[PATCH] D98046: [TableGen] Fix excessive compile time issue in FixedLenDecoderEmitter

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/utils/TableGen/FixedLenDecoderEmitter.cpp:1125-1133
+    o.indent(Indentation);
+    if (UseInsertBits)
+      o << "insertBits(tmp, ";
+    else
+      o << "tmp = ";
+    o << "fieldFromInstruction(insn, " << EF.Base << ", " << EF.Width << ')';
+    if (UseInsertBits)
----------------
dsanders wrote:
> It looks like insertBits has implementations that cover both values of UseInsertBits. Would it make sense to always use insertBits here and rely on the type of tmp to pick the appropriate version of insertBits()?
Using insertBits relies on us having written the initial `tmp = 0;` line, which we prefer to avoid for the simple cases. I think that's the only reason not to use insertBits in all cases.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D98046/new/

https://reviews.llvm.org/D98046