[mips] Lower EH_RETURN.

Patch by Sasa Stankovic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173862 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/Target/Mips/MipsSEInstrInfo.cpp b/lib/Target/Mips/MipsSEInstrInfo.cpp
index cd8f9f41d7..a9809ef712 100644
--- a/lib/Target/Mips/MipsSEInstrInfo.cpp
+++ b/lib/Target/Mips/MipsSEInstrInfo.cpp
@@ -220,6 +220,10 @@ bool MipsSEInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const {
   case Mips::ExtractElementF64:
     ExpandExtractElementF64(MBB, MI);
     break;
+  case Mips::MIPSeh_return32:
+  case Mips::MIPSeh_return64:
+    ExpandEhReturn(MBB, MI);
+    break;
   }
 
   MBB.erase(MI);
@@ -356,6 +360,31 @@ void MipsSEInstrInfo::ExpandBuildPairF64(MachineBasicBlock &MBB,
     .addReg(HiReg);
 }
 
+void MipsSEInstrInfo::ExpandEhReturn(MachineBasicBlock &MBB,
+                                     MachineBasicBlock::iterator I) const {
+  // This pseudo instruction is generated as part of the lowering of
+  // ISD::EH_RETURN. We convert it to a stack increment by OffsetReg, and
+  // indirect jump to TargetReg
+  const MipsSubtarget &STI = TM.getSubtarget<MipsSubtarget>();
+  unsigned ADDU = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
+  unsigned OR = STI.isABI_N64() ? Mips::OR64 : Mips::OR;
+  unsigned JR = STI.isABI_N64() ? Mips::JR64 : Mips::JR;
+  unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
+  unsigned RA = STI.isABI_N64() ? Mips::RA_64 : Mips::RA;
+  unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
+  unsigned OffsetReg = I->getOperand(0).getReg();
+  unsigned TargetReg = I->getOperand(1).getReg();
+
+  // or   $ra, $v0, $zero
+  // addu $sp, $sp, $v1
+  // jr   $ra
+  BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(OR), RA)
+      .addReg(TargetReg).addReg(ZERO);
+  BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(ADDU), SP)
+      .addReg(SP).addReg(OffsetReg);
+  BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(JR)).addReg(RA);
+}
+
 const MipsInstrInfo *llvm::createMipsSEInstrInfo(MipsTargetMachine &TM) {
   return new MipsSEInstrInfo(TM);
 }