[Thumb] 32-bit encodings of 'cps' are not valid for v7M

v7M only allows the 16-bit encoding of the 'cps' (Change Processor
State) instruction, and does not have the 32-bit encoding which is
valid from v6T2 onwards.

llvm-svn: 218382

2 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrThumb2.td b/llvm/lib/Target/ARM/ARMInstrThumb2.td
index 01e6e1891fc..6d45f0549d9 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb2.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb2.td
@@ -3674,7 +3674,8 @@ let isBranch = 1, isTerminator = 1 in {
 // operands, create 3 versions of the same instruction. Once there's a clean
 // framework to represent optional operands, change this behavior.
 class t2CPS<dag iops, string asm_op> : T2XI<(outs), iops, NoItinerary,
-            !strconcat("cps", asm_op), []> {
+            !strconcat("cps", asm_op), []>,
+          Requires<[IsThumb2, IsNotMClass]> {
   bits<2> imod;
   bits<3> iflags;
   bits<5> mode;
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 7e33ec5617d..211157c7203 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5514,6 +5514,8 @@ bool ARMAsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
     Operands.push_back(ARMOperand::CreateImm(
           MCConstantExpr::Create(ProcessorIMod, getContext()),
                                  NameLoc, NameLoc));
+  } else if (Mnemonic == "cps" && isMClass()) {
+    return Error(NameLoc, "instruction 'cps' requires effect for M-class");
   }
 
   // Add the remaining tokens in the mnemonic.