[llvm-dev] Proposal: On re-purposing/reorganizing MIR sigils ('&', '$', '%').

[Puyan Lotfi via llvm-dev]

Hi

A few of us have discussed enhancing the MIR vregs to include support for
named-vregs. At the moment named regs are only supported for physical
registers and number regs are reserved for vregs.

We've decided that to properly implement a syntax for MIR named vregs we
first need to reorganized the sigils used for physical registers and
external symbols so our proposal is to swap the sigil used for external
symbols ('$') for the ampersand ('&') and re-purpose dollar-sign for
physregs so that physregs have the dollar-sign sigil and vregs have the
percentage ('%') sigil:

essentially:

BL *&*__divsi3 ...

...

$eax = ...

%123 = ...

%vregFooBar = ...


I have an initial patch attached (replaces '$' for '&' for external
symbols). Hoping to open some dialog with the community before doing more
implementation work.

Thanks

PL
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