Changes in directory llvm/lib/Target/X86:
X86ISelDAGToDAG.cpp updated: 1.48 -> 1.49
---
Log message:
Prevent certain nodes that have already been selected from being folded into
X86 addressing mode. Currently we do not allow any node whose target node
produces a chain as well as any node that is at the root of the addressing
mode expression tree.
---
Diffs of the changes: (+40 -19)
X86ISelDAGToDAG.cpp | 59 +++++++++++++++++++++++++++++++++++-----------------
1 files changed, 40 insertions(+), 19 deletions(-)
Index: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
diff -u llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:1.48
llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:1.49
--- llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:1.48 Fri Feb 10 16:46:26 2006
+++ llvm/lib/Target/X86/X86ISelDAGToDAG.cpp Fri Feb 10 20:05:36 2006
@@ -107,7 +107,7 @@
private:
void Select(SDOperand &Result, SDOperand N);
- bool MatchAddress(SDOperand N, X86ISelAddressMode &AM);
+ bool MatchAddress(SDOperand N, X86ISelAddressMode &AM, bool isRoot = true);
bool SelectAddr(SDOperand N, SDOperand &Base, SDOperand &Scale,
SDOperand &Index, SDOperand &Disp);
bool SelectLEAAddr(SDOperand N, SDOperand &Base, SDOperand &Scale,
@@ -252,7 +252,26 @@
/// MatchAddress - Add the specified node to the specified addressing mode,
/// returning true if it cannot be done. This just pattern matches for the
/// addressing mode
-bool X86DAGToDAGISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM) {
+bool X86DAGToDAGISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM,
+ bool isRoot) {
+ bool StopHere = false;
+ // If N has already been selected, we may or may not want to fold its
+ // operands into the addressing mode. It will result in code duplication!
+ // FIXME: Right now we do. That is, as long as the selected target node
+ // does not produce a chain. This may require a more sophisticated
heuristics.
+ std::map<SDOperand, SDOperand>::iterator CGMI=
CodeGenMap.find(N.getValue(0));
+ if (CGMI != CodeGenMap.end()) {
+ if (isRoot)
+ // Stop here if it is a root. It's probably not profitable to go deeper.
+ StopHere = true;
+ else {
+ for (unsigned i = 0, e = CGMI->second.Val->getNumValues(); i != e; ++i) {
+ if (CGMI->second.Val->getValueType(i) == MVT::Other)
+ StopHere = true;
+ }
+ }
+ }
+
switch (N.getOpcode()) {
default: break;
case ISD::FrameIndex:
@@ -287,7 +306,7 @@
return false;
case ISD::SHL:
- if (AM.IndexReg.Val == 0 && AM.Scale == 1)
+ if (!StopHere && AM.IndexReg.Val == 0 && AM.Scale == 1)
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1)))
{
unsigned Val = CN->getValue();
if (Val == 1 || Val == 2 || Val == 3) {
@@ -313,7 +332,7 @@
case ISD::MUL:
// X*[3,5,9] -> X+X*[2,4,8]
- if (AM.IndexReg.Val == 0 && AM.BaseType == X86ISelAddressMode::RegBase &&
+ if (!StopHere && AM.IndexReg.Val == 0 && AM.BaseType ==
X86ISelAddressMode::RegBase &&
AM.Base.Reg.Val == 0)
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1)))
if (CN->getValue() == 3 || CN->getValue() == 5 || CN->getValue() == 9)
{
@@ -341,15 +360,17 @@
break;
case ISD::ADD: {
- X86ISelAddressMode Backup = AM;
- if (!MatchAddress(N.Val->getOperand(0), AM) &&
- !MatchAddress(N.Val->getOperand(1), AM))
- return false;
- AM = Backup;
- if (!MatchAddress(N.Val->getOperand(1), AM) &&
- !MatchAddress(N.Val->getOperand(0), AM))
- return false;
- AM = Backup;
+ if (!StopHere) {
+ X86ISelAddressMode Backup = AM;
+ if (!MatchAddress(N.Val->getOperand(0), AM, false) &&
+ !MatchAddress(N.Val->getOperand(1), AM, false))
+ return false;
+ AM = Backup;
+ if (!MatchAddress(N.Val->getOperand(1), AM, false) &&
+ !MatchAddress(N.Val->getOperand(0), AM, false))
+ return false;
+ AM = Backup;
+ }
break;
}
}
@@ -474,7 +495,7 @@
if (Opcode >= ISD::BUILTIN_OP_END && Opcode < X86ISD::FIRST_NUMBER) {
Result = N;
#ifndef NDEBUG
- DEBUG(std::cerr << std::string(Indent, ' '));
+ DEBUG(std::cerr << std::string(Indent-2, ' '));
DEBUG(std::cerr << "== ");
DEBUG(Node->dump(CurDAG));
DEBUG(std::cerr << "\n");
@@ -487,7 +508,7 @@
if (CGMI != CodeGenMap.end()) {
Result = CGMI->second;
#ifndef NDEBUG
- DEBUG(std::cerr << std::string(Indent, ' '));
+ DEBUG(std::cerr << std::string(Indent-2, ' '));
DEBUG(std::cerr << "== ");
DEBUG(Result.Val->dump(CurDAG));
DEBUG(std::cerr << "\n");
@@ -574,7 +595,7 @@
}
#ifndef NDEBUG
- DEBUG(std::cerr << std::string(Indent, ' '));
+ DEBUG(std::cerr << std::string(Indent-2, ' '));
DEBUG(std::cerr << "== ");
DEBUG(Result.Val->dump(CurDAG));
DEBUG(std::cerr << "\n");
@@ -682,7 +703,7 @@
}
#ifndef NDEBUG
- DEBUG(std::cerr << std::string(Indent, ' '));
+ DEBUG(std::cerr << std::string(Indent-2, ' '));
DEBUG(std::cerr << "== ");
DEBUG(Result.Val->dump(CurDAG));
DEBUG(std::cerr << "\n");
@@ -721,7 +742,7 @@
SDOperand(CurDAG->getTargetNode(Opc, VT, Result), 0);
#ifndef NDEBUG
- DEBUG(std::cerr << std::string(Indent, ' '));
+ DEBUG(std::cerr << std::string(Indent-2, ' '));
DEBUG(std::cerr << "== ");
DEBUG(Result.Val->dump(CurDAG));
DEBUG(std::cerr << "\n");
@@ -733,7 +754,7 @@
SelectCode(Result, N);
#ifndef NDEBUG
- DEBUG(std::cerr << std::string(Indent, ' '));
+ DEBUG(std::cerr << std::string(Indent-2, ' '));
DEBUG(std::cerr << "=> ");
DEBUG(Result.Val->dump(CurDAG));
DEBUG(std::cerr << "\n");
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