From 19cc61111120087619b496732b249b48b1fbe27e Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 28 May 2024 13:29:30 +0200 Subject: Avoid pessimistic constraints for asm memory constraints We process asm memory input/outputs with constraints to ESCAPED but for this temporarily build an ADDR_EXPR. The issue is that the used build_fold_addr_expr ends up wrapping the ADDR_EXPR in a conversion which ends up producing &ANYTHING constraints which is quite bad. The following uses get_constraint_for_address_of instead, avoiding the temporary tree and the unhandled conversion. This avoids a gcc.dg/tree-ssa/restrict-9.c FAIL with the fix for PR115236. * tree-ssa-structalias.cc (find_func_aliases): Use get_constraint_for_address_of to build escape constraints for asm inputs and outputs. --- gcc/tree-ssa-structalias.cc | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'gcc') diff --git a/gcc/tree-ssa-structalias.cc b/gcc/tree-ssa-structalias.cc index f93c5df..9cec2c6 100644 --- a/gcc/tree-ssa-structalias.cc +++ b/gcc/tree-ssa-structalias.cc @@ -5269,7 +5269,11 @@ find_func_aliases (struct function *fn, gimple *origt) /* A memory constraint makes the address of the operand escape. */ if (!allows_reg && allows_mem) - make_escape_constraint (build_fold_addr_expr (op)); + { + auto_vec tmpc; + get_constraint_for_address_of (op, &tmpc); + make_constraints_to (escaped_id, tmpc); + } /* The asm may read global memory, so outputs may point to any global memory. */ @@ -5298,7 +5302,11 @@ find_func_aliases (struct function *fn, gimple *origt) /* A memory constraint makes the address of the operand escape. */ if (!allows_reg && allows_mem) - make_escape_constraint (build_fold_addr_expr (op)); + { + auto_vec tmpc; + get_constraint_for_address_of (op, &tmpc); + make_constraints_to (escaped_id, tmpc); + } /* Strictly we'd only need the constraint to ESCAPED if the asm clobbers memory, otherwise using something along the lines of per-call clobbers/uses would be enough. */ -- cgit v1.1