Teach FastISel about thiscall (and, hence, about callee-pop).

http://reviews.llvm.org/D22115

llvm-svn: 275135

1 files changed, 12 insertions, 5 deletions

diff --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp
index 1457553e55f..6258e4f6cf3 100644
--- a/llvm/lib/Target/X86/X86FastISel.cpp
+++ b/llvm/lib/Target/X86/X86FastISel.cpp
@@ -1151,14 +1151,15 @@ bool X86FastISel::X86SelectRet(const Instruction *I) {
   if (CC != CallingConv::C &&
       CC != CallingConv::Fast &&
       CC != CallingConv::X86_FastCall &&
+      CC != CallingConv::X86_ThisCall &&
       CC != CallingConv::X86_64_SysV)
     return false;
 
   if (Subtarget->isCallingConvWin64(CC))
     return false;
 
-  // Don't handle popping bytes on return for now.
-  if (X86MFInfo->getBytesToPopOnReturn() != 0)
+  // Don't handle popping bytes if they don't fit the ret's immediate.
+  if (!isUInt<16>(X86MFInfo->getBytesToPopOnReturn()))
     return false;
 
   // fastcc with -tailcallopt is intended to provide a guaranteed
@@ -1261,9 +1262,15 @@ bool X86FastISel::X86SelectRet(const Instruction *I) {
   }
 
   // Now emit the RET.
-  MachineInstrBuilder MIB =
-    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
-            TII.get(Subtarget->is64Bit() ? X86::RETQ : X86::RETL));
+  MachineInstrBuilder MIB;
+  if (X86MFInfo->getBytesToPopOnReturn()) {
+    MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
+                  TII.get(Subtarget->is64Bit() ? X86::RETIQ : X86::RETIL))
+              .addImm(X86MFInfo->getBytesToPopOnReturn());
+  } else {
+    MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
+                  TII.get(Subtarget->is64Bit() ? X86::RETQ : X86::RETL));
+  }
   for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
     MIB.addReg(RetRegs[i], RegState::Implicit);
   return true;