llvm-toolchain/debian/patches/rL306267.diff

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

--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -366,6 +366,19 @@
 /// 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
 //
--- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -471,21 +471,7 @@
       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 @@
         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;
     }
   }
--- 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 @@
 }
 
 /// 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 @@
   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 @@
         // 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 @@
   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 @@
       unsigned NumMaskedBits = AndMask.countPopulation();
       if (!MatchBitReversals && NumMaskedBits % 8 != 0)
         return Result;
-      
+
       auto &Res = collectBitParts(I->getOperand(0), MatchBSwaps,
                                   MatchBitReversals, BPS);
       if (!Res)