/// insertPrologEpilogCode - Scan the function for modified callee saved /// registers, insert spill code for these callee saved registers, then add /// prolog and epilog code to the function. /// void PEI::insertPrologEpilogCode(MachineFunction &Fn) { const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering(); // Add prologue to the function... TFI.emitPrologue(Fn, *SaveBlock); // Add epilogue to restore the callee-save registers in each exiting block. for (MachineBasicBlock *RestoreBlock : RestoreBlocks) TFI.emitEpilogue(Fn, *RestoreBlock); // Emit additional code that is required to support segmented stacks, if // we've been asked for it. This, when linked with a runtime with support // for segmented stacks (libgcc is one), will result in allocating stack // space in small chunks instead of one large contiguous block. if (Fn.shouldSplitStack()) TFI.adjustForSegmentedStacks(Fn, *SaveBlock); // Emit additional code that is required to explicitly handle the stack in // HiPE native code (if needed) when loaded in the Erlang/OTP runtime. The // approach is rather similar to that of Segmented Stacks, but it uses a // different conditional check and another BIF for allocating more stack // space. if (Fn.getFunction()->getCallingConv() == CallingConv::HiPE) TFI.adjustForHiPEPrologue(Fn, *SaveBlock); }