Hi!
The first testcase below ICEs e.g. with -O2 on s390x-linux, the
second with -O2 -m32 on x86_64-linux. We have
<bb 2> [local count: 1073741824]:
if (x_4(D) != 0)
goto <bb 3>; [33.00%]
else
goto <bb 4>; [67.00%]
<bb 3> [local count: 354334800]:
_7 = qux (42);
foo (0, &<retval>, _7);
<bb 4> [local count: 1073741824]:
return <retval>;
on a target where <retval> has gimple reg type but is
aggregate_value_p and TREE_ADDRESSABLE too.
fnsplit splits this into
<bb 2> [local count: 354334800]:
_1 = qux (42);
foo (0, &<retval>, _1);
<bb 3> [local count: 354334800]:
return <retval>;
in the *.part.0 function and
if (x_4(D) != 0)
goto <bb 3>; [33.00%]
else
goto <bb 4>; [67.00%]
<bb 3> [local count: 354334800]:
<retval> = _Z3bari.part.0 ();
<bb 4> [local count: 1073741824]:
return <retval>;
in the original function. Now, dunno if already that isn't
invalid because <retval> has TREE_ADDRESSABLE set in the latter, but
at least it is accepted by tree-cfg.cc verification.
tree lhs = gimple_call_lhs (stmt);
if (lhs
&& (!is_gimple_reg (lhs)
&& (!is_gimple_lvalue (lhs)
|| verify_types_in_gimple_reference
(TREE_CODE (lhs) == WITH_SIZE_EXPR
? TREE_OPERAND (lhs, 0) : lhs, true))))
{
error ("invalid LHS in gimple call");
return true;
}
While lhs is not is_gimple_reg, it is is_gimple_lvalue here.
Now, inlining of the *.part.0 fn back into the original results
in
<retval> = a;
statement which already is diagnosed by verify_gimple_assign_single:
case VAR_DECL:
case PARM_DECL:
if (!is_gimple_reg (lhs)
&& !is_gimple_reg (rhs1)
&& is_gimple_reg_type (TREE_TYPE (lhs)))
{
error ("invalid RHS for gimple memory store: %qs", code_name);
debug_generic_stmt (lhs);
debug_generic_stmt (rhs1);
return true;
}
__float128/long double are is_gimple_reg_type, but both operands
aren't is_gimple_reg.
The following patch fixes it by doing separate load and store, i.e.
_42 = a;
<retval> = 42;
in this case. If we want to change verify_gimple_assign to disallow
!is_gimple_reg (lhs) for is_gimple_reg_type (TREE_TYPE (lhs)), we'd
need to change fnsplit instead, but I'd be afraid such a change would
be more stage1 material (and certainly nothing that should be
even backported to release branches).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2026-03-05 Jakub Jelinek <[email protected]>
PR tree-optimization/124135
* tree-inline.cc (expand_call_inline): If both gimple_call_lhs (stmt)
and use_retvar aren't gimple regs but have gimple reg type, use
separate load of use_retva into SSA_NAME and then store of it
into gimple_call_lhs (stmt).
* g++.dg/torture/pr124135-1.C: New test.
* g++.dg/torture/pr124135-2.C: New test.
--- gcc/tree-inline.cc.jj 2026-02-17 15:56:32.000000000 +0100
+++ gcc/tree-inline.cc 2026-03-05 18:39:59.590916480 +0100
@@ -5336,7 +5336,20 @@ expand_call_inline (basic_block bb, gimp
if (use_retvar && gimple_call_lhs (stmt))
{
gimple *old_stmt = stmt;
- stmt = gimple_build_assign (gimple_call_lhs (stmt), use_retvar);
+ tree lhs = gimple_call_lhs (stmt);
+ if (!is_gimple_reg (lhs)
+ && !is_gimple_reg (use_retvar)
+ && is_gimple_reg_type (TREE_TYPE (lhs)))
+ {
+ /* If both lhs and use_retvar aren't gimple regs, yet have
+ gimple reg type, copy through a temporary SSA_NAME. */
+ gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (lhs)),
+ use_retvar);
+ gimple_set_location (g, gimple_location (old_stmt));
+ gsi_insert_before (&stmt_gsi, g, GSI_SAME_STMT);
+ use_retvar = gimple_assign_lhs (g);
+ }
+ stmt = gimple_build_assign (lhs, use_retvar);
gimple_set_location (stmt, gimple_location (old_stmt));
gsi_replace (&stmt_gsi, stmt, false);
maybe_clean_or_replace_eh_stmt (old_stmt, stmt);
--- gcc/testsuite/g++.dg/torture/pr124135-1.C.jj 2026-03-05
18:44:28.110424486 +0100
+++ gcc/testsuite/g++.dg/torture/pr124135-1.C 2026-03-05 18:44:54.106989715
+0100
@@ -0,0 +1,20 @@
+// PR tree-optimization/124135
+// { dg-do compile }
+
+void foo (char, long double *, int);
+int qux (int);
+
+long double
+bar (int x)
+{
+ long double a;
+ if (x)
+ foo (0, &a, qux (42));
+ return a;
+}
+
+void
+baz (int x)
+{
+ bar (x);
+}
--- gcc/testsuite/g++.dg/torture/pr124135-2.C.jj 2026-03-05
18:45:43.132169811 +0100
+++ gcc/testsuite/g++.dg/torture/pr124135-2.C 2026-03-05 18:46:23.855488751
+0100
@@ -0,0 +1,27 @@
+// PR tree-optimization/124135
+// { dg-do compile }
+
+#ifdef __SIZEOF_FLOAT128__
+void foo (char, __float128 *, int);
+int qux (int);
+
+__float128
+bar (int x)
+{
+ __float128 a;
+ if (x)
+ foo (0, &a, qux (42));
+ return a;
+}
+
+void
+baz (int x)
+{
+ bar (x);
+}
+#else
+void
+baz ()
+{
+}
+#endif
Jakub
