Re: [PR84682] disregard address constraints on non-addresses

[Jeff Law <law at redhat dot com>]

On 03/08/2018 11:45 PM, Alexandre Oliva wrote:
> LRA gets very confused when non-addresses are passed as operands to
> asms with address contraints.  Even if other constraints are
> available, and the operand is a perfect fit for them, we'd still
> attempt to process the operand as an address, and fail miserably at
> that.
> 
> Truth is, address constraints expect operands allowed by
> address_operand, and we make sure this is the case throughout the
> compiler, even in asm statements.  The problem was that, if multiple
> constraints were available, we wouldn't insist that the operand be
> allowed by address_operand, but we would proceed as if it was,
> regardless of any other constraints.
> 
> To address this problem, I've arranged for LRA to attempt to deal with
> address-constrained operands as addresses only when the is_address
> flag is set, and to not set this flag in preprocess_constraints for
> asm operands that are not allowed by address_operand.
> 
> Regstrapped on i686- and x86_64-linux-gnu.  Ok to install?
> 
> for  gcc/ChangeLog
> 
> 	PR rtl-optimization/84682
> 	* lra-constraints.c (process_address_1): Check is_address flag
> 	for address constraints.
> 	(process_alt_operands): Likewise.
> 	* lra.c (lra_set_insn_recog_data): Pass asm operand locs to
> 	preprocess_constraints.
> 	* recog.h (preprocess_constraints): Add oploc parameter.
> 	Adjust callers.
> 	* recog.c (preprocess_constraints): Test address_operand for
> 	CT_ADDRESS constraints.
> 
> for  gcc/testsuite/ChangeLog
> 
> 	PR rtl-optimization/84682
> 	* gcc.dg/torture/pr84682-1.c: New.
> 	* gcc.dg/torture/pr84682-2.c: New.
> 	* gcc.dg/torture/pr84682-3.c: New.
I went ahead and committed this to the trunk.

jeff