[PATCH] D142216: [MC] Store number of implicit operands in MCInstrDesc. NFC.

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/include/llvm/MC/MCInstrDesc.h:209
+  unsigned char NumImplicitDefs; // Num of regs implicitly defined
   uint64_t Flags;                // Flags identifying machine instr class
   uint64_t TSFlags;              // Target Specific Flag values
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arsenm wrote:
> foad wrote:
> > arsenm wrote:
> > > Could these be reordered to avoid the alignment padding?
> > You could avoid some internal padding but I don't think you could make the struct any smaller overall.
> > 
> > I didn't worry too much about the exact layout of this struct until the end of the whole stack of patches.
> Probably could force the 64-bit fields to 4-byte alignment and see how compile time benchmarks look
The final layout is 24 bytes of which 22 are used, so it didn't seem worth playing that kind of trick.


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142216/new/

https://reviews.llvm.org/D142216