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Re: [PATCH][M68K] Fix extendsidi pattern to handle ColdFire
Jeff Law wrote:
Maxim Kuvyrkov wrote:
So why bother with operand3 at all as all its alternatives are 'X'?
but in the rm->d case you end up allocating an unnecessary scratch
But why? In rm->d case the constraints in the (match_scratch)'es are
'X', so the RA/reload should not assign anything meaningful to them.
Or am I misinterpreting GCC Internals?
Operand3 was introduced for the sake of making output code cleaner;
operands = adjust_address (operands, SImode,
which_alternative == 0 ? 4 : 0);
While this construct has been working without declaring the operand in
the pattern for years, it is cleaner, in my opinion, to explicitly
declare every operand in use by the pattern.