From bc7728c156b75aff4e30086b530e95a80a020301 Mon Sep 17 00:00:00 2001
From: Max Wang <mwang@fb.com>
Date: Thu, 19 Jan 2017 22:45:26 -0800
Subject: [PATCH] Don't do branch profiling for profiling translations

Reviewed By: markw65

Differential Revision: D4435131

fbshipit-source-id: 0eff93f31119627615ecdbe7955fa5c2bfaeba4b
---
 hphp/runtime/vm/jit/types.h      | 18 ++++++++++++++++++
 hphp/runtime/vm/jit/vasm-x64.cpp | 11 ++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/hphp/runtime/vm/jit/types.h b/hphp/runtime/vm/jit/types.h
index c39647de1c4..12854ac40d4 100644
--- a/hphp/runtime/vm/jit/types.h
+++ b/hphp/runtime/vm/jit/types.h
@@ -104,6 +104,24 @@ inline std::string show(TransKind k) {
   not_reached();
 }
 
+inline bool isProfiling(TransKind k) {
+  switch (k) {
+    case TransKind::Profile:
+    case TransKind::ProfPrologue:
+      return true;
+
+    case TransKind::Anchor:
+    case TransKind::Interp:
+    case TransKind::Live:
+    case TransKind::LivePrologue:
+    case TransKind::Optimize:
+    case TransKind::OptPrologue:
+    case TransKind::Invalid:
+      return false;
+  }
+  always_assert(false);
+}
+
 inline bool isPrologue(TransKind k) {
   switch (k) {
     case TransKind::LivePrologue:
diff --git a/hphp/runtime/vm/jit/vasm-x64.cpp b/hphp/runtime/vm/jit/vasm-x64.cpp
index 1026e93cbca..301016054f4 100644
--- a/hphp/runtime/vm/jit/vasm-x64.cpp
+++ b/hphp/runtime/vm/jit/vasm-x64.cpp
@@ -1043,11 +1043,12 @@ void optimizeX64(Vunit& unit, const Abi& abi, bool regalloc) {
 
   assertx(checkWidths(unit));
 
-  if (abi.canSpill && RuntimeOption::EvalProfBranchSampleFreq > 0) {
-    // Only profile branches if we're allowed to spill (and if branch profiling
-    // is on, of course).  This is not only for the freedom to generate
-    // arbitrary code, but also because we don't want to profile unique stubs
-    // and such.
+  if (unit.context && isProfiling(unit.context->kind) && abi.canSpill &&
+      RuntimeOption::EvalProfBranchSampleFreq > 0) {
+    // Even when branch profiling is on, we still only want to profile
+    // non-profiling translations of PHP functions.  We also require that we
+    // can spill, so that we can generate arbitrary profiling code, and also to
+    // ensure we don't profile unique stubs and such.
     profile_branches(unit);
   }
 
-- 
2.11.4.GIT