Merge isObjectPointerWithTrustworthySize with getPointerSize. Use it when

looking at the size of the pointee. Fixes PR11390!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144773 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 58 insertions, 30 deletions

diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 8f5f157..f5688cb 100644
--- a/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -274,43 +274,35 @@ static Value *getStoredPointerOperand(Instruction *I) {
   }
 }
 
-static uint64_t getPointerSize(Value *V, AliasAnalysis &AA) {
+static uint64_t getPointerSize(const Value *V, AliasAnalysis &AA) {
   const TargetData *TD = AA.getTargetData();
 
-  if (CallInst *CI = dyn_cast<CallInst>(V)) {
-    assert(isMalloc(CI) && "Expected Malloc call!");
-    if (ConstantInt *C = dyn_cast<ConstantInt>(CI->getArgOperand(0)))
+  if (const CallInst *CI = extractMallocCall(V)) {
+    if (const ConstantInt *C = dyn_cast<ConstantInt>(CI->getArgOperand(0)))
       return C->getZExtValue();
-    return AliasAnalysis::UnknownSize;
   }
 
   if (TD == 0)
     return AliasAnalysis::UnknownSize;
 
-  if (AllocaInst *A = dyn_cast<AllocaInst>(V)) {
+  if (const AllocaInst *A = dyn_cast<AllocaInst>(V)) {
     // Get size information for the alloca
-    if (ConstantInt *C = dyn_cast<ConstantInt>(A->getArraySize()))
+    if (const ConstantInt *C = dyn_cast<ConstantInt>(A->getArraySize()))
       return C->getZExtValue() * TD->getTypeAllocSize(A->getAllocatedType());
-    return AliasAnalysis::UnknownSize;
   }
 
-  assert(isa<Argument>(V) && "Expected AllocaInst, malloc call or Argument!");
-  PointerType *PT = cast<PointerType>(V->getType());
-  return TD->getTypeAllocSize(PT->getElementType());
-}
+  if (const Argument *A = dyn_cast<Argument>(V)) {
+    if (A->hasByValAttr())
+      if (PointerType *PT = dyn_cast<PointerType>(A->getType()))
+        return TD->getTypeAllocSize(PT->getElementType());
+  }
 
-/// isObjectPointerWithTrustworthySize - Return true if the specified Value* is
-/// pointing to an object with a pointer size we can trust.
-static bool isObjectPointerWithTrustworthySize(const Value *V) {
-  if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
-    return !AI->isArrayAllocation();
-  if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
-    return !GV->mayBeOverridden();
-  if (const Argument *A = dyn_cast<Argument>(V))
-    return A->hasByValAttr();
-  if (isMalloc(V))
-    return true;
-  return false;
+  if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
+    if (!GV->mayBeOverridden())
+      return TD->getTypeAllocSize(GV->getType()->getElementType());
+  }
+
+  return AliasAnalysis::UnknownSize;
 }
 
 namespace {
@@ -329,8 +321,8 @@ namespace {
 static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
                                    const AliasAnalysis::Location &Earlier,
                                    AliasAnalysis &AA,
-                                   int64_t& EarlierOff,
-                                   int64_t& LaterOff) {
+                                   int64_t &EarlierOff,
+                                   int64_t &LaterOff) {
   const Value *P1 = Earlier.Ptr->stripPointerCasts();
   const Value *P2 = Later.Ptr->stripPointerCasts();
 
@@ -377,12 +369,10 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
     return OverwriteUnknown;
 
   // If the "Later" store is to a recognizable object, get its size.
-  if (isObjectPointerWithTrustworthySize(UO2)) {
-    uint64_t ObjectSize =
-      TD.getTypeAllocSize(cast<PointerType>(UO2->getType())->getElementType());
+  uint64_t ObjectSize = getPointerSize(UO2, AA);
+  if (ObjectSize != AliasAnalysis::UnknownSize)
     if (ObjectSize == Later.Size && ObjectSize >= Earlier.Size)
       return OverwriteComplete;
-  }
 
   // Okay, we have stores to two completely different pointers.  Try to
   // decompose the pointer into a "base + constant_offset" form.  If the base
diff --git a/test/Transforms/DeadStoreElimination/pr11390.ll b/test/Transforms/DeadStoreElimination/pr11390.ll
new file mode 100644
index 0000000..fc58fc9
--- /dev/null
+++ b/test/Transforms/DeadStoreElimination/pr11390.ll
@@ -0,0 +1,38 @@
+; RUN: opt -basicaa -dse -S -o - | FileCheck %s
+; PR11390
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define fastcc void @cat_domain(i8* nocapture %name, i8* nocapture %domain, i8** 
+nocapture %s) nounwind uwtable {
+entry:
+  %call = tail call i64 @strlen(i8* %name) nounwind readonly
+  %call1 = tail call i64 @strlen(i8* %domain) nounwind readonly
+  %add = add i64 %call, 1
+  %add2 = add i64 %add, %call1
+  %add3 = add i64 %add2, 1
+  %call4 = tail call noalias i8* @malloc(i64 %add3) nounwind
+  store i8* %call4, i8** %s, align 8
+  %tobool = icmp eq i8* %call4, null
+  br i1 %tobool, label %return, label %if.end
+
+if.end:                                           ; preds = %entry
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %call4, i8* %name, i64 %call, i32 1, i1 false)
+  %arrayidx = getelementptr inbounds i8* %call4, i64 %call
+  store i8 46, i8* %arrayidx, align 1
+; CHECK: store i8 46
+  %add.ptr5 = getelementptr inbounds i8* %call4, i64 %add
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %add.ptr5, i8* %domain, i64 %call1, i32 1, i1 false)
+  %arrayidx8 = getelementptr inbounds i8* %call4, i64 %add2
+  store i8 0, i8* %arrayidx8, align 1
+  br label %return
+
+return:                                           ; preds = %if.end, %entry
+  ret void
+}
+
+declare i64 @strlen(i8* nocapture) nounwind readonly
+
+declare noalias i8* @malloc(i64) nounwind
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind