Allow targets to specify register classes whose member registers should not be renamed to break anti-dependencies. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86628 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index c10900c..17b50bd 100644
--- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -99,12 +99,24 @@
 
 
 AggressiveAntiDepBreaker::
-AggressiveAntiDepBreaker(MachineFunction& MFi) : 
+AggressiveAntiDepBreaker(MachineFunction& MFi,
+                         TargetSubtarget::ExcludedRCVector& ExcludedRCs) : 
   AntiDepBreaker(), MF(MFi),
   MRI(MF.getRegInfo()),
   TRI(MF.getTarget().getRegisterInfo()),
   AllocatableSet(TRI->getAllocatableSet(MF)),
   State(NULL), SavedState(NULL) {
+  /* Remove all registers from excluded RCs from the allocatable
+     register set. */
+  for (unsigned i = 0, e = ExcludedRCs.size(); i < e; ++i) {
+    BitVector NotRenameable = TRI->getAllocatableSet(MF, ExcludedRCs[i]).flip();
+    AllocatableSet &= NotRenameable;
+  }
+
+  DEBUG(errs() << "AntiDep Renameable Registers:");
+  DEBUG(for (int r = AllocatableSet.find_first(); r != -1; 
+             r = AllocatableSet.find_next(r))
+          errs() << " " << TRI->getName(r));
 }
 
 AggressiveAntiDepBreaker::~AggressiveAntiDepBreaker() {
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.h b/lib/CodeGen/AggressiveAntiDepBreaker.h
index c512168..fb5b869 100644
--- a/lib/CodeGen/AggressiveAntiDepBreaker.h
+++ b/lib/CodeGen/AggressiveAntiDepBreaker.h
@@ -23,6 +23,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/ScheduleDAG.h"
+#include "llvm/Target/TargetSubtarget.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/SmallSet.h"
@@ -112,7 +113,7 @@
     /// AllocatableSet - The set of allocatable registers.
     /// We'll be ignoring anti-dependencies on non-allocatable registers,
     /// because they may not be safe to break.
-    const BitVector AllocatableSet;
+    BitVector AllocatableSet;
 
     /// State - The state used to identify and rename anti-dependence
     /// registers.
@@ -124,7 +125,8 @@
     AggressiveAntiDepState *SavedState;
 
   public:
-    AggressiveAntiDepBreaker(MachineFunction& MFi);
+    AggressiveAntiDepBreaker(MachineFunction& MFi, 
+                             TargetSubtarget::ExcludedRCVector& ExcludedRCs);
     ~AggressiveAntiDepBreaker();
     
     /// GetMaxTrials - As anti-dependencies are broken, additional
diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index 3ed61a2..5917e76 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -216,13 +216,14 @@
 
   // Check for explicit enable/disable of post-ra scheduling.
   TargetSubtarget::AntiDepBreakMode AntiDepMode = TargetSubtarget::ANTIDEP_NONE;
+  TargetSubtarget::ExcludedRCVector ExcludedRCs;
   if (EnablePostRAScheduler.getPosition() > 0) {
     if (!EnablePostRAScheduler)
       return false;
   } else {
     // Check that post-RA scheduling is enabled for this target.
     const TargetSubtarget &ST = Fn.getTarget().getSubtarget<TargetSubtarget>();
-    if (!ST.enablePostRAScheduler(OptLevel, AntiDepMode))
+    if (!ST.enablePostRAScheduler(OptLevel, AntiDepMode, ExcludedRCs))
       return false;
   }
 
@@ -243,7 +244,7 @@
     (ScheduleHazardRecognizer *)new SimpleHazardRecognizer();
   AntiDepBreaker *ADB = 
     ((AntiDepMode == TargetSubtarget::ANTIDEP_ALL) ?
-     (AntiDepBreaker *)new AggressiveAntiDepBreaker(Fn) :
+     (AntiDepBreaker *)new AggressiveAntiDepBreaker(Fn, ExcludedRCs) :
      ((AntiDepMode == TargetSubtarget::ANTIDEP_CRITICAL) ? 
       (AntiDepBreaker *)new CriticalAntiDepBreaker(Fn) : NULL));