diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 5 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 64 |
2 files changed, 36 insertions, 33 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index cbd43cb6cab..95b429b915c 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -9750,11 +9750,10 @@ void SelectionDAGISel::LowerArguments(const Function &F) { // If this argument is live outside of the entry block, insert a copy from // wherever we got it to the vreg that other BB's will reference it as. - if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::CopyFromReg) { + if (Res.getOpcode() == ISD::CopyFromReg) { // If we can, though, try to skip creating an unnecessary vreg. // FIXME: This isn't very clean... it would be nice to make this more - // general. It's also subtly incompatible with the hacks FastISel - // uses with vregs. + // general. unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg(); if (TargetRegisterInfo::isVirtualRegister(Reg)) { FuncInfo->ValueMap[&Arg] = Reg; diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index 77a8037623a..c7a199bf2e0 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -503,6 +503,40 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) { Fn.getContext().diagnose(DiagFallback); } + // Replace forward-declared registers with the registers containing + // the desired value. + // Note: it is important that this happens **before** the call to + // EmitLiveInCopies, since implementations can skip copies of unused + // registers. If we don't apply the reg fixups before, some registers may + // appear as unused and will be skipped, resulting in bad MI. + MachineRegisterInfo &MRI = MF->getRegInfo(); + for (DenseMap<unsigned, unsigned>::iterator I = FuncInfo->RegFixups.begin(), + E = FuncInfo->RegFixups.end(); + I != E; ++I) { + unsigned From = I->first; + unsigned To = I->second; + // If To is also scheduled to be replaced, find what its ultimate + // replacement is. + while (true) { + DenseMap<unsigned, unsigned>::iterator J = FuncInfo->RegFixups.find(To); + if (J == E) + break; + To = J->second; + } + // Make sure the new register has a sufficiently constrained register class. + if (TargetRegisterInfo::isVirtualRegister(From) && + TargetRegisterInfo::isVirtualRegister(To)) + MRI.constrainRegClass(To, MRI.getRegClass(From)); + // Replace it. + + // Replacing one register with another won't touch the kill flags. + // We need to conservatively clear the kill flags as a kill on the old + // register might dominate existing uses of the new register. + if (!MRI.use_empty(To)) + MRI.clearKillFlags(From); + MRI.replaceRegWith(From, To); + } + // If the first basic block in the function has live ins that need to be // copied into vregs, emit the copies into the top of the block before // emitting the code for the block. @@ -622,36 +656,6 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) { // Determine if floating point is used for msvc computeUsesMSVCFloatingPoint(TM.getTargetTriple(), Fn, MF->getMMI()); - // Replace forward-declared registers with the registers containing - // the desired value. - MachineRegisterInfo &MRI = MF->getRegInfo(); - for (DenseMap<unsigned, unsigned>::iterator - I = FuncInfo->RegFixups.begin(), E = FuncInfo->RegFixups.end(); - I != E; ++I) { - unsigned From = I->first; - unsigned To = I->second; - // If To is also scheduled to be replaced, find what its ultimate - // replacement is. - while (true) { - DenseMap<unsigned, unsigned>::iterator J = FuncInfo->RegFixups.find(To); - if (J == E) break; - To = J->second; - } - // Make sure the new register has a sufficiently constrained register class. - if (TargetRegisterInfo::isVirtualRegister(From) && - TargetRegisterInfo::isVirtualRegister(To)) - MRI.constrainRegClass(To, MRI.getRegClass(From)); - // Replace it. - - - // Replacing one register with another won't touch the kill flags. - // We need to conservatively clear the kill flags as a kill on the old - // register might dominate existing uses of the new register. - if (!MRI.use_empty(To)) - MRI.clearKillFlags(From); - MRI.replaceRegWith(From, To); - } - TLI->finalizeLowering(*MF); // Release function-specific state. SDB and CurDAG are already cleared |
