.ASSUME cannot cause observable escaping of addresses so we do not
consider address-takens as part of its arguments as needing
TREE_ADDRESSABLE to be set. Without this VN will not be able to
disambiguate against calls and replicate IPA analysis predicate
conditions as optimization. Similarly for PTA we do not need to
generate any constraints for .ASSUME.
Bootstrapped and tested on x86_64-unknown-linux-gnu w/o the PTA hunk
sofar, that part still pending testing. Will push if that's successful.
Richard.
PR tree-optimization/127693
* tree-ssa-operands.cc (operands_scanner::parse_ssa_operands):
For IFN_ASSUME do not cause address-takens.
* tree-ssa.cc (execute_update_addresses_taken): Likewise, but
still make sure to not rewrite to a register.
* tree-ssa-structalias.cc (find_func_aliases_for_call): No
side-effects from IFN_ASSUME, so produce no constraints.
---
gcc/gimple-ssa-pta-constraints.cc | 4 ++++
gcc/tree-ssa-operands.cc | 5 ++++-
gcc/tree-ssa.cc | 14 ++++++++++++++
3 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/gcc/gimple-ssa-pta-constraints.cc
b/gcc/gimple-ssa-pta-constraints.cc
index fe8bd738f33..17b5989b06b 100644
--- a/gcc/gimple-ssa-pta-constraints.cc
+++ b/gcc/gimple-ssa-pta-constraints.cc
@@ -2125,6 +2125,10 @@ find_func_aliases_for_call (struct function *fn, gcall
*t)
if (gimple_call_internal_p (t, IFN_DEFERRED_INIT))
return;
+ /* .ASSUME produces a flag and has no observable side-effects. */
+ if (gimple_call_internal_p (t, IFN_ASSUME))
+ return;
+
fi = get_fi_for_callee (t);
if (!in_ipa_mode
|| (fi->decl && fndecl && !fi->is_fn_info))
diff --git a/gcc/tree-ssa-operands.cc b/gcc/tree-ssa-operands.cc
index d7a79f40f9d..c526c842b2f 100644
--- a/gcc/tree-ssa-operands.cc
+++ b/gcc/tree-ssa-operands.cc
@@ -953,6 +953,7 @@ operands_scanner::parse_ssa_operands ()
{
enum gimple_code code = gimple_code (stmt);
size_t i, n, start = 0;
+ int flags = 0;
switch (code)
{
@@ -985,6 +986,8 @@ operands_scanner::parse_ssa_operands ()
case GIMPLE_CALL:
/* Add call-clobbered operands, if needed. */
maybe_add_call_vops (as_a <gcall *> (stmt));
+ if (gimple_call_internal_p (stmt, IFN_ASSUME))
+ flags |= opf_non_addressable;
/* FALLTHRU */
case GIMPLE_ASSIGN:
@@ -996,7 +999,7 @@ operands_scanner::parse_ssa_operands ()
do_default:
n = gimple_num_ops (stmt);
for (i = start; i < n; i++)
- get_expr_operands (gimple_op_ptr (stmt, i), opf_use);
+ get_expr_operands (gimple_op_ptr (stmt, i), opf_use | flags);
break;
}
}
diff --git a/gcc/tree-ssa.cc b/gcc/tree-ssa.cc
index 436c88d47d5..b0cd2aa1b43 100644
--- a/gcc/tree-ssa.cc
+++ b/gcc/tree-ssa.cc
@@ -1954,6 +1954,20 @@ execute_update_addresses_taken (void)
else if (is_asan_mark_p (stmt)
|| gimple_call_internal_p (stmt, IFN_GOMP_SIMT_ENTER))
;
+ else if (gimple_call_internal_p (stmt, IFN_ASSUME))
+ {
+ /* An address-taken arguments are not relevant for aliasing
+ and we never expand the call (and need the address).
+ But we can't use a register. */
+ for (unsigned i = 1; i < gimple_call_num_args (stmt); ++i)
+ {
+ tree arg = gimple_call_arg (stmt, i);
+ if (TREE_CODE (arg) == ADDR_EXPR)
+ bitmap_set_bit (not_reg_needs,
+ DECL_UID (get_base_address
+ (TREE_OPERAND (arg, 0))));
+ }
+ }
else
set_addresses_taken (stmt, addresses_taken);
}
--
2.51.0
