Add @earlyclobber TableGen constraint
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91554 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/TargetInstrDesc.h b/include/llvm/Target/TargetInstrDesc.h
index b0ed0bf..9efb683 100644
--- a/include/llvm/Target/TargetInstrDesc.h
+++ b/include/llvm/Target/TargetInstrDesc.h
@@ -25,9 +25,10 @@
//===----------------------------------------------------------------------===//
namespace TOI {
- // Operand constraints: only "tied_to" for now.
+ // Operand constraints
enum OperandConstraint {
- TIED_TO = 0 // Must be allocated the same register as.
+ TIED_TO = 0, // Must be allocated the same register as.
+ EARLY_CLOBBER // Operand is an early clobber register operand
};
/// OperandFlags - These are flags set on operands, but should be considered
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 12b974d..e3b8709 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -555,8 +555,13 @@
Operands.back().ParentMI = this;
// If the operand is a register, update the operand's use list.
- if (Op.isReg())
+ if (Op.isReg()) {
Operands.back().AddRegOperandToRegInfo(RegInfo);
+ // If the register operand is flagged as early, mark the operand as such
+ unsigned OpNo = Operands.size() - 1;
+ if (TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+ Operands[OpNo].setIsEarlyClobber(true);
+ }
return;
}
}
@@ -573,8 +578,12 @@
// Do explicitly set the reginfo for this operand though, to ensure the
// next/prev fields are properly nulled out.
- if (Operands[OpNo].isReg())
+ if (Operands[OpNo].isReg()) {
Operands[OpNo].AddRegOperandToRegInfo(0);
+ // If the register operand is flagged as early, mark the operand as such
+ if (TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+ Operands[OpNo].setIsEarlyClobber(true);
+ }
} else if (Operands.size()+1 <= Operands.capacity()) {
// Otherwise, we have to remove register operands from their register use
@@ -594,8 +603,12 @@
Operands.insert(Operands.begin()+OpNo, Op);
Operands[OpNo].ParentMI = this;
- if (Operands[OpNo].isReg())
+ if (Operands[OpNo].isReg()) {
Operands[OpNo].AddRegOperandToRegInfo(RegInfo);
+ // If the register operand is flagged as early, mark the operand as such
+ if (TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+ Operands[OpNo].setIsEarlyClobber(true);
+ }
// Re-add all the implicit ops.
for (unsigned i = OpNo+1, e = Operands.size(); i != e; ++i) {
@@ -613,6 +626,11 @@
// Re-add all the operands.
AddRegOperandsToUseLists(*RegInfo);
+
+ // If the register operand is flagged as early, mark the operand as such
+ if (Operands[OpNo].isReg()
+ && TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+ Operands[OpNo].setIsEarlyClobber(true);
}
}
diff --git a/utils/TableGen/CodeGenInstruction.cpp b/utils/TableGen/CodeGenInstruction.cpp
index e6ed709..c69ce96 100644
--- a/utils/TableGen/CodeGenInstruction.cpp
+++ b/utils/TableGen/CodeGenInstruction.cpp
@@ -18,14 +18,35 @@
using namespace llvm;
static void ParseConstraint(const std::string &CStr, CodeGenInstruction *I) {
- // FIXME: Only supports TIED_TO for now.
+ // EARLY_CLOBBER: @early $reg
+ std::string::size_type wpos = CStr.find_first_of(" \t");
+ std::string::size_type start = CStr.find_first_not_of(" \t");
+ std::string Tok = CStr.substr(start, wpos - start);
+ if (Tok == "@earlyclobber") {
+ std::string Name = CStr.substr(wpos+1);
+ wpos = Name.find_first_not_of(" \t");
+ if (wpos == std::string::npos)
+ throw "Illegal format for @earlyclobber constraint: '" + CStr + "'";
+ Name = Name.substr(wpos);
+ std::pair<unsigned,unsigned> Op =
+ I->ParseOperandName(Name, false);
+
+ // Build the string for the operand
+ std::string OpConstraint = "(1 << TOI::EARLY_CLOBBER)";
+ if (!I->OperandList[Op.first].Constraints[Op.second].empty())
+ throw "Operand '" + Name + "' cannot have multiple constraints!";
+ I->OperandList[Op.first].Constraints[Op.second] = OpConstraint;
+ return;
+ }
+
+ // Only other constraint is "TIED_TO" for now.
std::string::size_type pos = CStr.find_first_of('=');
assert(pos != std::string::npos && "Unrecognized constraint");
- std::string::size_type start = CStr.find_first_not_of(" \t");
+ start = CStr.find_first_not_of(" \t");
std::string Name = CStr.substr(start, pos - start);
// TIED_TO: $src1 = $dst
- std::string::size_type wpos = Name.find_first_of(" \t");
+ wpos = Name.find_first_of(" \t");
if (wpos == std::string::npos)
throw "Illegal format for tied-to constraint: '" + CStr + "'";
std::string DestOpName = Name.substr(0, wpos);
@@ -47,7 +68,6 @@
std::string OpConstraint =
"((" + utostr(FlatOpNo) + " << 16) | (1 << TOI::TIED_TO))";
-
if (!I->OperandList[DestOp.first].Constraints[DestOp.second].empty())
throw "Operand '" + DestOpName + "' cannot have multiple constraints!";
I->OperandList[DestOp.first].Constraints[DestOp.second] = OpConstraint;