[llvm] r295776 - [AArch64, X86] Guard against both instrs being wild cards

[Evandro Menezes via llvm-commits]

Author: evandro
Date: Tue Feb 21 16:16:11 2017
New Revision: 295776

URL: http://llvm.org/viewvc/llvm-project?rev=295776&view=rev
Log:
[AArch64, X86] Guard against both instrs being wild cards

If both instrs are wild cards, the result can be a crash.

Modified:
    llvm/trunk/lib/Target/AArch64/AArch64MacroFusion.cpp
    llvm/trunk/lib/Target/X86/X86MacroFusion.cpp

Modified: llvm/trunk/lib/Target/AArch64/AArch64MacroFusion.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64MacroFusion.cpp?rev=295776&r1=295775&r2=295776&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64MacroFusion.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64MacroFusion.cpp Tue Feb 21 16:16:11 2017
@@ -34,12 +34,13 @@ static bool shouldScheduleAdjacent(const
                                    const AArch64Subtarget &ST,
                                    const MachineInstr *First,
                                    const MachineInstr *Second) {
+  assert((First || Second) && "At least one instr must be specified");
   unsigned FirstOpcode =
-      First ? First->getOpcode()
-            : static_cast<unsigned>(AArch64::INSTRUCTION_LIST_END);
+    First ? First->getOpcode()
+	  : static_cast<unsigned>(AArch64::INSTRUCTION_LIST_END);
   unsigned SecondOpcode =
-      Second ? Second->getOpcode()
-             : static_cast<unsigned>(AArch64::INSTRUCTION_LIST_END);
+    Second ? Second->getOpcode()
+           : static_cast<unsigned>(AArch64::INSTRUCTION_LIST_END);
 
   if (ST.hasArithmeticBccFusion())
     // Fuse CMN, CMP, TST followed by Bcc.

Modified: llvm/trunk/lib/Target/X86/X86MacroFusion.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86MacroFusion.cpp?rev=295776&r1=295775&r2=295776&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86MacroFusion.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86MacroFusion.cpp Tue Feb 21 16:16:11 2017
@@ -44,12 +44,13 @@ static bool shouldScheduleAdjacent(const
     FuseInc
   } FuseKind;
 
+  assert((First || Second) && "At least one instr must be specified");
   unsigned FirstOpcode = First
-                             ? First->getOpcode()
-                             : static_cast<unsigned>(X86::INSTRUCTION_LIST_END);
-  unsigned SecondOpcode =
-      Second ? Second->getOpcode()
-             : static_cast<unsigned>(X86::INSTRUCTION_LIST_END);
+                         ? First->getOpcode()
+                         : static_cast<unsigned>(X86::INSTRUCTION_LIST_END);
+  unsigned SecondOpcode = Second
+                          ? Second->getOpcode()
+                          : static_cast<unsigned>(X86::INSTRUCTION_LIST_END);
 
   switch (SecondOpcode) {
   default:
@@ -215,7 +216,7 @@ void X86MacroFusion::apply(ScheduleDAGIn
   // For now, assume targets can only fuse with the branch.
   SUnit &ExitSU = DAG->ExitSU;
   MachineInstr *Branch = ExitSU.getInstr();
-  if (!shouldScheduleAdjacent(ST, nullptr, Branch))
+  if (!Branch || !shouldScheduleAdjacent(ST, nullptr, Branch))
     return;
 
   for (SDep &PredDep : ExitSU.Preds) {