[llvm] r211056 - [PPC64] Fix PR19893 - improve code generation for local function addresses
Bill Schmidt
wschmidt at linux.vnet.ibm.com
Mon Jun 16 14:36:02 PDT 2014
Author: wschmidt
Date: Mon Jun 16 16:36:02 2014
New Revision: 211056
URL: http://llvm.org/viewvc/llvm-project?rev=211056&view=rev
Log:
[PPC64] Fix PR19893 - improve code generation for local function addresses
Rafael opened http://llvm.org/bugs/show_bug.cgi?id=19893 to track non-optimal
code generation for forming a function address that is local to the compile
unit. The existing code was treating both local and non-local functions
identically.
This patch fixes the problem by properly identifying local functions and
generating the proper addis/addi code. I also noticed that Rafael's earlier
changes to correct the surrounding code in PPCISelLowering.cpp were also
needed for fast instruction selection in PPCFastISel.cpp, so this patch
fixes that code as well.
The existing test/CodeGen/PowerPC/func-addr.ll is modified to test the new
code generation. I've added a -O0 run line to test the fast-isel code as
well.
Tested on powerpc64[le]-unknown-linux-gnu with no regressions.
Modified:
llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp
llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
llvm/trunk/test/CodeGen/PowerPC/func-addr.ll
Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=211056&r1=211055&r2=211056&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Mon Jun 16 16:36:02 2014
@@ -365,8 +365,8 @@ void PPCAsmPrinter::EmitInstruction(cons
// Transform %Xd = ADDIStocHA %X2, <ga:@sym>
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
- // Change the opcode to ADDIS8. If the global address is external,
- // has common linkage, is a function address, or is a jump table
+ // Change the opcode to ADDIS8. If the global address is external, has
+ // common linkage, is a non-local function address, or is a jump table
// address, then generate a TOC entry and reference that. Otherwise
// reference the symbol directly.
TmpInst.setOpcode(PPC::ADDIS8);
@@ -375,7 +375,7 @@ void PPCAsmPrinter::EmitInstruction(cons
"Invalid operand for ADDIStocHA!");
MCSymbol *MOSymbol = nullptr;
bool IsExternal = false;
- bool IsFunction = false;
+ bool IsNonLocalFunction = false;
bool IsCommon = false;
bool IsAvailExt = false;
@@ -384,15 +384,16 @@ void PPCAsmPrinter::EmitInstruction(cons
MOSymbol = getSymbol(GV);
IsExternal = GV->isDeclaration();
IsCommon = GV->hasCommonLinkage();
- IsFunction = GV->getType()->getElementType()->isFunctionTy();
+ IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
+ (GV->isDeclaration() || GV->isWeakForLinker());
IsAvailExt = GV->hasAvailableExternallyLinkage();
} else if (MO.isCPI())
MOSymbol = GetCPISymbol(MO.getIndex());
else if (MO.isJTI())
MOSymbol = GetJTISymbol(MO.getIndex());
- if (IsExternal || IsFunction || IsCommon || IsAvailExt || MO.isJTI() ||
- TM.getCodeModel() == CodeModel::Large)
+ if (IsExternal || IsNonLocalFunction || IsCommon || IsAvailExt ||
+ MO.isJTI() || TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
const MCExpr *Exp =
@@ -451,17 +452,19 @@ void PPCAsmPrinter::EmitInstruction(cons
assert((MO.isGlobal() || MO.isCPI()) && "Invalid operand for ADDItocL");
MCSymbol *MOSymbol = nullptr;
bool IsExternal = false;
- bool IsFunction = false;
+ bool IsNonLocalFunction = false;
if (MO.isGlobal()) {
const GlobalValue *GV = MO.getGlobal();
MOSymbol = getSymbol(GV);
IsExternal = GV->isDeclaration();
- IsFunction = GV->getType()->getElementType()->isFunctionTy();
+ IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
+ (GV->isDeclaration() || GV->isWeakForLinker());
} else if (MO.isCPI())
MOSymbol = GetCPISymbol(MO.getIndex());
- if (IsFunction || IsExternal || TM.getCodeModel() == CodeModel::Large)
+ if (IsNonLocalFunction || IsExternal ||
+ TM.getCodeModel() == CodeModel::Large)
MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
const MCExpr *Exp =
Modified: llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp?rev=211056&r1=211055&r2=211056&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp Mon Jun 16 16:36:02 2014
@@ -1858,7 +1858,6 @@ unsigned PPCFastISel::PPCMaterializeGV(c
// FIXME: Jump tables are not yet required because fast-isel doesn't
// handle switches; if that changes, we need them as well. For now,
// what follows assumes everything's a generic (or TLS) global address.
- const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
// FIXME: We don't yet handle the complexity of TLS.
if (GV->isThreadLocal())
@@ -1871,8 +1870,8 @@ unsigned PPCFastISel::PPCMaterializeGV(c
.addGlobalAddress(GV)
.addReg(PPC::X2);
else {
- // If the address is an externally defined symbol, a symbol with
- // common or externally available linkage, a function address, or a
+ // If the address is an externally defined symbol, a symbol with common
+ // or externally available linkage, a non-local function address, or a
// jump table address (not yet needed), or if we are generating code
// for large code model, we generate:
// LDtocL(GV, ADDIStocHA(%X2, GV))
@@ -1883,12 +1882,13 @@ unsigned PPCFastISel::PPCMaterializeGV(c
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::ADDIStocHA),
HighPartReg).addReg(PPC::X2).addGlobalAddress(GV);
- // !GVar implies a function address. An external variable is one
- // without an initializer.
// If/when switches are implemented, jump tables should be handled
// on the "if" path here.
- if (CModel == CodeModel::Large || !GVar || !GVar->hasInitializer() ||
- GVar->hasCommonLinkage() || GVar->hasAvailableExternallyLinkage())
+ if (CModel == CodeModel::Large ||
+ (GV->getType()->getElementType()->isFunctionTy() &&
+ (GV->isDeclaration() || GV->isWeakForLinker())) ||
+ GV->isDeclaration() || GV->hasCommonLinkage() ||
+ GV->hasAvailableExternallyLinkage())
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(PPC::LDtocL),
DestReg).addGlobalAddress(GV).addReg(HighPartReg);
else
Modified: llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp?rev=211056&r1=211055&r2=211056&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp Mon Jun 16 16:36:02 2014
@@ -1454,10 +1454,10 @@ SDNode *PPCDAGToDAGISel::Select(SDNode *
if (CModel != CodeModel::Medium && CModel != CodeModel::Large)
break;
- // The first source operand is a TargetGlobalAddress or a
- // TargetJumpTable. If it is an externally defined symbol, a symbol
- // with common linkage, a function address, or a jump table address,
- // or if we are generating code for large code model, we generate:
+ // 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:
// LDtocL(<ga:@sym>, ADDIStocHA(%X2, <ga:@sym>))
// Otherwise we generate:
// ADDItocL(ADDIStocHA(%X2, <ga:@sym>), <ga:@sym>)
@@ -1472,7 +1472,8 @@ SDNode *PPCDAGToDAGISel::Select(SDNode *
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(GA)) {
const GlobalValue *GValue = G->getGlobal();
- if (GValue->getType()->getElementType()->isFunctionTy() ||
+ if ((GValue->getType()->getElementType()->isFunctionTy() &&
+ (GValue->isDeclaration() || GValue->isWeakForLinker())) ||
GValue->isDeclaration() || GValue->hasCommonLinkage() ||
GValue->hasAvailableExternallyLinkage())
return CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
Modified: llvm/trunk/test/CodeGen/PowerPC/func-addr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/func-addr.ll?rev=211056&r1=211055&r2=211056&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/func-addr.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/func-addr.ll Mon Jun 16 16:36:02 2014
@@ -1,4 +1,5 @@
; RUN: llc -mtriple powerpc64-linux < %s | FileCheck %s
+; RUN: llc -O0 -mtriple powerpc64-linux < %s | FileCheck %s
define void @foo() {
ret void
@@ -6,15 +7,10 @@ define void @foo() {
declare i32 @bar(i8*)
; CHECK-LABEL: {{^}}zed:
-; CHECK: addis 3, 2, .LC1 at toc@ha
-; CHECK-NEXT: ld 3, .LC1 at toc@l(3)
+; CHECK: addis 3, 2, foo at toc@ha
+; CHECK-NEXT: addi 3, 3, foo at toc@l
; CHECK-NEXT: bl bar
-
-; CHECK-LABEL: .section .toc,"aw", at progbits
-; CHECK: .LC1:
-; CHECK-NEXT: .tc foo[TC],foo
-
define void @zed() {
call i32 @bar(i8* bitcast (void ()* @foo to i8*))
ret void
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