On Aug 29, 2013, at 12:36 AM, Richard Biener <rguent...@suse.de> wrote:
> On Wed, 28 Aug 2013, Mike Stump wrote:
>
>> On Aug 28, 2013, at 3:22 AM, Richard Biener <rguent...@suse.de> wrote:
>>> Btw, rtl.h still wastes space with
>>>
>>> struct GTY((variable_size)) hwivec_def {
>>> int num_elem; /* number of elements */
>>> HOST_WIDE_INT elem[1];
>>> };
>>>
>>> struct GTY((chain_next ("RTX_NEXT (&%h)"),
>>> chain_prev ("RTX_PREV (&%h)"), variable_size)) rtx_def {
>>> ...
>>> /* The first element of the operands of this rtx.
>>> The number of operands and their types are controlled
>>> by the `code' field, according to rtl.def. */
>>> union u {
>>> rtunion fld[1];
>>> HOST_WIDE_INT hwint[1];
>>> struct block_symbol block_sym;
>>> struct real_value rv;
>>> struct fixed_value fv;
>>> struct hwivec_def hwiv;
>>> } GTY ((special ("rtx_def"), desc ("GET_CODE (&%0)"))) u;
>>> };
>>>
>>> there are 32bits available before the union. If you don't use
>>> those for num_elem then all wide-ints will at least take as
>>> much space as DOUBLE_INTs originally took - and large ints
>>> that would have required DOUBLE_INTs in the past will now
>>> require more space than before. Which means your math
>>> motivating the 'num_elem' encoding stuff is wrong. With
>>> moving 'num_elem' before u you can even re-use the hwint
>>> field in the union as the existing double-int code does
>>> (which in fact could simply do the encoding trick in the
>>> old CONST_DOUBLE scheme, similar for the tree INTEGER_CST
>>> container).
>>
>> So, HOST_WIDE_INT is likely 64 bits, and likely is 64 bit aligned. The
>> base (stuff before the union) is 32 bits. There is a 32 bit gap, even
>> if not used before the HOST_WIDE_INT elem. We place the num_elem is
>> this gap.
>
> No, you don't. You place num_elem 64bit aligned _after_ the gap.
> And you have another 32bit gap, as you say, before elem.
Ah, ok, I get it, thanks for the explanation. This removes the second gap
creator and puts the field into the gap before the u union.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index ce40347..143f298 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -594,7 +594,7 @@ immed_wide_int_const (const wide_int &v, enum machine_mode
mode)
/* It is so tempting to just put the mode in here. Must control
myself ... */
PUT_MODE (value, VOIDmode);
- HWI_PUT_NUM_ELEM (CONST_WIDE_INT_VEC (value), len);
+ CWI_PUT_NUM_ELEM (value, len);
for (i = 0; i < len; i++)
CONST_WIDE_INT_ELT (value, i) = v.elt (i);
diff --git a/gcc/print-rtl.c b/gcc/print-rtl.c
index 3620bd6..8dad9f6 100644
--- a/gcc/print-rtl.c
+++ b/gcc/print-rtl.c
@@ -616,7 +616,7 @@ print_rtx (const_rtx in_rtx)
case CONST_WIDE_INT:
if (! flag_simple)
fprintf (outfile, " ");
- hwivec_output_hex (outfile, CONST_WIDE_INT_VEC (in_rtx));
+ cwi_output_hex (outfile, in_rtx);
break;
#endif
diff --git a/gcc/read-rtl.c b/gcc/read-rtl.c
index 707ef3f..c198b5b 100644
--- a/gcc/read-rtl.c
+++ b/gcc/read-rtl.c
@@ -1352,7 +1352,6 @@ read_rtx_code (const char *code_name)
read_name (&name);
validate_const_wide_int (name.string);
{
- hwivec hwiv;
const char *s = name.string;
int len;
int index = 0;
@@ -1377,7 +1376,6 @@ read_rtx_code (const char *code_name)
return_rtx = const_wide_int_alloc (wlen);
- hwiv = CONST_WIDE_INT_VEC (return_rtx);
while (pos > 0)
{
#if HOST_BITS_PER_WIDE_INT == 64
@@ -1385,13 +1383,13 @@ read_rtx_code (const char *code_name)
#else
sscanf (s + pos, "%8" HOST_WIDE_INT_PRINT "x", &wi);
#endif
- XHWIVEC_ELT (hwiv, index++) = wi;
+ CWI_ELT (return_rtx, index++) = wi;
pos -= gs;
}
strncpy (buf, s, gs - pos);
buf [gs - pos] = 0;
sscanf (buf, "%" HOST_WIDE_INT_PRINT "x", &wi);
- XHWIVEC_ELT (hwiv, index++) = wi;
+ CWI_ELT (return_rtx, index++) = wi;
/* TODO: After reading, do we want to canonicalize with:
value = lookup_const_wide_int (value); ? */
}
diff --git a/gcc/rtl.c b/gcc/rtl.c
index 074e425..b913d0d 100644
--- a/gcc/rtl.c
+++ b/gcc/rtl.c
@@ -225,18 +225,18 @@ rtx_alloc_stat (RTX_CODE code MEM_STAT_DECL)
return rtx_alloc_stat_v (code PASS_MEM_STAT, 0);
}
-/* Write the wide constant OP0 to OUTFILE. */
+/* Write the wide constant X to OUTFILE. */
void
-hwivec_output_hex (FILE *outfile, const_hwivec op0)
+cwi_output_hex (FILE *outfile, const_rtx x)
{
- int i = HWI_GET_NUM_ELEM (op0);
+ int i = CWI_GET_NUM_ELEM (x);
gcc_assert (i > 0);
- if (XHWIVEC_ELT (op0, i-1) == 0)
+ if (CWI_ELT (x, i-1) == 0)
fprintf (outfile, "0x");
- fprintf (outfile, HOST_WIDE_INT_PRINT_HEX, XHWIVEC_ELT (op0, --i));
+ fprintf (outfile, HOST_WIDE_INT_PRINT_HEX, CWI_ELT (x, --i));
while (--i >= 0)
- fprintf (outfile, HOST_WIDE_INT_PRINT_PADDED_HEX, XHWIVEC_ELT (op0, i));
+ fprintf (outfile, HOST_WIDE_INT_PRINT_PADDED_HEX, CWI_ELT (x, i));
}
@@ -843,12 +843,12 @@ rtl_check_failed_block_symbol (const char *file, int
line, const char *func)
/* XXX Maybe print the vector? */
void
-hwivec_check_failed_bounds (const_hwivec r, int n, const char *file, int line,
- const char *func)
+cwi_check_failed_bounds (const_rtx x, int n, const char *file, int line,
+ const char *func)
{
internal_error
("RTL check: access of hwi elt %d of vector with last elt %d in %s, at
%s:%d",
- n, GET_NUM_ELEM (r) - 1, func, trim_filename (file), line);
+ n, CWI_GET_NUM_ELEM (x) - 1, func, trim_filename (file), line);
}
/* XXX Maybe print the vector? */
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 6b45b41..a218ee9 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -252,12 +252,14 @@ struct GTY(()) object_block {
};
struct GTY((variable_size)) hwivec_def {
- int num_elem; /* number of elements */
HOST_WIDE_INT elem[1];
};
-#define HWI_GET_NUM_ELEM(HWIVEC) ((HWIVEC)->num_elem)
-#define HWI_PUT_NUM_ELEM(HWIVEC, NUM) ((HWIVEC)->num_elem = (NUM))
+/* Number of elements of the HWIVEC if RTX is a CONST_WIDE_INT. */
+#define CWI_GET_NUM_ELEM(RTX) \
+ ((int)RTL_FLAG_CHECK1("CWI_GET_NUM_ELEM", (RTX),
CONST_WIDE_INT)->u2.num_elem)
+#define CWI_PUT_NUM_ELEM(RTX, NUM) \
+ (RTL_FLAG_CHECK1("CWI_PUT_NUM_ELEM", (RTX), CONST_WIDE_INT)->u2.num_elem =
(NUM))
/* RTL expression ("rtx"). */
@@ -345,6 +347,14 @@ struct GTY((chain_next ("RTX_NEXT (&%h)"),
1 in a VALUE or DEBUG_EXPR is NO_LOC_P in var-tracking.c. */
unsigned return_val : 1;
+ union {
+ /* RTXs are free to use up to 32 bit from here. */
+
+ /* In a CONST_WIDE_INT (aka hwivec_def), this is the number of
HOST_WIDE_INTs
+ in the hwivec_def. */
+ unsigned GTY ((tag ("CONST_WIDE_INT"))) num_elem:32;
+ } GTY ((desc ("GET_CODE (&%0)"))) u2;
+
/* The first element of the operands of this rtx.
The number of operands and their types are controlled
by the `code' field, according to rtl.def. */
@@ -643,12 +653,14 @@ equality. */
__FUNCTION__); \
&_rtx->u.hwint[_n]; }))
-#define XHWIVEC_ELT(HWIVEC, I) __extension__ \
-(*({ __typeof (HWIVEC) const _hwivec = (HWIVEC); const int _i = (I); \
- if (_i < 0 || _i >= HWI_GET_NUM_ELEM (_hwivec)) \
- hwivec_check_failed_bounds (_hwivec, _i, __FILE__, __LINE__, \
- __FUNCTION__); \
- &_hwivec->elem[_i]; }))
+#define CWI_ELT(RTX, I) __extension__ \
+(*({ __typeof (RTX) const _rtx = (RTX);
\
+ int _max = CWI_GET_NUM_ELEM (_rtx); \
+ const int _i = (I); \
+ if (_i < 0 || _i >= _max) \
+ cwi_check_failed_bounds (_rtx, _i, __FILE__, __LINE__, \
+ __FUNCTION__); \
+ &_rtx->u.hwiv.elem[_i]; }))
#define XCWINT(RTX, N, C) __extension__
\
(*({ __typeof (RTX) const _rtx = (RTX);
\
@@ -711,8 +723,8 @@ extern void rtl_check_failed_code_mode (const_rtx, enum
rtx_code, enum machine_m
ATTRIBUTE_NORETURN;
extern void rtl_check_failed_block_symbol (const char *, int, const char *)
ATTRIBUTE_NORETURN;
-extern void hwivec_check_failed_bounds (const_hwivec, int, const char *, int,
- const char *)
+extern void cwi_check_failed_bounds (const_rtx, int, const char *, int,
+ const char *)
ATTRIBUTE_NORETURN;
extern void rtvec_check_failed_bounds (const_rtvec, int, const char *, int,
const char *)
@@ -726,7 +738,7 @@ extern void rtvec_check_failed_bounds (const_rtvec, int,
const char *, int,
#define RTL_CHECKC2(RTX, N, C1, C2) ((RTX)->u.fld[N])
#define RTVEC_ELT(RTVEC, I) ((RTVEC)->elem[I])
#define XWINT(RTX, N) ((RTX)->u.hwint[N])
-#define XHWIVEC_ELT(HWIVEC, I) ((HWIVEC)->elem[I])
+#define CWI_ELT(RTX, I) ((RTX)->u.hwiv.elem[I])
#define XCWINT(RTX, N, C) ((RTX)->u.hwint[N])
#define XCMWINT(RTX, N, C, M) ((RTX)->u.hwint[N])
#define XCNMWINT(RTX, N, C, M) ((RTX)->u.hwint[N])
@@ -1223,8 +1235,8 @@ rhs_regno (const_rtx x)
CONST_WIDE_INT_ELT gets one of the elements. 0 is the least
significant HOST_WIDE_INT. */
#define CONST_WIDE_INT_VEC(RTX) HWIVEC_CHECK (RTX, CONST_WIDE_INT)
-#define CONST_WIDE_INT_NUNITS(RTX) HWI_GET_NUM_ELEM (CONST_WIDE_INT_VEC (RTX))
-#define CONST_WIDE_INT_ELT(RTX, N) XHWIVEC_ELT (CONST_WIDE_INT_VEC (RTX), N)
+#define CONST_WIDE_INT_NUNITS(RTX) CWI_GET_NUM_ELEM (RTX)
+#define CONST_WIDE_INT_ELT(RTX, N) CWI_ELT (RTX, N)
/* For a CONST_DOUBLE:
#if TARGET_SUPPORTS_WIDE_INT == 0
@@ -1982,7 +1994,7 @@ extern void end_sequence (void);
#if TARGET_SUPPORTS_WIDE_INT == 0
extern double_int rtx_to_double_int (const_rtx);
#endif
-extern void hwivec_output_hex (FILE *, const_hwivec);
+extern void cwi_output_hex (FILE *, const_rtx);
#ifndef GENERATOR_FILE
extern rtx immed_wide_int_const (const wide_int &cst, enum machine_mode mode);
#endif
