RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-22 18:54:02 +01:00
Code Issues Projects Releases Wiki Activity

Revert 122011, 122012, 122013, 122023 adding back an important optimization.

Browse Source 
I added a note, but suggestions on how to add a test are really welcome.

llvm-svn: 122138
This commit is contained in:
Rafael Espindola 2010-12-18 03:57:21 +00:00
parent bdf06d6c7b
commit f3aeaaa3f4
3 changed files with 69 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
include/llvm/MC/MCExpr.h
View File

@ -44,12 +44,14 @@ private:
MCExpr(const MCExpr&); // DO NOT IMPLEMENT
void operator=(const MCExpr&); // DO NOT IMPLEMENT
bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout,
bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs) const;
protected:
explicit MCExpr(ExprKind _Kind) : Kind(_Kind) {}
bool EvaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
bool EvaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs,
bool InSet) const;
public:
@ -76,16 +78,11 @@ public:
/// values. If not given, then only non-symbolic expressions will be
/// evaluated.
/// @result - True on success.
bool EvaluateAsAbsolute(int64_t &Res) const {
return EvaluateAsAbsolute(Res, 0, 0);
}
bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const{
return EvaluateAsAbsolute(Res, &Layout, 0);
}
bool EvaluateAsAbsolute(int64_t &Res) const;
bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
const SectionAddrMap &Addrs) const {
return EvaluateAsAbsolute(Res, &Layout, &Addrs);
}
const SectionAddrMap &Addrs) const;
/// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
/// value, i.e. an expression of the fixed form (a - b + constant).
@ -93,10 +90,7 @@ public:
/// @param Res - The relocatable value, if evaluation succeeds.
/// @param Layout - The assembler layout object to use for evaluating values.
/// @result - True on success.
bool EvaluateAsRelocatable(MCValue &Res,
const MCAsmLayout *Layout = 0) const {
return EvaluateAsRelocatableImpl(Res, Layout, 0, false);
}
bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout = 0) const;
/// @}

72
lib/MC/MCExpr.cpp
View File

@ -237,7 +237,27 @@ void MCTargetExpr::Anchor() {}
/* *** */
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout,
bool MCExpr::EvaluateAsAbsolute(int64_t &Res) const {
return EvaluateAsAbsolute(Res, 0, 0, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
const MCAsmLayout &Layout) const {
return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
const MCAsmLayout &Layout,
const SectionAddrMap &Addrs) const {
return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
return EvaluateAsAbsolute(Res, &Asm, 0, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs) const {
MCValue Value;
@ -247,8 +267,7 @@ bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout,
return true;
}
// FIXME: This use of Addrs is wrong, right?
if (!EvaluateAsRelocatableImpl(Value, Layout, Addrs, /*InSet=*/Addrs) ||
if (!EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, Addrs) ||
!Value.isAbsolute()) {
// EvaluateAsAbsolute is defined to return the "current value" of
// the expression if we are given a Layout object, even in cases
@ -304,7 +323,13 @@ static void AttemptToFoldSymbolOffsetDifference(const MCAsmLayout *Layout,
///
/// \returns True on success, false if the result is not representable in an
/// MCValue.
static bool EvaluateSymbolicAdd(const MCAsmLayout *Layout,
/// NOTE: It is really important to have both the Asm and Layout arguments.
/// They might look redundant, but this function can be used before layout
/// is done (see the object streamer for example) and having the Asm argument
/// lets us avoid relocations.
static bool EvaluateSymbolicAdd(const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs,
bool InSet,
const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
@ -353,14 +378,17 @@ static bool EvaluateSymbolicAdd(const MCAsmLayout *Layout,
// Absolutize symbol differences between defined symbols when we have a
// layout object and the target requests it.
if (Layout && A && B) {
const MCAssembler &Asm = Layout->getAssembler();
assert((!Layout || Asm) &&
"Must have an assembler object if layout is given!");
if (Asm && A && B) {
const MCSymbol &SA = A->getSymbol();
const MCSymbol &SB = B->getSymbol();
const MCObjectFormat &F = Asm.getBackend().getObjectFormat();
const MCObjectFormat &F = Asm->getBackend().getObjectFormat();
if (SA.isDefined() && SB.isDefined() && F.isAbsolute(InSet, SA, SB)) {
MCSymbolData &AD = Asm.getSymbolData(A->getSymbol());
MCSymbolData &BD = Asm.getSymbolData(B->getSymbol());
MCSymbolData &AD = Asm->getSymbolData(A->getSymbol());
MCSymbolData &BD = Asm->getSymbolData(B->getSymbol());
if (AD.getFragment() == BD.getFragment()) {
Res = MCValue::get(+ AD.getOffset()
@ -391,7 +419,17 @@ static bool EvaluateSymbolicAdd(const MCAsmLayout *Layout,
return true;
}
bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
const MCAsmLayout *Layout) const {
if (Layout)
return EvaluateAsRelocatableImpl(Res, &Layout->getAssembler(), Layout,
0, false);
else
return EvaluateAsRelocatableImpl(Res, 0, 0, 0, false);
}
bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs,
bool InSet) const {
@ -411,8 +449,10 @@ bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
// Evaluate recursively if this is a variable.
if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None) {
bool Ret = Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Layout,
Addrs, true);
bool Ret = Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Asm,
Layout,
Addrs,
true);
// If we failed to simplify this to a constant, let the target
// handle it.
if (Ret && !Res.getSymA() && !Res.getSymB())
@ -427,7 +467,7 @@ bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
MCValue Value;
if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Layout,
if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout,
Addrs, InSet))
return false;
@ -461,9 +501,9 @@ bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
MCValue LHSValue, RHSValue;
if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Layout,
if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Asm, Layout,
Addrs, InSet) ||
!ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Layout,
!ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Asm, Layout,
Addrs, InSet))
return false;
@ -475,13 +515,13 @@ bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
return false;
case MCBinaryExpr::Sub:
// Negate RHS and add.
return EvaluateSymbolicAdd(Layout, Addrs, InSet, LHSValue,
return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
RHSValue.getSymB(), RHSValue.getSymA(),
-RHSValue.getConstant(),
Res);
case MCBinaryExpr::Add:
return EvaluateSymbolicAdd(Layout, Addrs, InSet, LHSValue,
return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
RHSValue.getSymA(), RHSValue.getSymB(),
RHSValue.getConstant(),
Res);

8
lib/MC/MCObjectStreamer.cpp
View File

@ -85,7 +85,7 @@ void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
// Avoid fixups when possible.
int64_t AbsValue;
if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue, getAssembler())) {
EmitIntValue(AbsValue, Size, AddrSpace);
return;
}
@ -116,7 +116,7 @@ void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) {
void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value,
unsigned AddrSpace) {
int64_t IntValue;
if (Value->EvaluateAsAbsolute(IntValue)) {
if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) {
EmitULEB128IntValue(IntValue, AddrSpace);
return;
}
@ -126,7 +126,7 @@ void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value,
void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value,
unsigned AddrSpace) {
int64_t IntValue;
if (Value->EvaluateAsAbsolute(IntValue)) {
if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) {
EmitSLEB128IntValue(IntValue, AddrSpace);
return;
}
@ -206,7 +206,7 @@ void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
MCBinaryExpr::Create(MCBinaryExpr::Sub, LabelRef, LastLabelRef,
getContext());
int64_t Res;
if (AddrDelta->EvaluateAsAbsolute(Res)) {
if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
MCDwarfLineAddr::Emit(this, LineDelta, Res);
return;
}