diff mbox

patch to fix constant math - second small patch

Message ID 509BF65C.8050905@naturalbridge.com
State New
Headers show

Commit Message

Kenneth Zadeck Nov. 8, 2012, 6:13 p.m. UTC 
I have added the proper doc.  OK to commit?

Kenny


On 10/08/2012 05:06 AM, Richard Guenther wrote:
> On Sat, Oct 6, 2012 at 12:48 AM, Kenneth Zadeck
> <zadeck@naturalbridge.com> wrote:
>> This patch adds machinery to genmodes.c so that largest possible sizes of
>> various data structures can be determined at gcc build time.  These
>> functions create 3 symbols that are available in insn-modes.h:
>> MAX_BITSIZE_MODE_INT - the bitsize of the largest int.
>> MAX_BITSIZE_MODE_PARTIAL_INT - the bitsize of the largest partial int.
>> MAX_BITSIZE_MODE_ANY_INT - the largest bitsize of any kind of int.
> Ok.  Please document these macros in rtl.texi.
>
> Richard.
2012-11-8  Kenneth Zadeck <zadeck@naturalbridge.com>

   	* genmodes.c (emit_max_int): New function.
	(emit_insn_modes_h): Added call to emit_max_function.
	* doc/rtl.texi (MAX_BITSIZE_MODE_INT, MAX_BITSIZE_MODE_PARTIAL_INT,
	MAX_BITSIZE_MODE_ANY_INT, MAX_BITSIZE_MODE_ANY_MODE): Added doc.

Comments

Richard Biener Nov. 26, 2012, 3:30 p.m. UTC | #1 
On Thu, Nov 8, 2012 at 7:13 PM, Kenneth Zadeck <zadeck@naturalbridge.com> wrote:
> I have added the proper doc.  OK to commit?

Ok.

Thanks,
Richard.

> Kenny
>
>
>
> On 10/08/2012 05:06 AM, Richard Guenther wrote:
>>
>> On Sat, Oct 6, 2012 at 12:48 AM, Kenneth Zadeck
>> <zadeck@naturalbridge.com> wrote:
>>>
>>> This patch adds machinery to genmodes.c so that largest possible sizes of
>>> various data structures can be determined at gcc build time.  These
>>> functions create 3 symbols that are available in insn-modes.h:
>>> MAX_BITSIZE_MODE_INT - the bitsize of the largest int.
>>> MAX_BITSIZE_MODE_PARTIAL_INT - the bitsize of the largest partial int.
>>> MAX_BITSIZE_MODE_ANY_INT - the largest bitsize of any kind of int.
>>
>> Ok.  Please document these macros in rtl.texi.
>>
>> Richard.
>
>
diff mbox

Patch

diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index 07c480d..6842cb8 100644
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -1458,6 +1458,28 @@  Returns the number of units contained in a mode, i.e.,
 Returns the narrowest mode in mode class @var{c}.
 @end table
 
+The following 4 variables are defined on every target.   They can be
+used to allocate buffers that are guaranteed to be large enough to
+hold any value that can be represented on the target.   
+
+@table @code
+@findex MAX_BITSIZE_MODE_INT
+@item MAX_BITSIZE_MODE_INT
+The bitsize of the largest integer mode defined on the target.
+
+@findex MAX_BITSIZE_MODE_PARTIAL_INT
+@item MAX_BITSIZE_MODE_PARTIAL_INT
+The bitsize of the largest partial integer mode defined on the target.
+
+@findex MAX_BITSIZE_MODE_ANY_INT
+@item MAX_BITSIZE_MODE_ANY_INT
+The maximum of MAX_BITSIZE_MODE_INT and MAX_BITSIZE_MODE_PARTIAL_INT.
+
+@findex MAX_BITSIZE_MODE_ANY_MODE
+@item MAX_BITSIZE_MODE_ANY_MODE
+The bitsize of the largest mode on the target.   
+@end table
+
 @findex byte_mode
 @findex word_mode
 The global variables @code{byte_mode} and @code{word_mode} contain modes
diff --git a/gcc/genmodes.c b/gcc/genmodes.c
index d0095c3..3e63cc7 100644
--- a/gcc/genmodes.c
+++ b/gcc/genmodes.c
@@ -849,6 +849,38 @@  calc_wider_mode (void)
 
 #define print_closer() puts ("};")
 
+/* Compute the max bitsize of some of the classes of integers.  It may
+   be that there are needs for the other integer classes, and this
+   code is easy to extend.  */
+static void
+emit_max_int (void)
+{
+  unsigned int max, mmax;
+  struct mode_data *i;
+  int j;
+
+  puts ("");
+  for (max = 1, i = modes[MODE_INT]; i; i = i->next)
+    if (max < i->bytesize)
+	max = i->bytesize;
+  printf ("#define MAX_BITSIZE_MODE_INT %d*BITS_PER_UNIT\n", max);
+  mmax = max;
+  for (max = 1, i = modes[MODE_PARTIAL_INT]; i; i = i->next)
+    if (max < i->bytesize)
+	max = i->bytesize;
+  printf ("#define MAX_BITSIZE_MODE_PARTIAL_INT %d*BITS_PER_UNIT\n", max);
+  if (max > mmax)
+    mmax = max;
+  printf ("#define MAX_BITSIZE_MODE_ANY_INT %d*BITS_PER_UNIT\n", mmax);
+
+  mmax = 0;
+  for (j = 0; j < MAX_MODE_CLASS; j++)
+    for (i = modes[j]; i; i = i->next)
+      if (mmax < i->bytesize)
+	mmax = i->bytesize;
+  printf ("#define MAX_BITSIZE_MODE_ANY_MODE %d*BITS_PER_UNIT\n", mmax);
+}
+
 static void
 emit_insn_modes_h (void)
 {
@@ -913,6 +945,7 @@  enum machine_mode\n{");
 #endif
   printf ("#define CONST_MODE_IBIT%s\n", adj_ibit ? "" : " const");
   printf ("#define CONST_MODE_FBIT%s\n", adj_fbit ? "" : " const");
+  emit_max_int ();
   puts ("\
 \n\
 #endif /* insn-modes.h */");
diff --git a/gcc/machmode.def b/gcc/machmode.def
index 631015f..7186cb4 100644
--- a/gcc/machmode.def
+++ b/gcc/machmode.def
@@ -180,8 +180,11 @@  RANDOM_MODE (BLK);
 FRACTIONAL_INT_MODE (BI, 1, 1);
 
 /* Basic integer modes.  We go up to TI in generic code (128 bits).
-   The name OI is reserved for a 256-bit type (needed by some back ends).
-   FIXME TI shouldn't be generically available either.  */
+   TImode is needed here because the some front ends now genericly
+   support __int128.  If the front ends decide to generically support
+   larger types, then corresponding modes must be added here.  The
+   name OI is reserved for a 256-bit type (needed by some back ends).
+    */
 INT_MODE (QI, 1);
 INT_MODE (HI, 2);
 INT_MODE (SI, 4);