diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index c7a199bf2e0..5c41e6a72a5 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -656,6 +656,35 @@ 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. + 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 |
