[llvm] r354884 - [DAG] Fix constant store folding to handle non-byte sizes.
Nirav Dave via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 26 07:02:33 PST 2019
Author: niravd
Date: Tue Feb 26 07:02:32 2019
New Revision: 354884
URL: http://llvm.org/viewvc/llvm-project?rev=354884&view=rev
Log:
[DAG] Fix constant store folding to handle non-byte sizes.
Avoid crashes from zero-byte values due to sub-byte store sizes.
Reviewers: uabelho, courbet, rnk
Reviewed By: courbet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58626
Modified:
llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
llvm/trunk/test/CodeGen/X86/constant-combines.ll
Modified: llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h?rev=354884&r1=354883&r2=354884&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SelectionDAGAddressAnalysis.h Tue Feb 26 07:02:32 2019
@@ -62,14 +62,15 @@ public:
// Returns true if `Other` (with size `OtherSize`) can be proven to be fully
// contained in `*this` (with size `Size`).
- bool contains(int64_t Size, const BaseIndexOffset &Other, int64_t OtherSize,
- const SelectionDAG &DAG) const {
- int64_t Offset;
- return contains(Size, Other, OtherSize, DAG, Offset);
- }
+ bool contains(const SelectionDAG &DAG, int64_t BitSize,
+ const BaseIndexOffset &Other, int64_t OtherBitSize,
+ int64_t &BitOffset) const;
- bool contains(int64_t Size, const BaseIndexOffset &Other, int64_t OtherSize,
- const SelectionDAG &DAG, int64_t &Offset) const;
+ bool contains(const SelectionDAG &DAG, int64_t BitSize,
+ const BaseIndexOffset &Other, int64_t OtherBitSize) const {
+ int64_t BitOffset;
+ return contains(DAG, BitSize, Other, OtherBitSize, BitOffset);
+ }
// Returns true `BasePtr0` and `BasePtr1` can be proven to alias/not alias, in
// which case `IsAlias` is set to true/false.
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=354884&r1=354883&r2=354884&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Feb 26 07:02:32 2019
@@ -15427,13 +15427,13 @@ SDValue DAGCombiner::visitSTORE(SDNode *
!ST1->getBasePtr().isUndef()) {
const BaseIndexOffset STBase = BaseIndexOffset::match(ST, DAG);
const BaseIndexOffset ChainBase = BaseIndexOffset::match(ST1, DAG);
- unsigned STByteSize = ST->getMemoryVT().getSizeInBits() / 8;
- unsigned ChainByteSize = ST1->getMemoryVT().getSizeInBits() / 8;
+ unsigned STBitSize = ST->getMemoryVT().getSizeInBits();
+ unsigned ChainBitSize = ST1->getMemoryVT().getSizeInBits();
// If this is a store who's preceding store to a subset of the current
// location and no one other node is chained to that store we can
// effectively drop the store. Do not remove stores to undef as they may
// be used as data sinks.
- if (STBase.contains(STByteSize, ChainBase, ChainByteSize, DAG)) {
+ if (STBase.contains(DAG, STBitSize, ChainBase, ChainBitSize)) {
CombineTo(ST1, ST1->getChain());
return SDValue();
}
@@ -15442,17 +15442,17 @@ SDValue DAGCombiner::visitSTORE(SDNode *
// able to fold ST's value into the preceding stored value. As we know
// the other uses of ST1's chain are unconcerned with ST, this folding
// will not affect those nodes.
- int64_t Offset;
- if (ChainBase.contains(ChainByteSize, STBase, STByteSize, DAG,
- Offset)) {
+ int64_t BitOffset;
+ if (ChainBase.contains(DAG, ChainBitSize, STBase, STBitSize,
+ BitOffset)) {
SDValue ChainValue = ST1->getValue();
if (auto *C1 = dyn_cast<ConstantSDNode>(ChainValue)) {
if (auto *C = dyn_cast<ConstantSDNode>(Value)) {
APInt Val = C1->getAPIntValue();
- APInt InsertVal = C->getAPIntValue().zextOrTrunc(STByteSize * 8);
+ APInt InsertVal = C->getAPIntValue().zextOrTrunc(STBitSize);
// FIXME: Handle Big-endian mode.
if (!DAG.getDataLayout().isBigEndian()) {
- Val.insertBits(InsertVal, Offset * 8);
+ Val.insertBits(InsertVal, BitOffset);
SDValue NewSDVal =
DAG.getConstant(Val, SDLoc(C), ChainValue.getValueType(),
C1->isTargetOpcode(), C1->isOpaque());
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp?rev=354884&r1=354883&r2=354884&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp Tue Feb 26 07:02:32 2019
@@ -135,9 +135,10 @@ bool BaseIndexOffset::computeAliasing(co
return false; // Cannot determine whether the pointers alias.
}
-bool BaseIndexOffset::contains(int64_t Size, const BaseIndexOffset &Other,
- int64_t OtherSize, const SelectionDAG &DAG,
- int64_t &Offset) const {
+bool BaseIndexOffset::contains(const SelectionDAG &DAG, int64_t BitSize,
+ const BaseIndexOffset &Other,
+ int64_t OtherBitSize, int64_t &BitOffset) const {
+ int64_t Offset;
if (!equalBaseIndex(Other, DAG, Offset))
return false;
if (Offset >= 0) {
@@ -145,7 +146,8 @@ bool BaseIndexOffset::contains(int64_t S
// [-------*this---------]
// [---Other--]
// ==Offset==>
- return Offset + OtherSize <= Size;
+ BitOffset = 8 * Offset;
+ return BitOffset + OtherBitSize <= BitSize;
}
// Other starts strictly before *this, it cannot be fully contained.
// [-------*this---------]
Modified: llvm/trunk/test/CodeGen/X86/constant-combines.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/constant-combines.ll?rev=354884&r1=354883&r2=354884&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/constant-combines.ll (original)
+++ llvm/trunk/test/CodeGen/X86/constant-combines.ll Tue Feb 26 07:02:32 2019
@@ -38,3 +38,15 @@ entry:
store float %8, float* %0, align 4
ret void
}
+
+
+define void @bitstore_fold() {
+; CHECK-LABEL: bitstore_fold:
+; CHECK: # %bb.0: # %BB
+; CHECK-NEXT: movl $-2, 0
+; CHECK-NEXT: retq
+BB:
+ store i32 -1, i32* null
+ store i1 false, i1* null
+ ret void
+}
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