<div dir="ltr">It's generally good to not checkin entirely dead & untested code - could you include a unit test to demonstrate correctness, at least?</div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Apr 27, 2016 at 5:51 AM, Artur Pilipenko via llvm-commits <span dir="ltr"><<a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: apilipenko<br>
Date: Wed Apr 27 07:51:01 2016<br>
New Revision: 267708<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=267708&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=267708&view=rev</a><br>
Log:<br>
NFC. Introduce Value::getPointerDerferecnceableBytes<br>
<br>
Extract a part of isDereferenceableAndAlignedPointer functionality to Value::getPointerDerferecnceableBytes. Currently it's a NFC, but in future I'm going to accumulate all the logic about value dereferenceability in this function similarly to Value::getPointerAlignment function (D16144).<br>
<br>
Reviewed By: reames<br>
<br>
Differential Revision: <a href="http://reviews.llvm.org/D17572" rel="noreferrer" target="_blank">http://reviews.llvm.org/D17572</a><br>
<br>
Modified:<br>
llvm/trunk/include/llvm/IR/Value.h<br>
llvm/trunk/lib/Analysis/Loads.cpp<br>
llvm/trunk/lib/IR/Value.cpp<br>
<br>
Modified: llvm/trunk/include/llvm/IR/Value.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Value.h?rev=267708&r1=267707&r2=267708&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Value.h?rev=267708&r1=267707&r2=267708&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/include/llvm/IR/Value.h (original)<br>
+++ llvm/trunk/include/llvm/IR/Value.h Wed Apr 27 07:51:01 2016<br>
@@ -504,6 +504,13 @@ public:<br>
return const_cast<Value*>(this)->stripInBoundsOffsets();<br>
}<br>
<br>
+ /// \brief Returns the number of bytes known to be dereferenceable for the<br>
+ /// pointer value.<br>
+ ///<br>
+ /// If CanBeNull is set by this function the pointer can either be null or be<br>
+ /// dereferenceable up to the returned number of bytes.<br>
+ unsigned getPointerDereferenceableBytes(bool &CanBeNull) const;<br>
+<br>
/// \brief Returns an alignment of the pointer value.<br>
///<br>
/// Returns an alignment which is either specified explicitly, e.g. via<br>
<br>
Modified: llvm/trunk/lib/Analysis/Loads.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/Loads.cpp?rev=267708&r1=267707&r2=267708&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/Loads.cpp?rev=267708&r1=267707&r2=267708&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/Analysis/Loads.cpp (original)<br>
+++ llvm/trunk/lib/Analysis/Loads.cpp Wed Apr 27 07:51:01 2016<br>
@@ -33,34 +33,9 @@ static bool isDereferenceableFromAttribu<br>
assert(Offset.isNonNegative() && "offset can't be negative");<br>
assert(Ty->isSized() && "must be sized");<br>
<br>
- APInt DerefBytes(Offset.getBitWidth(), 0);<br>
bool CheckForNonNull = false;<br>
- if (const Argument *A = dyn_cast<Argument>(BV)) {<br>
- DerefBytes = A->getDereferenceableBytes();<br>
- if (!DerefBytes.getBoolValue()) {<br>
- DerefBytes = A->getDereferenceableOrNullBytes();<br>
- CheckForNonNull = true;<br>
- }<br>
- } else if (auto CS = ImmutableCallSite(BV)) {<br>
- DerefBytes = CS.getDereferenceableBytes(0);<br>
- if (!DerefBytes.getBoolValue()) {<br>
- DerefBytes = CS.getDereferenceableOrNullBytes(0);<br>
- CheckForNonNull = true;<br>
- }<br>
- } else if (const LoadInst *LI = dyn_cast<LoadInst>(BV)) {<br>
- if (MDNode *MD = LI->getMetadata(LLVMContext::MD_dereferenceable)) {<br>
- ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0));<br>
- DerefBytes = CI->getLimitedValue();<br>
- }<br>
- if (!DerefBytes.getBoolValue()) {<br>
- if (MDNode *MD =<br>
- LI->getMetadata(LLVMContext::MD_dereferenceable_or_null)) {<br>
- ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0));<br>
- DerefBytes = CI->getLimitedValue();<br>
- }<br>
- CheckForNonNull = true;<br>
- }<br>
- }<br>
+ APInt DerefBytes(Offset.getBitWidth(),<br>
+ BV->getPointerDereferenceableBytes(CheckForNonNull));<br>
<br>
if (DerefBytes.getBoolValue())<br>
if (DerefBytes.uge(Offset + DL.getTypeStoreSize(Ty)))<br>
<br>
Modified: llvm/trunk/lib/IR/Value.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Value.cpp?rev=267708&r1=267707&r2=267708&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Value.cpp?rev=267708&r1=267707&r2=267708&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/IR/Value.cpp (original)<br>
+++ llvm/trunk/lib/IR/Value.cpp Wed Apr 27 07:51:01 2016<br>
@@ -525,6 +525,40 @@ Value *Value::stripInBoundsOffsets() {<br>
return stripPointerCastsAndOffsets<PSK_InBounds>(this);<br>
}<br>
<br>
+unsigned Value::getPointerDereferenceableBytes(bool &CanBeNull) const {<br>
+ assert(getType()->isPointerTy() && "must be pointer");<br>
+<br>
+ unsigned DerefBytes = 0;<br>
+ CanBeNull = false;<br>
+ if (const Argument *A = dyn_cast<Argument>(this)) {<br>
+ DerefBytes = A->getDereferenceableBytes();<br>
+ if (DerefBytes == 0) {<br>
+ DerefBytes = A->getDereferenceableOrNullBytes();<br>
+ CanBeNull = true;<br>
+ }<br>
+ } else if (auto CS = ImmutableCallSite(this)) {<br>
+ DerefBytes = CS.getDereferenceableBytes(0);<br>
+ if (DerefBytes == 0) {<br>
+ DerefBytes = CS.getDereferenceableOrNullBytes(0);<br>
+ CanBeNull = true;<br>
+ }<br>
+ } else if (const LoadInst *LI = dyn_cast<LoadInst>(this)) {<br>
+ if (MDNode *MD = LI->getMetadata(LLVMContext::MD_dereferenceable)) {<br>
+ ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0));<br>
+ DerefBytes = CI->getLimitedValue();<br>
+ }<br>
+ if (DerefBytes == 0) {<br>
+ if (MDNode *MD =<br>
+ LI->getMetadata(LLVMContext::MD_dereferenceable_or_null)) {<br>
+ ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0));<br>
+ DerefBytes = CI->getLimitedValue();<br>
+ }<br>
+ CanBeNull = true;<br>
+ }<br>
+ }<br>
+ return DerefBytes;<br>
+}<br>
+<br>
unsigned Value::getPointerAlignment(const DataLayout &DL) const {<br>
assert(getType()->isPointerTy() && "must be pointer");<br>
<br>
<br>
<br>
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</blockquote></div><br></div>