Development release 20120425 of mspgcc is now available.
This is a development release. It begins the path to 20-bit support by
adding int20_t and uint20_t: these are implemented under the covers by a new
type attribute __a20__ which indicates that the 32-bit type it attaches to
maintains only 20 bits of precision, uses a single 20-bit register, but two
words when placed in memory. It is available via <stdint.h> when compiling
with -mcpu=430x (which is implied by any -mmcu option that identifies a 430X
CPU).
The purpose of this type is primarily to simplify validation of the sorts of
operations that will be needed for 20-bit pointers, but it may also come in
handy when a little extra precision is required. An example of use:
#include <inttypes.h>
#include <stdio.h>
uint16_t vals[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9,
0x8001, 0x8002, 0x8002, 0x8004, 0x8005,
0xf000 };
void main (void)
{
int i;
uint20_t sv;
sv = 0;
for (i = 0; i < sizeof(vals)/sizeof(*vals); ++i) {
sv += vals[i];
printf("Add %04" PRIx16 " produces %05" PRIx20 "\n", vals[i], sv);
}
}
Add 0001 produces 00001
Add 0002 produces 00003
Add 0003 produces 00006
Add 0004 produces 0000a
Add 0005 produces 0000f
Add 0006 produces 00015
Add 0007 produces 0001c
Add 0008 produces 00024
Add 0009 produces 0002d
Add 8001 produces 0802e
Add 8002 produces 10030
Add 8002 produces 18032
Add 8004 produces 20036
Add 8005 produces 2803b
Add f000 produces 3703b
(Careful experimenters will notice that the generated code in this case
includes unnecessary register moves. Should somebody care to document this
in a ticket, I'll try to take a look; at the moment, correctness is what I'm
after, and speed can follow at a later time.)
More examples are in the mspgcc repository in the tests/master branch.
Companion to attribute __a20__ is a pair of function attributes __sr16__ and
__sr20__, which cause any callee-saved registers within the function to
be preserved to 16 (default, historical) or 20 (new) bits. As a general
rule (but not enforced), if you are using __a20__ values you'll want to add
-msr20 to your compiler flags so that the values aren't clobbered in
function calls (including interrupts).
Finally, this release introduces the mechanism by which compilation features
can be identified within the source at compile-time. The __MSP430X__
preprocessor symbol, historically defined only for CPUX-compatible MCUs, now
contains the same value as __MSP430_CPU__ but also encodes bits indicating
CPUX-related compilation features. For example:
#if __MSP430X__ & __MSP430_CPUX_FEATURE_SR20__
pushm.a #2, r11
#elif __MSP430X__
pushm #2, r11
#else /* CPUX */
push r11
push r10
#endif /* CPUX */
A persistent version of the above documentation, as well as an outline of
the similar attributes and compiler options that will enable use of 20-bit
values as pointers, will be appearing on the mspgcc wiki over the next week
or so.
The patch bundle for 20120425 is available at:
https://sourceforge.net/projects/mspgcc/files/mspgcc/DEVEL-4.7.x
The tag workspace/release/20120425 in
git://mspgcc.git.sourceforge.net/gitroot/mspgcc/mspgcc checks out a
workspace configured for this release. The tag workspace/master checks out
a workspace configured for the development series.
Downstream packagers: please don't bundle this. It's so experimental, only
people who are build from source should be playing with it. The stable series
remains LTS-20120406.
As usual, please submit problems as tracker tickets at:
https://sourceforge.net/tracker/?group_id=42303&atid=432701
Summary of changes in mspgcc release 20120425 since release 20120407
binutils: no changes
gcc: changes from gcc-4.7.0-20120407 to gcc-4.7.0-20120425:
- 5ff0c47 [2012-04-25 03:36:18 -0500] Update DEV-PHASE for release
- 150e88f [2012-04-24 14:48:07 -0500] Anticipatory patch for PR
middle-end/53104
- 086a2c8 [2012-04-24 13:54:22 -0500] Anticipatory patch for PR
middle-end/53103
- 519cc89 [2012-04-11 18:10:41 -0500] Anticipatory patch for PR
middle-end/52940
- 770d836 [2012-04-09 17:29:18 -0500] Anticipatory patch for PR
middle-end/52919
- cdf7d6e [2012-04-03 16:44:16 -0500] Anticipatory patch for PR
middle-end/52856
- cffacc3 [2012-04-25 02:31:46 -0500] Update for release
- fcf6556 [2012-04-23 17:40:08 -0500] Support extend from psi, and
truncate to/from psi
- c9c18ad [2012-04-24 13:56:32 -0500] Support zero-extend load byte
into PSI as well as HI reg
- a0a3396 [2012-04-10 17:29:34 -0500] SF 3512818 rework rotate to use
430x repeat feature
- fccc558 [2012-04-09 20:12:20 -0500] Support shift to PREC-1 for PSImode
- 1e49a19 [2012-04-11 11:14:37 -0500] Add CPUX repeated instruction support
- 13e444c [2012-04-08 11:42:29 -0500] Support saving 20-bit registers
within functions
- fad4a26 [2012-04-03 12:35:29 -0500] Partially working support for
a20 comparisons
- 2e42b9f [2012-04-03 09:36:53 -0500] Correct instruction lengths for
extended instructions
- f67b68c [2012-04-03 08:11:05 -0500] Incomplete support for passing
a20 args around in functions
- 64b825f [2012-04-02 17:59:55 -0500] Add PSImode as 20-bit integer
via __a20__ attribute on long int
- 926fe46 [2012-04-02 14:55:47 -0500] Uniformly use TARGET_CPUX when
mcu has CPUX support
gdb: no changes
msp430-libc: changes from msp430libc-20120224 to msp430libc-20120425:
- f7aa387 [2012-04-25 02:41:38 -0500] Regenerate
- 5503065 [2012-04-25 02:41:38 -0500] Update version number and release notes
- 3904c1d [2012-04-08 15:13:10 -0500] Add -msr20 recognition to
assembly sources
- 5851e48 [2012-03-06 08:54:22 -0600] Add int20_t support
msp430mcu: changes from msp430mcu-20120407 to msp430mcu-20120425:
- efd322e [2012-04-25 02:42:37 -0500] Regenerate
- 56f216c [2012-04-25 02:42:30 -0500] Update version number and release notes
- c4cde23 [2012-04-03 09:53:36 -0500] Add __a20__ to 20-bit
peripheral register declarations
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