[llvm] r257158 - [WinEH] Update WinEHFuncInfo if StackColoring merges allocas

[David Majnemer via llvm-commits]

Author: majnemer
Date: Fri Jan  8 02:03:55 2016
New Revision: 257158

URL: http://llvm.org/viewvc/llvm-project?rev=257158&view=rev
Log:
[WinEH] Update WinEHFuncInfo if StackColoring merges allocas

Windows EH keeping track of which frame index corresponds to a catchpad
in order to inform the runtime where the catch parameter should be
initialized.  LLVM's optimizations are able to prove that the memory
used by the catch parameter can be reused with another memory
optimization, changing it's frame index.

We need to keep WinEHFuncInfo up to date with respect to this or we will
miscompile/assert.

This fixes PR26069.

Added:
    llvm/trunk/test/CodeGen/X86/catchpad-lifetime.ll
Modified:
    llvm/trunk/lib/CodeGen/StackColoring.cpp
    llvm/trunk/lib/CodeGen/WinEHPrepare.cpp

Modified: llvm/trunk/lib/CodeGen/StackColoring.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StackColoring.cpp?rev=257158&r1=257157&r2=257158&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/StackColoring.cpp (original)
+++ llvm/trunk/lib/CodeGen/StackColoring.cpp Fri Jan  8 02:03:55 2016
@@ -43,6 +43,7 @@
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/CodeGen/StackProtector.h"
+#include "llvm/CodeGen/WinEHFuncInfo.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
@@ -570,6 +571,12 @@ void StackColoring::remapInstructions(De
       }
     }
 
+  if (WinEHFuncInfo *EHInfo = MF->getWinEHFuncInfo())
+    for (WinEHTryBlockMapEntry &TBME : EHInfo->TryBlockMap)
+      for (WinEHHandlerType &H : TBME.HandlerArray)
+        if (SlotRemap.count(H.CatchObj.FrameIndex))
+          H.CatchObj.FrameIndex = SlotRemap[H.CatchObj.FrameIndex];
+
   DEBUG(dbgs()<<"Fixed "<<FixedMemOp<<" machine memory operands.\n");
   DEBUG(dbgs()<<"Fixed "<<FixedDbg<<" debug locations.\n");
   DEBUG(dbgs()<<"Fixed "<<FixedInstr<<" machine instructions.\n");

Modified: llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/WinEHPrepare.cpp?rev=257158&r1=257157&r2=257158&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/WinEHPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/WinEHPrepare.cpp Fri Jan  8 02:03:55 2016
@@ -144,10 +144,11 @@ static void addTryBlockMapEntry(WinEHFun
       HT.TypeDescriptor = cast<GlobalVariable>(TypeInfo->stripPointerCasts());
     HT.Adjectives = cast<ConstantInt>(CPI->getArgOperand(1))->getZExtValue();
     HT.Handler = CPI->getParent();
-    if (isa<ConstantPointerNull>(CPI->getArgOperand(2)))
-      HT.CatchObj.Alloca = nullptr;
+    if (auto *AI =
+            dyn_cast<AllocaInst>(CPI->getArgOperand(2)->stripPointerCasts()))
+      HT.CatchObj.Alloca = AI;
     else
-      HT.CatchObj.Alloca = cast<AllocaInst>(CPI->getArgOperand(2));
+      HT.CatchObj.Alloca = nullptr;
     TBME.HandlerArray.push_back(HT);
   }
   FuncInfo.TryBlockMap.push_back(TBME);

Added: llvm/trunk/test/CodeGen/X86/catchpad-lifetime.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/catchpad-lifetime.ll?rev=257158&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/catchpad-lifetime.ll (added)
+++ llvm/trunk/test/CodeGen/X86/catchpad-lifetime.ll Fri Jan  8 02:03:55 2016
@@ -0,0 +1,53 @@
+; RUN: llc < %s | FileCheck %s
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "x86_64-pc-windows-msvc"
+
+declare void @throw()
+
+declare i32 @__CxxFrameHandler3(...)
+
+define void @test1() personality i32 (...)* @__CxxFrameHandler3 {
+entry:
+  %alloca2 = alloca i8*, align 4
+  %alloca1 = alloca i8*, align 4
+  store volatile i8* null, i8** %alloca1
+  invoke void @throw()
+          to label %unreachable unwind label %catch.dispatch
+
+; CHECK-LABEL: test1:
+; CHECK: movq  $0, -16(%rbp)
+; CHECK: callq throw
+
+catch.dispatch:                                   ; preds = %entry
+  %cs = catchswitch within none [label %catch.pad] unwind to caller
+
+catch.pad:                                        ; preds = %catch.dispatch
+  %cp = catchpad within %cs [i8* null, i32 0, i8** %alloca1]
+  store volatile i8* null, i8** %alloca1
+  %bc1 = bitcast i8** %alloca1 to i8*
+  call void @llvm.lifetime.end(i64 4, i8* nonnull %bc1)
+  %bc2 = bitcast i8** %alloca2 to i8*
+  call void @llvm.lifetime.start(i64 4, i8* %bc2)
+  store volatile i8* null, i8** %alloca1
+  unreachable
+
+; CHECK-LABEL: "?catch$2@?0?test1 at 4HA"
+; CHECK: movq  $0, -16(%rbp)
+; CHECK: movq  $0, -16(%rbp)
+; CHECK: ud2
+
+unreachable:                                      ; preds = %entry
+  unreachable
+}
+
+; CHECK-LABEL: $cppxdata$test1:
+; CHECK: .long   32                      # CatchObjOffset
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start(i64, i8* nocapture) #0
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end(i64, i8* nocapture) #0
+
+attributes #0 = { argmemonly nounwind }