Pull in r329771 from upstream llvm trunk (by Craig Topper):

  [X86] In X86FlagsCopyLowering, when rewriting a memory setcc we need
  to emit an explicit MOV8mr instruction.

  Previously the code only knew how to handle setcc to a register.

  This should fix a crash in the chromium build.

This fixes various assertion failures while building ports targeting
i386:
* www/firefox: isReg() && "This is not a register operand!"
* www/iridium, www/qt5-webengine: (I.atEnd() || std::next(I) ==
  def_instr_end()) && "getVRegDef assumes a single definition or no
  definition"
* devel/powerpc64-gcc: FromReg != ToReg && "Cannot replace a reg with
  itself"

Reported by:	jbeich
PR:		225330, 227686, 227698, 227699
MFC after:	1 week
X-MFC-With:	r332833

1 files changed, 22 insertions, 3 deletions

diff --git a/contrib/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp b/contrib/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
index 1b6369b7bfd9..1fd1c704d79a 100644
--- a/contrib/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
+++ b/contrib/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
@@ -770,8 +770,27 @@ void X86FlagsCopyLoweringPass::rewriteSetCC(MachineBasicBlock &TestMBB,
   if (!CondReg)
     CondReg = promoteCondToReg(TestMBB, TestPos, TestLoc, Cond);
 
-  // Rewriting this is trivial: we just replace the register and remove the
-  // setcc.
-  MRI->replaceRegWith(SetCCI.getOperand(0).getReg(), CondReg);
+  // Rewriting a register def is trivial: we just replace the register and
+  // remove the setcc.
+  if (!SetCCI.mayStore()) {
+    assert(SetCCI.getOperand(0).isReg() &&
+           "Cannot have a non-register defined operand to SETcc!");
+    MRI->replaceRegWith(SetCCI.getOperand(0).getReg(), CondReg);
+    SetCCI.eraseFromParent();
+    return;
+  }
+
+  // Otherwise, we need to emit a store.
+  auto MIB = BuildMI(*SetCCI.getParent(), SetCCI.getIterator(),
+                     SetCCI.getDebugLoc(), TII->get(X86::MOV8mr));
+  // Copy the address operands.
+  for (int i = 0; i < X86::AddrNumOperands; ++i)
+    MIB.add(SetCCI.getOperand(i));
+
+  MIB.addReg(CondReg);
+
+  MIB->setMemRefs(SetCCI.memoperands_begin(), SetCCI.memoperands_end());
+
   SetCCI.eraseFromParent();
+  return;
 }