Support a valid, but not very useful, encoding of CPSIE where none of the AIF bits are set.

llvm-svn: 141190

3 files changed, 22 insertions, 12 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 56f9955cf53..355bb98e8bc 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -2085,20 +2085,24 @@ parseProcIFlagsOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
   assert(Tok.is(AsmToken::Identifier) && "Token is not an Identifier");
   StringRef IFlagsStr = Tok.getString();
 
+  // An iflags string of "none" is interpreted to mean that none of the AIF
+  // bits are set.  Not a terribly useful instruction, but a valid encoding.
   unsigned IFlags = 0;
-  for (int i = 0, e = IFlagsStr.size(); i != e; ++i) {
-    unsigned Flag = StringSwitch<unsigned>(IFlagsStr.substr(i, 1))
-    .Case("a", ARM_PROC::A)
-    .Case("i", ARM_PROC::I)
-    .Case("f", ARM_PROC::F)
-    .Default(~0U);
-
-    // If some specific iflag is already set, it means that some letter is
-    // present more than once, this is not acceptable.
-    if (Flag == ~0U || (IFlags & Flag))
-      return MatchOperand_NoMatch;
+  if (IFlagsStr != "none") {
+        for (int i = 0, e = IFlagsStr.size(); i != e; ++i) {
+      unsigned Flag = StringSwitch<unsigned>(IFlagsStr.substr(i, 1))
+        .Case("a", ARM_PROC::A)
+        .Case("i", ARM_PROC::I)
+        .Case("f", ARM_PROC::F)
+        .Default(~0U);
+
+      // If some specific iflag is already set, it means that some letter is
+      // present more than once, this is not acceptable.
+      if (Flag == ~0U || (IFlags & Flag))
+        return MatchOperand_NoMatch;
 
-    IFlags |= Flag;
+      IFlags |= Flag;
+    }
   }
 
   Parser.Lex(); // Eat identifier token.
diff --git a/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index e70f8460d6f..83cf58b30f4 100644
--- a/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/llvm/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -624,6 +624,9 @@ void ARMInstPrinter::printCPSIFlag(const MCInst *MI, unsigned OpNum,
   for (int i=2; i >= 0; --i)
     if (IFlags & (1 << i))
       O << ARM_PROC::IFlagsToString(1 << i);
+
+  if (IFlags == 0)
+    O << "none";
 }
 
 void ARMInstPrinter::printMSRMaskOperand(const MCInst *MI, unsigned OpNum,
diff --git a/llvm/test/MC/ARM/arm_instructions.s b/llvm/test/MC/ARM/arm_instructions.s
index 5bc4ba4d99d..186954cafa5 100644
--- a/llvm/test/MC/ARM/arm_instructions.s
+++ b/llvm/test/MC/ARM/arm_instructions.s
@@ -71,3 +71,6 @@
 @ CHECK: ssat16  r0, #7, r0 @ encoding: [0x30,0x0f,0xa6,0xe6]
         ssat16  r0, #7, r0
 
+@ CHECK: cpsie none, #0                @ encoding: [0x00,0x00,0x0a,0xf1]
+        cpsie none, #0
+