7ae15df8f25a599.

Change-Id: I6f8ac0320592a94314386b04cdb0c7e0e6da6994

compiler/optimizing/code_generator_x86.cc

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 4ab398e..797fe32 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -1078,8 +1078,15 @@
   DCHECK(GetCompilerOptions().GetImplicitStackOverflowChecks());
 
   if (GetCompilerOptions().CountHotnessInCompiledCode()) {
-    __ addw(Address(kMethodRegisterArgument, ArtMethod::HotnessCountOffset().Int32Value()),
+    NearLabel overflow;
+    __ cmpw(Address(kMethodRegisterArgument,
+                    ArtMethod::HotnessCountOffset().Int32Value()),
+            Immediate(ArtMethod::MaxCounter()));
+    __ j(kEqual, &overflow);
+    __ addw(Address(kMethodRegisterArgument,
+                    ArtMethod::HotnessCountOffset().Int32Value()),
             Immediate(1));
+    __ Bind(&overflow);
   }
 
   if (!skip_overflow_check) {
@@ -1385,7 +1392,13 @@
     if (codegen_->GetCompilerOptions().CountHotnessInCompiledCode()) {
       __ pushl(EAX);
       __ movl(EAX, Address(ESP, kX86WordSize));
-      __ addw(Address(EAX, ArtMethod::HotnessCountOffset().Int32Value()), Immediate(1));
+          NearLabel overflow;
+      __ cmpw(Address(EAX, ArtMethod::HotnessCountOffset().Int32Value()),
+              Immediate(ArtMethod::MaxCounter()));
+      __ j(kEqual, &overflow);
+      __ addw(Address(EAX, ArtMethod::HotnessCountOffset().Int32Value()),
+              Immediate(1));
+      __ Bind(&overflow);
       __ popl(EAX);
     }
     GenerateSuspendCheck(info->GetSuspendCheck(), successor);