Richard Sandiford - Re: [RTL, ColdFire 24/63] Add support for a MODE_INDEX_REG_CLASS macro (original) (raw)

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Roman Zippel zippel@linux-m68k.org writes:

On Mon, 12 Feb 2007, Jeffrey Law wrote:

And I believe this is the source of your problem. The backend has lied to reload.

double_reg_address_ok is computed by generating some RTL for addresses, then passing them along to G_I_L_A. If G_I_L_A returns true, then reload deems it is free to generate reg+reg addressing modes.

I disagree, I believe it's reload that lies to the back end. To be specfific reload asks whether (mem:qi (plus (reg %fp) (reg))) is valid, which the back end answers truthfully and reload then assumes this is valid for any mode. If the latter were true, the mode argument of G_I_L_A would be entirely useless.

Exactly!

Richard

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