[PS4 UBSAN] Emit ud2 for ubsantrap for the PS4 target.

[wolfgangp]

Summary

For the PS4 target we want to emit a ud2 opcode for a ubsantrap instead of ud1.

[probinson]

One minor thing and LGTM.

llvm/lib/Target/X86/X86ISelLowering.cpp

538

I'd prefer

if (...isPS4CPU())
  setOperationAction(..., Expand);
else
  setOperationAction(..., Legal);

as being a bit clearer.

llvm/lib/Target/X86/X86ISelLowering.cpp

X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
   setOperationAction(ISD::FRAME_TO_ARGS_OFFSET, MVT::i32, Custom);
   setOperationAction(ISD::FRAME_TO_ARGS_OFFSET, MVT::i64, Custom);
 
   setOperationAction(ISD::INIT_TRAMPOLINE, MVT::Other, Custom);
   setOperationAction(ISD::ADJUST_TRAMPOLINE, MVT::Other, Custom);
 
   setOperationAction(ISD::TRAP, MVT::Other, Legal);
   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
+  if (Subtarget.getTargetTriple().isPS4CPU())
+    setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
+  else
     setOperationAction(ISD::UBSANTRAP, MVT::Other, Legal);
 
   // VASTART needs to be custom lowered to use the VarArgsFrameIndex
   setOperationAction(ISD::VASTART           , MVT::Other, Custom);
   setOperationAction(ISD::VAEND             , MVT::Other, Expand);
   bool Is64Bit = Subtarget.is64Bit();
   setOperationAction(ISD::VAARG,  MVT::Other, Is64Bit ? Custom : Expand);
   setOperationAction(ISD::VACOPY, MVT::Other, Is64Bit ? Custom : Expand);
 

llvm/test/CodeGen/X86/ubsantrap.ll

 ; RUN: llc -mtriple=x86_64-linux-gnu %s -o - | FileCheck %s
+; RUN: llc -mtriple=x86_64-scei-ps4 %s -o - | FileCheck --check-prefix=PS4 %s
 
 define void @test_ubsantrap() {
 ; CHECK-LABEL: test_ubsantrap
 ; CHECK: ud1l 12(%eax), %eax
+; PS4-LABEL: test_ubsantrap
+; PS4-NOT:   ud1
+; PS4:       ud2
   call void @llvm.ubsantrap(i8 12)
   ret void
 }
 
 define void @test_ubsantrap_function() {
 ; CHECK-LABEL: test_ubsantrap_function:
 ; CHECK: movl $12, %edi
 ; CHECK: callq wibble
   call void @llvm.ubsantrap(i8 12) "trap-func-name"="wibble"
   ret void
 }
 
 declare void @llvm.ubsantrap(i8)