[clang] [llvm] [SystemZ] Add support for __builtin_setjmp and __builtin_longjmp (PR #116642)

[Ulrich Weigand via cfe-commits]

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@@ -940,6 +945,240 @@ bool SystemZTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
   return SystemZVectorConstantInfo(Imm).isVectorConstantLegal(Subtarget);
 }
 
+MachineBasicBlock *
+SystemZTargetLowering::emitEHSjLjSetJmp(MachineInstr &MI,
+                                        MachineBasicBlock *MBB) const {
+  DebugLoc DL = MI.getDebugLoc();
+  const TargetInstrInfo *TII = Subtarget.getInstrInfo();
+  const SystemZRegisterInfo *TRI = Subtarget.getRegisterInfo();
+
+  MachineFunction *MF = MBB->getParent();
+  MachineRegisterInfo &MRI = MF->getRegInfo();
+
+  const BasicBlock *BB = MBB->getBasicBlock();
+  MachineFunction::iterator I = ++MBB->getIterator();
+
+  Register DstReg = MI.getOperand(0).getReg();
+  const TargetRegisterClass *RC = MRI.getRegClass(DstReg);
+  assert(TRI->isTypeLegalForClass(*RC, MVT::i32) && "Invalid destination!");
+  Register mainDstReg = MRI.createVirtualRegister(RC);
+  Register restoreDstReg = MRI.createVirtualRegister(RC);
+
+  MVT PVT = getPointerTy(MF->getDataLayout());
+  assert((PVT == MVT::i64 || PVT == MVT::i32) && "Invalid Pointer Size!");
+  // For v = setjmp(buf), we generate.
+  // Algorithm:
+  //
+  //                 ---------
+  //                | thisMBB |
+  //                 ---------
+  //                     |
+  //         ------------------------
+  //        |                        |
+  //     ----------           ---------------
+  //    |  mainMBB |         | restoreMBB    |
+  //    |   v = 0  |         |  v = 1        |
+  //     ----------           ---------------
+  //        |                        |
+  //         -------------------------
+  //                     |
+  //           -----------------------------
+  //          |       sinkMBB               |
+  //          | phi(v_mainMBB,v_restoreMBB) |
+  //           -----------------------------
+  // thisMBB:
+  //  buf[0] = Frame Pointer if hasFP.
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uweigand wrote:

Use `FPOffset` here to be consistent with the code below.

https://github.com/llvm/llvm-project/pull/116642