Hi!
The first hunk before the if (!from...) part shows a typo I've made in a
recent change, the last argument of simplify_gen_subreg is byte offset, and
the subreg has same bitsize outer and inner modes, so using byte offset 1
makes no sense at all.
Another issue that the testcase suffers from is that the simplify_gen_rtx
(preexisting issue) can fail, and in that case trying to read_complex_part
from that NULL will ICE. The patch tries harder by trying to simplify the
2 halves separately, and for all cases when simplify_gen_subreg fails which
can happen because of various reasons, there is the fallback to go through
memory.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/7.3?
2017-12-30 Jakub Jelinek <ja...@redhat.com>
PR middle-end/83609
* expr.c (expand_assignment): Fix up a typo in simplify_gen_subreg
last argument when extracting from CONCAT. If either from_real or
from_imag is NULL, use expansion through memory. If result is not
a CONCAT and simplify_gen_subreg fails, try to simplify_gen_subreg
the parts directly to inner mode, if even that fails, use expansion
through memory.
* gcc.dg/pr83609.c: New test.
* g++.dg/opt/pr83609.C: New test.
--- gcc/expr.c.jj 2017-12-21 09:43:19.797042465 +0100
+++ gcc/expr.c 2017-12-30 13:49:19.634057445 +0100
@@ -5158,7 +5158,9 @@ expand_assignment (tree to, tree from, b
from_mode, 0);
rtx from_imag
= simplify_gen_subreg (to_mode, XEXP (result, 1),
- from_mode, 1);
+ from_mode, 0);
+ if (!from_real || !from_imag)
+ goto concat_store_slow;
emit_move_insn (XEXP (to_rtx, 0), from_real);
emit_move_insn (XEXP (to_rtx, 1), from_imag);
}
@@ -5167,14 +5169,35 @@ expand_assignment (tree to, tree from, b
rtx from_rtx
= simplify_gen_subreg (GET_MODE (to_rtx), result,
TYPE_MODE (TREE_TYPE (from)), 0);
- emit_move_insn (XEXP (to_rtx, 0),
- read_complex_part (from_rtx, false));
- emit_move_insn (XEXP (to_rtx, 1),
- read_complex_part (from_rtx, true));
+ if (from_rtx)
+ {
+ emit_move_insn (XEXP (to_rtx, 0),
+ read_complex_part (from_rtx, false));
+ emit_move_insn (XEXP (to_rtx, 1),
+ read_complex_part (from_rtx, true));
+ }
+ else
+ {
+ machine_mode to_mode
+ = GET_MODE_INNER (GET_MODE (to_rtx));
+ rtx from_real
+ = simplify_gen_subreg (to_mode, result,
+ TYPE_MODE (TREE_TYPE (from)),
+ 0);
+ rtx from_imag
+ = simplify_gen_subreg (to_mode, result,
+ TYPE_MODE (TREE_TYPE (from)),
+ GET_MODE_SIZE (to_mode));
+ if (!from_real || !from_imag)
+ goto concat_store_slow;
+ emit_move_insn (XEXP (to_rtx, 0), from_real);
+ emit_move_insn (XEXP (to_rtx, 1), from_imag);
+ }
}
}
else
{
+ concat_store_slow:;
rtx temp = assign_stack_temp (GET_MODE (to_rtx),
GET_MODE_SIZE (GET_MODE (to_rtx)));
write_complex_part (temp, XEXP (to_rtx, 0), false);
--- gcc/testsuite/gcc.dg/pr83609.c.jj 2017-12-30 13:47:49.350044674 +0100
+++ gcc/testsuite/gcc.dg/pr83609.c 2017-12-30 13:42:52.227002619 +0100
@@ -0,0 +1,29 @@
+/* PR middle-end/83609 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-tree-forwprop -fno-tree-ccp -fno-tree-fre
-fno-tree-pre -fno-code-hoisting" } */
+
+#if __SIZEOF_LONG_LONG__ == 2 * __SIZEOF_FLOAT__
+_Complex float
+foo (void)
+{
+ _Complex float c;
+ *((unsigned long long *)&c) = 0x123456789abcdef0ULL;
+ return c;
+}
+
+int
+main ()
+{
+ union { _Complex float c; unsigned long long l; } u;
+ u.c = foo ();
+ if (u.l != 0x123456789abcdef0ULL)
+ __builtin_abort ();
+ return 0;
+}
+#else
+int
+main ()
+{
+ return 0;
+}
+#endif
--- gcc/testsuite/g++.dg/opt/pr83609.C.jj 2017-12-30 13:48:18.937048860
+0100
+++ gcc/testsuite/g++.dg/opt/pr83609.C 2017-12-30 13:46:25.968032868 +0100
@@ -0,0 +1,28 @@
+// PR middle-end/83609
+// { dg-do compile }
+// { dg-options "-O2 -fno-tree-forwprop" }
+
+template <typename> class B;
+template <> struct B<float>
+{
+ float foo () { return __real__ b; }
+ _Complex float b;
+};
+
+void bar (int);
+
+template <class T>
+void
+baz ()
+{
+ B<T> h;
+ T *a = (T *) &h;
+ a[0] = a[1] = 6;
+ h.foo () ? void () : bar (7);
+}
+
+int
+main ()
+{
+ baz<float> ();
+}
Jakub
