Move Post RA Scheduling flag bit into SchedMachineModel

Refactoring; no functional changes intended

    Removed PostRAScheduler bits from subtargets (X86, ARM).
    Added PostRAScheduler bit to MCSchedModel class.
    This bit is set by a CPU's scheduling model (if it exists).
    Removed enablePostRAScheduler() function from TargetSubtargetInfo and subclasses.
    Fixed the existing enablePostMachineScheduler() method to use the MCSchedModel (was just returning false!).
    Added methods to TargetSubtargetInfo to allow overrides for AntiDepBreakMode, CriticalPathRCs, and OptLevel for PostRAScheduling.
    Added enablePostRAScheduler() function to PostRAScheduler class which queries the subtarget for the above values.
    Preserved existing scheduler behavior for ARM, MIPS, PPC, and X86: 
       a. ARM overrides the CPU's postRA settings by enabling postRA for any non-Thumb or Thumb2 subtarget. 
       b. MIPS overrides the CPU's postRA settings by enabling postRA for everything. 
       c. PPC overrides the CPU's postRA settings by enabling postRA for everything. 
       d. X86 is the only target that actually has postRA specified via sched model info.

Differential Revision: http://reviews.llvm.org/D4217

llvm-svn: 213101

12 files changed, 45 insertions, 92 deletions

diff --git a/llvm/lib/Target/ARM/ARMSubtarget.cpp b/llvm/lib/Target/ARM/ARMSubtarget.cpp
index 0c6ff529653..ea9e2b84c19 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.cpp
+++ b/llvm/lib/Target/ARM/ARMSubtarget.cpp
@@ -191,7 +191,6 @@ void ARMSubtarget::initializeEnvironment() {
   InThumbMode = false;
   HasThumb2 = false;
   NoARM = false;
-  PostRAScheduler = false;
   IsR9Reserved = ReserveR9;
   UseMovt = false;
   SupportsTailCall = false;
@@ -308,9 +307,6 @@ void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
     SupportsTailCall = !isThumb1Only();
   }
 
-  if (!isThumb() || hasThumb2())
-    PostRAScheduler = true;
-
   switch (Align) {
     case DefaultAlign:
       // Assume pre-ARMv6 doesn't support unaligned accesses.
@@ -425,25 +421,15 @@ bool ARMSubtarget::hasSinCos() const {
     !getTargetTriple().isOSVersionLT(7, 0);
 }
 
-// Enable the PostMachineScheduler if the target selects it instead of
-// PostRAScheduler. Currently only available on the command line via
-// -misched-postra.
+// This overrides the PostRAScheduler bit in the SchedModel for any CPU.
 bool ARMSubtarget::enablePostMachineScheduler() const {
-  return PostRAScheduler;
+  return (!isThumb() || hasThumb2());
 }
 
 bool ARMSubtarget::enableAtomicExpandLoadLinked() const {
   return hasAnyDataBarrier() && !isThumb1Only();
 }
 
-bool ARMSubtarget::enablePostRAScheduler(
-           CodeGenOpt::Level OptLevel,
-           TargetSubtargetInfo::AntiDepBreakMode& Mode,
-           RegClassVector& CriticalPathRCs) const {
-  Mode = TargetSubtargetInfo::ANTIDEP_NONE;
-  return PostRAScheduler && OptLevel >= CodeGenOpt::Default;
-}
-
 bool ARMSubtarget::useMovt(const MachineFunction &MF) const {
   // NOTE Windows on ARM needs to use mov.w/mov.t pairs to materialise 32-bit
   // immediates as it is inherently position independent, and may be out of
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 626bb0e7860..ffaff89f04e 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -105,9 +105,6 @@ protected:
   /// NoARM - True if subtarget does not support ARM mode execution.
   bool NoARM;
 
-  /// PostRAScheduler - True if using post-register-allocation scheduler.
-  bool PostRAScheduler;
-
   /// IsR9Reserved - True if R9 is a not available as general purpose register.
   bool IsR9Reserved;
 
@@ -429,12 +426,7 @@ public:
   bool hasSinCos() const;
 
   /// True for some subtargets at > -O0.
-  bool enablePostMachineScheduler() const;
-
-  /// enablePostRAScheduler - True at 'More' optimization.
-  bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
-                             TargetSubtargetInfo::AntiDepBreakMode& Mode,
-                             RegClassVector& CriticalPathRCs) const override;
+  bool enablePostMachineScheduler() const override;
 
   // enableAtomicExpandLoadLinked - True if we need to expand our atomics.
   bool enableAtomicExpandLoadLinked() const override;
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 902735d7810..d63b712f83d 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -177,15 +177,17 @@ MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
   UseSmallSection = !IsLinux && (RM == Reloc::Static);
 }
 
-bool
-MipsSubtarget::enablePostRAScheduler(CodeGenOpt::Level OptLevel,
-                                    TargetSubtargetInfo::AntiDepBreakMode &Mode,
-                                     RegClassVector &CriticalPathRCs) const {
-  Mode = TargetSubtargetInfo::ANTIDEP_NONE;
+/// This overrides the PostRAScheduler bit in the SchedModel for any CPU.
+bool MipsSubtarget::enablePostMachineScheduler() const { return true; }
+
+void MipsSubtarget::getCriticalPathRCs(RegClassVector &CriticalPathRCs) const {
   CriticalPathRCs.clear();
-  CriticalPathRCs.push_back(isGP64bit() ? &Mips::GPR64RegClass
-                                        : &Mips::GPR32RegClass);
-  return OptLevel >= CodeGenOpt::Aggressive;
+  CriticalPathRCs.push_back(isGP64bit() ?
+                            &Mips::GPR64RegClass : &Mips::GPR32RegClass);
+}
+
+CodeGenOpt::Level MipsSubtarget::getOptLevelToEnablePostRAScheduler() const {
+  return CodeGenOpt::Aggressive;
 }
 
 MipsSubtarget &
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.h b/llvm/lib/Target/Mips/MipsSubtarget.h
index 6f6e2a67140..944e629898b 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.h
+++ b/llvm/lib/Target/Mips/MipsSubtarget.h
@@ -160,9 +160,10 @@ protected:
   std::unique_ptr<const MipsTargetLowering> TLInfoSE;
 
 public:
-  bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
-                             AntiDepBreakMode& Mode,
-                             RegClassVector& CriticalPathRCs) const override;
+  /// This overrides the PostRAScheduler bit in the SchedModel for each CPU.
+  bool enablePostMachineScheduler() const override;
+  void getCriticalPathRCs(RegClassVector &CriticalPathRCs) const override;
+  CodeGenOpt::Level getOptLevelToEnablePostRAScheduler() const override;
 
   /// Only O32 and EABI supported right now.
   bool isABI_EABI() const { return MipsABI == EABI; }
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
index 2e1b74a1317..b51512d335f 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -222,22 +222,6 @@ bool PPCSubtarget::hasLazyResolverStub(const GlobalValue *GV,
          GV->hasCommonLinkage() || isDecl;
 }
 
-bool PPCSubtarget::enablePostRAScheduler(
-           CodeGenOpt::Level OptLevel,
-           TargetSubtargetInfo::AntiDepBreakMode& Mode,
-           RegClassVector& CriticalPathRCs) const {
-  Mode = TargetSubtargetInfo::ANTIDEP_ALL;
-
-  CriticalPathRCs.clear();
-
-  if (isPPC64())
-    CriticalPathRCs.push_back(&PPC::G8RCRegClass);
-  else
-    CriticalPathRCs.push_back(&PPC::GPRCRegClass);
-    
-  return OptLevel >= CodeGenOpt::Default;
-}
-
 // Embedded cores need aggressive scheduling (and some others also benefit).
 static bool needsAggressiveScheduling(unsigned Directive) {
   switch (Directive) {
@@ -259,6 +243,19 @@ bool PPCSubtarget::enableMachineScheduler() const {
   return needsAggressiveScheduling(DarwinDirective);
 }
 
+// This overrides the PostRAScheduler bit in the SchedModel for each CPU.
+bool PPCSubtarget::enablePostMachineScheduler() const { return true; }
+
+PPCGenSubtargetInfo::AntiDepBreakMode PPCSubtarget::getAntiDepBreakMode() const {
+  return TargetSubtargetInfo::ANTIDEP_ALL;
+}
+
+void PPCSubtarget::getCriticalPathRCs(RegClassVector &CriticalPathRCs) const {
+  CriticalPathRCs.clear();
+  CriticalPathRCs.push_back(isPPC64() ?
+                            &PPC::G8RCRegClass : &PPC::GPRCRegClass);
+}
+
 void PPCSubtarget::overrideSchedPolicy(MachineSchedPolicy &Policy,
                                        MachineInstr *begin,
                                        MachineInstr *end,
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.h b/llvm/lib/Target/PowerPC/PPCSubtarget.h
index 2a166995d92..96d3d6209f9 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.h
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.h
@@ -225,15 +225,15 @@ public:
   bool isDarwinABI() const { return isDarwin(); }
   bool isSVR4ABI() const { return !isDarwin(); }
 
-  /// enablePostRAScheduler - True at 'More' optimization.
-  bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
-                             TargetSubtargetInfo::AntiDepBreakMode& Mode,
-                             RegClassVector& CriticalPathRCs) const override;
-
   bool enableEarlyIfConversion() const override { return hasISEL(); }
 
   // Scheduling customization.
   bool enableMachineScheduler() const override;
+  // This overrides the PostRAScheduler bit in the SchedModel for each CPU.
+  bool enablePostMachineScheduler() const override;
+  AntiDepBreakMode getAntiDepBreakMode() const override;
+  void getCriticalPathRCs(RegClassVector &CriticalPathRCs) const override;
+
   void overrideSchedPolicy(MachineSchedPolicy &Policy,
                            MachineInstr *begin,
                            MachineInstr *end,
diff --git a/llvm/lib/Target/TargetSubtargetInfo.cpp b/llvm/lib/Target/TargetSubtargetInfo.cpp
index 87b6b661d31..386a813b057 100644
--- a/llvm/lib/Target/TargetSubtargetInfo.cpp
+++ b/llvm/lib/Target/TargetSubtargetInfo.cpp
@@ -53,16 +53,7 @@ bool TargetSubtargetInfo::enableRALocalReassignment(
 }
 
 bool TargetSubtargetInfo::enablePostMachineScheduler() const {
-  return false;
-}
-
-bool TargetSubtargetInfo::enablePostRAScheduler(
-          CodeGenOpt::Level OptLevel,
-          AntiDepBreakMode& Mode,
-          RegClassVector& CriticalPathRCs) const {
-  Mode = ANTIDEP_NONE;
-  CriticalPathRCs.clear();
-  return false;
+  return getSchedModel()->PostRAScheduler;
 }
 
 bool TargetSubtargetInfo::useAA() const {
diff --git a/llvm/lib/Target/X86/X86Schedule.td b/llvm/lib/Target/X86/X86Schedule.td
index 25c5a6bfa1f..b76850aa1c8 100644
--- a/llvm/lib/Target/X86/X86Schedule.td
+++ b/llvm/lib/Target/X86/X86Schedule.td
@@ -633,6 +633,7 @@ def GenericModel : SchedMachineModel {
   let MicroOpBufferSize = 32;
   let LoadLatency = 4;
   let HighLatency = 10;
+  let PostRAScheduler = 0;
 }
 
 include "X86ScheduleAtom.td"
diff --git a/llvm/lib/Target/X86/X86ScheduleAtom.td b/llvm/lib/Target/X86/X86ScheduleAtom.td
index 3256ee7c6e4..c8820aa2d8d 100644
--- a/llvm/lib/Target/X86/X86ScheduleAtom.td
+++ b/llvm/lib/Target/X86/X86ScheduleAtom.td
@@ -538,6 +538,7 @@ def AtomModel : SchedMachineModel {
   // On the Atom, the throughput for taken branches is 2 cycles. For small
   // simple loops, expand by a small factor to hide the backedge cost.
   let LoopMicroOpBufferSize = 10;
+  let PostRAScheduler = 1;
 
   let Itineraries = AtomItineraries;
 }
diff --git a/llvm/lib/Target/X86/X86ScheduleSLM.td b/llvm/lib/Target/X86/X86ScheduleSLM.td
index 823d10140e3..90d85878812 100644
--- a/llvm/lib/Target/X86/X86ScheduleSLM.td
+++ b/llvm/lib/Target/X86/X86ScheduleSLM.td
@@ -19,6 +19,7 @@ def SLMModel : SchedMachineModel {
   let MicroOpBufferSize = 32; // Based on the reorder buffer.
   let LoadLatency = 3;
   let MispredictPenalty = 10;
+  let PostRAScheduler = 1;
 
   // For small loops, expand by a small factor to hide the backedge cost.
   let LoopMicroOpBufferSize = 10;
diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index 79b7e68c320..d1b71c48a92 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -219,9 +219,6 @@ void X86Subtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
   // Make sure the right MCSchedModel is used.
   InitCPUSchedModel(CPUName);
 
-  if (X86ProcFamily == IntelAtom || X86ProcFamily == IntelSLM)
-    PostRAScheduler = true;
-
   InstrItins = getInstrItineraryForCPU(CPUName);
 
   // It's important to keep the MCSubtargetInfo feature bits in sync with
@@ -286,7 +283,6 @@ void X86Subtarget::initializeEnvironment() {
   HasCmpxchg16b = false;
   UseLeaForSP = false;
   HasSlowDivide = false;
-  PostRAScheduler = false;
   PadShortFunctions = false;
   CallRegIndirect = false;
   LEAUsesAG = false;
@@ -359,16 +355,7 @@ X86Subtarget::X86Subtarget(const std::string &TT, const std::string &CPU,
                     is64Bit() ? -8 : -4),
       JITInfo(hasSSE1()) {}
 
-bool
-X86Subtarget::enablePostRAScheduler(CodeGenOpt::Level OptLevel,
-                                    TargetSubtargetInfo::AntiDepBreakMode &Mode,
-                                    RegClassVector &CriticalPathRCs) const {
-  Mode = TargetSubtargetInfo::ANTIDEP_CRITICAL;
-  CriticalPathRCs.clear();
-  return PostRAScheduler && OptLevel >= CodeGenOpt::Default;
-}
-
-bool
-X86Subtarget::enableEarlyIfConversion() const {
+bool X86Subtarget::enableEarlyIfConversion() const {
   return hasCMov() && X86EarlyIfConv;
 }
+
diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index 09db0ebc5a9..30c3b08a890 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -170,9 +170,6 @@ protected:
   /// full divides and should be used when possible.
   bool HasSlowDivide;
 
-  /// PostRAScheduler - True if using post-register-allocation scheduler.
-  bool PostRAScheduler;
-
   /// PadShortFunctions - True if the short functions should be padded to prevent
   /// a stall when returning too early.
   bool PadShortFunctions;
@@ -453,18 +450,15 @@ public:
   /// Enable the MachineScheduler pass for all X86 subtargets.
   bool enableMachineScheduler() const override { return true; }
 
-  /// enablePostRAScheduler - run for Atom optimization.
-  bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
-                             TargetSubtargetInfo::AntiDepBreakMode& Mode,
-                             RegClassVector& CriticalPathRCs) const override;
-
-  bool postRAScheduler() const { return PostRAScheduler; }
-
   bool enableEarlyIfConversion() const override;
 
   /// getInstrItins = Return the instruction itineraries based on the
   /// subtarget selection.
   const InstrItineraryData &getInstrItineraryData() const { return InstrItins; }
+
+  AntiDepBreakMode getAntiDepBreakMode() const override {
+    return TargetSubtargetInfo::ANTIDEP_CRITICAL;
+  }
 };
 
 } // End llvm namespace