[PATCH] D84833: Implement indirect branch generation in position independent code for the RISC-V target

[msizanoen1 via Phabricator via llvm-commits]

msizanoen1 updated this revision to Diff 281579.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84833/new/

https://reviews.llvm.org/D84833

Files:
  llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
  llvm/test/CodeGen/RISCV/branch-relaxation.ll


Index: llvm/test/CodeGen/RISCV/branch-relaxation.ll
===================================================================
--- llvm/test/CodeGen/RISCV/branch-relaxation.ll
+++ llvm/test/CodeGen/RISCV/branch-relaxation.ll
@@ -32,8 +32,7 @@
 ; CHECK-NEXT:    andi a0, a0, 1
 ; CHECK-NEXT:    bnez a0, .LBB1_1
 ; CHECK-NEXT:  # %bb.3:
-; CHECK-NEXT:    lui a0, %hi(.LBB1_2)
-; CHECK-NEXT:    jalr zero, %lo(.LBB1_2)(a0)
+; CHECK-NEXT:    jump .LBB1_2, a0
 ; CHECK-NEXT:  .LBB1_1: # %iftrue
 ; CHECK-NEXT:    #APP
 ; CHECK-NEXT:    #NO_APP
Index: llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -384,10 +384,6 @@
 
   MachineFunction *MF = MBB.getParent();
   MachineRegisterInfo &MRI = MF->getRegInfo();
-  const auto &TM = static_cast<const RISCVTargetMachine &>(MF->getTarget());
-
-  if (TM.isPositionIndependent())
-    report_fatal_error("Unable to insert indirect branch");
 
   if (!isInt<32>(BrOffset))
     report_fatal_error(
@@ -399,15 +395,13 @@
   Register ScratchReg = MRI.createVirtualRegister(&RISCV::GPRRegClass);
   auto II = MBB.end();
 
-  MachineInstr &LuiMI = *BuildMI(MBB, II, DL, get(RISCV::LUI), ScratchReg)
-                             .addMBB(&DestBB, RISCVII::MO_HI);
-  BuildMI(MBB, II, DL, get(RISCV::PseudoBRIND))
-      .addReg(ScratchReg, RegState::Kill)
-      .addMBB(&DestBB, RISCVII::MO_LO);
+  MachineInstr &MI = *BuildMI(MBB, II, DL, get(RISCV::PseudoJump))
+                          .addReg(ScratchReg, RegState::Define | RegState::Dead)
+                          .addMBB(&DestBB);
 
   RS->enterBasicBlockEnd(MBB);
   unsigned Scav = RS->scavengeRegisterBackwards(RISCV::GPRRegClass,
-                                                LuiMI.getIterator(), false, 0);
+                                                MI.getIterator(), false, 0);
   MRI.replaceRegWith(ScratchReg, Scav);
   MRI.clearVirtRegs();
   RS->setRegUsed(Scav);


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