R600/SI: Rename encoding field to match docs for VOP3b
[oota-llvm.git] / lib / Target / R600 / AMDGPUSubtarget.cpp
index d5203611756ff710181f04469972ed4985c57a8d..f7078863cb66434baa7222d673eee07c15acee0c 100644 (file)
 //===----------------------------------------------------------------------===//
 
 #include "AMDGPUSubtarget.h"
+#include "R600ISelLowering.h"
 #include "R600InstrInfo.h"
+#include "R600MachineScheduler.h"
+#include "SIISelLowering.h"
 #include "SIInstrInfo.h"
-
+#include "SIMachineFunctionInfo.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/CodeGen/MachineScheduler.h"
 
 using namespace llvm;
 
@@ -27,34 +31,60 @@ using namespace llvm;
 #define GET_SUBTARGETINFO_CTOR
 #include "AMDGPUGenSubtargetInfo.inc"
 
-AMDGPUSubtarget::AMDGPUSubtarget(StringRef TT, StringRef GPU, StringRef FS) :
-  AMDGPUGenSubtargetInfo(TT, GPU, FS),
-  DevName(GPU),
-  Is64bit(false),
-  DumpCode(false),
-  R600ALUInst(false),
-  HasVertexCache(false),
-  TexVTXClauseSize(0),
-  Gen(AMDGPUSubtarget::R600),
-  FP64(false),
-  CaymanISA(false),
-  EnableIRStructurizer(true),
-  EnablePromoteAlloca(false),
-  EnableIfCvt(true),
-  WavefrontSize(0),
-  CFALUBug(false),
-  LocalMemorySize(0),
-  InstrItins(getInstrItineraryForCPU(GPU)) {
-
-  SmallString<256> FullFS("+promote-alloca,");
+AMDGPUSubtarget &
+AMDGPUSubtarget::initializeSubtargetDependencies(StringRef TT, StringRef GPU, StringRef FS) {
+  // Determine default and user-specified characteristics
+  // On SI+, we want FP64 denormals to be on by default. FP32 denormals can be
+  // enabled, but some instructions do not respect them and they run at the
+  // double precision rate, so don't enable by default.
+  //
+  // We want to be able to turn these off, but making this a subtarget feature
+  // for SI has the unhelpful behavior that it unsets everything else if you
+  // disable it.
+
+  SmallString<256> FullFS("+promote-alloca,+fp64-denormals,");
   FullFS += FS;
 
+  if (GPU == "" && Triple(TT).getArch() == Triple::amdgcn)
+    GPU = "SI";
+
   ParseSubtargetFeatures(GPU, FullFS);
 
+  // FIXME: I don't think think Evergreen has any useful support for
+  // denormals, but should be checked. Should we issue a warning somewhere
+  // if someone tries to enable these?
+  if (getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS) {
+    FP32Denormals = false;
+    FP64Denormals = false;
+  }
+  return *this;
+}
+
+AMDGPUSubtarget::AMDGPUSubtarget(StringRef TT, StringRef GPU, StringRef FS,
+                                 TargetMachine &TM)
+    : AMDGPUGenSubtargetInfo(TT, GPU, FS), DevName(GPU), Is64bit(false),
+      DumpCode(false), R600ALUInst(false), HasVertexCache(false),
+      TexVTXClauseSize(0), Gen(AMDGPUSubtarget::R600), FP64(false),
+      FP64Denormals(false), FP32Denormals(false),
+      FastFMAF32(false), CaymanISA(false),
+      FlatAddressSpace(false), EnableIRStructurizer(true),
+      EnablePromoteAlloca(false), EnableIfCvt(true),
+      EnableLoadStoreOpt(false), WavefrontSize(0), CFALUBug(false), LocalMemorySize(0),
+      EnableVGPRSpilling(false),
+      FrameLowering(TargetFrameLowering::StackGrowsUp,
+                    64 * 16, // Maximum stack alignment (long16)
+                    0),
+      InstrItins(getInstrItineraryForCPU(GPU)),
+      TargetTriple(TT) {
+
+  initializeSubtargetDependencies(TT, GPU, FS);
+
   if (getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS) {
     InstrInfo.reset(new R600InstrInfo(*this));
+    TLInfo.reset(new R600TargetLowering(TM, *this));
   } else {
     InstrInfo.reset(new SIInstrInfo(*this));
+    TLInfo.reset(new SITargetLowering(TM, *this));
   }
 }
 
@@ -71,3 +101,33 @@ unsigned AMDGPUSubtarget::getStackEntrySize() const {
     llvm_unreachable("Illegal wavefront size.");
   }
 }
+
+unsigned AMDGPUSubtarget::getAmdKernelCodeChipID() const {
+  switch(getGeneration()) {
+  default: llvm_unreachable("ChipID unknown");
+  case SEA_ISLANDS: return 12;
+  }
+}
+
+bool AMDGPUSubtarget::isVGPRSpillingEnabled(
+                                       const SIMachineFunctionInfo *MFI) const {
+  return MFI->getShaderType() == ShaderType::COMPUTE || EnableVGPRSpilling;
+}
+
+void AMDGPUSubtarget::overrideSchedPolicy(MachineSchedPolicy &Policy,
+                                          MachineInstr *begin,
+                                          MachineInstr *end,
+                                          unsigned NumRegionInstrs) const {
+  if (getGeneration() >= SOUTHERN_ISLANDS) {
+
+    // Track register pressure so the scheduler can try to decrease
+    // pressure once register usage is above the threshold defined by
+    // SIRegisterInfo::getRegPressureSetLimit()
+    Policy.ShouldTrackPressure = true;
+
+    // Enabling both top down and bottom up scheduling seems to give us less
+    // register spills than just using one of these approaches on its own.
+    Policy.OnlyTopDown = false;
+    Policy.OnlyBottomUp = false;
+  }
+}