Extract LaneBitmask into a separate type

Specifically avoid implicit conversions from/to integral types to
avoid potential errors when changing the underlying type. For example,
a typical initialization of a "full" mask was "LaneMask = ~0u", which
would result in a value of 0x00000000FFFFFFFF if the type was extended
to uint64_t.

Differential Revision: https://reviews.llvm.org/D27454

llvm-svn: 289820

1 files changed, 6 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 7e58955f69f..76f7eb34d54 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -456,15 +456,18 @@ bool MIParser::parseBasicBlockLiveins(MachineBasicBlock &MBB) {
     if (parseNamedRegister(Reg))
       return true;
     lex();
-    LaneBitmask Mask = ~LaneBitmask(0);
+    LaneBitmask Mask = LaneBitmask::getAll();
     if (consumeIfPresent(MIToken::colon)) {
       // Parse lane mask.
       if (Token.isNot(MIToken::IntegerLiteral) &&
           Token.isNot(MIToken::HexLiteral))
         return error("expected a lane mask");
-      static_assert(sizeof(LaneBitmask) == sizeof(unsigned), "");
-      if (getUnsigned(Mask))
+      static_assert(sizeof(LaneBitmask::Type) == sizeof(unsigned),
+                    "Use correct get-function for lane mask");
+      LaneBitmask::Type V;
+      if (getUnsigned(V))
         return error("invalid lane mask value");
+      Mask = LaneBitmask(V);
       lex();
     }
     MBB.addLiveIn(Reg, Mask);