This patch makes expand_debug_expr track polynomial memory offsets.
It simplifies the handling of the case in which the reference is not
to the first byte of the base, which seemed non-trivial enough to
make it worth splitting out as a separate patch.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* tree.h (get_inner_reference): Add a version that returns the
offset and size as poly_int64_pods rather than HOST_WIDE_INTs.
* cfgexpand.c (expand_debug_expr): Track polynomial offsets. Simply
the case in which bitpos is not associated with the first byte.
Index: gcc/tree.h
===================================================================
--- gcc/tree.h 2017-10-23 17:11:40.253962440 +0100
+++ gcc/tree.h 2017-10-23 17:18:40.711668346 +0100
@@ -5610,6 +5610,17 @@ extern bool complete_ctor_at_level_p (co
the access position and size. */
extern tree get_inner_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
tree *, machine_mode *, int *, int *, int *);
+/* Temporary. */
+inline tree
+get_inner_reference (tree exp, poly_int64_pod *pbitsize,
+ poly_int64_pod *pbitpos, tree *poffset,
+ machine_mode *pmode, int *punsignedp,
+ int *preversep, int *pvolatilep)
+{
+ return get_inner_reference (exp, &pbitsize->coeffs[0], &pbitpos->coeffs[0],
+ poffset, pmode, punsignedp, preversep,
+ pvolatilep);
+}
extern tree build_personality_function (const char *);
Index: gcc/cfgexpand.c
===================================================================
--- gcc/cfgexpand.c 2017-10-23 17:16:59.700268356 +0100
+++ gcc/cfgexpand.c 2017-10-23 17:18:40.711668346 +0100
@@ -4450,7 +4450,7 @@ expand_debug_expr (tree exp)
case VIEW_CONVERT_EXPR:
{
machine_mode mode1;
- HOST_WIDE_INT bitsize, bitpos;
+ poly_int64 bitsize, bitpos;
tree offset;
int reversep, volatilep = 0;
tree tem
@@ -4458,7 +4458,7 @@ expand_debug_expr (tree exp)
&unsignedp, &reversep, &volatilep);
rtx orig_op0;
- if (bitsize == 0)
+ if (known_zero (bitsize))
return NULL;
orig_op0 = op0 = expand_debug_expr (tem);
@@ -4501,19 +4501,14 @@ expand_debug_expr (tree exp)
if (mode1 == VOIDmode)
/* Bitfield. */
mode1 = smallest_int_mode_for_size (bitsize);
- if (bitpos >= BITS_PER_UNIT)
+ poly_int64 bytepos = bits_to_bytes_round_down (bitpos);
+ if (maybe_nonzero (bytepos))
{
- op0 = adjust_address_nv (op0, mode1, bitpos / BITS_PER_UNIT);
- bitpos %= BITS_PER_UNIT;
+ op0 = adjust_address_nv (op0, mode1, bytepos);
+ bitpos = num_trailing_bits (bitpos);
}
- else if (bitpos < 0)
- {
- HOST_WIDE_INT units
- = (-bitpos + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
- op0 = adjust_address_nv (op0, mode1, -units);
- bitpos += units * BITS_PER_UNIT;
- }
- else if (bitpos == 0 && bitsize == GET_MODE_BITSIZE (mode))
+ else if (known_zero (bitpos)
+ && must_eq (bitsize, GET_MODE_BITSIZE (mode)))
op0 = adjust_address_nv (op0, mode, 0);
else if (GET_MODE (op0) != mode1)
op0 = adjust_address_nv (op0, mode1, 0);
@@ -4524,17 +4519,18 @@ expand_debug_expr (tree exp)
set_mem_attributes (op0, exp, 0);
}
- if (bitpos == 0 && mode == GET_MODE (op0))
+ if (known_zero (bitpos) && mode == GET_MODE (op0))
return op0;
- if (bitpos < 0)
+ if (may_lt (bitpos, 0))
return NULL;
if (GET_MODE (op0) == BLKmode)
return NULL;
- if ((bitpos % BITS_PER_UNIT) == 0
- && bitsize == GET_MODE_BITSIZE (mode1))
+ poly_int64 bytepos;
+ if (multiple_p (bitpos, BITS_PER_UNIT, &bytepos)
+ && must_eq (bitsize, GET_MODE_BITSIZE (mode1)))
{
machine_mode opmode = GET_MODE (op0);
@@ -4547,12 +4543,11 @@ expand_debug_expr (tree exp)
debug stmts). The gen_subreg below would rightfully
crash, and the address doesn't really exist, so just
drop it. */
- if (bitpos >= GET_MODE_BITSIZE (opmode))
+ if (must_ge (bitpos, GET_MODE_BITSIZE (opmode)))
return NULL;
- if ((bitpos % GET_MODE_BITSIZE (mode)) == 0)
- return simplify_gen_subreg (mode, op0, opmode,
- bitpos / BITS_PER_UNIT);
+ if (multiple_p (bitpos, GET_MODE_BITSIZE (mode)))
+ return simplify_gen_subreg (mode, op0, opmode, bytepos);
}
return simplify_gen_ternary (SCALAR_INT_MODE_P (GET_MODE (op0))
@@ -4562,7 +4557,8 @@ expand_debug_expr (tree exp)
GET_MODE (op0) != VOIDmode
? GET_MODE (op0)
: TYPE_MODE (TREE_TYPE (tem)),
- op0, GEN_INT (bitsize), GEN_INT (bitpos));
+ op0, gen_int_mode (bitsize, word_mode),
+ gen_int_mode (bitpos, word_mode));
}
case ABS_EXPR:
