On Sun, Jan 25, 2015 at 3:25 PM, Mikael Pettersson <mikpeli...@gmail.com> wrote:
> This backports the fixes for PR middle-end/57748, a wrong-code and ICE
> regression, to the 4.8 branch.
>
> Tested extensively on x86_64, powerpc64, sparc64, ARMv{5,7}, and m68k.
>
> Ok for 4.8?
Ok - I assume you have checked that all relevant patches in this area have
been backported already?
Thanks,
Richard.
> (I don't have commit rights.)
>
> /Mikael
>
> gcc/
>
> 2015-01-25 Mikael Pettersson <mikpeli...@gmail.com>
>
> Backport from mainline
>
> 2013-09-20 Bernd Edlinger <bernd.edlin...@hotmail.de>
>
> PR middle-end/57748
> * expr.c (expand_assignment): Remove misalignp code path.
>
> 2014-01-08 Bernd Edlinger <bernd.edlin...@hotmail.de>
>
> PR middle-end/57748
> * expr.h (expand_expr_real, expand_expr_real_1): Add new parameter
> inner_reference_p.
> (expand_expr, expand_normal): Adjust.
> * expr.c (expand_expr_real, expand_expr_real_1): Add new parameter
> inner_reference_p. Use inner_reference_p to expand inner references.
> (store_expr): Adjust.
> * cfgexpand.c (expand_call_stmt): Adjust.
>
> gcc/testsuite/
>
> 2015-01-25 Mikael Pettersson <mikpeli...@gmail.com>
>
> Backport from mainline
>
> 2013-09-20 Bernd Edlinger <bernd.edlin...@hotmail.de>
>
> PR middle-end/57748
> * gcc.dg/torture/pr57748-1.c: New test.
> * gcc.dg/torture/pr57748-2.c: New test.
>
> 2014-01-08 Bernd Edlinger <bernd.edlin...@hotmail.de>
>
> PR middle-end/57748
> * gcc.dg/torture/pr57748-3.c: New test.
> * gcc.dg/torture/pr57748-4.c: New test.
>
> diff -rupN gcc-4.8-20150122/gcc/cfgexpand.c
> gcc-4.8-20150122.pr57748/gcc/cfgexpand.c
> --- gcc-4.8-20150122/gcc/cfgexpand.c 2014-01-07 17:49:22.000000000 +0100
> +++ gcc-4.8-20150122.pr57748/gcc/cfgexpand.c 2015-01-25 15:00:35.240949368
> +0100
> @@ -2111,7 +2111,7 @@ expand_call_stmt (gimple stmt)
> if (lhs)
> expand_assignment (lhs, exp, false);
> else
> - expand_expr_real_1 (exp, const0_rtx, VOIDmode, EXPAND_NORMAL, NULL);
> + expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL);
>
> mark_transaction_restart_calls (stmt);
> }
> diff -rupN gcc-4.8-20150122/gcc/expr.c gcc-4.8-20150122.pr57748/gcc/expr.c
> --- gcc-4.8-20150122/gcc/expr.c 2014-11-28 18:06:23.000000000 +0100
> +++ gcc-4.8-20150122.pr57748/gcc/expr.c 2015-01-25 15:00:35.240949368 +0100
> @@ -4708,8 +4708,6 @@ 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,
> @@ -4728,40 +4726,7 @@ 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.
> @@ -4900,17 +4865,6 @@ 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 ();
> @@ -5262,7 +5216,7 @@ store_expr (tree exp, rtx target, int ca
> temp = expand_expr_real (exp, tmp_target, GET_MODE (target),
> (call_param_p
> ? EXPAND_STACK_PARM : EXPAND_NORMAL),
> - &alt_rtl);
> + &alt_rtl, false);
> }
>
> /* If TEMP is a VOIDmode constant and the mode of the type of EXP is not
> @@ -7881,11 +7835,21 @@ expand_constructor (tree exp, rtx target
> address, and ALT_RTL is non-NULL, then *ALT_RTL is set to the
> DECL_RTL of the VAR_DECL. *ALT_RTL is also set if EXP is a
> COMPOUND_EXPR whose second argument is such a VAR_DECL, and so on
> - recursively. */
> + recursively.
> +
> + If INNER_REFERENCE_P is true, we are expanding an inner reference.
> + In this case, we don't adjust a returned MEM rtx that wouldn't be
> + sufficiently aligned for its mode; instead, it's up to the caller
> + to deal with it afterwards. This is used to make sure that unaligned
> + base objects for which out-of-bounds accesses are supported, for
> + example record types with trailing arrays, aren't realigned behind
> + the back of the caller.
> + The normal operating mode is to pass FALSE for this parameter. */
>
> rtx
> expand_expr_real (tree exp, rtx target, enum machine_mode tmode,
> - enum expand_modifier modifier, rtx *alt_rtl)
> + enum expand_modifier modifier, rtx *alt_rtl,
> + bool inner_reference_p)
> {
> rtx ret;
>
> @@ -7897,7 +7861,8 @@ expand_expr_real (tree exp, rtx target,
> return ret ? ret : const0_rtx;
> }
>
> - ret = expand_expr_real_1 (exp, target, tmode, modifier, alt_rtl);
> + ret = expand_expr_real_1 (exp, target, tmode, modifier, alt_rtl,
> + inner_reference_p);
> return ret;
> }
>
> @@ -9190,7 +9155,8 @@ expand_expr_real_2 (sepops ops, rtx targ
>
> rtx
> expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
> - enum expand_modifier modifier, rtx *alt_rtl)
> + enum expand_modifier modifier, rtx *alt_rtl,
> + bool inner_reference_p)
> {
> rtx op0, op1, temp, decl_rtl;
> tree type;
> @@ -9336,7 +9302,7 @@ expand_expr_real_1 (tree exp, rtx target
>
> set_curr_insn_location (gimple_location (g));
> r = expand_expr_real (gimple_assign_rhs_to_tree (g), target,
> - tmode, modifier, NULL);
> + tmode, modifier, NULL, inner_reference_p);
> set_curr_insn_location (saved_loc);
> if (REG_P (r) && !REG_EXPR (r))
> set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (exp), r);
> @@ -9557,7 +9523,8 @@ expand_expr_real_1 (tree exp, rtx target
> case SAVE_EXPR:
> {
> tree val = treeop0;
> - rtx ret = expand_expr_real_1 (val, target, tmode, modifier, alt_rtl);
> + rtx ret = expand_expr_real_1 (val, target, tmode, modifier, alt_rtl,
> + inner_reference_p);
>
> if (!SAVE_EXPR_RESOLVED_P (exp))
> {
> @@ -9706,6 +9673,7 @@ expand_expr_real_1 (tree exp, rtx target
> MEM_VOLATILE_P (temp) = 1;
> if (modifier != EXPAND_WRITE
> && modifier != EXPAND_MEMORY
> + && !inner_reference_p
> && mode != BLKmode
> && align < GET_MODE_ALIGNMENT (mode))
> {
> @@ -9940,18 +9908,19 @@ expand_expr_real_1 (tree exp, rtx target
> computation, since it will need a temporary and TARGET is known
> to have to do. This occurs in unchecked conversion in Ada. */
> orig_op0 = op0
> - = expand_expr (tem,
> - (TREE_CODE (TREE_TYPE (tem)) == UNION_TYPE
> - && COMPLETE_TYPE_P (TREE_TYPE (tem))
> - && (TREE_CODE (TYPE_SIZE (TREE_TYPE (tem)))
> - != INTEGER_CST)
> - && modifier != EXPAND_STACK_PARM
> - ? target : NULL_RTX),
> - VOIDmode,
> - (modifier == EXPAND_INITIALIZER
> - || modifier == EXPAND_CONST_ADDRESS
> - || modifier == EXPAND_STACK_PARM)
> - ? modifier : EXPAND_NORMAL);
> + = expand_expr_real (tem,
> + (TREE_CODE (TREE_TYPE (tem)) == UNION_TYPE
> + && COMPLETE_TYPE_P (TREE_TYPE (tem))
> + && (TREE_CODE (TYPE_SIZE (TREE_TYPE (tem)))
> + != INTEGER_CST)
> + && modifier != EXPAND_STACK_PARM
> + ? target : NULL_RTX),
> + VOIDmode,
> + (modifier == EXPAND_INITIALIZER
> + || modifier == EXPAND_CONST_ADDRESS
> + || modifier == EXPAND_STACK_PARM)
> + ? modifier : EXPAND_NORMAL,
> + NULL, true);
>
>
> /* If the bitfield is volatile, we want to access it in the
> @@ -10302,17 +10271,18 @@ expand_expr_real_1 (tree exp, rtx target
> {
> /* See the normal_inner_ref case for the rationale. */
> orig_op0
> - = expand_expr (tem,
> - (TREE_CODE (TREE_TYPE (tem)) == UNION_TYPE
> - && (TREE_CODE (TYPE_SIZE (TREE_TYPE (tem)))
> - != INTEGER_CST)
> - && modifier != EXPAND_STACK_PARM
> - ? target : NULL_RTX),
> - VOIDmode,
> - (modifier == EXPAND_INITIALIZER
> - || modifier == EXPAND_CONST_ADDRESS
> - || modifier == EXPAND_STACK_PARM)
> - ? modifier : EXPAND_NORMAL);
> + = expand_expr_real (tem,
> + (TREE_CODE (TREE_TYPE (tem)) == UNION_TYPE
> + && (TREE_CODE (TYPE_SIZE (TREE_TYPE (tem)))
> + != INTEGER_CST)
> + && modifier != EXPAND_STACK_PARM
> + ? target : NULL_RTX),
> + VOIDmode,
> + (modifier == EXPAND_INITIALIZER
> + || modifier == EXPAND_CONST_ADDRESS
> + || modifier == EXPAND_STACK_PARM)
> + ? modifier : EXPAND_NORMAL,
> + NULL, true);
>
> if (MEM_P (orig_op0))
> {
> @@ -10339,8 +10309,8 @@ expand_expr_real_1 (tree exp, rtx target
> }
>
> if (!op0)
> - op0 = expand_expr (treeop0,
> - NULL_RTX, VOIDmode, modifier);
> + op0 = expand_expr_real (treeop0, NULL_RTX, VOIDmode, modifier,
> + NULL, inner_reference_p);
>
> /* If the input and output modes are both the same, we are done. */
> if (mode == GET_MODE (op0))
> @@ -10407,50 +10377,53 @@ expand_expr_real_1 (tree exp, rtx target
> op0 = copy_rtx (op0);
> set_mem_align (op0, MAX (MEM_ALIGN (op0), TYPE_ALIGN (type)));
> }
> - else if (mode != BLKmode
> - && MEM_ALIGN (op0) < GET_MODE_ALIGNMENT (mode)
> - /* If the target does have special handling for unaligned
> - loads of mode then use them. */
> - && ((icode = optab_handler (movmisalign_optab, mode))
> - != CODE_FOR_nothing))
> - {
> - rtx reg, insn;
> -
> - op0 = adjust_address (op0, mode, 0);
> - /* We've already validated the memory, and we're creating a
> - new pseudo destination. The predicates really can't
> - fail. */
> - reg = gen_reg_rtx (mode);
> -
> - /* Nor can the insn generator. */
> - insn = GEN_FCN (icode) (reg, op0);
> - emit_insn (insn);
> - return reg;
> - }
> - else if (STRICT_ALIGNMENT
> + else if (modifier != EXPAND_WRITE
> + && modifier != EXPAND_MEMORY
> + && !inner_reference_p
> && mode != BLKmode
> && MEM_ALIGN (op0) < GET_MODE_ALIGNMENT (mode))
> {
> - tree inner_type = TREE_TYPE (treeop0);
> - HOST_WIDE_INT temp_size
> - = MAX (int_size_in_bytes (inner_type),
> - (HOST_WIDE_INT) GET_MODE_SIZE (mode));
> - rtx new_rtx
> - = assign_stack_temp_for_type (mode, temp_size, type);
> - rtx new_with_op0_mode
> - = adjust_address (new_rtx, GET_MODE (op0), 0);
> -
> - gcc_assert (!TREE_ADDRESSABLE (exp));
> -
> - if (GET_MODE (op0) == BLKmode)
> - emit_block_move (new_with_op0_mode, op0,
> - GEN_INT (GET_MODE_SIZE (mode)),
> - (modifier == EXPAND_STACK_PARM
> - ? BLOCK_OP_CALL_PARM : BLOCK_OP_NORMAL));
> - else
> - emit_move_insn (new_with_op0_mode, op0);
> + /* If the target does have special handling for unaligned
> + loads of mode then use them. */
> + if ((icode = optab_handler (movmisalign_optab, mode))
> + != CODE_FOR_nothing)
> + {
> + rtx reg, insn;
>
> - op0 = new_rtx;
> + op0 = adjust_address (op0, mode, 0);
> + /* We've already validated the memory, and we're creating a
> + new pseudo destination. The predicates really can't
> + fail. */
> + reg = gen_reg_rtx (mode);
> +
> + /* Nor can the insn generator. */
> + insn = GEN_FCN (icode) (reg, op0);
> + emit_insn (insn);
> + return reg;
> + }
> + else if (STRICT_ALIGNMENT)
> + {
> + tree inner_type = TREE_TYPE (treeop0);
> + HOST_WIDE_INT temp_size
> + = MAX (int_size_in_bytes (inner_type),
> + (HOST_WIDE_INT) GET_MODE_SIZE (mode));
> + rtx new_rtx
> + = assign_stack_temp_for_type (mode, temp_size, type);
> + rtx new_with_op0_mode
> + = adjust_address (new_rtx, GET_MODE (op0), 0);
> +
> + gcc_assert (!TREE_ADDRESSABLE (exp));
> +
> + if (GET_MODE (op0) == BLKmode)
> + emit_block_move (new_with_op0_mode, op0,
> + GEN_INT (GET_MODE_SIZE (mode)),
> + (modifier == EXPAND_STACK_PARM
> + ? BLOCK_OP_CALL_PARM :
> BLOCK_OP_NORMAL));
> + else
> + emit_move_insn (new_with_op0_mode, op0);
> +
> + op0 = new_rtx;
> + }
> }
>
> op0 = adjust_address (op0, mode, 0);
> @@ -10550,7 +10523,7 @@ expand_expr_real_1 (tree exp, rtx target
> /* WITH_SIZE_EXPR expands to its first argument. The caller should
> have pulled out the size to use in whatever context it needed. */
> return expand_expr_real (treeop0, original_target, tmode,
> - modifier, alt_rtl);
> + modifier, alt_rtl, inner_reference_p);
>
> default:
> return expand_expr_real_2 (&ops, target, tmode, modifier);
> diff -rupN gcc-4.8-20150122/gcc/expr.h gcc-4.8-20150122.pr57748/gcc/expr.h
> --- gcc-4.8-20150122/gcc/expr.h 2014-04-04 16:09:23.000000000 +0200
> +++ gcc-4.8-20150122.pr57748/gcc/expr.h 2015-01-25 15:00:35.240949368 +0100
> @@ -41,7 +41,8 @@ along with GCC; see the file COPYING3.
> is a constant that is not a legitimate address.
> EXPAND_WRITE means we are only going to write to the resulting rtx.
> EXPAND_MEMORY means we are interested in a memory result, even if
> - the memory is constant and we could have propagated a constant value. */
> + the memory is constant and we could have propagated a constant value,
> + or the memory is unaligned on a STRICT_ALIGNMENT target. */
> enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
> EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
> EXPAND_MEMORY};
> @@ -428,9 +429,9 @@ extern rtx force_operand (rtx, rtx);
>
> /* Work horses for expand_expr. */
> extern rtx expand_expr_real (tree, rtx, enum machine_mode,
> - enum expand_modifier, rtx *);
> + enum expand_modifier, rtx *, bool);
> extern rtx expand_expr_real_1 (tree, rtx, enum machine_mode,
> - enum expand_modifier, rtx *);
> + enum expand_modifier, rtx *, bool);
> extern rtx expand_expr_real_2 (sepops, rtx, enum machine_mode,
> enum expand_modifier);
>
> @@ -441,13 +442,13 @@ static inline rtx
> expand_expr (tree exp, rtx target, enum machine_mode mode,
> enum expand_modifier modifier)
> {
> - return expand_expr_real (exp, target, mode, modifier, NULL);
> + return expand_expr_real (exp, target, mode, modifier, NULL, false);
> }
>
> static inline rtx
> expand_normal (tree exp)
> {
> - return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL);
> + return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL,
> false);
> }
>
> /* At the start of a function, record that we have no previously-pushed
> diff -rupN gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-1.c
> gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-1.c
> --- gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-1.c 1970-01-01
> 01:00:00.000000000 +0100
> +++ gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-1.c
> 2015-01-25 15:00:32.660962074 +0100
> @@ -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;
> +}
> diff -rupN gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-2.c
> gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-2.c
> --- gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-2.c 1970-01-01
> 01:00:00.000000000 +0100
> +++ gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-2.c
> 2015-01-25 15:00:32.660962074 +0100
> @@ -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;
> +}
> diff -rupN gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-3.c
> gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-3.c
> --- gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-3.c 1970-01-01
> 01:00:00.000000000 +0100
> +++ gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-3.c
> 2015-01-25 15:00:35.240949368 +0100
> @@ -0,0 +1,40 @@
> +/* PR middle-end/57748 */
> +/* { dg-do run } */
> +/* wrong code in expand_expr_real_1. */
> +
> +#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 (P *p)
> +{
> + if (p->b[0][0] != 3 || p->b[0][1] != 4)
> + abort ();
> +}
> +
> +void __attribute__((noinline, noclone))
> +foo (struct T *t)
> +{
> + V a = { 3, 4 };
> + t->s.b[0] = a;
> +}
> +
> +int
> +main ()
> +{
> + struct T *t = (struct T *) calloc (128, 1);
> +
> + foo (t);
> + check (&t->s);
> +
> + free (t);
> + return 0;
> +}
> diff -rupN gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-4.c
> gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-4.c
> --- gcc-4.8-20150122/gcc/testsuite/gcc.dg/torture/pr57748-4.c 1970-01-01
> 01:00:00.000000000 +0100
> +++ gcc-4.8-20150122.pr57748/gcc/testsuite/gcc.dg/torture/pr57748-4.c
> 2015-01-25 15:00:35.240949368 +0100
> @@ -0,0 +1,40 @@
> +/* PR middle-end/57748 */
> +/* { dg-do run } */
> +/* wrong code in expand_expr_real_1. */
> +
> +#include <stdlib.h>
> +
> +extern void abort (void);
> +
> +typedef long long V
> + __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
> +
> +typedef struct S { V b[1]; } P __attribute__((aligned (1)));
> +
> +struct __attribute__((packed)) T { char c; P s; };
> +
> +void __attribute__((noinline, noclone))
> +check (P *p)
> +{
> + if (p->b[1][0] != 3 || p->b[1][1] != 4)
> + abort ();
> +}
> +
> +void __attribute__((noinline, noclone))
> +foo (struct T *t)
> +{
> + V a = { 3, 4 };
> + t->s.b[1] = a;
> +}
> +
> +int
> +main ()
> +{
> + struct T *t = (struct T *) calloc (128, 1);
> +
> + foo (t);
> + check (&t->s);
> +
> + free (t);
> + return 0;
> +}
