This fell out of me looking into PR119835. This doesn't resolve the underlying
issue, but instead of failing GIMPLE semantics verification just by chance in
the 'GIMPLE pass: nrv' context, it makes the issue observable generally.
(... thereby regressing a small number of offloading test cases where host vs.
offload compilers disagree on 'aggregate_value_p' for functions that return
aggregate types.)
This cross-references just the three places in the code that I ran into;
likely there are more?
No regressions for powerpc64le-unknown-linux-gnu, x86_64-pc-linux-gnu bootstrap
and 'make check' (without offloading configured).
PR middle-end/119835
gcc/
* tree-cfg.cc (verify_gimple_return): Verify 'GIMPLE_RETURN' vs.
'RESULT_DECL' if 'aggregate_value_p'.
* gimplify.cc (gimplify_return_expr): Cross-reference it.
* tree-nrv.cc (pass_nrv::execute): Likewise.
---
gcc/gimplify.cc | 1 +
gcc/tree-cfg.cc | 23 +++++++++++++++++++++++
gcc/tree-nrv.cc | 1 +
3 files changed, 25 insertions(+)
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 4f385b1b779..ac296ab70bf 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -1903,6 +1903,7 @@ gimplify_return_expr (tree stmt, gimple_seq *pre_p)
}
/* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
+ This is checked in 'tree-cfg.cc:verify_gimple_return'.
Recall that aggregate_value_p is FALSE for any aggregate type that is
returned in registers. If we're returning values in registers, then
we don't want to extend the lifetime of the RESULT_DECL, particularly
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index 6a95b82ff40..2fc99d54934 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -4892,6 +4892,29 @@ verify_gimple_return (greturn *stmt)
return true;
}
+ /* Verify 'gimplify.cc:gimplify_return_expr' property:
+ "If aggregate_value_p is true, then we can return the bare RESULT_DECL."
+ */
+ tree decl_result = DECL_RESULT (current_function_decl);
+ if (aggregate_value_p (decl_result, current_function_decl))
+ {
+ tree op_check;
+ if (TREE_CODE (op) == SSA_NAME)
+ op_check = SSA_NAME_VAR (op);
+ else
+ op_check = op;
+ if (op_check != decl_result)
+ {
+ error ("operand in return statement differs from %qs",
+ get_tree_code_name (TREE_CODE (decl_result)));
+ if (op != op_check)
+ debug_generic_stmt (op);
+ debug_generic_stmt (op_check);
+ debug_generic_stmt (decl_result);
+ return true;
+ }
+ }
+
if ((TREE_CODE (op) == RESULT_DECL
&& DECL_BY_REFERENCE (op))
|| (TREE_CODE (op) == SSA_NAME
diff --git a/gcc/tree-nrv.cc b/gcc/tree-nrv.cc
index 180ce39de4c..6ac77567600 100644
--- a/gcc/tree-nrv.cc
+++ b/gcc/tree-nrv.cc
@@ -174,6 +174,7 @@ pass_nrv::execute (function *fun)
/* In a function with an aggregate return value, the
gimplifier has changed all non-empty RETURN_EXPRs to
return the RESULT_DECL. */
+ /* See also 'tree-cfg.cc:verify_gimple_return'. */
ret_val = gimple_return_retval (return_stmt);
if (ret_val)
gcc_assert (ret_val == result);
--
2.34.1
