This fixes PRs 52080 (unexpected access to adjacent fields for bitfield
access), 52097 (ICE with the C++ memory model enabled) and 48124
(wrong code accessing adjacent objects). It's an unchanged re-post
of the RFCs I sent out during stage4 (it now re-uses the pointer
for DECL_QUALIFIER instead of enlarging each FIELD_DECL).
The core of the patch is computation of an underlying FIELD_DECL that
should be used for the access of bitfield FIELD_DECLs (or at least
constrain such access). This computation is done when laying out
a RECORD_TYPE, for simplicity after it has been layed out. This
FIELD_DECL is currently only used to constrain bitfield accesses,
so it employs a 1:1 mapping. I plan to change this to a 1:n
(1 bitfield group, multiple possibly overlapping representatives)
when resuming work on lowering bitfield accesses on the gimple level
(to address PR48696).
This patch also completely replaces get_bit_range (which is where
PR52097 ICEs) by a trivial implementation.
There is PR52134 which will make this patch cause 1 gnat regression.
Bootstrapped and tested on
{x86_64,i586,s390,s390x,ia64,ppc,ppc64}-suse-linux-gnu.
If there are no serious objections (or reasonable requests) I plan
to go forward with this version early next week.
If you have a weird target it might be good to double-check codegen
quality for bitfield stores (which is what you should have done
with the C++ memory model enabled already).
Thanks,
Richard.
2012-03-05 Richard Guenther <rguent...@suse.de>
* tree.h (DECL_BIT_FIELD_REPRESENTATIVE): New define.
* stor-layout.c (start_bitfield_representative): New function.
(finish_bitfield_representative): Likewise.
(finish_bitfield_layout): Likewise.
(finish_record_layout): Call finish_bitfield_layout.
* tree-streamer-in.c (lto_input_ts_field_decl_tree_pointers):
Stream DECL_BIT_FIELD_REPRESENTATIVE.
* tree-streamer-out.c (write_ts_field_decl_tree_pointers): Likewise.
PR middle-end/52080
PR middle-end/52097
PR middle-end/48124
* expr.c (get_bit_range): Unconditionally extract bitrange
from DECL_BIT_FIELD_REPRESENTATIVE.
(expand_assignment): Adjust call to get_bit_range.
* gimplify.c (gimplify_expr): Translate bitfield accesses
to BIT_FIELD_REFs of the representative.
* tree-sra.c (create_access_replacement): Only rename the
replacement if we can rewrite it into SSA form. Properly
mark register typed replacements that we cannot rewrite
with TREE_ADDRESSABLE.
* gcc.dg/torture/pr48124-1.c: New testcase.
* gcc.dg/torture/pr48124-2.c: Likewise.
* gcc.dg/torture/pr48124-3.c: Likewise.
* gcc.dg/torture/pr48124-4.c: Likewise.
Index: gcc/stor-layout.c
===================================================================
*** gcc/stor-layout.c.orig 2012-02-21 12:59:35.000000000 +0100
--- gcc/stor-layout.c 2012-02-24 12:53:11.000000000 +0100
*************** finalize_type_size (tree type)
*** 1722,1727 ****
--- 1722,1908 ----
}
}
+ /* Return a new underlying object for a bitfield started with FIELD. */
+
+ static tree
+ start_bitfield_representative (tree field)
+ {
+ tree repr = make_node (FIELD_DECL);
+ DECL_FIELD_OFFSET (repr) = DECL_FIELD_OFFSET (field);
+ /* Force the representative to begin at an BITS_PER_UNIT aligned
+ boundary - C++ may use tail-padding of a base object to
+ continue packing bits so the bitfield region does not start
+ at bit zero (see g++.dg/abi/bitfield5.C for example).
+ Unallocated bits may happen for other reasons as well,
+ for example Ada which allows explicit bit-granular structure layout. */
+ DECL_FIELD_BIT_OFFSET (repr)
+ = size_binop (BIT_AND_EXPR,
+ DECL_FIELD_BIT_OFFSET (field),
+ bitsize_int (~(BITS_PER_UNIT - 1)));
+ SET_DECL_OFFSET_ALIGN (repr, DECL_OFFSET_ALIGN (field));
+ DECL_SIZE (repr) = DECL_SIZE (field);
+ DECL_PACKED (repr) = DECL_PACKED (field);
+ DECL_CONTEXT (repr) = DECL_CONTEXT (field);
+ return repr;
+ }
+
+ /* Finish up a bitfield group that was started by creating the underlying
+ object REPR with the last fied in the bitfield group FIELD. */
+
+ static void
+ finish_bitfield_representative (tree repr, tree field)
+ {
+ unsigned HOST_WIDE_INT bitsize, maxbitsize, modesize;
+ enum machine_mode mode = BLKmode;
+ tree nextf, size;
+
+ size = size_diffop (DECL_FIELD_OFFSET (field),
+ DECL_FIELD_OFFSET (repr));
+ gcc_assert (host_integerp (size, 1));
+ bitsize = (tree_low_cst (size, 1) * BITS_PER_UNIT
+ + tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)
+ - tree_low_cst (DECL_FIELD_BIT_OFFSET (repr), 1)
+ + tree_low_cst (DECL_SIZE (field), 1));
+
+ /* Now nothing tells us how to pad out bitsize ... */
+ nextf = DECL_CHAIN (field);
+ while (nextf && TREE_CODE (nextf) != FIELD_DECL)
+ nextf = DECL_CHAIN (nextf);
+ if (nextf)
+ {
+ tree maxsize;
+ /* If there was an error, the field may be not layed out
+ correctly. Don't bother to do anything. */
+ if (TREE_TYPE (nextf) == error_mark_node)
+ return;
+ maxsize = size_diffop (DECL_FIELD_OFFSET (nextf),
+ DECL_FIELD_OFFSET (repr));
+ gcc_assert (host_integerp (maxsize, 1));
+ maxbitsize = (tree_low_cst (maxsize, 1) * BITS_PER_UNIT
+ + tree_low_cst (DECL_FIELD_BIT_OFFSET (nextf), 1)
+ - tree_low_cst (DECL_FIELD_BIT_OFFSET (repr), 1));
+ }
+ else
+ {
+ /* ??? If you consider that tail-padding of this struct might be
+ re-used when deriving from it we cannot really do the following
+ and thus need to set maxsize to bitsize? */
+ tree maxsize = size_diffop (TYPE_SIZE_UNIT (DECL_CONTEXT (field)),
+ DECL_FIELD_OFFSET (repr));
+ gcc_assert (host_integerp (maxsize, 1));
+ maxbitsize = (tree_low_cst (maxsize, 1) * BITS_PER_UNIT
+ - tree_low_cst (DECL_FIELD_BIT_OFFSET (repr), 1));
+ }
+
+ /* Only if we don't artificially break up the representative in
+ the middle of a large bitfield with different possibly
+ overlapping representatives. And all representatives start
+ at byte offset. */
+ gcc_assert (maxbitsize % BITS_PER_UNIT == 0);
+
+ /* Round up bitsize to multiples of BITS_PER_UNIT. */
+ bitsize = (bitsize + BITS_PER_UNIT - 1) & ~(BITS_PER_UNIT - 1);
+
+ /* Find the smallest nice mode to use.
+ ??? Possibly use get_best_mode with appropriate arguments instead
+ (which would eventually require splitting representatives here). */
+ for (modesize = bitsize; modesize <= maxbitsize; modesize += BITS_PER_UNIT)
+ {
+ mode = mode_for_size (modesize, MODE_INT, 1);
+ if (mode != BLKmode)
+ break;
+ }
+
+ if (mode == BLKmode)
+ {
+ /* We really want a BLKmode representative only as a last resort,
+ considering the member b in
+ struct { int a : 7; int b : 17; int c; } __attribute__((packed));
+ Otherwise we simply want to split the representative up
+ allowing for overlaps within the bitfield region as required for
+ struct { int a : 7; int b : 7; int c : 10; int d; }
__attribute__((packed));
+ [0, 15] HImode for a and b, [8, 23] HImode for c. */
+ DECL_SIZE (repr) = bitsize_int (bitsize);
+ DECL_SIZE_UNIT (repr) = size_int (bitsize / BITS_PER_UNIT);
+ DECL_MODE (repr) = BLKmode;
+ TREE_TYPE (repr) = build_array_type_nelts (unsigned_char_type_node,
+ bitsize / BITS_PER_UNIT);
+ }
+ else
+ {
+ DECL_SIZE (repr) = bitsize_int (modesize);
+ DECL_SIZE_UNIT (repr) = size_int (modesize / BITS_PER_UNIT);
+ DECL_MODE (repr) = mode;
+ TREE_TYPE (repr) = lang_hooks.types.type_for_mode (mode, 1);
+ }
+
+ /* Remember whether the bitfield group is at the end of the
+ structure or not. */
+ DECL_CHAIN (repr) = nextf;
+ }
+
+ /* Compute and set FIELD_DECLs for the underlying objects we should
+ use for bitfield access for the structure layed out with RLI. */
+
+ static void
+ finish_bitfield_layout (record_layout_info rli)
+ {
+ tree field, prev;
+ tree repr = NULL_TREE;
+
+ /* Unions would be special, for the ease of type-punning optimizations
+ we could use the underlying type as hint for the representative
+ if the bitfield would fit and the representative would not exceed
+ the union in size. */
+ if (TREE_CODE (rli->t) != RECORD_TYPE)
+ return;
+
+ for (prev = NULL_TREE, field = TYPE_FIELDS (rli->t);
+ field; field = DECL_CHAIN (field))
+ {
+ if (TREE_CODE (field) != FIELD_DECL)
+ continue;
+
+ /* In the C++ memory model, consecutive bit fields in a structure are
+ considered one memory location and updating a memory location
+ may not store into adjacent memory locations. */
+ if (!repr
+ && DECL_BIT_FIELD_TYPE (field))
+ {
+ /* Start new representative. */
+ repr = start_bitfield_representative (field);
+ }
+ else if (repr
+ && ! DECL_BIT_FIELD_TYPE (field))
+ {
+ /* Finish off new representative. */
+ finish_bitfield_representative (repr, prev);
+ repr = NULL_TREE;
+ }
+ else if (DECL_BIT_FIELD_TYPE (field))
+ {
+ /* Zero-size bitfields finish off a representative and
+ do not have a representative themselves. This is
+ required by the C++ memory model. */
+ if (integer_zerop (DECL_SIZE (field)))
+ {
+ finish_bitfield_representative (repr, prev);
+ repr = NULL_TREE;
+ }
+ }
+ else
+ continue;
+
+ if (repr)
+ DECL_BIT_FIELD_REPRESENTATIVE (field) = repr;
+
+ prev = field;
+ }
+
+ if (repr)
+ finish_bitfield_representative (repr, prev);
+ }
+
/* Do all of the work required to layout the type indicated by RLI,
once the fields have been laid out. This function will call `free'
for RLI, unless FREE_P is false. Passing a value other than false
*************** finish_record_layout (record_layout_info
*** 1742,1747 ****
--- 1923,1931 ----
/* Perform any last tweaks to the TYPE_SIZE, etc. */
finalize_type_size (rli->t);
+ /* Compute bitfield representatives. */
+ finish_bitfield_layout (rli);
+
/* Propagate TYPE_PACKED to variants. With C++ templates,
handle_packed_attribute is too early to do this. */
for (variant = TYPE_NEXT_VARIANT (rli->t); variant;
Index: gcc/tree.h
===================================================================
*** gcc/tree.h.orig 2012-02-21 12:59:35.000000000 +0100
--- gcc/tree.h 2012-02-24 12:52:39.000000000 +0100
*************** struct GTY(()) tree_decl_with_rtl {
*** 3021,3026 ****
--- 3021,3031 ----
#define DECL_BIT_FIELD_TYPE(NODE) \
(FIELD_DECL_CHECK (NODE)->field_decl.bit_field_type)
+ /* In a FIELD_DECL of a RECORD_TYPE, this is a pointer to the storage
+ representative FIELD_DECL. */
+ #define DECL_BIT_FIELD_REPRESENTATIVE(NODE) \
+ (FIELD_DECL_CHECK (NODE)->field_decl.qualifier)
+
/* For a FIELD_DECL in a QUAL_UNION_TYPE, records the expression, which
if nonzero, indicates that the field occupies the type. */
#define DECL_QUALIFIER(NODE) (FIELD_DECL_CHECK (NODE)->field_decl.qualifier)
Index: gcc/tree-sra.c
===================================================================
*** gcc/tree-sra.c.orig 2012-02-21 12:59:35.000000000 +0100
--- gcc/tree-sra.c 2012-02-24 12:52:39.000000000 +0100
*************** create_access_replacement (struct access
*** 1922,1934 ****
repl = create_tmp_var (access->type, "SR");
add_referenced_var (repl);
! if (rename)
mark_sym_for_renaming (repl);
! if (!access->grp_partial_lhs
! && (TREE_CODE (access->type) == COMPLEX_TYPE
! || TREE_CODE (access->type) == VECTOR_TYPE))
! DECL_GIMPLE_REG_P (repl) = 1;
DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
DECL_ARTIFICIAL (repl) = 1;
--- 1922,1940 ----
repl = create_tmp_var (access->type, "SR");
add_referenced_var (repl);
! if (!access->grp_partial_lhs
! && rename)
mark_sym_for_renaming (repl);
! if (TREE_CODE (access->type) == COMPLEX_TYPE
! || TREE_CODE (access->type) == VECTOR_TYPE)
! {
! if (!access->grp_partial_lhs)
! DECL_GIMPLE_REG_P (repl) = 1;
! }
! else if (access->grp_partial_lhs
! && is_gimple_reg_type (access->type))
! TREE_ADDRESSABLE (repl) = 1;
DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
DECL_ARTIFICIAL (repl) = 1;
Index: gcc/tree-cfg.c
===================================================================
*** gcc/tree-cfg.c.orig 2012-02-24 12:29:18.000000000 +0100
--- gcc/tree-cfg.c 2012-02-24 12:52:39.000000000 +0100
*************** verify_expr (tree *tp, int *walk_subtree
*** 2879,2895 ****
error ("invalid position or size operand to BIT_FIELD_REF");
return t;
}
! else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
! && (TYPE_PRECISION (TREE_TYPE (t))
! != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
{
error ("integral result type precision does not match "
"field size of BIT_FIELD_REF");
return t;
}
! if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
! && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
! != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
{
error ("mode precision of non-integral result does not "
"match field size of BIT_FIELD_REF");
--- 2879,2897 ----
error ("invalid position or size operand to BIT_FIELD_REF");
return t;
}
! if (INTEGRAL_TYPE_P (TREE_TYPE (t))
! && (TYPE_PRECISION (TREE_TYPE (t))
! != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
{
error ("integral result type precision does not match "
"field size of BIT_FIELD_REF");
return t;
}
! else if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
! && !AGGREGATE_TYPE_P (TREE_TYPE (t))
! && TYPE_MODE (TREE_TYPE (t)) != BLKmode
! && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
! != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
{
error ("mode precision of non-integral result does not "
"match field size of BIT_FIELD_REF");
Index: gcc/expr.c
===================================================================
*** gcc/expr.c.orig 2012-02-21 12:59:35.000000000 +0100
--- gcc/expr.c 2012-02-24 12:52:39.000000000 +0100
*************** optimize_bitfield_assignment_op (unsigne
*** 4439,4551 ****
/* In the C++ memory model, consecutive bit fields in a structure are
considered one memory location.
! Given a COMPONENT_REF, this function returns the bit range of
! consecutive bits in which this COMPONENT_REF belongs in. The
! values are returned in *BITSTART and *BITEND. If either the C++
! memory model is not activated, or this memory access is not thread
! visible, 0 is returned in *BITSTART and *BITEND.
!
! EXP is the COMPONENT_REF.
! INNERDECL is the actual object being referenced.
! BITPOS is the position in bits where the bit starts within the structure.
! BITSIZE is size in bits of the field being referenced in EXP.
!
! For example, while storing into FOO.A here...
!
! struct {
! BIT 0:
! unsigned int a : 4;
! unsigned int b : 1;
! BIT 8:
! unsigned char c;
! unsigned int d : 6;
! } foo;
!
! ...we are not allowed to store past <b>, so for the layout above, a
! range of 0..7 (because no one cares if we store into the
! padding). */
static void
get_bit_range (unsigned HOST_WIDE_INT *bitstart,
unsigned HOST_WIDE_INT *bitend,
! tree exp, tree innerdecl,
! HOST_WIDE_INT bitpos, HOST_WIDE_INT bitsize)
{
! tree field, record_type, fld;
! bool found_field = false;
! bool prev_field_is_bitfield;
gcc_assert (TREE_CODE (exp) == COMPONENT_REF);
! /* If other threads can't see this value, no need to restrict stores. */
! if (ALLOW_STORE_DATA_RACES
! || ((TREE_CODE (innerdecl) == MEM_REF
! || TREE_CODE (innerdecl) == TARGET_MEM_REF)
! && !ptr_deref_may_alias_global_p (TREE_OPERAND (innerdecl, 0)))
! || (DECL_P (innerdecl)
! && ((TREE_CODE (innerdecl) == VAR_DECL
! && DECL_THREAD_LOCAL_P (innerdecl))
! || !TREE_STATIC (innerdecl))))
{
*bitstart = *bitend = 0;
return;
}
! /* Bit field we're storing into. */
! field = TREE_OPERAND (exp, 1);
! record_type = DECL_FIELD_CONTEXT (field);
!
! /* Count the contiguous bitfields for the memory location that
! contains FIELD. */
! *bitstart = 0;
! prev_field_is_bitfield = true;
! for (fld = TYPE_FIELDS (record_type); fld; fld = DECL_CHAIN (fld))
! {
! tree t, offset;
! enum machine_mode mode;
! int unsignedp, volatilep;
!
! if (TREE_CODE (fld) != FIELD_DECL)
! continue;
!
! t = build3 (COMPONENT_REF, TREE_TYPE (exp),
! unshare_expr (TREE_OPERAND (exp, 0)),
! fld, NULL_TREE);
! get_inner_reference (t, &bitsize, &bitpos, &offset,
! &mode, &unsignedp, &volatilep, true);
!
! if (field == fld)
! found_field = true;
!
! if (DECL_BIT_FIELD_TYPE (fld) && bitsize > 0)
! {
! if (prev_field_is_bitfield == false)
! {
! *bitstart = bitpos;
! prev_field_is_bitfield = true;
! }
! }
! else
! {
! prev_field_is_bitfield = false;
! if (found_field)
! break;
! }
! }
! gcc_assert (found_field);
! if (fld)
! {
! /* We found the end of the bit field sequence. Include the
! padding up to the next field and be done. */
! *bitend = bitpos - 1;
! }
! else
! {
! /* If this is the last element in the structure, include the padding
! at the end of structure. */
! *bitend = TREE_INT_CST_LOW (TYPE_SIZE (record_type)) - 1;
! }
}
/* Returns true if the MEM_REF REF refers to an object that does not
--- 4439,4481 ----
/* In the C++ memory model, consecutive bit fields in a structure are
considered one memory location.
! Given a COMPONENT_REF EXP at bit position BITPOS, this function
! returns the bit range of consecutive bits in which this COMPONENT_REF
! belongs in. The values are returned in *BITSTART and *BITEND.
! If the access does not need to be restricted 0 is returned in
! *BITSTART and *BITEND. */
static void
get_bit_range (unsigned HOST_WIDE_INT *bitstart,
unsigned HOST_WIDE_INT *bitend,
! tree exp,
! HOST_WIDE_INT bitpos)
{
! unsigned HOST_WIDE_INT bitoffset;
! tree field, repr, offset;
gcc_assert (TREE_CODE (exp) == COMPONENT_REF);
! field = TREE_OPERAND (exp, 1);
! repr = DECL_BIT_FIELD_REPRESENTATIVE (field);
! /* If we do not have a DECL_BIT_FIELD_REPRESENTATIVE there is no
! need to limit the range we can access. */
! if (!repr)
{
*bitstart = *bitend = 0;
return;
}
! /* Compute the adjustment to bitpos from the offset of the field
! relative to the representative. */
! offset = size_diffop (DECL_FIELD_OFFSET (field),
! DECL_FIELD_OFFSET (repr));
! bitoffset = (tree_low_cst (offset, 1) * BITS_PER_UNIT
! + tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)
! - tree_low_cst (DECL_FIELD_BIT_OFFSET (repr), 1));
! *bitstart = bitpos - bitoffset;
! *bitend = *bitstart + tree_low_cst (DECL_SIZE (repr), 1) - 1;
}
/* Returns true if the MEM_REF REF refers to an object that does not
*************** expand_assignment (tree to, tree from, b
*** 4673,4680 ****
if (TREE_CODE (to) == COMPONENT_REF
&& DECL_BIT_FIELD_TYPE (TREE_OPERAND (to, 1)))
! get_bit_range (&bitregion_start, &bitregion_end,
! to, tem, bitpos, bitsize);
/* If we are going to use store_bit_field and extract_bit_field,
make sure to_rtx will be safe for multiple use. */
--- 4603,4609 ----
if (TREE_CODE (to) == COMPONENT_REF
&& DECL_BIT_FIELD_TYPE (TREE_OPERAND (to, 1)))
! get_bit_range (&bitregion_start, &bitregion_end, to, bitpos);
/* If we are going to use store_bit_field and extract_bit_field,
make sure to_rtx will be safe for multiple use. */
Index: gcc/testsuite/gcc.dg/torture/pr48124-1.c
===================================================================
*** /dev/null 1970-01-01 00:00:00.000000000 +0000
--- gcc/testsuite/gcc.dg/torture/pr48124-1.c 2012-02-24 12:52:39.000000000
+0100
***************
*** 0 ****
--- 1,33 ----
+ /* { dg-do run } */
+ /* { dg-options "-fno-toplevel-reorder" } */
+
+ extern void abort (void);
+
+ struct S
+ {
+ signed a : 26;
+ signed b : 16;
+ signed c : 10;
+ volatile signed d : 14;
+ };
+
+ static struct S e = { 0, 0, 0, 1 };
+ static int f = 1;
+
+ void __attribute__((noinline))
+ foo (void)
+ {
+ e.d = 0;
+ f = 2;
+ }
+
+ int
+ main ()
+ {
+ if (e.a || e.b || e.c || e.d != 1 || f != 1)
+ abort ();
+ foo ();
+ if (e.a || e.b || e.c || e.d || f != 2)
+ abort ();
+ return 0;
+ }
Index: gcc/testsuite/gcc.dg/torture/pr48124-2.c
===================================================================
*** /dev/null 1970-01-01 00:00:00.000000000 +0000
--- gcc/testsuite/gcc.dg/torture/pr48124-2.c 2012-02-24 12:52:39.000000000
+0100
***************
*** 0 ****
--- 1,27 ----
+ /* { dg-do run } */
+
+ extern void abort (void);
+
+ static volatile struct S0 {
+ short f3[9];
+ unsigned f8 : 15;
+ } s = {1};
+ static unsigned short sh = 0x1234;
+
+ struct S0 a, b;
+ int vi = 0;
+
+ void func_4()
+ {
+ s.f8 |= 1;
+ sh = 15;
+ if (vi) a = b;
+ }
+
+ int main()
+ {
+ func_4();
+ if (sh != 15)
+ abort ();
+ return 0;
+ }
Index: gcc/testsuite/gcc.dg/torture/pr48124-3.c
===================================================================
*** /dev/null 1970-01-01 00:00:00.000000000 +0000
--- gcc/testsuite/gcc.dg/torture/pr48124-3.c 2012-02-24 12:52:39.000000000
+0100
***************
*** 0 ****
--- 1,32 ----
+ /* { dg-do run } */
+
+ extern void abort (void);
+ struct S1
+ {
+ int f0;
+ int:1;
+ int f3;
+ int:1;
+ int:0;
+ int f6:1;
+ };
+ int g_13 = 1;
+ volatile struct S1 g_118 = {
+ 1
+ };
+
+ void __attribute__((noinline))
+ func_46 ()
+ {
+ for (g_13 = 0; g_13 >= 0; g_13 -= 1)
+ g_118.f6 = 0;
+ }
+
+ int
+ main ()
+ {
+ func_46 ();
+ if (g_13 != -1)
+ abort ();
+ return 0;
+ }
Index: gcc/testsuite/gcc.dg/torture/pr48124-4.c
===================================================================
*** /dev/null 1970-01-01 00:00:00.000000000 +0000
--- gcc/testsuite/gcc.dg/torture/pr48124-4.c 2012-02-24 12:52:39.000000000
+0100
***************
*** 0 ****
--- 1,28 ----
+ /* { dg-do run } */
+
+ extern void abort (void);
+ struct S1 {
+ unsigned f0, f1;
+ unsigned short f2, f3;
+ unsigned f4 : 16;
+ unsigned f5, f6;
+ volatile unsigned f7 : 28;
+ };
+ static struct S1 g_76;
+ static struct S1 g_245 = {0,0,0,0,0,0,0,1};
+ static signed char g_323 = 0x80;
+ static void func_1(void)
+ {
+ g_245.f7 &= 1;
+ for (g_323 = 0; g_323 <= -1; g_323 -= 2) {
+ g_76 = g_76;
+ g_76.f4 ^= 11;
+ }
+ }
+ int main()
+ {
+ func_1();
+ if (g_323 != 0 || g_245.f7 != 1)
+ abort ();
+ return 0;
+ }
Index: gcc/tree-streamer-in.c
===================================================================
*** gcc/tree-streamer-in.c.orig 2012-02-21 12:59:35.000000000 +0100
--- gcc/tree-streamer-in.c 2012-02-24 12:52:39.000000000 +0100
*************** lto_input_ts_field_decl_tree_pointers (s
*** 640,646 ****
{
DECL_FIELD_OFFSET (expr) = stream_read_tree (ib, data_in);
DECL_BIT_FIELD_TYPE (expr) = stream_read_tree (ib, data_in);
! /* Do not stream DECL_QUALIFIER, it is useless after gimplification. */
DECL_FIELD_BIT_OFFSET (expr) = stream_read_tree (ib, data_in);
DECL_FCONTEXT (expr) = stream_read_tree (ib, data_in);
}
--- 640,646 ----
{
DECL_FIELD_OFFSET (expr) = stream_read_tree (ib, data_in);
DECL_BIT_FIELD_TYPE (expr) = stream_read_tree (ib, data_in);
! DECL_BIT_FIELD_REPRESENTATIVE (expr) = stream_read_tree (ib, data_in);
DECL_FIELD_BIT_OFFSET (expr) = stream_read_tree (ib, data_in);
DECL_FCONTEXT (expr) = stream_read_tree (ib, data_in);
}
Index: gcc/tree-streamer-out.c
===================================================================
*** gcc/tree-streamer-out.c.orig 2012-02-21 12:59:35.000000000 +0100
--- gcc/tree-streamer-out.c 2012-02-24 12:52:39.000000000 +0100
*************** write_ts_field_decl_tree_pointers (struc
*** 552,558 ****
{
stream_write_tree (ob, DECL_FIELD_OFFSET (expr), ref_p);
stream_write_tree (ob, DECL_BIT_FIELD_TYPE (expr), ref_p);
! /* Do not stream DECL_QUALIFIER, it is useless after gimplification. */
stream_write_tree (ob, DECL_FIELD_BIT_OFFSET (expr), ref_p);
stream_write_tree (ob, DECL_FCONTEXT (expr), ref_p);
}
--- 552,558 ----
{
stream_write_tree (ob, DECL_FIELD_OFFSET (expr), ref_p);
stream_write_tree (ob, DECL_BIT_FIELD_TYPE (expr), ref_p);
! stream_write_tree (ob, DECL_BIT_FIELD_REPRESENTATIVE (expr), ref_p);
stream_write_tree (ob, DECL_FIELD_BIT_OFFSET (expr), ref_p);
stream_write_tree (ob, DECL_FCONTEXT (expr), ref_p);
}
