From 885019ef10249956270c4d6812e4b79cc0009f84 Mon Sep 17 00:00:00 2001
From: William Chen <william.chen@futurewei.com>
Date: Thu, 13 May 2021 11:37:58 -0700
Subject: [PATCH 1/2] Not generating prolog/epilog when not needed

---
 .../include/cg/aarch64/aarch64_proepilog.h    |  1 +
 src/mapleall/maple_be/include/cg/proepilog.h  |  8 +++++-
 .../src/cg/aarch64/aarch64_proepilog.cpp      | 27 ++++++++++++++++++-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/mapleall/maple_be/include/cg/aarch64/aarch64_proepilog.h b/src/mapleall/maple_be/include/cg/aarch64/aarch64_proepilog.h
index 918353e049..b35fc050af 100644
--- a/src/mapleall/maple_be/include/cg/aarch64/aarch64_proepilog.h
+++ b/src/mapleall/maple_be/include/cg/aarch64/aarch64_proepilog.h
@@ -31,6 +31,7 @@ class AArch64GenProEpilog : public GenProEpilog {
   ~AArch64GenProEpilog() override = default;
 
   bool TailCallOpt() override;
+  bool NeedProEpilog() override;
   void Run() override;
  private:
   void GenStackGuard(BB&);
diff --git a/src/mapleall/maple_be/include/cg/proepilog.h b/src/mapleall/maple_be/include/cg/proepilog.h
index 5ceedf2d6e..445dcb3b26 100644
--- a/src/mapleall/maple_be/include/cg/proepilog.h
+++ b/src/mapleall/maple_be/include/cg/proepilog.h
@@ -35,6 +35,12 @@ class GenProEpilog {
     return false;
   }
 
+  virtual bool NeedProEpilog() {
+    return true;
+  }
+
+
+
   /* CFI related routines */
   int64 GetOffsetFromCFA() const {
     return offsetFromCfa;
@@ -56,4 +62,4 @@ class GenProEpilog {
 CGFUNCPHASE(CgDoGenProEpiLog, "generateproepilog")
 }  /* namespace maplebe */
 
-#endif  /* MAPLEBE_INCLUDE_CG_PROEPILOG_H */
\ No newline at end of file
+#endif  /* MAPLEBE_INCLUDE_CG_PROEPILOG_H */
diff --git a/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp b/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp
index a2c9af8ef6..72ff14dfe8 100644
--- a/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp
+++ b/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp
@@ -219,6 +219,31 @@ bool AArch64GenProEpilog::TailCallOpt() {
   return true;
 }
 
+bool AArch64GenProEpilog::NeedProEpilog() {
+  if (cgFunc.GetMirModule().GetSrcLang() != kSrcLangC) {
+    return true;
+  } else if (static_cast<AArch64MemLayout *>(cgFunc.GetMemlayout())->GetSizeOfLocals() > 0 ||
+       cgFunc.GetFunction().GetAttr(FUNCATTR_varargs) || cgFunc.HasVLAOrAlloca()) {
+    return true;
+  }
+  auto &aarchCGFunc = static_cast<AArch64CGFunc&>(cgFunc);
+  const MapleVector<AArch64reg> &regsToRestore = aarchCGFunc.GetCalleeSavedRegs();
+  size_t calleeSavedRegSize = kTwoRegister;
+  CHECK_FATAL(regsToRestore.size() >= calleeSavedRegSize, "Forgot FP and LR ?");
+  if (regsToRestore.size() > calleeSavedRegSize || aarchCGFunc.HasStackLoadStore() || HasLoop() ||
+      cgFunc.GetFunction().GetAttr(FUNCATTR_callersensitive)) {
+    return true;
+  }
+  FOR_ALL_BB(bb, &cgFunc) {
+    FOR_BB_INSNS_REV(insn, bb) {
+      if (insn->IsCall()) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 void AArch64GenProEpilog::GenStackGuard(BB &bb) {
   auto &aarchCGFunc = static_cast<AArch64CGFunc&>(cgFunc);
   CG *currCG = cgFunc.GetCG();
@@ -1741,7 +1766,7 @@ void AArch64GenProEpilog::GenerateEpilogForCleanup(BB &bb) {
 void AArch64GenProEpilog::Run() {
   CHECK_FATAL(cgFunc.GetFunction().GetBody()->GetFirst()->GetOpCode() == OP_label,
               "The first statement should be a label");
-  cgFunc.SetHasProEpilogue(true);
+  cgFunc.SetHasProEpilogue(NeedProEpilog());
   if (cgFunc.GetHasProEpilogue()) {
     GenStackGuard(*(cgFunc.GetFirstBB()));
   }
-- 
Gitee


From 59797c8af9d201d649a1db3d67fd97f3c5bfdb33 Mon Sep 17 00:00:00 2001
From: William Chen <william.chen@futurewei.com>
Date: Fri, 14 May 2021 09:42:24 -0700
Subject: [PATCH 2/2] Turn on tail call opt TailCallOpt()

---
 .../src/cg/aarch64/aarch64_proepilog.cpp      | 27 ++++++++-----------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp b/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp
index 72ff14dfe8..45bbe7ff2e 100644
--- a/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp
+++ b/src/mapleall/maple_be/src/cg/aarch64/aarch64_proepilog.cpp
@@ -143,21 +143,12 @@ void AArch64GenProEpilog::TailCallBBOpt(const BB &exitBB, std::set<Insn*> &callI
  *  Return value: true if function do not need Prologue/Epilogue. false otherwise.
  */
 bool AArch64GenProEpilog::TailCallOpt() {
-  auto &aarchCGFunc = static_cast<AArch64CGFunc&>(cgFunc);
-  BB *exitBB = nullptr;
-  const MapleVector<AArch64reg> &regsToRestore = aarchCGFunc.GetCalleeSavedRegs();
-
-  size_t calleeSavedRegSize = 2;
-  CHECK_FATAL(regsToRestore.size() >= calleeSavedRegSize, "Forgot FP and LR ?");
-
-  if (regsToRestore.size() > calleeSavedRegSize || aarchCGFunc.HasStackLoadStore() || HasLoop() ||
-      cgFunc.GetFunction().GetAttr(FUNCATTR_callersensitive) || IsFuncNeedFrame(cgFunc.GetName())) {
+  size_t exitBBSize = cgFunc.GetExitBBsVec().size();
+  if (exitBBSize > 1) {
     return false;
   }
 
-  size_t exitBBSize = cgFunc.GetExitBBsVec().size();
-  CHECK_FATAL(exitBBSize == 1, "Should not be exist multiple exits.");
-
+  BB *exitBB = nullptr;
   if (exitBBSize == 0) {
     if (cgFunc.GetLastBB()->GetPrev()->GetFirstStmt() == cgFunc.GetCleanupLabel() &&
         cgFunc.GetLastBB()->GetPrev()->GetPrev() != nullptr) {
@@ -234,10 +225,14 @@ bool AArch64GenProEpilog::NeedProEpilog() {
       cgFunc.GetFunction().GetAttr(FUNCATTR_callersensitive)) {
     return true;
   }
-  FOR_ALL_BB(bb, &cgFunc) {
-    FOR_BB_INSNS_REV(insn, bb) {
-      if (insn->IsCall()) {
-        return true;
+  if (cgFunc.GetCG()->DoPrologueEpilogue()) {
+    return !TailCallOpt();
+  } else {
+    FOR_ALL_BB(bb, &cgFunc) {
+      FOR_BB_INSNS_REV(insn, bb) {
+        if (insn->IsCall()) {
+          return true;
+        }
       }
     }
   }
-- 
Gitee