Prevent LoopVectorizer and SLPVectorizer running if the target has no vector registers.

XCore target: Add XCoreTargetTransformInfo
This is where getNumberOfRegisters() resides, which in turn returns the
number of vector registers (=0).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190936 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 107 insertions, 0 deletions

diff --git a/lib/Target/XCore/XCore.h b/lib/Target/XCore/XCore.h
index 2f375fc952..73c310be03 100644
--- a/lib/Target/XCore/XCore.h
+++ b/lib/Target/XCore/XCore.h
@@ -31,6 +31,8 @@ namespace llvm {
                                    CodeGenOpt::Level OptLevel);
   ModulePass *createXCoreLowerThreadLocalPass();
 
+  ImmutablePass *createXCoreTargetTransformInfoPass(const XCoreTargetMachine *TM);
+
 } // end namespace llvm;
 
 #endif
diff --git a/lib/Target/XCore/XCoreTargetMachine.cpp b/lib/Target/XCore/XCoreTargetMachine.cpp
index 3ef1520c71..9ae0b860df 100644
--- a/lib/Target/XCore/XCoreTargetMachine.cpp
+++ b/lib/Target/XCore/XCoreTargetMachine.cpp
@@ -70,3 +70,11 @@ bool XCorePassConfig::addInstSelector() {
 extern "C" void LLVMInitializeXCoreTarget() {
   RegisterTargetMachine<XCoreTargetMachine> X(TheXCoreTarget);
 }
+
+void XCoreTargetMachine::addAnalysisPasses(PassManagerBase &PM) {
+  // Add first the target-independent BasicTTI pass, then our XCore pass. This
+  // allows the XCore pass to delegate to the target independent layer when
+  // appropriate.
+  PM.add(createBasicTargetTransformInfoPass(this));
+  PM.add(createXCoreTargetTransformInfoPass(this));
+}
diff --git a/lib/Target/XCore/XCoreTargetMachine.h b/lib/Target/XCore/XCoreTargetMachine.h
index eb9a1aa420..a19a67727f 100644
--- a/lib/Target/XCore/XCoreTargetMachine.h
+++ b/lib/Target/XCore/XCoreTargetMachine.h
@@ -57,6 +57,8 @@ public:
 
   // Pass Pipeline Configuration
   virtual TargetPassConfig *createPassConfig(PassManagerBase &PM);
+
+  virtual void addAnalysisPasses(PassManagerBase &PM);
 };
 
 } // end namespace llvm
diff --git a/lib/Target/XCore/XCoreTargetTransformInfo.cpp b/lib/Target/XCore/XCoreTargetTransformInfo.cpp
new file mode 100644
index 0000000000..4862138834
--- /dev/null
+++ b/lib/Target/XCore/XCoreTargetTransformInfo.cpp
@@ -0,0 +1,85 @@
+//===-- XCoreTargetTransformInfo.cpp - XCore specific TTI pass ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements a TargetTransformInfo analysis pass specific to the
+/// XCore target machine. It uses the target's detailed information to provide
+/// more precise answers to certain TTI queries, while letting the target
+/// independent and default TTI implementations handle the rest.
+///
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "xcoretti"
+#include "XCore.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/CostTable.h"
+using namespace llvm;
+
+// Declare the pass initialization routine locally as target-specific passes
+// don't havve a target-wide initialization entry point, and so we rely on the
+// pass constructor initialization.
+namespace llvm {
+void initializeXCoreTTIPass(PassRegistry &);
+}
+
+namespace {
+
+class XCoreTTI : public ImmutablePass, public TargetTransformInfo {
+  const XCoreTargetMachine *TM;
+
+public:
+  XCoreTTI() : ImmutablePass(ID), TM(0) {
+    llvm_unreachable("This pass cannot be directly constructed");
+  }
+
+  XCoreTTI(const XCoreTargetMachine *TM)
+      : ImmutablePass(ID), TM(TM) {
+    initializeXCoreTTIPass(*PassRegistry::getPassRegistry());
+  }
+
+  virtual void initializePass() {
+    pushTTIStack(this);
+  }
+
+  virtual void finalizePass() {
+    popTTIStack();
+  }
+
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    TargetTransformInfo::getAnalysisUsage(AU);
+  }
+
+  static char ID;
+
+  virtual void *getAdjustedAnalysisPointer(const void *ID) {
+    if (ID == &TargetTransformInfo::ID)
+      return (TargetTransformInfo*)this;
+    return this;
+  }
+
+  unsigned getNumberOfRegisters(bool Vector) const {
+    if (Vector) {
+       return 0;
+    }
+    return 12;
+  }
+};
+
+} // end anonymous namespace
+
+INITIALIZE_AG_PASS(XCoreTTI, TargetTransformInfo, "xcoretti",
+                   "XCore Target Transform Info", true, true, false)
+char XCoreTTI::ID = 0;
+
+
+ImmutablePass *
+llvm::createXCoreTargetTransformInfoPass(const XCoreTargetMachine *TM) {
+  return new XCoreTTI(TM);
+}
diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp
index 1d82c7b8f5..30908c8ebf 100644
--- a/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -909,6 +909,11 @@ struct LoopVectorize : public LoopPass {
     DT = &getAnalysis<DominatorTree>();
     TLI = getAnalysisIfAvailable<TargetLibraryInfo>();
 
+    // If the target claims to have no vector registers don't attempt
+    // vectorization.
+    if (!TTI->getNumberOfRegisters(true))
+      return false;
+
     if (DL == NULL) {
       DEBUG(dbgs() << "LV: Not vectorizing because of missing data layout");
       return false;
diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index b287ca7c8d..cd3f723cd3 100644
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -1572,6 +1572,11 @@ struct SLPVectorizer : public FunctionPass {
     StoreRefs.clear();
     bool Changed = false;
 
+    // If the target claims to have no vector registers don't attempt
+    // vectorization.
+    if (!TTI->getNumberOfRegisters(true))
+      return false;
+
     // Must have DataLayout. We can't require it because some tests run w/o
     // triple.
     if (!DL)