[llvm] r187703 - X86: correct tail return address calculation

[Tim Northover]

Author: tnorthover
Date: Sun Aug  4 04:35:57 2013
New Revision: 187703

URL: http://llvm.org/viewvc/llvm-project?rev=187703&view=rev
Log:
X86: correct tail return address calculation

Due to the weird and wondeful usual arithmetic conversions, some
calculations involving negative values were getting performed in
uint32_t and then promoted to int64_t, which is really not a good
idea.

Patch by Katsuhiro Ueno.

Added:
    llvm/trunk/test/CodeGen/X86/tailcall-calleesave.ll
Modified:
    llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FrameLowering.cpp?rev=187703&r1=187702&r2=187703&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FrameLowering.cpp Sun Aug  4 04:35:57 2013
@@ -1323,7 +1323,7 @@ X86FrameLowering::processFunctionBeforeC
   unsigned SlotSize = RegInfo->getSlotSize();
 
   X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
-  int32_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
+  int64_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
 
   if (TailCallReturnAddrDelta < 0) {
     // create RETURNADDR area
@@ -1336,7 +1336,7 @@ X86FrameLowering::processFunctionBeforeC
     //   }
     //   [EBP]
     MFI->CreateFixedObject(-TailCallReturnAddrDelta,
-                           (-1U*SlotSize)+TailCallReturnAddrDelta, true);
+                           TailCallReturnAddrDelta - SlotSize, true);
   }
 
   if (hasFP(MF)) {

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=187703&r1=187702&r2=187703&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sun Aug  4 04:35:57 2013
@@ -2456,7 +2456,8 @@ EmitTailCallStoreRetAddr(SelectionDAG &
   if (!FPDiff) return Chain;
   // Calculate the new stack slot for the return address.
   int NewReturnAddrFI =
-    MF.getFrameInfo()->CreateFixedObject(SlotSize, FPDiff-SlotSize, false);
+    MF.getFrameInfo()->CreateFixedObject(SlotSize, (int64_t)FPDiff - SlotSize,
+                                         false);
   SDValue NewRetAddrFrIdx = DAG.getFrameIndex(NewReturnAddrFI, PtrVT);
   Chain = DAG.getStore(Chain, dl, RetAddrFrIdx, NewRetAddrFrIdx,
                        MachinePointerInfo::getFixedStack(NewReturnAddrFI),
@@ -3323,7 +3324,8 @@ SDValue X86TargetLowering::getReturnAddr
   if (ReturnAddrIndex == 0) {
     // Set up a frame object for the return address.
     unsigned SlotSize = RegInfo->getSlotSize();
-    ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(SlotSize, -SlotSize,
+    ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(SlotSize,
+                                                           -(int64_t)SlotSize,
                                                            false);
     FuncInfo->setRAIndex(ReturnAddrIndex);
   }

Added: llvm/trunk/test/CodeGen/X86/tailcall-calleesave.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/tailcall-calleesave.ll?rev=187703&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/tailcall-calleesave.ll (added)
+++ llvm/trunk/test/CodeGen/X86/tailcall-calleesave.ll Sun Aug  4 04:35:57 2013
@@ -0,0 +1,19 @@
+; RUN: llc -march=x86 -tailcallopt < %s | FileCheck %s
+
+target triple = "i686-apple-darwin"
+
+declare fastcc void @foo(i32, i32, i32, i32, i32, i32)
+declare i32* @bar(i32*)
+
+define fastcc void @hoge(i32 %b) nounwind {
+; Do not overwrite pushed callee-save registers
+; CHECK: pushl
+; CHECK: subl $[[SIZE:[0-9]+]], %esp
+; CHECK-NOT: [[SIZE]](%esp)
+  %a = alloca i32
+  store i32 0, i32* %a
+  %d = tail call i32* @bar(i32* %a) nounwind
+  store i32 %b, i32* %d
+  tail call fastcc void @foo(i32 1, i32 2, i32 3, i32 4, i32 5, i32 6) nounwind
+  ret void
+}