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| author | Richard Biener <rguenther@suse.de> | 2024-05-28 13:29:30 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2024-05-28 14:12:46 +0200 |
| commit | 19cc61111120087619b496732b249b48b1fbe27e (patch) | |
| tree | 014b0d9091e3770fd05155f6aefd691c0e70de39 /gcc | |
| parent | eaaa4b88038d4d6eda1b20ab662f1568fd9be31f (diff) | |
| download | gcc-19cc61111120087619b496732b249b48b1fbe27e.zip gcc-19cc61111120087619b496732b249b48b1fbe27e.tar.gz gcc-19cc61111120087619b496732b249b48b1fbe27e.tar.bz2 | |
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.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/tree-ssa-structalias.cc | 12 |
1 files changed, 10 insertions, 2 deletions
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<ce_s> 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<ce_s> 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. */ |