Hi!
On the following testcase we ICE on i686-linux (32-bit), because we store
(first 96-bit, then 72-bit) structure into the first part of a 2x 96-bit
complex long double, and for 96-bit floats there is no corresponding
integral mode that covers it and we ICE when op0 is not in MEM (it is a
REG).
The following patch handles the simple case where the whole dest REG is
covered and value is a MEM using a load from the memory, and for the rest
just spills on the stack, similarly how we punt when for stores to complex
REGs if the bitsize/bitnum cover portions of both halves.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-11-19 Jakub Jelinek <ja...@redhat.com>
PR middle-end/90840
* expmed.c (store_bit_field_1): Handle the case where op0 is not a MEM
and has a mode that doesn't have corresponding integral type.
* gcc.c-torture/compile/pr90840.c: New test.
--- gcc/expmed.c.jj 2019-11-15 00:37:32.000000000 +0100
+++ gcc/expmed.c 2019-11-19 17:09:22.035129617 +0100
@@ -840,6 +840,27 @@ store_bit_field_1 (rtx str_rtx, poly_uin
if (MEM_P (op0))
op0 = adjust_bitfield_address_size (op0, op0_mode.else_blk (),
0, MEM_SIZE (op0));
+ else if (!op0_mode.exists ())
+ {
+ if (ibitnum == 0
+ && known_eq (ibitsize, GET_MODE_BITSIZE (GET_MODE (op0)))
+ && MEM_P (value)
+ && !reverse)
+ {
+ value = adjust_address (value, GET_MODE (op0), 0);
+ emit_move_insn (op0, value);
+ return true;
+ }
+ if (!fallback_p)
+ return false;
+ rtx temp = assign_stack_temp (GET_MODE (op0),
+ GET_MODE_SIZE (GET_MODE (op0)));
+ emit_move_insn (temp, op0);
+ store_bit_field_1 (temp, bitsize, bitnum, 0, 0, fieldmode, value,
+ reverse, fallback_p);
+ emit_move_insn (op0, temp);
+ return true;
+ }
else
op0 = gen_lowpart (op0_mode.require (), op0);
}
--- gcc/testsuite/gcc.c-torture/compile/pr90840.c.jj 2019-11-19
17:18:31.361918896 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr90840.c 2019-11-19
17:11:06.010575339 +0100
@@ -0,0 +1,19 @@
+/* PR middle-end/90840 */
+struct S { long long a; int b; };
+struct S foo (void);
+struct __attribute__((packed)) T { long long a; char b; };
+struct T baz (void);
+
+void
+bar (void)
+{
+ _Complex long double c;
+ *(struct S *) &c = foo ();
+}
+
+void
+qux (void)
+{
+ _Complex long double c;
+ *(struct T *) &c = baz ();
+}
Jakub
