summaryrefslogtreecommitdiff
path: root/llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp')
-rw-r--r--llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp86
1 files changed, 46 insertions, 40 deletions
diff --git a/llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp b/llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
index 400701c4e5c2..a28816cc87b7 100644
--- a/llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
+++ b/llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
@@ -117,6 +117,7 @@ public:
struct CallInfo {
uint32_t Kind;
uint32_t AccessIndex;
+ uint32_t RecordAlignment;
MDNode *Metadata;
Value *Base;
};
@@ -130,6 +131,8 @@ private:
BPFPreserveFieldInfoAI = 4,
};
+ const DataLayout *DL = nullptr;
+
std::map<std::string, GlobalVariable *> GEPGlobals;
// A map to link preserve_*_access_index instrinsic calls.
std::map<CallInst *, std::pair<CallInst *, CallInfo>> AIChain;
@@ -154,11 +157,11 @@ private:
void replaceWithGEP(std::vector<CallInst *> &CallList,
uint32_t NumOfZerosIndex, uint32_t DIIndex);
bool HasPreserveFieldInfoCall(CallInfoStack &CallStack);
- void GetStorageBitRange(DICompositeType *CTy, DIDerivedType *MemberTy,
- uint32_t AccessIndex, uint32_t &StartBitOffset,
- uint32_t &EndBitOffset);
+ void GetStorageBitRange(DIDerivedType *MemberTy, uint32_t RecordAlignment,
+ uint32_t &StartBitOffset, uint32_t &EndBitOffset);
uint32_t GetFieldInfo(uint32_t InfoKind, DICompositeType *CTy,
- uint32_t AccessIndex, uint32_t PatchImm);
+ uint32_t AccessIndex, uint32_t PatchImm,
+ uint32_t RecordAlignment);
Value *computeBaseAndAccessKey(CallInst *Call, CallInfo &CInfo,
std::string &AccessKey, MDNode *&BaseMeta);
@@ -182,6 +185,7 @@ bool BPFAbstractMemberAccess::runOnModule(Module &M) {
if (M.debug_compile_units().empty())
return false;
+ DL = &M.getDataLayout();
return doTransformation(M);
}
@@ -243,6 +247,8 @@ bool BPFAbstractMemberAccess::IsPreserveDIAccessIndexCall(const CallInst *Call,
report_fatal_error("Missing metadata for llvm.preserve.array.access.index intrinsic");
CInfo.AccessIndex = getConstant(Call->getArgOperand(2));
CInfo.Base = Call->getArgOperand(0);
+ CInfo.RecordAlignment =
+ DL->getABITypeAlignment(CInfo.Base->getType()->getPointerElementType());
return true;
}
if (GV->getName().startswith("llvm.preserve.union.access.index")) {
@@ -252,6 +258,8 @@ bool BPFAbstractMemberAccess::IsPreserveDIAccessIndexCall(const CallInst *Call,
report_fatal_error("Missing metadata for llvm.preserve.union.access.index intrinsic");
CInfo.AccessIndex = getConstant(Call->getArgOperand(1));
CInfo.Base = Call->getArgOperand(0);
+ CInfo.RecordAlignment =
+ DL->getABITypeAlignment(CInfo.Base->getType()->getPointerElementType());
return true;
}
if (GV->getName().startswith("llvm.preserve.struct.access.index")) {
@@ -261,6 +269,8 @@ bool BPFAbstractMemberAccess::IsPreserveDIAccessIndexCall(const CallInst *Call,
report_fatal_error("Missing metadata for llvm.preserve.struct.access.index intrinsic");
CInfo.AccessIndex = getConstant(Call->getArgOperand(2));
CInfo.Base = Call->getArgOperand(0);
+ CInfo.RecordAlignment =
+ DL->getABITypeAlignment(CInfo.Base->getType()->getPointerElementType());
return true;
}
if (GV->getName().startswith("llvm.bpf.preserve.field.info")) {
@@ -509,40 +519,29 @@ uint64_t BPFAbstractMemberAccess::getConstant(const Value *IndexValue) {
}
/// Get the start and the end of storage offset for \p MemberTy.
-/// The storage bits are corresponding to the LLVM internal types,
-/// and the storage bits for the member determines what load width
-/// to use in order to extract the bitfield value.
-void BPFAbstractMemberAccess::GetStorageBitRange(DICompositeType *CTy,
- DIDerivedType *MemberTy,
- uint32_t AccessIndex,
+void BPFAbstractMemberAccess::GetStorageBitRange(DIDerivedType *MemberTy,
+ uint32_t RecordAlignment,
uint32_t &StartBitOffset,
uint32_t &EndBitOffset) {
- auto SOff = dyn_cast<ConstantInt>(MemberTy->getStorageOffsetInBits());
- assert(SOff);
- StartBitOffset = SOff->getZExtValue();
-
- EndBitOffset = CTy->getSizeInBits();
- uint32_t Index = AccessIndex + 1;
- for (; Index < CTy->getElements().size(); ++Index) {
- auto Member = cast<DIDerivedType>(CTy->getElements()[Index]);
- if (!Member->getStorageOffsetInBits()) {
- EndBitOffset = Member->getOffsetInBits();
- break;
- }
- SOff = dyn_cast<ConstantInt>(Member->getStorageOffsetInBits());
- assert(SOff);
- unsigned BitOffset = SOff->getZExtValue();
- if (BitOffset != StartBitOffset) {
- EndBitOffset = BitOffset;
- break;
- }
- }
+ uint32_t MemberBitSize = MemberTy->getSizeInBits();
+ uint32_t MemberBitOffset = MemberTy->getOffsetInBits();
+ uint32_t AlignBits = RecordAlignment * 8;
+ if (RecordAlignment > 8 || MemberBitSize > AlignBits)
+ report_fatal_error("Unsupported field expression for llvm.bpf.preserve.field.info, "
+ "requiring too big alignment");
+
+ StartBitOffset = MemberBitOffset & ~(AlignBits - 1);
+ if ((StartBitOffset + AlignBits) < (MemberBitOffset + MemberBitSize))
+ report_fatal_error("Unsupported field expression for llvm.bpf.preserve.field.info, "
+ "cross alignment boundary");
+ EndBitOffset = StartBitOffset + AlignBits;
}
uint32_t BPFAbstractMemberAccess::GetFieldInfo(uint32_t InfoKind,
DICompositeType *CTy,
uint32_t AccessIndex,
- uint32_t PatchImm) {
+ uint32_t PatchImm,
+ uint32_t RecordAlignment) {
if (InfoKind == BPFCoreSharedInfo::FIELD_EXISTENCE)
return 1;
@@ -557,9 +556,10 @@ uint32_t BPFAbstractMemberAccess::GetFieldInfo(uint32_t InfoKind,
if (!MemberTy->isBitField()) {
PatchImm += MemberTy->getOffsetInBits() >> 3;
} else {
- auto SOffset = dyn_cast<ConstantInt>(MemberTy->getStorageOffsetInBits());
- assert(SOffset);
- PatchImm += SOffset->getZExtValue() >> 3;
+ unsigned SBitOffset, NextSBitOffset;
+ GetStorageBitRange(MemberTy, RecordAlignment, SBitOffset,
+ NextSBitOffset);
+ PatchImm += SBitOffset >> 3;
}
}
return PatchImm;
@@ -576,7 +576,7 @@ uint32_t BPFAbstractMemberAccess::GetFieldInfo(uint32_t InfoKind,
return SizeInBits >> 3;
unsigned SBitOffset, NextSBitOffset;
- GetStorageBitRange(CTy, MemberTy, AccessIndex, SBitOffset, NextSBitOffset);
+ GetStorageBitRange(MemberTy, RecordAlignment, SBitOffset, NextSBitOffset);
SizeInBits = NextSBitOffset - SBitOffset;
if (SizeInBits & (SizeInBits - 1))
report_fatal_error("Unsupported field expression for llvm.bpf.preserve.field.info");
@@ -636,7 +636,7 @@ uint32_t BPFAbstractMemberAccess::GetFieldInfo(uint32_t InfoKind,
}
unsigned SBitOffset, NextSBitOffset;
- GetStorageBitRange(CTy, MemberTy, AccessIndex, SBitOffset, NextSBitOffset);
+ GetStorageBitRange(MemberTy, RecordAlignment, SBitOffset, NextSBitOffset);
if (NextSBitOffset - SBitOffset > 64)
report_fatal_error("too big field size for llvm.bpf.preserve.field.info");
@@ -667,7 +667,7 @@ uint32_t BPFAbstractMemberAccess::GetFieldInfo(uint32_t InfoKind,
}
unsigned SBitOffset, NextSBitOffset;
- GetStorageBitRange(CTy, MemberTy, AccessIndex, SBitOffset, NextSBitOffset);
+ GetStorageBitRange(MemberTy, RecordAlignment, SBitOffset, NextSBitOffset);
if (NextSBitOffset - SBitOffset > 64)
report_fatal_error("too big field size for llvm.bpf.preserve.field.info");
@@ -822,14 +822,20 @@ Value *BPFAbstractMemberAccess::computeBaseAndAccessKey(CallInst *Call,
AccessKey += ":" + std::to_string(AccessIndex);
MDNode *MDN = CInfo.Metadata;
+ uint32_t RecordAlignment = CInfo.RecordAlignment;
// At this stage, it cannot be pointer type.
auto *CTy = cast<DICompositeType>(stripQualifiers(cast<DIType>(MDN)));
- PatchImm = GetFieldInfo(InfoKind, CTy, AccessIndex, PatchImm);
+ PatchImm = GetFieldInfo(InfoKind, CTy, AccessIndex, PatchImm,
+ RecordAlignment);
}
- // Access key is the type name + reloc type + patched imm + access string,
+ // Access key is the
+ // "llvm." + type name + ":" + reloc type + ":" + patched imm + "$" +
+ // access string,
// uniquely identifying one relocation.
- AccessKey = TypeName + ":" + std::to_string(InfoKind) + ":" +
+ // The prefix "llvm." indicates this is a temporary global, which should
+ // not be emitted to ELF file.
+ AccessKey = "llvm." + TypeName + ":" + std::to_string(InfoKind) + ":" +
std::to_string(PatchImm) + "$" + AccessKey;
return Base;
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-06 14:48:08 +0000