ARM64: diagnose use of v16-v31 in certain indexed NEON instructions.

Someone couldn't bear to have a completely orthogonal set of floating-point
registers, so we've got some instructions that only accept v0-v15 (coming in
ARMv9, V128_prime: you're allowed v2, v3, v5, v7, ...).

Anyway, we were permitting even the out of range registers during assembly
(CodeGen handled it correctly). This adds a diagnostic.

llvm-svn: 207412

2 files changed, 14 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM64/ARM64RegisterInfo.td b/llvm/lib/Target/ARM64/ARM64RegisterInfo.td
index 514ba07bb0a..3a8e969a01f 100644
--- a/llvm/lib/Target/ARM64/ARM64RegisterInfo.td
+++ b/llvm/lib/Target/ARM64/ARM64RegisterInfo.td
@@ -431,7 +431,11 @@ def VectorRegAsmOperand : AsmOperandClass { let Name = "VectorReg"; }
 let ParserMatchClass = VectorRegAsmOperand in {
 def V64  : RegisterOperand<FPR64, "printVRegOperand">;
 def V128 : RegisterOperand<FPR128, "printVRegOperand">;
-def V128_lo : RegisterOperand<FPR128_lo, "printVRegOperand">;
+}
+
+def VectorRegLoAsmOperand : AsmOperandClass { let Name = "VectorRegLo"; }
+def V128_lo : RegisterOperand<FPR128_lo, "printVRegOperand"> {
+  let ParserMatchClass = VectorRegLoAsmOperand;
 }
 
 class TypedVecListAsmOperand<int count, int regsize, int lanes, string kind>
diff --git a/llvm/lib/Target/ARM64/AsmParser/ARM64AsmParser.cpp b/llvm/lib/Target/ARM64/AsmParser/ARM64AsmParser.cpp
index 5fe0acc59da..71cf100daf9 100644
--- a/llvm/lib/Target/ARM64/AsmParser/ARM64AsmParser.cpp
+++ b/llvm/lib/Target/ARM64/AsmParser/ARM64AsmParser.cpp
@@ -688,6 +688,10 @@ public:
   }
   bool isReg() const { return Kind == k_Register && !Reg.isVector; }
   bool isVectorReg() const { return Kind == k_Register && Reg.isVector; }
+  bool isVectorRegLo() const {
+    return Kind == k_Register && Reg.isVector &&
+      ARM64MCRegisterClasses[ARM64::FPR128_loRegClassID].contains(Reg.RegNum);
+  }
 
   /// Is this a vector list with the type implicit (presumably attached to the
   /// instruction itself)?
@@ -1059,6 +1063,11 @@ public:
     Inst.addOperand(MCOperand::CreateReg(getReg()));
   }
 
+  void addVectorRegLoOperands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    Inst.addOperand(MCOperand::CreateReg(getReg()));
+  }
+
   template <unsigned NumRegs>
   void addVectorList64Operands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");