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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57748
(comment #36, attachment 30782)
--- a/gcc/expr.c 2013-08-06 00:09:45.000000000 +0200
+++ b/gcc/expr.c 2013-09-10 08:23:09.570951685 +0200
@@ -4691,8 +4691,6 @@ expand_assignment (tree to, tree from, b
int unsignedp;
int volatilep = 0;
tree tem;
- bool misalignp;
- rtx mem = NULL_RTX;
push_temp_slots ();
tem = get_inner_reference (to, &bitsize, &bitpos, &offset, &mode1,
@@ -4702,40 +4700,7 @@ expand_assignment (tree to, tree from, b
&& DECL_BIT_FIELD_TYPE (TREE_OPERAND (to, 1)))
get_bit_range (&bitregion_start, &bitregion_end, to, &bitpos, &offset);
- /* If we are going to use store_bit_field and extract_bit_field,
- make sure to_rtx will be safe for multiple use. */
- mode = TYPE_MODE (TREE_TYPE (tem));
- if (TREE_CODE (tem) == MEM_REF
- && mode != BLKmode
- && ((align = get_object_alignment (tem))
- < GET_MODE_ALIGNMENT (mode))
- && ((icode = optab_handler (movmisalign_optab, mode))
- != CODE_FOR_nothing))
- {
- struct expand_operand ops[2];
-
- misalignp = true;
- to_rtx = gen_reg_rtx (mode);
- mem = expand_expr (tem, NULL_RTX, VOIDmode, EXPAND_WRITE);
-
- /* If the misaligned store doesn't overwrite all bits, perform
- rmw cycle on MEM. */
- if (bitsize != GET_MODE_BITSIZE (mode))
- {
- create_input_operand (&ops[0], to_rtx, mode);
- create_fixed_operand (&ops[1], mem);
- /* The movmisalign<mode> pattern cannot fail, else the assignment
- would silently be omitted. */
- expand_insn (icode, 2, ops);
-
- mem = copy_rtx (mem);
- }
- }
- else
- {
- misalignp = false;
- to_rtx = expand_expr (tem, NULL_RTX, VOIDmode, EXPAND_WRITE);
- }
+ to_rtx = expand_expr (tem, NULL_RTX, VOIDmode, EXPAND_WRITE);
/* If the bitfield is volatile, we want to access it in the
field's mode, not the computed mode.
@@ -4773,6 +4738,8 @@ expand_assignment (tree to, tree from, b
if (MEM_P (to_rtx)
&& GET_MODE (to_rtx) == BLKmode
&& GET_MODE (XEXP (to_rtx, 0)) != VOIDmode
+ && bitregion_start == 0
+ && bitregion_end == 0
&& bitsize > 0
&& (bitpos % bitsize) == 0
&& (bitsize % GET_MODE_ALIGNMENT (mode1)) == 0
@@ -4874,17 +4841,6 @@ expand_assignment (tree to, tree from, b
get_alias_set (to), nontemporal);
}
- if (misalignp)
- {
- struct expand_operand ops[2];
-
- create_fixed_operand (&ops[0], mem);
- create_input_operand (&ops[1], to_rtx, mode);
- /* The movmisalign<mode> pattern cannot fail, else the assignment
- would silently be omitted. */
- expand_insn (icode, 2, ops);
- }
-
if (result)
preserve_temp_slots (result);
pop_temp_slots ();
@@ -9905,7 +9861,7 @@ expand_expr_real_1 (tree exp, rtx target
&& modifier != EXPAND_STACK_PARM
? target : NULL_RTX),
VOIDmode,
- modifier == EXPAND_SUM ? EXPAND_NORMAL : modifier);
+ EXPAND_MEMORY);
/* If the bitfield is volatile, we want to access it in the
field's mode, not the computed mode.
--- a/gcc/testsuite/gcc.dg/torture/pr57748-1.c 1970-01-01 01:00:00.000000000 +0100
+++ b/gcc/testsuite/gcc.dg/torture/pr57748-1.c 2013-09-06 08:38:03.718686940 +0200
@@ -0,0 +1,49 @@
+/* PR middle-end/57748 */
+/* { dg-do run } */
+/* ICE in expand_assignment:
+ misalignp == true, !MEM_P (to_rtx), offset != 0,
+ => gcc_assert (TREE_CODE (offset) == INTEGER_CST) */
+
+#include <stdlib.h>
+
+extern void abort (void);
+
+typedef long long V
+ __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
+
+typedef struct S { V a; V b[0]; } P __attribute__((aligned (1)));
+
+struct __attribute__((packed)) T { char c; P s; };
+
+void __attribute__((noinline, noclone))
+check (struct T *t)
+{
+ if (t->s.b[0][0] != 3 || t->s.b[0][1] != 4)
+ abort ();
+}
+
+int __attribute__((noinline, noclone))
+get_i (void)
+{
+ return 0;
+}
+
+void __attribute__((noinline, noclone))
+foo (P *p)
+{
+ V a = { 3, 4 };
+ int i = get_i ();
+ p->b[i] = a;
+}
+
+int
+main ()
+{
+ struct T *t = (struct T *) calloc (128, 1);
+
+ foo (&t->s);
+ check (t);
+
+ free (t);
+ return 0;
+}
--- a/gcc/testsuite/gcc.dg/torture/pr57748-2.c 1970-01-01 01:00:00.000000000 +0100
+++ b/gcc/testsuite/gcc.dg/torture/pr57748-2.c 2013-09-06 08:38:03.718686940 +0200
@@ -0,0 +1,43 @@
+/* PR middle-end/57748 */
+/* { dg-do run } */
+/* wrong code in expand_assignment:
+ misalignp == true, !MEM_P (to_rtx),
+ offset == 0, bitpos >= GET_MODE_PRECISION,
+ => result = NULL. */
+
+#include <stdlib.h>
+
+extern void abort (void);
+
+typedef long long V
+ __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
+
+typedef struct S { V a; V b[0]; } P __attribute__((aligned (1)));
+
+struct __attribute__((packed)) T { char c; P s; };
+
+void __attribute__((noinline, noclone))
+check (struct T *t)
+{
+ if (t->s.b[0][0] != 3 || t->s.b[0][1] != 4)
+ abort ();
+}
+
+void __attribute__((noinline, noclone))
+foo (P *p)
+{
+ V a = { 3, 4 };
+ p->b[0] = a;
+}
+
+int
+main ()
+{
+ struct T *t = (struct T *) calloc (128, 1);
+
+ foo (&t->s);
+ check (t);
+
+ free (t);
+ return 0;
+}
--- a/gcc/testsuite/gcc.dg/torture/pr57748-3.c 1970-01-01 01:00:00.000000000 +0100
+++ b/gcc/testsuite/gcc.dg/torture/pr57748-3.c 2013-09-09 09:54:28.937891452 +0200
@@ -0,0 +1,49 @@
+/* PR middle-end/57748 */
+/* { dg-do run } */
+/* { dg-final { scan-assembler-not "movdqu" } } */
+/* data store race in expand_assignment:
+ misalignp == true, !MEM_P (to_rtx),
+ offset == 0, bitsize < GET_MODE_BITSIZE,
+ => rmw cycle on MEM. */
+
+#include <stdlib.h>
+
+typedef long long V
+ __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
+
+union x
+{
+ long long a;
+ float b;
+} __attribute__((aligned (1)));
+
+struct s
+{
+ union x xx[0];
+ V x;
+} __attribute__((packed));
+
+void __attribute__((noinline, noclone))
+check (union x *xx)
+{
+ if (xx[0].b != 3.14F || xx[1].a != 0x123456789ABCDEF)
+ abort ();
+}
+
+void __attribute__((noinline, noclone))
+foo (struct s * x)
+{
+ x->xx[0].a = -1;
+ x->xx[0].b = 3.14F;
+ x->x[1] = 0x123456789ABCDEF;
+}
+
+struct s ss;
+
+int
+main ()
+{
+ foo (&ss);
+ check (ss.xx);
+ return 0;
+}
--- a/gcc/testsuite/gcc.dg/torture/pr57748-4.c 1970-01-01 01:00:00.000000000 +0100
+++ b/gcc/testsuite/gcc.dg/torture/pr57748-4.c 2013-09-10 08:36:37.182962269 +0200
@@ -0,0 +1,50 @@
+/* PR middle-end/57748 */
+/* { dg-do run } */
+/* { dg-final { scan-assembler-not "movdqu" } } */
+/* wrong code in expand_expr_real_1:
+ read whole structure instead of only one member. */
+
+#include <stdlib.h>
+
+typedef long long V
+ __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
+
+union x
+{
+ long long a;
+ float b;
+} __attribute__((aligned (1)));
+
+struct s
+{
+ union x xx[0];
+ V x;
+} __attribute__((packed));
+
+void __attribute__((noinline, noclone))
+check (struct s *x)
+{
+ if (x->xx[0].b != 3.14F || x->xx[1].a != 0x123456789ABCDEF)
+ abort ();
+ if (x->xx[2].b != 3.14F || x->xx[3].a != 0x123456789ABCDEF)
+ abort ();
+}
+
+void __attribute__((noinline, noclone))
+foo (struct s * x)
+{
+ x->xx[0].a = -1;
+ x->xx[0].b = 3.14F;
+ x->x[1] = 0x123456789ABCDEF;
+}
+
+struct s ss[2];
+
+int
+main ()
+{
+ foo (ss);
+ foo (ss+1);
+ check (ss);
+ return 0;
+}
|
