rL306267

commit 5a057dc8edbb63887f8c611dd8ddf1b76997f07c
Author: Chandler Carruth <chandlerc@gmail.com>
Date:   Mon Jun 26 03:31:31 2017 +0000

    [InstCombine] Factor the logic for propagating !nonnull and !range
    metadata out of InstCombine and into helpers.

    NFC, this just exposes the logic used by InstCombine when propagating
    metadata from one load instruction to another. The plan is to use this
    in SROA to address PR32902.

    If anyone has better ideas about how to factor this or name variables,
    I'm all ears, but this seemed like a pretty good start and lets us make
    progress on the PR.

    This is based on a patch by Ariel Ben-Yehuda (D34285).

    git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306267 91177308-0d34-0410-b5e6-96231b3b80d8

Gbp-Pq: Name rL306267.diff

diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index 490a765c3fabcb93dc5436eb214c80bfcf0194cb..2d0f25b19e7cb28835827d79d6b2676a502686f7 100644 (file)
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -366,6 +366,19 @@ unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
 /// during lowering by the GC infrastructure.
 bool callsGCLeafFunction(ImmutableCallSite CS);
 
+/// Copy a nonnull metadata node to a new load instruction.
+///
+/// This handles mapping it to range metadata if the new load is an integer
+/// load instead of a pointer load.
+void copyNonnullMetadata(const LoadInst &OldLI, MDNode *N, LoadInst &NewLI);
+
+/// Copy a range metadata node to a new load instruction.
+///
+/// This handles mapping it to nonnull metadata if the new load is a pointer
+/// load instead of an integer load and the range doesn't cover null.
+void copyRangeMetadata(const DataLayout &DL, const LoadInst &OldLI, MDNode *N,
+                       LoadInst &NewLI);
+
 //===----------------------------------------------------------------------===//
 //  Intrinsic pattern matching
 //

diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 5789296b1ec98a2403c78de4eaede85d6db6cad3..1b126586c9a4c9e0735eb3a90e225753ad6fa76c 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -471,21 +471,7 @@ static LoadInst *combineLoadToNewType(InstCombiner &IC, LoadInst &LI, Type *NewT
       break;
 
     case LLVMContext::MD_nonnull:
-      // This only directly applies if the new type is also a pointer.
-      if (NewTy->isPointerTy()) {
-        NewLoad->setMetadata(ID, N);
-        break;
-      }
-      // If it's integral now, translate it to !range metadata.
-      if (NewTy->isIntegerTy()) {
-        auto *ITy = cast<IntegerType>(NewTy);
-        auto *NullInt = ConstantExpr::getPtrToInt(
-            ConstantPointerNull::get(cast<PointerType>(Ptr->getType())), ITy);
-        auto *NonNullInt =
-            ConstantExpr::getAdd(NullInt, ConstantInt::get(ITy, 1));
-        NewLoad->setMetadata(LLVMContext::MD_range,
-                             MDB.createRange(NonNullInt, NullInt));
-      }
+      copyNonnullMetadata(LI, N, *NewLoad);
       break;
     case LLVMContext::MD_align:
     case LLVMContext::MD_dereferenceable:
@@ -495,17 +481,7 @@ static LoadInst *combineLoadToNewType(InstCombiner &IC, LoadInst &LI, Type *NewT
         NewLoad->setMetadata(ID, N);
       break;
     case LLVMContext::MD_range:
-      // FIXME: It would be nice to propagate this in some way, but the type
-      // conversions make it hard.
-
-      // If it's a pointer now and the range does not contain 0, make it !nonnull.
-      if (NewTy->isPointerTy()) {
-        unsigned BitWidth = IC.getDataLayout().getTypeSizeInBits(NewTy);
-        if (!getConstantRangeFromMetadata(*N).contains(APInt(BitWidth, 0))) {
-          MDNode *NN = MDNode::get(LI.getContext(), None);
-          NewLoad->setMetadata(LLVMContext::MD_nonnull, NN);
-        }
-      }
+      copyRangeMetadata(IC.getDataLayout(), LI, N, *NewLoad);
       break;
     }
   }

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index 6e4174aa0cda144c6947c1fd92b6c27c1ac5f51a..f877264a6ec9199a0f6b9eebf8340411162d78ed 100644 (file)
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Analysis/LazyValueInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/CFG.h"
+#include "llvm/IR/ConstantRange.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/DataLayout.h"
@@ -1069,7 +1070,7 @@ static bool LdStHasDebugValue(DILocalVariable *DIVar, DIExpression *DIExpr,
 }
 
 /// See if there is a dbg.value intrinsic for DIVar for the PHI node.
-static bool PhiHasDebugValue(DILocalVariable *DIVar, 
+static bool PhiHasDebugValue(DILocalVariable *DIVar,
                              DIExpression *DIExpr,
                              PHINode *APN) {
   // Since we can't guarantee that the original dbg.declare instrinsic
@@ -1152,7 +1153,7 @@ void llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
   DbgValue->insertAfter(LI);
 }
 
-/// Inserts a llvm.dbg.value intrinsic after a phi 
+/// Inserts a llvm.dbg.value intrinsic after a phi
 /// that has an associated llvm.dbg.decl intrinsic.
 void llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
                                            PHINode *APN, DIBuilder &Builder) {
@@ -1723,12 +1724,12 @@ void llvm::combineMetadata(Instruction *K, const Instruction *J,
         // Preserve !invariant.group in K.
         break;
       case LLVMContext::MD_align:
-        K->setMetadata(Kind, 
+        K->setMetadata(Kind,
           MDNode::getMostGenericAlignmentOrDereferenceable(JMD, KMD));
         break;
       case LLVMContext::MD_dereferenceable:
       case LLVMContext::MD_dereferenceable_or_null:
-        K->setMetadata(Kind, 
+        K->setMetadata(Kind,
           MDNode::getMostGenericAlignmentOrDereferenceable(JMD, KMD));
         break;
     }
@@ -1812,6 +1813,49 @@ bool llvm::callsGCLeafFunction(ImmutableCallSite CS) {
   return false;
 }
 
+void llvm::copyNonnullMetadata(const LoadInst &OldLI, MDNode *N,
+                               LoadInst &NewLI) {
+  auto *NewTy = NewLI.getType();
+
+  // This only directly applies if the new type is also a pointer.
+  if (NewTy->isPointerTy()) {
+    NewLI.setMetadata(LLVMContext::MD_nonnull, N);
+    return;
+  }
+
+  // The only other translation we can do is to integral loads with !range
+  // metadata.
+  if (!NewTy->isIntegerTy())
+    return;
+
+  MDBuilder MDB(NewLI.getContext());
+  const Value *Ptr = OldLI.getPointerOperand();
+  auto *ITy = cast<IntegerType>(NewTy);
+  auto *NullInt = ConstantExpr::getPtrToInt(
+      ConstantPointerNull::get(cast<PointerType>(Ptr->getType())), ITy);
+  auto *NonNullInt = ConstantExpr::getAdd(NullInt, ConstantInt::get(ITy, 1));
+  NewLI.setMetadata(LLVMContext::MD_range,
+                    MDB.createRange(NonNullInt, NullInt));
+}
+
+void llvm::copyRangeMetadata(const DataLayout &DL, const LoadInst &OldLI,
+                             MDNode *N, LoadInst &NewLI) {
+  auto *NewTy = NewLI.getType();
+
+  // Give up unless it is converted to a pointer where there is a single very
+  // valuable mapping we can do reliably.
+  // FIXME: It would be nice to propagate this in more ways, but the type
+  // conversions make it hard.
+  if (!NewTy->isPointerTy())
+    return;
+
+  unsigned BitWidth = DL.getTypeSizeInBits(NewTy);
+  if (!getConstantRangeFromMetadata(*N).contains(APInt(BitWidth, 0))) {
+    MDNode *NN = MDNode::get(OldLI.getContext(), None);
+    NewLI.setMetadata(LLVMContext::MD_nonnull, NN);
+  }
+}
+
 namespace {
 /// A potential constituent of a bitreverse or bswap expression. See
 /// collectBitParts for a fuller explanation.
@@ -1933,7 +1977,7 @@ collectBitParts(Value *V, bool MatchBSwaps, bool MatchBitReversals,
       unsigned NumMaskedBits = AndMask.countPopulation();
       if (!MatchBitReversals && NumMaskedBits % 8 != 0)
         return Result;
-      
+
       auto &Res = collectBitParts(I->getOperand(0), MatchBSwaps,
                                   MatchBitReversals, BPS);
       if (!Res)