From 4d3d6e1a0c99e2212953a90185a8d027c595bf5a Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Thu, 27 May 2010 18:43:40 +0000
Subject: [PATCH] FastISel doesn't yet handle callee-pop functions.

To support this, move IsCalleePop from X86ISelLowering to X86Subtarget.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104866 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86FastISel.cpp     |  4 ++++
 lib/Target/X86/X86ISelLowering.cpp | 27 ++-------------------------
 lib/Target/X86/X86Subtarget.cpp    | 23 +++++++++++++++++++++++
 lib/Target/X86/X86Subtarget.h      |  4 ++++
 4 files changed, 33 insertions(+), 25 deletions(-)

diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 1bc5eb75d75..33a1919cce6 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -1314,6 +1314,10 @@ bool X86FastISel::X86SelectCall(const Instruction *I) {
   if (FTy->isVarArg())
     return false;
 
+  // Fast-isel doesn't know about callee-pop yet.
+  if (Subtarget->IsCalleePop(FTy->isVarArg(), CC))
+    return false;
+
   // Handle *simple* calls for now.
   const Type *RetTy = CS.getType();
   EVT RetVT;
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index b02c33d3f88..9d49941dc8f 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1383,29 +1383,6 @@ ArgsAreStructReturn(const SmallVectorImpl<ISD::InputArg> &Ins) {
   return Ins[0].Flags.isSRet();
 }
 
-/// IsCalleePop - Determines whether the callee is required to pop its
-/// own arguments. Callee pop is necessary to support tail calls.
-bool X86TargetLowering::IsCalleePop(bool IsVarArg,
-                                    CallingConv::ID CallingConv) const {
-  if (IsVarArg)
-    return false;
-
-  switch (CallingConv) {
-  default:
-    return false;
-  case CallingConv::X86_StdCall:
-    return !Subtarget->is64Bit();
-  case CallingConv::X86_FastCall:
-    return !Subtarget->is64Bit();
-  case CallingConv::X86_ThisCall:
-    return !Subtarget->is64Bit();
-  case CallingConv::Fast:
-    return GuaranteedTailCallOpt;
-  case CallingConv::GHC:
-    return GuaranteedTailCallOpt;
-  }
-}
-
 /// CCAssignFnForNode - Selects the correct CCAssignFn for a the
 /// given CallingConvention value.
 CCAssignFn *X86TargetLowering::CCAssignFnForNode(CallingConv::ID CC) const {
@@ -1722,7 +1699,7 @@ X86TargetLowering::LowerFormalArguments(SDValue Chain,
   }
 
   // Some CCs need callee pop.
-  if (IsCalleePop(isVarArg, CallConv)) {
+  if (Subtarget->IsCalleePop(isVarArg, CallConv)) {
     FuncInfo->setBytesToPopOnReturn(StackSize); // Callee pops everything.
   } else {
     FuncInfo->setBytesToPopOnReturn(0); // Callee pops nothing.
@@ -2173,7 +2150,7 @@ X86TargetLowering::LowerCall(SDValue Chain, SDValue Callee,
 
   // Create the CALLSEQ_END node.
   unsigned NumBytesForCalleeToPush;
-  if (IsCalleePop(isVarArg, CallConv))
+  if (Subtarget->IsCalleePop(isVarArg, CallConv))
     NumBytesForCalleeToPush = NumBytes;    // Callee pops everything
   else if (!Is64Bit && !IsTailCallConvention(CallConv) && IsStructRet)
     // If this is a call to a struct-return function, the callee
diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index 09a26858eb7..4012b50e53a 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -372,3 +372,26 @@ X86Subtarget::X86Subtarget(const std::string &TT, const std::string &FS,
   if (StackAlignment)
     stackAlignment = StackAlignment;
 }
+
+/// IsCalleePop - Determines whether the callee is required to pop its
+/// own arguments. Callee pop is necessary to support tail calls.
+bool X86Subtarget::IsCalleePop(bool IsVarArg,
+                               CallingConv::ID CallingConv) const {
+  if (IsVarArg)
+    return false;
+
+  switch (CallingConv) {
+  default:
+    return false;
+  case CallingConv::X86_StdCall:
+    return !is64Bit();
+  case CallingConv::X86_FastCall:
+    return !is64Bit();
+  case CallingConv::X86_ThisCall:
+    return !is64Bit();
+  case CallingConv::Fast:
+    return GuaranteedTailCallOpt;
+  case CallingConv::GHC:
+    return GuaranteedTailCallOpt;
+  }
+}
diff --git a/lib/Target/X86/X86Subtarget.h b/lib/Target/X86/X86Subtarget.h
index 646af91517f..8ad55b159d9 100644
--- a/lib/Target/X86/X86Subtarget.h
+++ b/lib/Target/X86/X86Subtarget.h
@@ -15,6 +15,7 @@
 #define X86SUBTARGET_H
 
 #include "llvm/Target/TargetSubtarget.h"
+#include "llvm/CallingConv.h"
 #include <string>
 
 namespace llvm {
@@ -237,6 +238,9 @@ public:
   /// indicating the number of scheduling cycles of backscheduling that
   /// should be attempted.
   unsigned getSpecialAddressLatency() const;
+
+  /// IsCalleePop - Test whether a function should pop its own arguments.
+  bool IsCalleePop(bool isVarArg, CallingConv::ID CallConv) const;
 };
 
 } // End llvm namespace
-- 
2.34.1