On May 6, 2018 7:59:33 PM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>At expansion time, we in various cases choose to assign_temp and ICE
>in that case on any expressions with TREE_ADDRESSABLE types. We don't
>want
>to create any temporaries for such types, the var needs to live in
>memory
>and if the constraint doesn't allow mem, we should just reject it as
>invalid.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
>trunk/8.2?
OK.
Richard.
>2018-05-06 Jakub Jelinek <ja...@redhat.com>
>
> PR c++/85659
> * cfgexpand.c (expand_asm_stmt): Don't create a temporary if
> the type is addressable. Don't force op into register if it has
> BLKmode.
>
> * g++.dg/ext/asm14.C: New test.
> * g++.dg/ext/asm15.C: New test.
> * g++.dg/ext/asm16.C: New test.
>
>--- gcc/cfgexpand.c.jj 2018-03-27 12:54:43.000000000 +0200
>+++ gcc/cfgexpand.c 2018-05-05 13:28:44.037551377 +0200
>@@ -3044,14 +3044,14 @@ expand_asm_stmt (gasm *stmt)
>
> generating_concat_p = 0;
>
>- if ((TREE_CODE (val) == INDIRECT_REF
>- && allows_mem)
>+ if ((TREE_CODE (val) == INDIRECT_REF && allows_mem)
> || (DECL_P (val)
> && (allows_mem || REG_P (DECL_RTL (val)))
> && ! (REG_P (DECL_RTL (val))
> && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
> || ! allows_reg
>- || is_inout)
>+ || is_inout
>+ || TREE_ADDRESSABLE (type))
> {
> op = expand_expr (val, NULL_RTX, VOIDmode,
> !allows_reg ? EXPAND_MEMORY : EXPAND_WRITE);
>@@ -3060,7 +3060,7 @@ expand_asm_stmt (gasm *stmt)
>
> if (! allows_reg && !MEM_P (op))
> error ("output number %d not directly addressable", i);
>- if ((! allows_mem && MEM_P (op))
>+ if ((! allows_mem && MEM_P (op) && GET_MODE (op) != BLKmode)
> || GET_CODE (op) == CONCAT)
> {
> rtx old_op = op;
>--- gcc/testsuite/g++.dg/ext/asm14.C.jj 2018-05-05 13:15:50.099258834
>+0200
>+++ gcc/testsuite/g++.dg/ext/asm14.C 2018-05-05 13:19:09.717327528
>+0200
>@@ -0,0 +1,10 @@
>+// PR c++/85659
>+// { dg-do compile }
>+
>+struct S { S (); ~S (); int s; };
>+
>+void
>+foo (S &s)
>+{
>+ __asm volatile ("" : "+m,r" (s) : : "memory");
>+}
>--- gcc/testsuite/g++.dg/ext/asm15.C.jj 2018-05-05 13:15:56.656261090
>+0200
>+++ gcc/testsuite/g++.dg/ext/asm15.C 2018-05-05 13:19:15.125329389
>+0200
>@@ -0,0 +1,10 @@
>+// PR c++/85659
>+// { dg-do compile }
>+
>+struct S { S (); ~S (); int s; };
>+
>+void
>+foo (S &s)
>+{
>+ __asm volatile ("" : "+r" (s) : : "memory"); // { dg-error "" }
>+}
>--- gcc/testsuite/g++.dg/ext/asm16.C.jj 2018-05-05 13:28:03.448530441
>+0200
>+++ gcc/testsuite/g++.dg/ext/asm16.C 2018-05-05 13:28:21.068539532
>+0200
>@@ -0,0 +1,10 @@
>+// PR c++/85659
>+// { dg-do compile }
>+
>+struct S { S (); ~S (); int s[64]; } s;
>+
>+void
>+foo ()
>+{
>+ __asm volatile ("" : "=r" (s) : : "memory"); // { dg-error "" }
>+}
>
> Jakub
