X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FR600%2FR600ControlFlowFinalizer.cpp;h=8e7bc1079b7bfdc1cd7b6a88f478e9a9e1c6d5be;hb=9f85dccfc64b5f0b0c63ddfa0a42d8615aa1fcb3;hp=6b42a7a9faf240f918d709d479f3fbbdfe47269d;hpb=5c0c884e423cd4dce8fbe3696fe935eaffdcffa7;p=oota-llvm.git

diff --git a/lib/Target/R600/R600ControlFlowFinalizer.cpp b/lib/Target/R600/R600ControlFlowFinalizer.cpp
index 6b42a7a9faf..8e7bc1079b7 100644
--- a/lib/Target/R600/R600ControlFlowFinalizer.cpp
+++ b/lib/Target/R600/R600ControlFlowFinalizer.cpp
@@ -12,9 +12,9 @@
 /// computing their address on the fly ; it also sets STACK_SIZE info.
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "r600cf"
 #include "llvm/Support/Debug.h"
 #include "AMDGPU.h"
+#include "AMDGPUSubtarget.h"
 #include "R600Defines.h"
 #include "R600InstrInfo.h"
 #include "R600MachineFunctionInfo.h"
@@ -26,6 +26,8 @@
 
 using namespace llvm;
 
+#define DEBUG_TYPE "r600cf"
+
 namespace {
 
 struct CFStack {
@@ -73,6 +75,44 @@ bool CFStack::branchStackContains(CFStack::StackItem Item) {
   return false;
 }
 
+bool CFStack::requiresWorkAroundForInst(unsigned Opcode) {
+  if (Opcode == AMDGPU::CF_ALU_PUSH_BEFORE && ST.hasCaymanISA() &&
+      getLoopDepth() > 1)
+    return true;
+
+  if (!ST.hasCFAluBug())
+    return false;
+
+  switch(Opcode) {
+  default: return false;
+  case AMDGPU::CF_ALU_PUSH_BEFORE:
+  case AMDGPU::CF_ALU_ELSE_AFTER:
+  case AMDGPU::CF_ALU_BREAK:
+  case AMDGPU::CF_ALU_CONTINUE:
+    if (CurrentSubEntries == 0)
+      return false;
+    if (ST.getWavefrontSize() == 64) {
+      // We are being conservative here.  We only require this work-around if
+      // CurrentSubEntries > 3 &&
+      // (CurrentSubEntries % 4 == 3 || CurrentSubEntries % 4 == 0)
+      //
+      // We have to be conservative, because we don't know for certain that
+      // our stack allocation algorithm for Evergreen/NI is correct.  Applying this
+      // work-around when CurrentSubEntries > 3 allows us to over-allocate stack
+      // resources without any problems.
+      return CurrentSubEntries > 3;
+    } else {
+      assert(ST.getWavefrontSize() == 32);
+      // We are being conservative here.  We only require the work-around if
+      // CurrentSubEntries > 7 &&
+      // (CurrentSubEntries % 8 == 7 || CurrentSubEntries % 8 == 0)
+      // See the comment on the wavefront size == 64 case for why we are
+      // being conservative.
+      return CurrentSubEntries > 7;
+    }
+  }
+}
+
 unsigned CFStack::getSubEntrySize(CFStack::StackItem Item) {
   switch(Item) {
   default:
@@ -430,25 +470,27 @@ private:
 
 public:
   R600ControlFlowFinalizer(TargetMachine &tm) : MachineFunctionPass(ID),
-    TII (0), TRI(0),
+    TII (nullptr), TRI(nullptr),
     ST(tm.getSubtarget<AMDGPUSubtarget>()) {
       const AMDGPUSubtarget &ST = tm.getSubtarget<AMDGPUSubtarget>();
       MaxFetchInst = ST.getTexVTXClauseSize();
   }
 
-  virtual bool runOnMachineFunction(MachineFunction &MF) {
-    TII=static_cast<const R600InstrInfo *>(MF.getTarget().getInstrInfo());
-    TRI=static_cast<const R600RegisterInfo *>(MF.getTarget().getRegisterInfo());
+  bool runOnMachineFunction(MachineFunction &MF) override {
+    TII = static_cast<const R600InstrInfo *>(
+        MF.getTarget().getSubtargetImpl()->getInstrInfo());
+    TRI = static_cast<const R600RegisterInfo *>(
+        MF.getTarget().getSubtargetImpl()->getRegisterInfo());
     R600MachineFunctionInfo *MFI = MF.getInfo<R600MachineFunctionInfo>();
 
-    CFStack CFStack(ST, MFI->ShaderType);
+    CFStack CFStack(ST, MFI->getShaderType());
     for (MachineFunction::iterator MB = MF.begin(), ME = MF.end(); MB != ME;
         ++MB) {
       MachineBasicBlock &MBB = *MB;
       unsigned CfCount = 0;
       std::vector<std::pair<unsigned, std::set<MachineInstr *> > > LoopStack;
       std::vector<MachineInstr * > IfThenElseStack;
-      if (MFI->ShaderType == 1) {
+      if (MFI->getShaderType() == ShaderType::VERTEX) {
         BuildMI(MBB, MBB.begin(), MBB.findDebugLoc(MBB.begin()),
             getHWInstrDesc(CF_CALL_FS));
         CfCount++;
@@ -463,18 +505,22 @@ public:
           DEBUG(dbgs() << CfCount << ":"; I->dump(););
           FetchClauses.push_back(MakeFetchClause(MBB, I));
           CfCount++;
+          LastAlu.back() = nullptr;
           continue;
         }
 
         MachineBasicBlock::iterator MI = I;
         if (MI->getOpcode() != AMDGPU::ENDIF)
-          LastAlu.back() = 0;
+          LastAlu.back() = nullptr;
         if (MI->getOpcode() == AMDGPU::CF_ALU)
           LastAlu.back() = MI;
         I++;
+        bool RequiresWorkAround =
+            CFStack.requiresWorkAroundForInst(MI->getOpcode());
         switch (MI->getOpcode()) {
         case AMDGPU::CF_ALU_PUSH_BEFORE:
-          if (ST.hasCaymanISA() && CFStack.getLoopDepth() > 1) {
+          if (RequiresWorkAround) {
+            DEBUG(dbgs() << "Applying bug work-around for ALU_PUSH_BEFORE\n");
             BuildMI(MBB, MI, MBB.findDebugLoc(MI), TII->get(AMDGPU::CF_PUSH_EG))
                 .addImm(CfCount + 1)
                 .addImm(1);
@@ -516,7 +562,7 @@ public:
           break;
         }
         case AMDGPU::IF_PREDICATE_SET: {
-          LastAlu.push_back(0);
+          LastAlu.push_back(nullptr);
           MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
               getHWInstrDesc(CF_JUMP))
               .addImm(0)
@@ -623,7 +669,7 @@ public:
     return false;
   }
 
-  const char *getPassName() const {
+  const char *getPassName() const override {
     return "R600 Control Flow Finalizer Pass";
   }
 };