From f828a0ccc7ecd54e71240e404f6c47c822ea6619 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Thu, 1 Oct 2015 18:44:59 +0000
Subject: [WinEH] Make FuncletLayout more robust against catchret

Catchret transfers control from a catch funclet to an earlier funclet.
However, it is not completely clear which funclet the catchret target is
part of.  Make this clear by stapling the catchret target's funclet
membership onto the CATCHRET SDAG node.

llvm-svn: 249052
---
 llvm/lib/Target/X86/X86FrameLowering.cpp | 12 ------------
 llvm/lib/Target/X86/X86InstrCompiler.td  |  8 ++++----
 llvm/lib/Target/X86/X86InstrInfo.cpp     |  8 +++++---
 llvm/lib/Target/X86/X86MCInstLower.cpp   | 29 +++++++++++++++++++++++++++++
 4 files changed, 38 insertions(+), 19 deletions(-)

(limited to 'llvm/lib/Target/X86')

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index ca5d5702813..fc192cd6bfd 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1120,24 +1120,12 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
       BuildMI(*RestoreMBB, RestoreMBBI, DL, TII.get(X86::JMP_4))
           .addMBB(TargetMBB);
     }
-    // Replace CATCHRET with the appropriate RET.
-    unsigned RetOp = STI.is64Bit() ? X86::RETQ : X86::RETL;
-    MachineBasicBlock::iterator NewExit =
-        BuildMI(MBB, MBBI, DL, TII.get(RetOp)).addReg(ReturnReg);
-    MBBI->eraseFromParent();
-    MBBI = NewExit;
   } else if (MBBI->getOpcode() == X86::CLEANUPRET) {
     NumBytes = MFI->getMaxCallFrameSize();
     assert(hasFP(MF) && "EH funclets without FP not yet implemented");
     BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
             MachineFramePtr)
         .setMIFlag(MachineInstr::FrameDestroy);
-    // Replace CLEANUPRET with the appropriate RET.
-    unsigned RetOp = STI.is64Bit() ? X86::RETQ : X86::RETL;
-    MachineBasicBlock::iterator NewExit =
-        BuildMI(MBB, MBBI, DL, TII.get(RetOp));
-    MBBI->eraseFromParent();
-    MBBI = NewExit;
   } else if (hasFP(MF)) {
     // Calculate required stack adjustment.
     uint64_t FrameSize = StackSize - SlotSize;
diff --git a/llvm/lib/Target/X86/X86InstrCompiler.td b/llvm/lib/Target/X86/X86InstrCompiler.td
index 8d94aaa0eac..654d8cc98fa 100644
--- a/llvm/lib/Target/X86/X86InstrCompiler.td
+++ b/llvm/lib/Target/X86/X86InstrCompiler.td
@@ -152,10 +152,10 @@ def EH_RETURN64   : I<0xC3, RawFrm, (outs), (ins GR64:$addr),
 
 }
 
-let isTerminator = 1, isBarrier = 1, hasCtrlDep = 1, isCodeGenOnly = 1, isReturn = 1 in {
-def CATCHRET : I<0, Pseudo, (outs), (ins brtarget32:$dst),
-		 "# CATCHRET",
-		 [(catchret bb:$dst)]>;
+let isTerminator = 1, hasSideEffects = 1, isBarrier = 1, hasCtrlDep = 1, isCodeGenOnly = 1, isReturn = 1 in {
+def CATCHRET : I<0, Pseudo, (outs), (ins brtarget32:$dst, brtarget32:$from),
+                 "# CATCHRET",
+                 [(catchret bb:$dst, bb:$from)]>;
 def CLEANUPRET : I<0, Pseudo, (outs), (ins), "# CLEANUPRET", [(cleanupret)]>;
 }
 
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 71b5ab4770a..b06eefb0727 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -101,9 +101,11 @@ struct X86MemoryFoldTableEntry {
 void X86InstrInfo::anchor() {}
 
 X86InstrInfo::X86InstrInfo(X86Subtarget &STI)
-    : X86GenInstrInfo(
-          (STI.isTarget64BitLP64() ? X86::ADJCALLSTACKDOWN64 : X86::ADJCALLSTACKDOWN32),
-          (STI.isTarget64BitLP64() ? X86::ADJCALLSTACKUP64 : X86::ADJCALLSTACKUP32)),
+    : X86GenInstrInfo((STI.isTarget64BitLP64() ? X86::ADJCALLSTACKDOWN64
+                                               : X86::ADJCALLSTACKDOWN32),
+                      (STI.isTarget64BitLP64() ? X86::ADJCALLSTACKUP64
+                                               : X86::ADJCALLSTACKUP32),
+                      X86::CATCHRET),
       Subtarget(STI), RI(STI.getTargetTriple()) {
 
   static const X86MemoryFoldTableEntry MemoryFoldTable2Addr[] = {
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index c61dc125ebc..e3a107ba224 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -531,6 +531,23 @@ ReSimplify:
     break;
   }
 
+  case X86::CLEANUPRET: {
+    // Replace CATCHRET with the appropriate RET.
+    OutMI = MCInst();
+    OutMI.setOpcode(getRetOpcode(AsmPrinter.getSubtarget()));
+    break;
+  }
+
+  case X86::CATCHRET: {
+    // Replace CATCHRET with the appropriate RET.
+    const X86Subtarget &Subtarget = AsmPrinter.getSubtarget();
+    unsigned ReturnReg = Subtarget.is64Bit() ? X86::RAX : X86::EAX;
+    OutMI = MCInst();
+    OutMI.setOpcode(getRetOpcode(Subtarget));
+    OutMI.addOperand(MCOperand::createReg(ReturnReg));
+    break;
+  }
+
   // TAILJMPd, TAILJMPd64 - Lower to the correct jump instructions.
   case X86::TAILJMPr:
   case X86::TAILJMPd:
@@ -1076,6 +1093,18 @@ void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
                             X86ATTInstPrinter::getRegisterName(Reg));
     break;
   }
+  case X86::CLEANUPRET: {
+    // Lower these as normal, but add some comments.
+    OutStreamer->AddComment("CLEANUPRET");
+    break;
+  }
+
+  case X86::CATCHRET: {
+    // Lower these as normal, but add some comments.
+    OutStreamer->AddComment("CATCHRET");
+    break;
+  }
+
   case X86::TAILJMPr:
   case X86::TAILJMPm:
   case X86::TAILJMPd:
-- 
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