X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FRegisterClassInfo.cpp;h=652bc3015a3d73171bb04ba6aea28a18662f2f66;hb=3756e70af69096a82b367ee9667e7720ca2201e4;hp=786d279c2b8c29e0a09a011d49b72fe7fa74a783;hpb=f39031b360f135ece3bdc86151804dd1f3f51733;p=oota-llvm.git

diff --git a/lib/CodeGen/RegisterClassInfo.cpp b/lib/CodeGen/RegisterClassInfo.cpp
index 786d279c2b8..652bc3015a3 100644
--- a/lib/CodeGen/RegisterClassInfo.cpp
+++ b/lib/CodeGen/RegisterClassInfo.cpp
@@ -15,15 +15,19 @@
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "regalloc"
-#include "RegisterClassInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/RegisterClassInfo.h"
 #include "llvm/Target/TargetMachine.h"
-
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
+static cl::opt<unsigned>
+StressRA("stress-regalloc", cl::Hidden, cl::init(0), cl::value_desc("N"),
+         cl::desc("Limit all regclasses to N registers"));
+
 RegisterClassInfo::RegisterClassInfo() : Tag(0), MF(0), TRI(0), CalleeSaved(0)
 {}
 
@@ -39,16 +43,15 @@ void RegisterClassInfo::runOnMachineFunction(const MachineFunction &mf) {
   }
 
   // Does this MF have different CSRs?
-  const unsigned *CSR = TRI->getCalleeSavedRegs(MF);
+  const uint16_t *CSR = TRI->getCalleeSavedRegs(MF);
   if (Update || CSR != CalleeSaved) {
     // Build a CSRNum map. Every CSR alias gets an entry pointing to the last
     // overlapping CSR.
     CSRNum.clear();
     CSRNum.resize(TRI->getNumRegs(), 0);
     for (unsigned N = 0; unsigned Reg = CSR[N]; ++N)
-      for (const unsigned *AS = TRI->getOverlaps(Reg);
-           unsigned Alias = *AS; ++AS)
-        CSRNum[Alias] = N + 1; // 0 means no CSR, 1 means CalleeSaved[0], ...
+      for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+        CSRNum[*AI] = N + 1; // 0 means no CSR, 1 means CalleeSaved[0], ...
     Update = true;
   }
   CalleeSaved = CSR;
@@ -81,7 +84,7 @@ void RegisterClassInfo::compute(const TargetRegisterClass *RC) const {
 
   // FIXME: Once targets reserve registers instead of removing them from the
   // allocation order, we can simply use begin/end here.
-  ArrayRef<unsigned> RawOrder = RC->getRawAllocationOrder(*MF);
+  ArrayRef<uint16_t> RawOrder = RC->getRawAllocationOrder(*MF);
   for (unsigned i = 0; i != RawOrder.size(); ++i) {
     unsigned PhysReg = RawOrder[i];
     // Remove reserved registers from the allocation order.
@@ -99,6 +102,10 @@ void RegisterClassInfo::compute(const TargetRegisterClass *RC) const {
   // CSR aliases go after the volatile registers, preserve the target's order.
   std::copy(CSRAlias.begin(), CSRAlias.end(), &RCI.Order[N]);
 
+  // Register allocator stress test.  Clip register class to N registers.
+  if (StressRA && RCI.NumRegs > StressRA)
+    RCI.NumRegs = StressRA;
+
   // Check if RC is a proper sub-class.
   if (const TargetRegisterClass *Super = TRI->getLargestLegalSuperClass(RC))
     if (Super != RC && getNumAllocatableRegs(Super) > RCI.NumRegs)