AMDGPU: Annotate call graph with used features

Previously this wouldn't detect used features indirectly
used in callee functions.

llvm-svn: 307967

1 files changed, 143 insertions, 67 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAnnotateKernelFeatures.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAnnotateKernelFeatures.cpp
index 7235d8fae33..c837180334c 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAnnotateKernelFeatures.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAnnotateKernelFeatures.cpp
@@ -15,8 +15,10 @@
 #include "AMDGPU.h"
 #include "AMDGPUSubtarget.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/CallGraphSCCPass.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
 
@@ -26,26 +28,30 @@ using namespace llvm;
 
 namespace {
 
-class AMDGPUAnnotateKernelFeatures : public ModulePass {
+class AMDGPUAnnotateKernelFeatures : public CallGraphSCCPass {
 private:
+  const TargetMachine *TM = nullptr;
   AMDGPUAS AS;
-  static bool hasAddrSpaceCast(const Function &F, AMDGPUAS AS);
 
-  void addAttrToCallers(Function *Intrin, StringRef AttrName);
+  bool addFeatureAttributes(Function &F);
+
+  void addAttrToCallers(Function &Intrin, StringRef AttrName);
   bool addAttrsForIntrinsics(Module &M, ArrayRef<StringRef[2]>);
 
 public:
   static char ID;
 
-  AMDGPUAnnotateKernelFeatures() : ModulePass(ID) {}
-  bool runOnModule(Module &M) override;
+  AMDGPUAnnotateKernelFeatures() : CallGraphSCCPass(ID) {}
+
+  bool doInitialization(CallGraph &CG) override;
+  bool runOnSCC(CallGraphSCC &SCC) override;
   StringRef getPassName() const override {
     return "AMDGPU Annotate Kernel Features";
   }
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();
-    ModulePass::getAnalysisUsage(AU);
+    CallGraphSCCPass::getAnalysisUsage(AU);
   }
 
   static bool visitConstantExpr(const ConstantExpr *CE, AMDGPUAS AS);
@@ -121,16 +127,108 @@ bool AMDGPUAnnotateKernelFeatures::visitConstantExprsRecursively(
   return false;
 }
 
-// Return true if an addrspacecast is used that requires the queue ptr.
-bool AMDGPUAnnotateKernelFeatures::hasAddrSpaceCast(const Function &F,
-    AMDGPUAS AS) {
+// We do not need to note the x workitem or workgroup id because they are always
+// initialized.
+//
+// TODO: We should not add the attributes if the known compile time workgroup
+// size is 1 for y/z.
+static StringRef intrinsicToAttrName(Intrinsic::ID ID, bool &IsQueuePtr) {
+  switch (ID) {
+  case Intrinsic::amdgcn_workitem_id_y:
+  case Intrinsic::r600_read_tidig_y:
+    return "amdgpu-work-item-id-y";
+  case Intrinsic::amdgcn_workitem_id_z:
+  case Intrinsic::r600_read_tidig_z:
+    return "amdgpu-work-item-id-z";
+  case Intrinsic::amdgcn_workgroup_id_y:
+  case Intrinsic::r600_read_tgid_y:
+    return "amdgpu-work-group-id-y";
+  case Intrinsic::amdgcn_workgroup_id_z:
+  case Intrinsic::r600_read_tgid_z:
+    return "amdgpu-work-group-id-z";
+  case Intrinsic::amdgcn_dispatch_ptr:
+    return "amdgpu-dispatch-ptr";
+  case Intrinsic::amdgcn_dispatch_id:
+    return "amdgpu-dispatch-id";
+  case Intrinsic::amdgcn_queue_ptr:
+  case Intrinsic::trap:
+  case Intrinsic::debugtrap:
+    IsQueuePtr = true;
+    return "amdgpu-queue-ptr";
+  default:
+    return "";
+  }
+}
+
+static bool handleAttr(Function &Parent, const Function &Callee,
+                       StringRef Name) {
+  if (Callee.hasFnAttribute(Name)) {
+    Parent.addFnAttr(Name);
+    return true;
+  }
+
+  return false;
+}
+
+static void copyFeaturesToFunction(Function &Parent, const Function &Callee,
+                                   bool &NeedQueuePtr) {
+
+  static const StringRef AttrNames[] = {
+    // .x omitted
+    { "amdgpu-work-item-id-y" },
+    { "amdgpu-work-item-id-z" },
+    // .x omitted
+    { "amdgpu-work-group-id-y" },
+    { "amdgpu-work-group-id-z" },
+    { "amdgpu-dispatch-ptr" },
+    { "amdgpu-dispatch-id" }
+  };
+
+  if (handleAttr(Parent, Callee, "amdgpu-queue-ptr"))
+    NeedQueuePtr = true;
+
+  for (StringRef AttrName : AttrNames)
+    handleAttr(Parent, Callee, AttrName);
+}
+
+bool AMDGPUAnnotateKernelFeatures::addFeatureAttributes(Function &F) {
+  bool HasApertureRegs = TM->getSubtarget<AMDGPUSubtarget>(F).hasApertureRegs();
   SmallPtrSet<const Constant *, 8> ConstantExprVisited;
 
-  for (const BasicBlock &BB : F) {
-    for (const Instruction &I : BB) {
+  bool Changed = false;
+  bool NeedQueuePtr = false;
+
+  for (BasicBlock &BB : F) {
+    for (Instruction &I : BB) {
+      CallSite CS(&I);
+      if (CS) {
+        Function *Callee = CS.getCalledFunction();
+
+        // TODO: Do something with indirect calls.
+        if (!Callee)
+          continue;
+
+        Intrinsic::ID IID = Callee->getIntrinsicID();
+        if (IID == Intrinsic::not_intrinsic) {
+          copyFeaturesToFunction(F, *Callee, NeedQueuePtr);
+          Changed = true;
+        } else {
+          StringRef AttrName = intrinsicToAttrName(IID, NeedQueuePtr);
+          if (!AttrName.empty()) {
+            F.addFnAttr(AttrName);
+            Changed = true;
+          }
+        }
+      }
+
+      if (NeedQueuePtr || HasApertureRegs)
+        continue;
+
       if (const AddrSpaceCastInst *ASC = dyn_cast<AddrSpaceCastInst>(&I)) {
-        if (castRequiresQueuePtr(ASC, AS))
-          return true;
+        if (castRequiresQueuePtr(ASC, AS)) {
+          NeedQueuePtr = true;
+          continue;
+        }
       }
 
       for (const Use &U : I.operands()) {
@@ -138,20 +236,27 @@ bool AMDGPUAnnotateKernelFeatures::hasAddrSpaceCast(const Function &F,
         if (!OpC)
           continue;
 
-        if (visitConstantExprsRecursively(OpC, ConstantExprVisited, AS))
-          return true;
+        if (visitConstantExprsRecursively(OpC, ConstantExprVisited, AS)) {
+          NeedQueuePtr = true;
+          break;
+        }
       }
     }
   }
 
-  return false;
+  if (NeedQueuePtr) {
+    F.addFnAttr("amdgpu-queue-ptr");
+    Changed = true;
+  }
+
+  return Changed;
 }
 
-void AMDGPUAnnotateKernelFeatures::addAttrToCallers(Function *Intrin,
+void AMDGPUAnnotateKernelFeatures::addAttrToCallers(Function &Intrin,
                                                     StringRef AttrName) {
   SmallPtrSet<Function *, 4> SeenFuncs;
 
-  for (User *U : Intrin->users()) {
+  for (User *U : Intrin.users()) {
     // CallInst is the only valid user for an intrinsic.
     CallInst *CI = cast<CallInst>(U);
 
@@ -168,7 +273,7 @@ bool AMDGPUAnnotateKernelFeatures::addAttrsForIntrinsics(
 
   for (const StringRef *Arr  : IntrinsicToAttr) {
     if (Function *Fn = M.getFunction(Arr[0])) {
-      addAttrToCallers(Fn, Arr[1]);
+      addAttrToCallers(*Fn, Arr[1]);
       Changed = true;
     }
   }
@@ -176,62 +281,33 @@ bool AMDGPUAnnotateKernelFeatures::addAttrsForIntrinsics(
   return Changed;
 }
 
-bool AMDGPUAnnotateKernelFeatures::runOnModule(Module &M) {
+bool AMDGPUAnnotateKernelFeatures::runOnSCC(CallGraphSCC &SCC) {
+  Module &M = SCC.getCallGraph().getModule();
   Triple TT(M.getTargetTriple());
-  AS = AMDGPU::getAMDGPUAS(M);
-
-  static const StringRef IntrinsicToAttr[][2] = {
-    // .x omitted
-    { "llvm.amdgcn.workitem.id.y", "amdgpu-work-item-id-y" },
-    { "llvm.amdgcn.workitem.id.z", "amdgpu-work-item-id-z" },
-
-    { "llvm.amdgcn.workgroup.id.y", "amdgpu-work-group-id-y" },
-    { "llvm.amdgcn.workgroup.id.z", "amdgpu-work-group-id-z" },
-
-    { "llvm.r600.read.tgid.y", "amdgpu-work-group-id-y" },
-    { "llvm.r600.read.tgid.z", "amdgpu-work-group-id-z" },
-
-    // .x omitted
-    { "llvm.r600.read.tidig.y", "amdgpu-work-item-id-y" },
-    { "llvm.r600.read.tidig.z", "amdgpu-work-item-id-z" }
-  };
-
-  static const StringRef HSAIntrinsicToAttr[][2] = {
-    { "llvm.amdgcn.dispatch.ptr", "amdgpu-dispatch-ptr" },
-    { "llvm.amdgcn.queue.ptr", "amdgpu-queue-ptr" },
-    { "llvm.amdgcn.dispatch.id", "amdgpu-dispatch-id" },
-    { "llvm.trap", "amdgpu-queue-ptr" },
-    { "llvm.debugtrap", "amdgpu-queue-ptr" }
-  };
-
-  // TODO: We should not add the attributes if the known compile time workgroup
-  // size is 1 for y/z.
 
-  // TODO: Intrinsics that require queue ptr.
+  bool Changed = false;
+  for (CallGraphNode *I : SCC) {
+    Function *F = I->getFunction();
+    if (!F || F->isDeclaration())
+      continue;
 
-  // We do not need to note the x workitem or workgroup id because they are
-  // always initialized.
+    Changed |= addFeatureAttributes(*F);
+  }
 
-  bool Changed = addAttrsForIntrinsics(M, IntrinsicToAttr);
-  if (TT.getOS() == Triple::AMDHSA || TT.getOS() == Triple::Mesa3D) {
-    Changed |= addAttrsForIntrinsics(M, HSAIntrinsicToAttr);
 
-    for (Function &F : M) {
-      if (F.hasFnAttribute("amdgpu-queue-ptr"))
-        continue;
+  return Changed;
+}
 
-      auto *TPC = getAnalysisIfAvailable<TargetPassConfig>();
-      bool HasApertureRegs = TPC && TPC->getTM<TargetMachine>()
-                                        .getSubtarget<AMDGPUSubtarget>(F)
-                                        .hasApertureRegs();
-      if (!HasApertureRegs && hasAddrSpaceCast(F, AS))
-        F.addFnAttr("amdgpu-queue-ptr");
-    }
-  }
+bool AMDGPUAnnotateKernelFeatures::doInitialization(CallGraph &CG) {
+  auto *TPC = getAnalysisIfAvailable<TargetPassConfig>();
+  if (!TPC)
+    report_fatal_error("TargetMachine is required");
 
-  return Changed;
+  AS = AMDGPU::getAMDGPUAS(CG.getModule());
+  TM = &TPC->getTM<TargetMachine>();
+  return false;
 }
 
-ModulePass *llvm::createAMDGPUAnnotateKernelFeaturesPass() {
+Pass *llvm::createAMDGPUAnnotateKernelFeaturesPass() {
   return new AMDGPUAnnotateKernelFeatures();
 }