From 54c8e5ecf4f49aa4f14481d3320339fcab72c3f9 Mon Sep 17 00:00:00 2001
From: fye <feng_ye_@hotmail.com>
Date: Fri, 6 May 2022 09:05:22 -0700
Subject: [PATCH] PGO: split critical edges

---
 .../maple_ipa/src/ipa_phase_manager.cpp        |  1 +
 .../maple_me/include/me_pgo_instrument.h       | 14 ++++++++++++--
 src/mapleall/maple_me/src/me_critical_edge.cpp | 18 ++++++++++++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/mapleall/maple_ipa/src/ipa_phase_manager.cpp b/src/mapleall/maple_ipa/src/ipa_phase_manager.cpp
index 8cf4d85bcd..05bc4b00fa 100644
--- a/src/mapleall/maple_ipa/src/ipa_phase_manager.cpp
+++ b/src/mapleall/maple_ipa/src/ipa_phase_manager.cpp
@@ -194,6 +194,7 @@ bool SCCProfile::PhaseRun(SCCNode<CGNode> &scc) {
   SetQuiet(true);
   AddPhase("mecfgbuild", true);
   if (Options::profileGen) {
+    AddPhase("splitcriticaledge", true);
     AddPhase("profileGen", true);
   } else {
     AddPhase("profileUse", true);
diff --git a/src/mapleall/maple_me/include/me_pgo_instrument.h b/src/mapleall/maple_me/include/me_pgo_instrument.h
index 9cefde6cc9..ba6727676b 100644
--- a/src/mapleall/maple_me/include/me_pgo_instrument.h
+++ b/src/mapleall/maple_me/include/me_pgo_instrument.h
@@ -93,6 +93,8 @@ class PGOInstrument {
   void GetInstrumentBBs(std::vector<BB*> &bbs) const {
     std::vector<Edge*> instrumentEdges;
     mst.GetInstrumentEdges(instrumentEdges);
+    std::unordered_set<BB*> visitedBBs;
+
     for (auto &edge : instrumentEdges) {
       BB *src = edge->GetSrcBB();
       BB *dest = edge->GetDestBB();
@@ -107,8 +109,16 @@ class PGOInstrument {
         bbs.push_back(dest);
       } else {
         if (func->GetMIRModule().IsCModule()) {
-          // If it is a c module, do not split the edge until the next PGO phase
-          bbs.push_back(dest);
+          if (src->GetKind() == kBBIgoto) {
+            if (visitedBBs.find(dest) == visitedBBs.end()) {
+              // In this case, we have to instrument it anyway
+              bbs.push_back(dest);
+              visitedBBs.insert(dest);
+            }
+          } else {
+            func->GetCfg()->DumpToFile("profGenErrorForCModule", false);
+            CHECK_FATAL(false, "Unexpected case %d -> %d", src->UintID(), dest->UintID());
+          }
         } else {
           func->GetCfg()->DumpToFile("profGenError", false);
           CHECK_FATAL(false, "impossible critial edge %d -> %d", src->UintID(), dest->UintID());
diff --git a/src/mapleall/maple_me/src/me_critical_edge.cpp b/src/mapleall/maple_me/src/me_critical_edge.cpp
index c37fe842a8..b04a72496f 100644
--- a/src/mapleall/maple_me/src/me_critical_edge.cpp
+++ b/src/mapleall/maple_me/src/me_critical_edge.cpp
@@ -19,6 +19,7 @@
 #include "me_dominance.h"
 #include "me_function.h"
 #include "me_loop_analysis.h"
+#include "me_irmap.h"
 
 // This phase finds critical edges and split them into two, because their
 // presence would restrict the optimizations performed by SSAPRE-based phases.
@@ -175,6 +176,23 @@ void MeSplitCEdge::BreakCriticalEdge(MeFunction &func, BB &pred, BB &succ) const
       UpdateCaseLabel(*newBB, func, pred, succ);
     }
   }
+  // profileGen invokes MESplitCEdge to remove critical edges without going through ME completely
+  // newBB needs to be materialized
+  if (Options::profileGen) {
+    LabelIdx succLabel = succ.GetBBLabel();
+    ASSERT(succLabel != 0, "succ's label missed");
+    if (func.GetIRMap() != nullptr) {
+      GotoNode stmt(OP_goto);
+      GotoMeStmt *gotoSucc = func.GetIRMap()->New<GotoMeStmt>(&stmt);
+      gotoSucc->SetOffset(succLabel);
+      newBB->AddMeStmtLast(gotoSucc);
+    } else {
+      GotoNode *gotoSucc = func.GetMirFunc()->GetCodeMempool()->New<GotoNode>(OP_goto);
+      gotoSucc->SetOffset(succLabel);
+      newBB->AddStmtNode(gotoSucc);
+    }
+    newBB->SetKind(kBBGoto);
+  }
 }
 
 // Is a critical edge is cut by bb
-- 
Gitee