ARM: fix more cases where predication may or may not be allowed

Unfortunately this addresses two issues (by the time I'd disentangled the logic
it wasn't worth putting it back to half-broken):

+ Coprocessor instructions should all be predicable in Thumb mode.
+ BKPT should never be predicable.

llvm-svn: 184965

1 files changed, 17 insertions, 19 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index f80fba61028..eda55502d2d 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -4966,28 +4966,26 @@ getMnemonicAcceptInfo(StringRef Mnemonic, bool &CanAcceptCarrySet,
   } else
     CanAcceptCarrySet = false;
 
-  if (Mnemonic == "cbnz" || Mnemonic == "setend" || Mnemonic == "cps" ||
-      Mnemonic == "mcr2" || Mnemonic == "it" || Mnemonic == "mcrr2" ||
-      Mnemonic == "cbz" || Mnemonic == "cdp2" || Mnemonic == "trap" ||
-      Mnemonic == "mrc2" || Mnemonic == "mrrc2" || Mnemonic == "setend" ||
-      ((Mnemonic == "clrex" ||  Mnemonic == "dmb" || Mnemonic == "dsb" ||
-       Mnemonic == "isb") && !isThumb()) ||
-      (Mnemonic == "nop" && isThumbOne()) ||
-      ((Mnemonic == "pld" || Mnemonic == "pli" || Mnemonic == "pldw" ||
-        Mnemonic == "ldc2" || Mnemonic == "ldc2l" ||
-        Mnemonic == "stc2" || Mnemonic == "stc2l") && !isThumb()) ||
-      ((Mnemonic.startswith("rfe") || Mnemonic.startswith("srs")) &&
-       !isThumb()) ||
-      Mnemonic.startswith("cps") || (Mnemonic == "movs" && isThumbOne())) {
+  if (Mnemonic == "bkpt" || Mnemonic == "cbnz" || Mnemonic == "setend" ||
+      Mnemonic == "cps" ||  Mnemonic == "it" ||  Mnemonic == "cbz" ||
+      Mnemonic == "trap" || Mnemonic == "setend" ||
+      Mnemonic.startswith("cps")) {
+    // These mnemonics are never predicable
     CanAcceptPredicationCode = false;
+  } else if (!isThumb()) {
+    // Some instructions are only predicable in Thumb mode
+    CanAcceptPredicationCode
+      = Mnemonic != "cdp2" && Mnemonic != "clrex" && Mnemonic != "mcr2" &&
+        Mnemonic != "mcrr2" && Mnemonic != "mrc2" && Mnemonic != "mrrc2" &&
+        Mnemonic != "dmb" && Mnemonic != "dsb" && Mnemonic != "isb" &&
+        Mnemonic != "pld" && Mnemonic != "pli" && Mnemonic != "pldw" &&
+        Mnemonic != "ldc2" && Mnemonic != "ldc2l" &&
+        Mnemonic != "stc2" && Mnemonic != "stc2l" &&
+        !Mnemonic.startswith("rfe") && !Mnemonic.startswith("srs");
+  } else if (isThumbOne()) {
+    CanAcceptPredicationCode = Mnemonic != "nop" && Mnemonic != "movs";
   } else
     CanAcceptPredicationCode = true;
-
-  if (isThumb()) {
-    if (Mnemonic == "bkpt" || Mnemonic == "mcr" || Mnemonic == "mcrr" ||
-        Mnemonic == "mrc" || Mnemonic == "mrrc" || Mnemonic == "cdp")
-      CanAcceptPredicationCode = false;
-  }
 }
 
 bool ARMAsmParser::shouldOmitCCOutOperand(StringRef Mnemonic,