This patch adds a fixed_size_mode machine_mode wrapper
for modes that are known to have a fixed size. That applies
to all current modes, but future patches will add support for
variable-sized modes.
The use of this class should be pretty restricted. One important
use case is to hold the mode of static data, which can never be
variable-sized with current file formats. Another is to hold
the modes of registers involved in __builtin_apply and
__builtin_result, since those interfaces don't cope well with
variable-sized data.
The class can also be useful when reinterpreting the contents of
a fixed-length bit string as a different kind of value.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* machmode.h (fixed_size_mode): New class.
* rtl.h (get_pool_mode): Return fixed_size_mode.
* gengtype.c (main): Add fixed_size_mode.
* target.def (get_raw_result_mode): Return a fixed_size_mode.
(get_raw_arg_mode): Likewise.
* doc/tm.texi: Regenerate.
* targhooks.h (default_get_reg_raw_mode): Return a fixed_size_mode.
* targhooks.c (default_get_reg_raw_mode): Likewise.
* config/ia64/ia64.c (ia64_get_reg_raw_mode): Likewise.
* config/mips/mips.c (mips_get_reg_raw_mode): Likewise.
* config/msp430/msp430.c (msp430_get_raw_arg_mode): Likewise.
(msp430_get_raw_result_mode): Likewise.
* config/avr/avr-protos.h (regmask): Use as_a <fixed_side_mode>
* dbxout.c (dbxout_parms): Require fixed-size modes.
* expr.c (copy_blkmode_from_reg, copy_blkmode_to_reg): Likewise.
* gimple-ssa-store-merging.c (encode_tree_to_bitpos): Likewise.
* omp-low.c (lower_oacc_reductions): Likewise.
* simplify-rtx.c (simplify_immed_subreg): Take fixed_size_modes.
(simplify_subreg): Update accordingly.
* varasm.c (constant_descriptor_rtx::mode): Change to fixed_size_mode.
(force_const_mem): Update accordingly. Return NULL_RTX for modes
that aren't fixed-size.
(get_pool_mode): Return a fixed_size_mode.
(output_constant_pool_2): Take a fixed_size_mode.
Index: gcc/machmode.h
===================================================================
--- gcc/machmode.h 2017-09-15 14:47:33.184331588 +0100
+++ gcc/machmode.h 2017-10-23 11:42:52.014721093 +0100
@@ -652,6 +652,39 @@ GET_MODE_2XWIDER_MODE (const T &m)
extern const unsigned char mode_complex[NUM_MACHINE_MODES];
#define GET_MODE_COMPLEX_MODE(MODE) ((machine_mode) mode_complex[MODE])
+/* Represents a machine mode that must have a fixed size. The main
+ use of this class is to represent the modes of objects that always
+ have static storage duration, such as constant pool entries.
+ (No current target supports the concept of variable-size static data.) */
+class fixed_size_mode
+{
+public:
+ typedef mode_traits<fixed_size_mode>::from_int from_int;
+
+ ALWAYS_INLINE fixed_size_mode () {}
+ ALWAYS_INLINE fixed_size_mode (from_int m) : m_mode (machine_mode (m)) {}
+ ALWAYS_INLINE fixed_size_mode (const scalar_mode &m) : m_mode (m) {}
+ ALWAYS_INLINE fixed_size_mode (const scalar_int_mode &m) : m_mode (m) {}
+ ALWAYS_INLINE fixed_size_mode (const scalar_float_mode &m) : m_mode (m) {}
+ ALWAYS_INLINE fixed_size_mode (const scalar_mode_pod &m) : m_mode (m) {}
+ ALWAYS_INLINE fixed_size_mode (const scalar_int_mode_pod &m) : m_mode (m) {}
+ ALWAYS_INLINE fixed_size_mode (const complex_mode &m) : m_mode (m) {}
+ ALWAYS_INLINE operator machine_mode () const { return m_mode; }
+
+ static bool includes_p (machine_mode);
+
+protected:
+ machine_mode m_mode;
+};
+
+/* Return true if MODE has a fixed size. */
+
+inline bool
+fixed_size_mode::includes_p (machine_mode)
+{
+ return true;
+}
+
extern opt_machine_mode mode_for_size (unsigned int, enum mode_class, int);
/* Return the machine mode to use for a MODE_INT of SIZE bits, if one
Index: gcc/rtl.h
===================================================================
--- gcc/rtl.h 2017-10-23 11:42:47.297720974 +0100
+++ gcc/rtl.h 2017-10-23 11:42:52.015721094 +0100
@@ -3020,7 +3020,7 @@ extern rtx force_const_mem (machine_mode
struct function;
extern rtx get_pool_constant (const_rtx);
extern rtx get_pool_constant_mark (rtx, bool *);
-extern machine_mode get_pool_mode (const_rtx);
+extern fixed_size_mode get_pool_mode (const_rtx);
extern rtx simplify_subtraction (rtx);
extern void decide_function_section (tree);
Index: gcc/gengtype.c
===================================================================
--- gcc/gengtype.c 2017-05-23 19:29:56.919436344 +0100
+++ gcc/gengtype.c 2017-10-23 11:42:52.014721093 +0100
@@ -5197,6 +5197,7 @@ #define POS_HERE(Call) do { pos.file = t
POS_HERE (do_scalar_typedef ("JCF_u2", &pos));
POS_HERE (do_scalar_typedef ("void", &pos));
POS_HERE (do_scalar_typedef ("machine_mode", &pos));
+ POS_HERE (do_scalar_typedef ("fixed_size_mode", &pos));
POS_HERE (do_typedef ("PTR",
create_pointer (resolve_typedef ("void", &pos)),
&pos));
Index: gcc/target.def
===================================================================
--- gcc/target.def 2017-10-23 11:41:23.134456913 +0100
+++ gcc/target.def 2017-10-23 11:42:52.017721094 +0100
@@ -5021,7 +5021,7 @@ DEFHOOK
"This target hook returns the mode to be used when accessing raw return\
registers in @code{__builtin_return}. Define this macro if the value\
in @var{reg_raw_mode} is not correct.",
- machine_mode, (int regno),
+ fixed_size_mode, (int regno),
default_get_reg_raw_mode)
/* Return a mode wide enough to copy any argument value that might be
@@ -5031,7 +5031,7 @@ DEFHOOK
"This target hook returns the mode to be used when accessing raw argument\
registers in @code{__builtin_apply_args}. Define this macro if the value\
in @var{reg_raw_mode} is not correct.",
- machine_mode, (int regno),
+ fixed_size_mode, (int regno),
default_get_reg_raw_mode)
HOOK_VECTOR_END (calls)
Index: gcc/doc/tm.texi
===================================================================
--- gcc/doc/tm.texi 2017-10-23 11:41:22.175925023 +0100
+++ gcc/doc/tm.texi 2017-10-23 11:42:52.012721093 +0100
@@ -4536,11 +4536,11 @@ This macro has effect in @option{-fpcc-s
nothing when you use @option{-freg-struct-return} mode.
@end defmac
-@deftypefn {Target Hook} machine_mode TARGET_GET_RAW_RESULT_MODE (int
@var{regno})
+@deftypefn {Target Hook} fixed_size_mode TARGET_GET_RAW_RESULT_MODE (int
@var{regno})
This target hook returns the mode to be used when accessing raw return
registers in @code{__builtin_return}. Define this macro if the value in
@var{reg_raw_mode} is not correct.
@end deftypefn
-@deftypefn {Target Hook} machine_mode TARGET_GET_RAW_ARG_MODE (int @var{regno})
+@deftypefn {Target Hook} fixed_size_mode TARGET_GET_RAW_ARG_MODE (int
@var{regno})
This target hook returns the mode to be used when accessing raw argument
registers in @code{__builtin_apply_args}. Define this macro if the value in
@var{reg_raw_mode} is not correct.
@end deftypefn
Index: gcc/targhooks.h
===================================================================
--- gcc/targhooks.h 2017-10-02 09:08:43.318933786 +0100
+++ gcc/targhooks.h 2017-10-23 11:42:52.017721094 +0100
@@ -233,7 +233,7 @@ extern int default_jump_align_max_skip (
extern section * default_function_section(tree decl, enum node_frequency freq,
bool startup, bool exit);
extern machine_mode default_dwarf_frame_reg_mode (int);
-extern machine_mode default_get_reg_raw_mode (int);
+extern fixed_size_mode default_get_reg_raw_mode (int);
extern bool default_keep_leaf_when_profiled ();
extern void *default_get_pch_validity (size_t *);
Index: gcc/targhooks.c
===================================================================
--- gcc/targhooks.c 2017-10-23 11:41:23.195392846 +0100
+++ gcc/targhooks.c 2017-10-23 11:42:52.017721094 +0100
@@ -1834,10 +1834,12 @@ default_dwarf_frame_reg_mode (int regno)
/* To be used by targets where reg_raw_mode doesn't return the right
mode for registers used in apply_builtin_return and apply_builtin_arg. */
-machine_mode
+fixed_size_mode
default_get_reg_raw_mode (int regno)
{
- return reg_raw_mode[regno];
+ /* Targets must override this hook if the underlying register is
+ variable-sized. */
+ return as_a <fixed_size_mode> (reg_raw_mode[regno]);
}
/* Return true if a leaf function should stay leaf even with profiling
Index: gcc/config/ia64/ia64.c
===================================================================
--- gcc/config/ia64/ia64.c 2017-10-23 11:41:32.363050263 +0100
+++ gcc/config/ia64/ia64.c 2017-10-23 11:42:52.009721093 +0100
@@ -329,7 +329,7 @@ static tree ia64_fold_builtin (tree, int
static tree ia64_builtin_decl (unsigned, bool);
static reg_class_t ia64_preferred_reload_class (rtx, reg_class_t);
-static machine_mode ia64_get_reg_raw_mode (int regno);
+static fixed_size_mode ia64_get_reg_raw_mode (int regno);
static section * ia64_hpux_function_section (tree, enum node_frequency,
bool, bool);
@@ -11328,7 +11328,7 @@ ia64_dconst_0_375 (void)
return ia64_dconst_0_375_rtx;
}
-static machine_mode
+static fixed_size_mode
ia64_get_reg_raw_mode (int regno)
{
if (FR_REGNO_P (regno))
Index: gcc/config/mips/mips.c
===================================================================
--- gcc/config/mips/mips.c 2017-10-23 11:41:32.365050264 +0100
+++ gcc/config/mips/mips.c 2017-10-23 11:42:52.010721093 +0100
@@ -1132,7 +1132,6 @@ static rtx mips_find_pic_call_symbol (rt
static int mips_register_move_cost (machine_mode, reg_class_t,
reg_class_t);
static unsigned int mips_function_arg_boundary (machine_mode, const_tree);
-static machine_mode mips_get_reg_raw_mode (int regno);
static rtx mips_gen_const_int_vector_shuffle (machine_mode, int);
/* This hash table keeps track of implicit "mips16" and "nomips16" attributes
@@ -6111,7 +6110,7 @@ mips_function_arg_boundary (machine_mode
/* Implement TARGET_GET_RAW_RESULT_MODE and TARGET_GET_RAW_ARG_MODE. */
-static machine_mode
+static fixed_size_mode
mips_get_reg_raw_mode (int regno)
{
if (TARGET_FLOATXX && FP_REG_P (regno))
Index: gcc/config/msp430/msp430.c
===================================================================
--- gcc/config/msp430/msp430.c 2017-10-23 11:41:23.047405581 +0100
+++ gcc/config/msp430/msp430.c 2017-10-23 11:42:52.011721093 +0100
@@ -1398,16 +1398,17 @@ msp430_return_in_memory (const_tree ret_
#undef TARGET_GET_RAW_ARG_MODE
#define TARGET_GET_RAW_ARG_MODE msp430_get_raw_arg_mode
-static machine_mode
+static fixed_size_mode
msp430_get_raw_arg_mode (int regno)
{
- return (regno == ARG_POINTER_REGNUM) ? VOIDmode : Pmode;
+ return as_a <fixed_size_mode> (regno == ARG_POINTER_REGNUM
+ ? VOIDmode : Pmode);
}
#undef TARGET_GET_RAW_RESULT_MODE
#define TARGET_GET_RAW_RESULT_MODE msp430_get_raw_result_mode
-static machine_mode
+static fixed_size_mode
msp430_get_raw_result_mode (int regno ATTRIBUTE_UNUSED)
{
return Pmode;
Index: gcc/config/avr/avr-protos.h
===================================================================
--- gcc/config/avr/avr-protos.h 2017-10-23 11:41:22.812366984 +0100
+++ gcc/config/avr/avr-protos.h 2017-10-23 11:42:52.007721093 +0100
@@ -132,7 +132,7 @@ extern bool avr_casei_sequence_check_ope
static inline unsigned
regmask (machine_mode mode, unsigned regno)
{
- return ((1u << GET_MODE_SIZE (mode)) - 1) << regno;
+ return ((1u << GET_MODE_SIZE (as_a <fixed_size_mode> (mode))) - 1) << regno;
}
extern void avr_fix_inputs (rtx*, unsigned, unsigned);
Index: gcc/dbxout.c
===================================================================
--- gcc/dbxout.c 2017-10-10 17:55:22.088175460 +0100
+++ gcc/dbxout.c 2017-10-23 11:42:52.011721093 +0100
@@ -3393,12 +3393,16 @@ dbxout_parms (tree parms)
{
++debug_nesting;
emit_pending_bincls_if_required ();
+ fixed_size_mode rtl_mode, type_mode;
for (; parms; parms = DECL_CHAIN (parms))
if (DECL_NAME (parms)
&& TREE_TYPE (parms) != error_mark_node
&& DECL_RTL_SET_P (parms)
- && DECL_INCOMING_RTL (parms))
+ && DECL_INCOMING_RTL (parms)
+ /* We can't represent variable-sized types in this format. */
+ && is_a <fixed_size_mode> (TYPE_MODE (TREE_TYPE (parms)), &type_mode)
+ && is_a <fixed_size_mode> (GET_MODE (DECL_RTL (parms)), &rtl_mode))
{
tree eff_type;
char letter;
@@ -3555,10 +3559,9 @@ dbxout_parms (tree parms)
/* Make a big endian correction if the mode of the type of the
parameter is not the same as the mode of the rtl. */
if (BYTES_BIG_ENDIAN
- && TYPE_MODE (TREE_TYPE (parms)) != GET_MODE (DECL_RTL (parms))
- && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parms))) <
UNITS_PER_WORD)
- number += (GET_MODE_SIZE (GET_MODE (DECL_RTL (parms)))
- - GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parms))));
+ && type_mode != rtl_mode
+ && GET_MODE_SIZE (type_mode) < UNITS_PER_WORD)
+ number += GET_MODE_SIZE (rtl_mode) - GET_MODE_SIZE (type_mode);
}
else
/* ??? We don't know how to represent this argument. */
Index: gcc/expr.c
===================================================================
--- gcc/expr.c 2017-10-23 11:42:34.915720660 +0100
+++ gcc/expr.c 2017-10-23 11:42:52.013721093 +0100
@@ -2628,9 +2628,10 @@ copy_blkmode_from_reg (rtx target, rtx s
rtx src = NULL, dst = NULL;
unsigned HOST_WIDE_INT bitsize = MIN (TYPE_ALIGN (type), BITS_PER_WORD);
unsigned HOST_WIDE_INT bitpos, xbitpos, padding_correction = 0;
- machine_mode mode = GET_MODE (srcreg);
- machine_mode tmode = GET_MODE (target);
- machine_mode copy_mode;
+ /* No current ABI uses variable-sized modes to pass a BLKmnode type. */
+ fixed_size_mode mode = as_a <fixed_size_mode> (GET_MODE (srcreg));
+ fixed_size_mode tmode = as_a <fixed_size_mode> (GET_MODE (target));
+ fixed_size_mode copy_mode;
/* BLKmode registers created in the back-end shouldn't have survived. */
gcc_assert (mode != BLKmode);
@@ -2728,19 +2729,21 @@ copy_blkmode_from_reg (rtx target, rtx s
}
}
-/* Copy BLKmode value SRC into a register of mode MODE. Return the
+/* Copy BLKmode value SRC into a register of mode MODE_IN. Return the
register if it contains any data, otherwise return null.
This is used on targets that return BLKmode values in registers. */
rtx
-copy_blkmode_to_reg (machine_mode mode, tree src)
+copy_blkmode_to_reg (machine_mode mode_in, tree src)
{
int i, n_regs;
unsigned HOST_WIDE_INT bitpos, xbitpos, padding_correction = 0, bytes;
unsigned int bitsize;
rtx *dst_words, dst, x, src_word = NULL_RTX, dst_word = NULL_RTX;
- machine_mode dst_mode;
+ /* No current ABI uses variable-sized modes to pass a BLKmnode type. */
+ fixed_size_mode mode = as_a <fixed_size_mode> (mode_in);
+ fixed_size_mode dst_mode;
gcc_assert (TYPE_MODE (TREE_TYPE (src)) == BLKmode);
Index: gcc/gimple-ssa-store-merging.c
===================================================================
--- gcc/gimple-ssa-store-merging.c 2017-10-09 11:50:52.446411111 +0100
+++ gcc/gimple-ssa-store-merging.c 2017-10-23 11:42:52.014721093 +0100
@@ -401,8 +401,11 @@ encode_tree_to_bitpos (tree expr, unsign
The awkwardness comes from the fact that bitpos is counted from the
most significant bit of a byte. */
+ /* We must be dealing with fixed-size data at this point, since the
+ total size is also fixed. */
+ fixed_size_mode mode = as_a <fixed_size_mode> (TYPE_MODE (TREE_TYPE (expr)));
/* Allocate an extra byte so that we have space to shift into. */
- unsigned int byte_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))) + 1;
+ unsigned int byte_size = GET_MODE_SIZE (mode) + 1;
unsigned char *tmpbuf = XALLOCAVEC (unsigned char, byte_size);
memset (tmpbuf, '\0', byte_size);
/* The store detection code should only have allowed constants that are
Index: gcc/omp-low.c
===================================================================
--- gcc/omp-low.c 2017-10-10 17:55:22.100175459 +0100
+++ gcc/omp-low.c 2017-10-23 11:42:52.015721094 +0100
@@ -5067,8 +5067,10 @@ lower_oacc_reductions (location_t loc, t
v1 = v2 = v3 = var;
/* Determine position in reduction buffer, which may be used
- by target. */
- machine_mode mode = TYPE_MODE (TREE_TYPE (var));
+ by target. The parser has ensured that this is not a
+ variable-sized type. */
+ fixed_size_mode mode
+ = as_a <fixed_size_mode> (TYPE_MODE (TREE_TYPE (var)));
unsigned align = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
offset = (offset + align - 1) & ~(align - 1);
tree off = build_int_cst (sizetype, offset);
Index: gcc/simplify-rtx.c
===================================================================
--- gcc/simplify-rtx.c 2017-10-23 11:41:41.550050496 +0100
+++ gcc/simplify-rtx.c 2017-10-23 11:42:52.016721094 +0100
@@ -48,8 +48,6 @@ #define HWI_SIGN_EXTEND(low) \
static rtx neg_const_int (machine_mode, const_rtx);
static bool plus_minus_operand_p (const_rtx);
static rtx simplify_plus_minus (enum rtx_code, machine_mode, rtx, rtx);
-static rtx simplify_immed_subreg (machine_mode, rtx, machine_mode,
- unsigned int);
static rtx simplify_associative_operation (enum rtx_code, machine_mode,
rtx, rtx);
static rtx simplify_relational_operation_1 (enum rtx_code, machine_mode,
@@ -5802,8 +5800,8 @@ simplify_ternary_operation (enum rtx_cod
and then repacking them again for OUTERMODE. */
static rtx
-simplify_immed_subreg (machine_mode outermode, rtx op,
- machine_mode innermode, unsigned int byte)
+simplify_immed_subreg (fixed_size_mode outermode, rtx op,
+ fixed_size_mode innermode, unsigned int byte)
{
enum {
value_bit = 8,
@@ -6171,7 +6169,18 @@ simplify_subreg (machine_mode outermode,
|| CONST_DOUBLE_AS_FLOAT_P (op)
|| GET_CODE (op) == CONST_FIXED
|| GET_CODE (op) == CONST_VECTOR)
- return simplify_immed_subreg (outermode, op, innermode, byte);
+ {
+ /* simplify_immed_subreg deconstructs OP into bytes and constructs
+ the result from bytes, so it only works if the sizes of the modes
+ are known at compile time. Cases that apply to general modes
+ should be handled here before calling simplify_immed_subreg. */
+ fixed_size_mode fs_outermode, fs_innermode;
+ if (is_a <fixed_size_mode> (outermode, &fs_outermode)
+ && is_a <fixed_size_mode> (innermode, &fs_innermode))
+ return simplify_immed_subreg (fs_outermode, op, fs_innermode, byte);
+
+ return NULL_RTX;
+ }
/* Changing mode twice with SUBREG => just change it once,
or not at all if changing back op starting mode. */
Index: gcc/varasm.c
===================================================================
--- gcc/varasm.c 2017-10-23 11:42:34.927720660 +0100
+++ gcc/varasm.c 2017-10-23 11:42:52.018721094 +0100
@@ -3584,7 +3584,7 @@ struct GTY((chain_next ("%h.next"), for_
rtx constant;
HOST_WIDE_INT offset;
hashval_t hash;
- machine_mode mode;
+ fixed_size_mode mode;
unsigned int align;
int labelno;
int mark;
@@ -3760,10 +3760,11 @@ simplify_subtraction (rtx x)
}
/* Given a constant rtx X, make (or find) a memory constant for its value
- and return a MEM rtx to refer to it in memory. */
+ and return a MEM rtx to refer to it in memory. IN_MODE is the mode
+ of X. */
rtx
-force_const_mem (machine_mode mode, rtx x)
+force_const_mem (machine_mode in_mode, rtx x)
{
struct constant_descriptor_rtx *desc, tmp;
struct rtx_constant_pool *pool;
@@ -3772,6 +3773,11 @@ force_const_mem (machine_mode mode, rtx
hashval_t hash;
unsigned int align;
constant_descriptor_rtx **slot;
+ fixed_size_mode mode;
+
+ /* We can't force variable-sized objects to memory. */
+ if (!is_a <fixed_size_mode> (in_mode, &mode))
+ return NULL_RTX;
/* If we're not allowed to drop X into the constant pool, don't. */
if (targetm.cannot_force_const_mem (mode, x))
@@ -3881,7 +3887,7 @@ get_pool_constant_mark (rtx addr, bool *
/* Similar, return the mode. */
-machine_mode
+fixed_size_mode
get_pool_mode (const_rtx addr)
{
return SYMBOL_REF_CONSTANT (addr)->mode;
@@ -3901,7 +3907,7 @@ constant_pool_empty_p (void)
in MODE with known alignment ALIGN. */
static void
-output_constant_pool_2 (machine_mode mode, rtx x, unsigned int align)
+output_constant_pool_2 (fixed_size_mode mode, rtx x, unsigned int align)
{
switch (GET_MODE_CLASS (mode))
{
