[PATCH] [ARM64] Re-work parsing of ADD/SUB shifted immediate operands

[Tim Northover]

Hi Bradley,

Fair enough. The difference is marginal either way on that one. I did spot another nit-pick though:

================
Comment at: lib/Target/ARM64/AsmParser/ARM64AsmParser.cpp:588
@@ +587,3 @@
+    int64_t Addend;
+    if (ARM64AsmParser::classifySymbolRef(ShiftedImm.Val, ELFRefKind,
+                                          DarwinRefKind, Addend)) {
----------------
I think this might be undefined behaviour if we're actually in the isImm case: accessing a union via a member that wasn't most recently written, or whatever.

If it was me I'd handle isShiftedImm entirely within its if block and reserve the rest of the function for the non-shifted case.

http://reviews.llvm.org/D3665