Add support for a pattern matching instruction selector. This is still in
the early implementation phases, so it is disabled by default
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7719 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/InstSelectPattern.cpp b/lib/Target/X86/InstSelectPattern.cpp
new file mode 100644
index 0000000..4b9e381
--- /dev/null
+++ b/lib/Target/X86/InstSelectPattern.cpp
@@ -0,0 +1,117 @@
+//===-- InstSelectPattern.cpp - A pattern matching inst selector for X86 --===//
+//
+// This file defines a pattern matching instruction selector for X86.
+//
+// FIXME: we could allocate one big array of unsigneds to use as the backing
+// store for all of the nodes costs arrays.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86.h"
+#include "llvm/Pass.h"
+#include "llvm/Function.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/SSARegMap.h"
+
+#include "X86RegisterInfo.h"
+
+// Include the generated instruction selector...
+#include "X86GenInstrSelector.inc"
+
+
+//===----------------------------------------------------------------------===//
+// User code
+//
+
+
+namespace {
+ struct ISel : public FunctionPass, SelectionDAGTargetBuilder {
+ TargetMachine &TM;
+ ISel(TargetMachine &tm) : TM(tm) {}
+ int VarArgsFrameIndex; // FrameIndex for start of varargs area
+
+ bool runOnFunction(Function &Fn) {
+ MachineFunction &MF = MachineFunction::construct(&Fn, TM);
+ SelectionDAG DAG(MF, TM, *this);
+
+ std::cerr << "\n\n\n=== "
+ << DAG.getMachineFunction().getFunction()->getName() << "\n";
+
+ DAG.dump();
+ X86ISel(DAG).generateCode();
+ std::cerr << "\n\n\n";
+ return true;
+ }
+
+ public: // Implementation of the SelectionDAGTargetBuilder class...
+ /// expandArguments - Add nodes to the DAG to indicate how to load arguments
+ /// off of the X86 stack.
+ void expandArguments(SelectionDAG &SD, MachineFunction &MF);
+ };
+}
+
+
+void ISel::expandArguments(SelectionDAG &SD, MachineFunction &F) {
+ // Add DAG nodes to load the arguments... On entry to a function on the X86,
+ // the stack frame looks like this:
+ //
+ // [ESP] -- return address
+ // [ESP + 4] -- first argument (leftmost lexically)
+ // [ESP + 8] -- second argument, if first argument is four bytes in size
+ // ...
+ //
+ unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
+ MachineFrameInfo *MFI = F.getFrameInfo();
+ const Function &Fn = *F.getFunction();
+
+ for (Function::const_aiterator I = Fn.abegin(), E = Fn.aend(); I != E; ++I) {
+ MVT::ValueType ObjectVT = SD.getValueType(I->getType());
+ unsigned ArgIncrement = 4;
+ unsigned ObjSize;
+ switch (ObjectVT) {
+ default: assert(0 && "Unhandled argument type!");
+ case MVT::i8: ObjSize = 1; break;
+ case MVT::i16: ObjSize = 2; break;
+ case MVT::i32: ObjSize = 4; break;
+ case MVT::i64: ObjSize = ArgIncrement = 8; break;
+ case MVT::f32: ObjSize = 4; break;
+ case MVT::f64: ObjSize = ArgIncrement = 8; break;
+ }
+ // Create the frame index object for this incoming parameter...
+ int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
+
+ // Create the SelectionDAG nodes corresponding to a load from this parameter
+ // FIXME:
+ SelectionDAGNode *FIN = new SelectionDAGNode(ISD::FrameIndex, MVT::i32);
+ FIN->addValue(new ReducedValue_FrameIndex_i32(FI));
+
+ SelectionDAGNode *Arg
+ = new SelectionDAGNode(ISD::Load, ObjectVT, F.begin(), FIN);
+
+ // Add the SelectionDAGNodes to the SelectionDAG... note that there is no
+ // reason to add chain nodes here. We know that no loads ore stores will
+ // ever alias these loads, so we are free to perform the load at any time in
+ // the function
+ SD.addNode(FIN);
+ SD.addNodeForValue(Arg, I);
+
+ ArgOffset += ArgIncrement; // Move on to the next argument...
+ }
+
+ // If the function takes variable number of arguments, make a frame index for
+ // the start of the first vararg value... for expansion of llvm.va_start.
+ if (Fn.getFunctionType()->isVarArg())
+ VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
+}
+
+
+/// createX86PatternInstructionSelector - This pass converts an LLVM function
+/// into a machine code representation using pattern matching and a machine
+/// description file.
+///
+Pass *createX86PatternInstructionSelector(TargetMachine &TM) {
+ return new ISel(TM);
+}
diff --git a/lib/Target/X86/Makefile b/lib/Target/X86/Makefile
index ff4ab7c..ee4cf8c 100644
--- a/lib/Target/X86/Makefile
+++ b/lib/Target/X86/Makefile
@@ -5,22 +5,25 @@
# Make sure that tblgen is run, first thing.
$(SourceDepend): X86GenRegisterInfo.h.inc X86GenRegisterNames.inc \
X86GenRegisterInfo.inc X86GenInstrNames.inc \
- X86GenInstrInfo.inc
+ X86GenInstrInfo.inc X86GenInstrSelector.inc
-X86GenRegisterNames.inc: X86.td X86RegisterInfo.td $(TBLGEN)
- $(TBLGEN) X86.td -gen-register-enums -o $@
+X86GenRegisterNames.inc: X86.td X86RegisterInfo.td ../Target.td $(TBLGEN)
+ $(TBLGEN) $< -gen-register-enums -o $@
-X86GenRegisterInfo.h.inc: X86.td X86RegisterInfo.td $(TBLGEN)
- $(TBLGEN) X86.td -gen-register-desc-header -o $@
+X86GenRegisterInfo.h.inc: X86.td X86RegisterInfo.td ../Target.td $(TBLGEN)
+ $(TBLGEN) $< -gen-register-desc-header -o $@
-X86GenRegisterInfo.inc: X86.td X86RegisterInfo.td $(TBLGEN)
- $(TBLGEN) X86.td -gen-register-desc -o $@
+X86GenRegisterInfo.inc: X86.td X86RegisterInfo.td ../Target.td $(TBLGEN)
+ $(TBLGEN) $< -gen-register-desc -o $@
-X86GenInstrNames.inc: X86.td X86InstrInfo.td $(TBLGEN)
- $(TBLGEN) X86.td -gen-instr-enums -o $@
+X86GenInstrNames.inc: X86.td X86InstrInfo.td ../Target.td $(TBLGEN)
+ $(TBLGEN) $< -gen-instr-enums -o $@
-X86GenInstrInfo.inc: X86.td X86InstrInfo.td $(TBLGEN)
- $(TBLGEN) X86.td -gen-instr-desc -o $@
+X86GenInstrInfo.inc: X86.td X86InstrInfo.td ../Target.td $(TBLGEN)
+ $(TBLGEN) $< -gen-instr-desc -o $@
+
+X86GenInstrSelector.inc: X86.td X86InstrInfo.td ../Target.td $(TBLGEN)
+ $(TBLGEN) $< -gen-instr-selector -o $@
clean::
$(VERB) rm -f *.inc
diff --git a/lib/Target/X86/X86.h b/lib/Target/X86/X86.h
index 61d3123..eec254c 100644
--- a/lib/Target/X86/X86.h
+++ b/lib/Target/X86/X86.h
@@ -18,6 +18,12 @@
///
Pass *createX86SimpleInstructionSelector(TargetMachine &TM);
+/// createX86PatternInstructionSelector - This pass converts an LLVM function
+/// into a machine code representation using pattern matching and a machine
+/// description file.
+///
+Pass *createX86PatternInstructionSelector(TargetMachine &TM);
+
/// createX86PeepholeOptimizer - Create a pass to perform X86 specific peephole
/// optimizations.
///
diff --git a/lib/Target/X86/X86ISelPattern.cpp b/lib/Target/X86/X86ISelPattern.cpp
new file mode 100644
index 0000000..4b9e381
--- /dev/null
+++ b/lib/Target/X86/X86ISelPattern.cpp
@@ -0,0 +1,117 @@
+//===-- InstSelectPattern.cpp - A pattern matching inst selector for X86 --===//
+//
+// This file defines a pattern matching instruction selector for X86.
+//
+// FIXME: we could allocate one big array of unsigneds to use as the backing
+// store for all of the nodes costs arrays.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86.h"
+#include "llvm/Pass.h"
+#include "llvm/Function.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/SSARegMap.h"
+
+#include "X86RegisterInfo.h"
+
+// Include the generated instruction selector...
+#include "X86GenInstrSelector.inc"
+
+
+//===----------------------------------------------------------------------===//
+// User code
+//
+
+
+namespace {
+ struct ISel : public FunctionPass, SelectionDAGTargetBuilder {
+ TargetMachine &TM;
+ ISel(TargetMachine &tm) : TM(tm) {}
+ int VarArgsFrameIndex; // FrameIndex for start of varargs area
+
+ bool runOnFunction(Function &Fn) {
+ MachineFunction &MF = MachineFunction::construct(&Fn, TM);
+ SelectionDAG DAG(MF, TM, *this);
+
+ std::cerr << "\n\n\n=== "
+ << DAG.getMachineFunction().getFunction()->getName() << "\n";
+
+ DAG.dump();
+ X86ISel(DAG).generateCode();
+ std::cerr << "\n\n\n";
+ return true;
+ }
+
+ public: // Implementation of the SelectionDAGTargetBuilder class...
+ /// expandArguments - Add nodes to the DAG to indicate how to load arguments
+ /// off of the X86 stack.
+ void expandArguments(SelectionDAG &SD, MachineFunction &MF);
+ };
+}
+
+
+void ISel::expandArguments(SelectionDAG &SD, MachineFunction &F) {
+ // Add DAG nodes to load the arguments... On entry to a function on the X86,
+ // the stack frame looks like this:
+ //
+ // [ESP] -- return address
+ // [ESP + 4] -- first argument (leftmost lexically)
+ // [ESP + 8] -- second argument, if first argument is four bytes in size
+ // ...
+ //
+ unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
+ MachineFrameInfo *MFI = F.getFrameInfo();
+ const Function &Fn = *F.getFunction();
+
+ for (Function::const_aiterator I = Fn.abegin(), E = Fn.aend(); I != E; ++I) {
+ MVT::ValueType ObjectVT = SD.getValueType(I->getType());
+ unsigned ArgIncrement = 4;
+ unsigned ObjSize;
+ switch (ObjectVT) {
+ default: assert(0 && "Unhandled argument type!");
+ case MVT::i8: ObjSize = 1; break;
+ case MVT::i16: ObjSize = 2; break;
+ case MVT::i32: ObjSize = 4; break;
+ case MVT::i64: ObjSize = ArgIncrement = 8; break;
+ case MVT::f32: ObjSize = 4; break;
+ case MVT::f64: ObjSize = ArgIncrement = 8; break;
+ }
+ // Create the frame index object for this incoming parameter...
+ int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
+
+ // Create the SelectionDAG nodes corresponding to a load from this parameter
+ // FIXME:
+ SelectionDAGNode *FIN = new SelectionDAGNode(ISD::FrameIndex, MVT::i32);
+ FIN->addValue(new ReducedValue_FrameIndex_i32(FI));
+
+ SelectionDAGNode *Arg
+ = new SelectionDAGNode(ISD::Load, ObjectVT, F.begin(), FIN);
+
+ // Add the SelectionDAGNodes to the SelectionDAG... note that there is no
+ // reason to add chain nodes here. We know that no loads ore stores will
+ // ever alias these loads, so we are free to perform the load at any time in
+ // the function
+ SD.addNode(FIN);
+ SD.addNodeForValue(Arg, I);
+
+ ArgOffset += ArgIncrement; // Move on to the next argument...
+ }
+
+ // If the function takes variable number of arguments, make a frame index for
+ // the start of the first vararg value... for expansion of llvm.va_start.
+ if (Fn.getFunctionType()->isVarArg())
+ VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
+}
+
+
+/// createX86PatternInstructionSelector - This pass converts an LLVM function
+/// into a machine code representation using pattern matching and a machine
+/// description file.
+///
+Pass *createX86PatternInstructionSelector(TargetMachine &TM) {
+ return new ISel(TM);
+}
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index 893e62f..2de30f7 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -20,6 +20,8 @@
cl::desc("Use Simple RA instead of Local RegAlloc"));
cl::opt<bool> PrintCode("print-machineinstrs",
cl::desc("Print generated machine code"));
+ cl::opt<bool> NoPatternISel("disable-pattern-isel", cl::init(true),
+ cl::desc("Use the 'simple' X86 instruction selector"));
}
// allocateX86TargetMachine - Allocate and return a subclass of TargetMachine
@@ -59,7 +61,10 @@
// FIXME: Implement the switch instruction in the instruction selector!
PM.add(createLowerSwitchPass());
- PM.add(createX86SimpleInstructionSelector(*this));
+ if (NoPatternISel)
+ PM.add(createX86SimpleInstructionSelector(*this));
+ else
+ PM.add(createX86PatternInstructionSelector(*this));
// TODO: optional optimizations go here