[llvm] r253708 - Weak non-function symbols were being accessed directly, which is
Eric Christopher via llvm-commits
llvm-commits at lists.llvm.org
Fri Nov 20 12:51:31 PST 2015
Author: echristo
Date: Fri Nov 20 14:51:31 2015
New Revision: 253708
URL: http://llvm.org/viewvc/llvm-project?rev=253708&view=rev
Log:
Weak non-function symbols were being accessed directly, which is
incorrect, as the chosen representative of the weak symbol may not live
with the code in question. Always indirect the access through the TOC
instead.
Patch by Kyle Butt!
Added:
llvm/trunk/test/CodeGen/PowerPC/mcm-13.ll
Modified:
llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp
llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp
llvm/trunk/lib/Target/PowerPC/PPCSubtarget.h
Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=253708&r1=253707&r2=253708&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Fri Nov 20 14:51:31 2015
@@ -669,28 +669,22 @@ void PPCAsmPrinter::EmitInstruction(cons
MO.isBlockAddress()) &&
"Invalid operand for ADDIStocHA!");
MCSymbol *MOSymbol = nullptr;
- bool IsExternal = false;
- bool IsNonLocalFunction = false;
- bool IsCommon = false;
- bool IsAvailExt = false;
+ bool GlobalToc = false;
if (MO.isGlobal()) {
const GlobalValue *GV = MO.getGlobal();
MOSymbol = getSymbol(GV);
- IsExternal = GV->isDeclaration();
- IsCommon = GV->hasCommonLinkage();
- IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
- !GV->isStrongDefinitionForLinker();
- IsAvailExt = GV->hasAvailableExternallyLinkage();
- } else if (MO.isCPI())
+ unsigned char GVFlags = Subtarget->classifyGlobalReference(GV);
+ GlobalToc = (GVFlags & PPCII::MO_NLP_FLAG);
+ } else if (MO.isCPI()) {
MOSymbol = GetCPISymbol(MO.getIndex());
- else if (MO.isJTI())
+ } else if (MO.isJTI()) {
MOSymbol = GetJTISymbol(MO.getIndex());
- else if (MO.isBlockAddress())
+ } else if (MO.isBlockAddress()) {
MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
+ }
- if (IsExternal || IsNonLocalFunction || IsCommon || IsAvailExt ||
- MO.isJTI() || MO.isBlockAddress() ||
+ if (GlobalToc || MO.isJTI() || MO.isBlockAddress() ||
TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
@@ -727,13 +721,14 @@ void PPCAsmPrinter::EmitInstruction(cons
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
}
else if (MO.isGlobal()) {
- const GlobalValue *GValue = MO.getGlobal();
- MOSymbol = getSymbol(GValue);
- if (GValue->getType()->getElementType()->isFunctionTy() ||
- GValue->isDeclaration() || GValue->hasCommonLinkage() ||
- GValue->hasAvailableExternallyLinkage() ||
- TM.getCodeModel() == CodeModel::Large)
- MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
+ const GlobalValue *GV = MO.getGlobal();
+ MOSymbol = getSymbol(GV);
+ DEBUG(
+ unsigned char GVFlags = Subtarget->classifyGlobalReference(GV);
+ assert((GVFlags & PPCII::MO_NLP_FLAG) &&
+ "LDtocL used on symbol that could be accessed directly is "
+ "invalid. Must match ADDIStocHA."));
+ MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
}
const MCExpr *Exp =
@@ -754,21 +749,18 @@ void PPCAsmPrinter::EmitInstruction(cons
const MachineOperand &MO = MI->getOperand(2);
assert((MO.isGlobal() || MO.isCPI()) && "Invalid operand for ADDItocL");
MCSymbol *MOSymbol = nullptr;
- bool IsExternal = false;
- bool IsNonLocalFunction = false;
if (MO.isGlobal()) {
const GlobalValue *GV = MO.getGlobal();
+ DEBUG(
+ unsigned char GVFlags = Subtarget->classifyGlobalReference(GV);
+ assert (
+ !(GVFlags & PPCII::MO_NLP_FLAG) &&
+ "Interposable definitions must use indirect access."));
MOSymbol = getSymbol(GV);
- IsExternal = GV->isDeclaration();
- IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
- !GV->isStrongDefinitionForLinker();
- } else if (MO.isCPI())
+ } else if (MO.isCPI()) {
MOSymbol = GetCPISymbol(MO.getIndex());
-
- if (IsNonLocalFunction || IsExternal ||
- TM.getCodeModel() == CodeModel::Large)
- MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
+ }
const MCExpr *Exp =
MCSymbolRefExpr::create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
Modified: llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp?rev=253708&r1=253707&r2=253708&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp Fri Nov 20 14:51:31 2015
@@ -1972,19 +1972,15 @@ unsigned PPCFastISel::PPCMaterializeGV(c
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDIStocHA),
HighPartReg).addReg(PPC::X2).addGlobalAddress(GV);
- // If/when switches are implemented, jump tables should be handled
- // on the "if" path here.
- if (CModel == CodeModel::Large ||
- (GV->getType()->getElementType()->isFunctionTy() &&
- !GV->isStrongDefinitionForLinker()) ||
- GV->isDeclaration() || GV->hasCommonLinkage() ||
- GV->hasAvailableExternallyLinkage())
+ unsigned char GVFlags = PPCSubTarget->classifyGlobalReference(GV);
+ if (GVFlags & PPCII::MO_NLP_FLAG) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::LDtocL),
DestReg).addGlobalAddress(GV).addReg(HighPartReg);
- else
+ } else {
// Otherwise generate the ADDItocL.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDItocL),
DestReg).addReg(HighPartReg).addGlobalAddress(GV);
+ }
}
return DestReg;
Modified: llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp?rev=253708&r1=253707&r2=253708&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp Fri Nov 20 14:51:31 2015
@@ -2902,9 +2902,7 @@ SDNode *PPCDAGToDAGISel::Select(SDNode *
break;
// The first source operand is a TargetGlobalAddress or a TargetJumpTable.
- // If it is an externally defined symbol, a symbol with common linkage,
- // a non-local function address, or a jump table address, or if we are
- // generating code for large code model, we generate:
+ // If it must be toc-referenced according to PPCSubTarget, we generate:
// LDtocL(<ga:@sym>, ADDIStocHA(%X2, <ga:@sym>))
// Otherwise we generate:
// ADDItocL(ADDIStocHA(%X2, <ga:@sym>), <ga:@sym>)
@@ -2919,13 +2917,12 @@ SDNode *PPCDAGToDAGISel::Select(SDNode *
MVT::i64, GA, SDValue(Tmp, 0)));
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(GA)) {
- const GlobalValue *GValue = G->getGlobal();
- if ((GValue->getType()->getElementType()->isFunctionTy() &&
- !GValue->isStrongDefinitionForLinker()) ||
- GValue->isDeclaration() || GValue->hasCommonLinkage() ||
- GValue->hasAvailableExternallyLinkage())
+ const GlobalValue *GV = G->getGlobal();
+ unsigned char GVFlags = PPCSubTarget->classifyGlobalReference(GV);
+ if (GVFlags & PPCII::MO_NLP_FLAG) {
return transferMemOperands(N, CurDAG->getMachineNode(PPC::LDtocL, dl,
MVT::i64, GA, SDValue(Tmp, 0)));
+ }
}
return CurDAG->getMachineNode(PPC::ADDItocL, dl, MVT::i64,
Modified: llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp?rev=253708&r1=253707&r2=253708&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp Fri Nov 20 14:51:31 2015
@@ -210,5 +210,33 @@ bool PPCSubtarget::enableSubRegLiveness(
return UseSubRegLiveness;
}
+unsigned char PPCSubtarget::classifyGlobalReference(
+ const GlobalValue *GV) const {
+ // Note that currently we don't generate non-pic references.
+ // If a caller wants that, this will have to be updated.
+
+ // Large code model always uses the TOC even for local symbols.
+ if (TM.getCodeModel() == CodeModel::Large)
+ return PPCII::MO_PIC_FLAG | PPCII::MO_NLP_FLAG;
+
+ unsigned char flags = PPCII::MO_PIC_FLAG;
+
+ // Only if the relocation mode is PIC do we have to worry about
+ // interposition. In all other cases we can use a slightly looser standard to
+ // decide how to access the symbol.
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ // If it's local, or it's non-default, it can't be interposed.
+ if (!GV->hasLocalLinkage() &&
+ GV->hasDefaultVisibility()) {
+ flags |= PPCII::MO_NLP_FLAG;
+ }
+ return flags;
+ }
+
+ if (GV->isStrongDefinitionForLinker())
+ return flags;
+ return flags | PPCII::MO_NLP_FLAG;
+}
+
bool PPCSubtarget::isELFv2ABI() const { return TM.isELFv2ABI(); }
bool PPCSubtarget::isPPC64() const { return TM.isPPC64(); }
Modified: llvm/trunk/lib/Target/PowerPC/PPCSubtarget.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCSubtarget.h?rev=253708&r1=253707&r2=253708&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCSubtarget.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCSubtarget.h Fri Nov 20 14:51:31 2015
@@ -285,6 +285,10 @@ public:
bool useAA() const override;
bool enableSubRegLiveness() const override;
+
+ /// classifyGlobalReference - Classify a global variable reference for the
+ /// current subtarget accourding to how we should reference it.
+ unsigned char classifyGlobalReference(const GlobalValue *GV) const;
};
} // End llvm namespace
Added: llvm/trunk/test/CodeGen/PowerPC/mcm-13.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/mcm-13.ll?rev=253708&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/mcm-13.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/mcm-13.ll Fri Nov 20 14:51:31 2015
@@ -0,0 +1,27 @@
+; RUN: llc -mcpu=pwr7 -O0 -code-model=medium <%s | FileCheck %s
+; RUN: llc -mcpu=pwr7 -O0 -code-model=large <%s | FileCheck %s
+
+; Test correct code generation for medium and large code model
+; for loading and storing a weak variable
+
+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-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+ at wi = weak global i32 0, align 4
+
+define signext i32 @test_weak() nounwind {
+entry:
+ %0 = load i32, i32* @wi, align 4
+ %inc = add nsw i32 %0, 1
+ store i32 %inc, i32* @wi, align 4
+ ret i32 %0
+}
+
+; CHECK-LABEL: test_weak:
+; CHECK: addis [[REG1:[0-9]+]], 2, .LC[[TOCNUM:[0-9]+]]@toc at ha
+; CHECK: ld [[REG2:[0-9]+]], .LC[[TOCNUM]]@toc at l([[REG1]])
+; CHECK: lwz {{[0-9]+}}, 0([[REG2]])
+; CHECK: stw {{[0-9]+}}, 0([[REG2]])
+; CHECK: .section .toc
+; CHECK: .LC[[TOCNUM]]:
+; CHECK: .tc {{[a-z0-9A-Z_.]+}}[TC],{{[a-z0-9A-Z_.]+}}
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