[llvm] r264358 - CXX TLS: collect return blocks after SelectAllBasicBlocks.

[Manman Ren via llvm-commits]

Author: mren
Date: Thu Mar 24 18:21:29 2016
New Revision: 264358

URL: http://llvm.org/viewvc/llvm-project?rev=264358&view=rev
Log:
CXX TLS: collect return blocks after SelectAllBasicBlocks.

It is incorrect to get the corresponding MBB for a ReturnInst before
SelectAllBasicBlocks since SelectAllBasicBlocks can change the
correspondence between a ReturnInst and the MBB it is in.

PR27062

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/trunk/test/CodeGen/X86/cxx_tlscc64.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=264358&r1=264357&r2=264358&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Thu Mar 24 18:21:29 2016
@@ -469,7 +469,6 @@ bool SelectionDAGISel::runOnMachineFunct
   MF->setHasInlineAsm(false);
 
   FuncInfo->SplitCSR = false;
-  SmallVector<MachineBasicBlock*, 4> Returns;
 
   // We split CSR if the target supports it for the given function
   // and the function has only return exits.
@@ -482,12 +481,8 @@ bool SelectionDAGISel::runOnMachineFunct
         continue;
 
       const TerminatorInst *Term = BB.getTerminator();
-      if (isa<UnreachableInst>(Term))
+      if (isa<UnreachableInst>(Term) || isa<ReturnInst>(Term))
         continue;
-      if (isa<ReturnInst>(Term)) {
-        Returns.push_back(FuncInfo->MBBMap[&BB]);
-        continue;
-      }
 
       // Bail out if the exit block is not Return nor Unreachable.
       FuncInfo->SplitCSR = false;
@@ -509,8 +504,21 @@ bool SelectionDAGISel::runOnMachineFunct
   RegInfo->EmitLiveInCopies(EntryMBB, TRI, *TII);
 
   // Insert copies in the entry block and the return blocks.
-  if (FuncInfo->SplitCSR)
+  if (FuncInfo->SplitCSR) {
+    SmallVector<MachineBasicBlock*, 4> Returns;
+    // Collect all the return blocks.
+    for (MachineBasicBlock &MBB : mf) {
+      if (!MBB.succ_empty())
+        continue;
+
+      MachineBasicBlock::iterator Term = MBB.getFirstTerminator();
+      if (Term != MBB.end() && Term->isReturn()) {
+        Returns.push_back(&MBB);
+        continue;
+      }
+    }
     TLI->insertCopiesSplitCSR(EntryMBB, Returns);
+  }
 
   DenseMap<unsigned, unsigned> LiveInMap;
   if (!FuncInfo->ArgDbgValues.empty())

Modified: llvm/trunk/test/CodeGen/X86/cxx_tlscc64.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/cxx_tlscc64.ll?rev=264358&r1=264357&r2=264358&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/cxx_tlscc64.ll (original)
+++ llvm/trunk/test/CodeGen/X86/cxx_tlscc64.ll Thu Mar 24 18:21:29 2016
@@ -151,5 +151,21 @@ entry:
   ret void
 }
 
+ at ssp_var = internal thread_local global i8 0, align 1
+
+; CHECK-LABEL: test_ssp
+; CHECK-NOT: pushq %r11
+; CHECK-NOT: pushq %r10
+; CHECK-NOT: pushq %r9
+; CHECK-NOT: pushq %r8
+; CHECK-NOT: pushq %rsi
+; CHECK-NOT: pushq %rdx
+; CHECK-NOT: pushq %rcx
+; CHECK-NOT: pushq %rbx
+; CHECK: callq
+define cxx_fast_tlscc nonnull i8* @test_ssp() #2 {
+  ret i8* @ssp_var
+}
 attributes #0 = { nounwind "no-frame-pointer-elim"="true" }
 attributes #1 = { nounwind }
+attributes #2 = { nounwind sspreq }