[Bug c++/79241] error wen compiling -Os, OK with another optimizations
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79241 --- Comment #9 from night_ghost at ykoctpa dot ru --- Seems that I missed a bugfix patch. Where I can download fixed GCC 5.4 to test?
[Bug target/70676] suboptimal code generation on AVR
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70676 night_ghost at ykoctpa dot ru changed: What|Removed |Added Status|RESOLVED|REOPENED Resolution|INVALID |--- --- Comment #9 from night_ghost at ykoctpa dot ru --- Really this is a best way to fix bugs! Just ignore them - like an ostrich, hiding head in the sand.
[Bug c++/79241] error wen compiling -Os, OK with another optimizations
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79241 --- Comment #7 from night_ghost at ykoctpa dot ru --- Created attachment 40779 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40779=edit testcase ii and console log. If I change from -Os to any other mode then it compiles OK
[Bug c++/79241] error wen compiling -Os, OK with another optimizations
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79241 --- Comment #5 from night_ghost at ykoctpa dot ru --- I'll try to exclude maximum of unneeded code from testcase and then upload it.
[Bug c++/79241] error wen compiling -Os, OK with another optimizations
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79241 --- Comment #2 from night_ghost at ykoctpa dot ru --- 90mbytes of code? you must be joking! But when I try to do a testcase with only few files then all compiles OK. Moreover the classes which uses FUNCTOR_BIND_MEMBER without additional "using namespace " all compiles fine too.
[Bug c++/79241] New: error wen compiling -Os, OK with another optimizations
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79241
Bug ID: 79241
Summary: error wen compiling -Os, OK with another optimizations
Product: gcc
Version: 4.8.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: night_ghost at ykoctpa dot ru
Target Milestone: ---
When I compile this (https://github.com/night-ghost/ardupilot) project with -Os
I got errors
==
In file included from
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/AP_HAL_Namespace.h:4:0,
from
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/AP_HAL.h:6,
from
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL_REVOMINI/AnalogIn.cpp:22:
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/utility/functor.h:
In instantiation of 'static constexpr Functor<RetType, Args> Functor<RetType,
Args>::bind(T*) [with T = REVOMINI::REVOMINIAnalogIn; RetType (T::*
method)(Args ...) = ::REVOMINIAnalogIn::_timer_event; RetType = void;
Args = {}]':
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL_REVOMINI/AnalogIn.cpp:48:43:
required from here
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/utility/functor.h:73:49:
error: could not convert '{obj, method_wrapper<REVOMINI::REVOMINIAnalogIn,
::REVOMINIAnalogIn::_timer_event>}' from '' to 'Functor'
return { obj, method_wrapper<T, method> };
^
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/utility/functor.h:74:5:
error: body of constexpr function 'static constexpr Functor<RetType, Args>
Functor<RetType, Args>::bind(T*) [with T = REVOMINI::REVOMINIAnalogIn; RetType
(T::* method)(Args ...) = ::REVOMINIAnalogIn::_timer_event; RetType =
void; Args = {}]' not a return-statement
}
^
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/utility/functor.h:
In static member function 'static constexpr Functor<RetType, Args>
Functor<RetType, Args>::bind(T*) [with T = REVOMINI::REVOMINIAnalogIn; RetType
(T::* method)(Args ...) = ::REVOMINIAnalogIn::_timer_event; RetType =
void; Args = {}]':
/mnt/disk_d/src/quad-copter/ardu-copter/3.4.2-git/ardupilot.3.4-revo/libraries/AP_HAL/utility/functor.h:74:5:
warning: control reaches end of non-void function [-Wreturn-type]
}
^
make: *** [/tmp/ArduCopter.build/libraries/AP_HAL_REVOMINI/AnalogIn.o] Ошибка 1
==
but all OK with -O0, -Og and -O2
moreover all turns to OK when I change
#include "functor.h"
to
#pragma GCC push_options
#pragma GCC optimize ("O2")
#include "functor.h"
#pragma GCC pop_options
(https://github.com/night-ghost/ardupilot/blob/RevoMini/libraries/AP_HAL/utility/functor.h)
tested on GCC 4.8.3, 4.9 and 5.4 with same results
[Bug target/70676] suboptimal code generation on AVR
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70676 --- Comment #6 from night_ghost at ykoctpa dot ru --- I reported not one case but suboptimal behavior while optimizing size - GCC optimization of sibling calls increases size of binary. There are a lot of such places in this code. And GCC never replaces call-ret sequence to jmp, relying on linkers optimizing by -relax. But including -relax flag often spoils the project to complete failure.
[Bug target/70677] Suboptimal cond on AVR: unneeded stack frame
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70677 --- Comment #6 from night_ghost at ykoctpa dot ru --- Thank you again for such good key - it saves me 150 bytes. Moreover this key is not listed in GCC's possible optimisations for AVR. PS. Why it not included by default to -Os? What can be affected by it?
[Bug target/70676] suboptimal code generation on AVR
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70676 --- Comment #4 from night_ghost at ykoctpa dot ru --- Created attachment 38551 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38551=edit testcase in attachment without -no-optimize-sibling-call reported bug can be found in MinimOsd_Extra.s on lines 2424, 3249 and so on - all POP's of epilogue can be done before comparison. If GCC can't move up epilogue to that place then such optimization is not suitable for -Os because it means "in size at the expense of the rest", especially on embedded, where task - to shove an elephant into a beaker (I can not better translate Russian proverb "Впихнуть невпихнуемое")
[Bug target/70677] Suboptimal cond on AVR: unneeded stack frame
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70677 --- Comment #4 from night_ghost at ykoctpa dot ru --- Created attachment 38550 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38550=edit testcase in attachment for AVR platform arduino.h is the most that neither is a standard :)
[Bug target/70677] Suboptimal cond on AVR: unneeded stack frame
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70677
--- Comment #2 from night_ghost at ykoctpa dot ru ---
all code samples from
https://github.com/night-ghost/minimosd-extra/tree/master/MinimOsd_Extra. When
I try to isolate a piece of code with a bug in one file, it is compiled
differently than in their native place.
Same stack usage in this code:
#include
#define SCK_PIN 13
#define MISO_PIN 12
#define MOSI_PIN 11
class SPI
{
public:
SPI(void);
static byte transfer(byte);
};
SPI::SPI()
{
// initialize the SPI pins
pinMode(SCK_PIN, OUTPUT);
pinMode(MOSI_PIN, OUTPUT);
pinMode(MISO_PIN, INPUT);
}
byte SPI::transfer(byte value){
SPDR = value;
while (!(SPSR & (1<<SPIF))) ;
return SPDR;
}
void MAX_write(byte addr, byte data){
register byte d=data;
SPI::transfer(addr);
SPI::transfer(d);
}
will be
void MAX_write(byte addr, byte data){
f06:<->cf 93 <-->push<-->r28
f08:<->df 93 <-->push<-->r29
f0a:<->1f 92 <-->push<-->r1
f0c:<->cd b7 <-->in<>r28, 0x3d<->; 61
f0e:<->de b7 <-->in<>r29, 0x3e<->; 62
register byte d=data;
SPI::transfer(addr);
f10:<->69 83 <-->std<--->Y+1, r22<-->; 0x01
f12:<->0e 94 e2 2e <-->call<-->0x5dc4<>; 0x5dc4 <_ZN3SPI8transferEh>
SPI::transfer(d);
f16:<->69 81 <-->ldd<--->r22, Y+1<-->; 0x01
f18:<->86 2f <-->mov<--->r24, r22
f1a:<->0e 94 e2 2e <-->call<-->0x5dc4<>; 0x5dc4 <_ZN3SPI8transferEh>
}
f1e:<->0f 90 <-->pop<--->r0
f20:<->df 91 <-->pop<--->r29
f22:<->cf 91 <-->pop<--->r28
f24:<->08 95 <-->ret
as one can see, "data" variable saved in stack, not in register
[Bug target/70676] suboptimal code generation on AVR
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70676
--- Comment #2 from night_ghost at ykoctpa dot ru ---
*** testcase for call+ret: (all code from
https://github.com/night-ghost/minimosd-extra/tree/master/MinimOsd_Extra),
compile with -fno-optimize-sibling-calls
#include
class SPI
{
public:
SPI(void);
static byte transfer(byte);
};
SPI::SPI()
{
#define SCK_PIN 13
#define MISO_PIN 12
#define MOSI_PIN 11
// initialize the SPI pins
pinMode(SCK_PIN, OUTPUT);
pinMode(MOSI_PIN, OUTPUT);
pinMode(MISO_PIN, INPUT);
}
byte SPI::transfer(byte value){
SPDR = value;
while (!(SPSR & (1<<SPIF))) ;
return SPDR;
}
byte MAX_read(byte addr){
SPI::transfer(addr);
return SPI::transfer(0xff);
}
*** testcase of splitting tail, compile without -fno-optimize-sibling-calls
#include
#define NOINLINE __attribute__ ((noinline))
struct Point {
byte x;
byte y;
};
typedef struct Point point;
static boolean inline is_alt(point p){
return (p.y & 0x40);
}
static void NOINLINE osd_printf_1(PGM_P fmt, float f){
Serial.printf_P(fmt, f);
}
static void NOINLINE osd_printf_2(PGM_P fmt, float f, byte c){
Serial.printf_P(fmt, f);
Serial.write(c);
}
static void panBatteryPercent(point p){
float val=2.0;
if (is_alt(p))
osd_printf_1(PSTR("%2.0f%%"),val);
else
osd_printf_2(PSTR("%4.0f\x01"),val,0x15);
}
}
>Provided you use -mrelax (or link with -Wl,--relax), the linker tries to
>replace [R]CALL+RET by [R]JMP instruction
Thanks for good key, it saves 700bytes of code (from 30642 to 29942)
[Bug target/70677] New: Suboptimal cond on AVR: unneeded stack frame
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70677
Bug ID: 70677
Summary: Suboptimal cond on AVR: unneeded stack frame
Product: gcc
Version: 5.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: night_ghost at ykoctpa dot ru
Target Milestone: ---
here a lot of commands to deal with stack frame for only one byte
//(out of scope:
struct Point {
byte x;
byte y;
};
static boolean inline is_alt(point p){
return (p.y & 0x40);
}
//)
static void panVel(point p){
1e14: cf 93 pushr28
1e16: df 93 pushr29
1e18: 1f 92 pushr1
1e1a: cd b7 in r28, 0x3d ; 61
1e1c: de b7 in r29, 0x3e ; 62
printSpeed(cnvGroundSpeed(),is_alt(p));
1e1e: 96 fb bst r25, 6
1e20: 22 27 eor r18, r18
1e22: 20 f9 bld r18, 0
1e24: 29 83 std Y+1, r18; 0x01
1e26: 0e 94 33 09 call0x1266; 0x1266 <_ZL14cnvGroundSpeedv>
1e2a: ab 01 movwr20, r22
1e2c: bc 01 movwr22, r24
}
1e2e: 29 81 ldd r18, Y+1; 0x01
1e30: 87 e8 ldi r24, 0x87 ; 135
1e32: 92 e0 ldi r25, 0x02 ; 2
1e34: 0e 94 c6 0e call0x1d8c; 0x1d8c <_ZL10printSpeedPKcfh>
1e38: 0f 90 pop r0
1e3a: df 91 pop r29
1e3c: cf 91 pop r28
1e3e: 08 95 ret
R18 can be PUSH'ed, moved to r28 or even calculated after call to x1266
[Bug target/70676] New: suboptimal code generation on AVR
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70676 Bug ID: 70676 Summary: suboptimal code generation on AVR Product: gcc Version: 5.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: night_ghost at ykoctpa dot ru Target Milestone: --- gcc -Os -fno-optimize-sibling-calls don't optimizes out tail recursion: return SPI::transfer(0xff); f54:8f ef ldi r24, 0xFF; 255 f56:0e 94 d9 2e call 0x5db2 ; 0x5db2 <_ZN3SPI8transferEh> } f5a:08 95 ret where it should be ldi r24, 0xFF; 255 jmp 0x5db2 ; 0x5db2 <_ZN3SPI8transferEh> Yes I can remove -fno-optimize-sibling-calls but then size of compiled project will be much more: with:30566 bytes (93.3% Full) without: 30772 bytes and binary don't fit to flash (30720 is maximum) Reason is that even with -Os optimize-sibling-calls tries to make epilogue for each tail recursion: 2080:<->92 e0 <-->ldi<--->r25, 0x02<->; 2 2082:<->df 91 <-->pop<--->r29 2084:<->cf 91 <-->pop<--->r28 2086:<->1f 91 <-->pop<--->r17 2088:<->0f 91 <-->pop<--->r16 208a:<->ff 90 <-->pop<--->r15 208c:<->ef 90 <-->pop<--->r14 208e:<->bf 90 <-->pop<--->r11 2090:<->af 90 <-->pop<--->r10 2092:<->9f 90 <-->pop<--->r9 2094:<->8f 90 <-->pop<--->r8 2096:<->0c 94 2a 0f <-->jmp<--->0x1e54<>; 0x1e54 <_ZL12osd_printf_1PKcf> (rjmp here) 209a:<->df 91 <-->pop<--->r29 209c:<->cf 91 <-->pop<--->r28 209e:<->1f 91 <-->pop<--->r17 20a0:<->0f 91 <-->pop<--->r16 20a2:<->ff 90 <-->pop<--->r15 20a4:<->ef 90 <-->pop<--->r14 20a6:<->bf 90 <-->pop<--->r11 20a8:<->af 90 <-->pop<--->r10 20aa:<->9f 90 <-->pop<--->r9 20ac:<->8f 90 <-->pop<--->r8 20ae:<->08 95 <-->ret Can GCC in -Os really optimize only size and rollback optimizations if size of "optimized" code is more than size of non-optimized ?
[Bug target/69049] [avr] strange/unnecessary commands in compiled code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69049 --- Comment #2 from night_ghost at ykoctpa dot ru --- 1) this is part of Arduino project so it should #include Arduino.h 2) GCC 5.3 don't has this bug so it can be closed
[Bug lto/69408] LD crashes with LTO
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69408 --- Comment #14 from night_ghost at ykoctpa dot ru --- Created attachment 37487 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37487=edit script to build GCC-avr and other tools use this script to build GCC
[Bug lto/69408] LD crashes with LTO
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69408 --- Comment #15 from night_ghost at ykoctpa dot ru --- steps to repeat: Arduino recent version should be installed GCC created by the above script should be in PATH and in Arduino's /usr/share/arduino/hardware/tools/avr un-tar testcase, cd to it. in mk/board_avr.mk one should set path to liblto_plugin.so then cd ArduCopter make after lots of compilation you'll get %% ArduCopter.elf collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped compilation terminated. make: *** [/tmp/ArduCopter.build/ArduCopter.elf] Ошибка 1 make: *** Удаляется файл `/tmp/ArduCopter.build/ArduCopter.elf' PS. I can't upload testcase because of size limit 1mb. Is there another way to send it?
[Bug lto/69408] LD crashes with LTO
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69408 --- Comment #4 from night_ghost at ykoctpa dot ru --- I can attach script which GCC has been built, and ZIP of the project tree which cause crash.
[Bug lto/69408] New: LD crashes with LTO
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69408 Bug ID: 69408 Summary: LD crashes with LTO Product: gcc Version: 5.3.0 Status: UNCONFIRMED Severity: critical Priority: P3 Component: lto Assignee: unassigned at gcc dot gnu.org Reporter: night_ghost at ykoctpa dot ru Target Milestone: --- trying to compile Arducopter 3.2.1 for AVR I got crash: %% ArduCopter.cpp %% ArduCopter.elf collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped compilation terminated. make: *** [/tmp/ArduCopter.build/ArduCopter.elf] Ошибка 1 make: *** Удаляется файл `/tmp/ArduCopter.build/ArduCopter.elf' but there is no .core file in popular places. without LTO build successed
[Bug lto/69408] LD crashes with LTO
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69408 --- Comment #2 from night_ghost at ykoctpa dot ru --- there are reqirements for reporting *language* bugs but no LTO bugs in https://gcc.gnu.org/bugs.html I can ZIP build tree but I saw a list of all that i can send in the "we do not want". Crash occurs on final linking so I can't give the refined test case. But crash always comes.
[Bug c/69049] New: [avr] strange/unnecessary commands in compiled code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69049
Bug ID: 69049
Summary: [avr] strange/unnecessary commands in compiled code
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: night_ghost at ykoctpa dot ru
Target Milestone: ---
small code
void deepSleep(uint16_t milliseconds) {
uint32_t microseconds = milliseconds * 1000L;
uint16_t sleep_periods = (microseconds - watchdogTime_us) /
watchdogTime_us;
while (sleep_periods >= 512) {
narcoleptic_sleep_down(WDTO_8S);
sleep_periods -= 512;
}
if (sleep_periods & 256) narcoleptic_sleep_down(WDTO_4S); /* xxx */
}
compiled as (see comments)
void deepSleep(uint16_t milliseconds) {
uint32_t microseconds = milliseconds * 1000L;
2fb2: 9c 01 movwr18, r24
2fb4: a8 ee ldi r26, 0xE8 ; 232
2fb6: b3 e0 ldi r27, 0x03 ; 3
2fb8: 0e 94 b8 33 call0x6770 ; 0x6770 <__umulhisi3>
uint16_t sleep_periods = (microseconds - watchdogTime_us) /
watchdogTime_us;
2fbc: 6c 19 sub r22, r12
2fbe: 7d 09 sbc r23, r13
2fc0: 8e 09 sbc r24, r14
2fc2: 9f 09 sbc r25, r15
2fc4: a7 01 movwr20, r14
2fc6: 96 01 movwr18, r12
2fc8: 0e 94 71 33 call0x66e2 ; 0x66e2 <__udivmodsi4>
2fcc: 69 01 movwr12, r18 // r12r13 === sleep_periods,
is'nt it?
while (sleep_periods >= 512) {
//{ why GCC adds 0 before comparison?
2fce: e1 2c mov r14, r1
2fd0: f1 2c mov r15, r1
2fd2: c7 01 movwr24, r14
2fd4: 8c 0d add r24, r12
2fd6: 9d 1d adc r25, r13
// carry NEVER can be set - r1===0
2fd8: 81 15 cp r24, r1
//}
2fda: 92 40 sbcir25, 0x02 ; 2
2fdc: 70 f0 brcs.+28; 0x2ffa
<_Z9deepSleepj+0x6c>
narcoleptic_sleep_down(WDTO_8S);
2fde: 89 e0 ldi r24, 0x09 ; 9
//{ why GCC saves unneeded LONG?
2fe0: 29 83 std Y+1, r18; 0x01
2fe2: 3a 83 std Y+2, r19; 0x02
2fe4: 4b 83 std Y+3, r20; 0x03
2fe6: 5c 83 std Y+4, r21; 0x04
//}
2fe8: 0e 94 c4 17 call0x2f88 ; 0x2f88
<_Z22narcoleptic_sleep_downh>
2fec: 62 e0 ldi r22, 0x02 ; 2
2fee: f6 1a sub r15, r22
//{ why GCC restores unneeded LONG?
2ff0: 5c 81 ldd r21, Y+4; 0x04
2ff2: 4b 81 ldd r20, Y+3; 0x03
2ff4: 3a 81 ldd r19, Y+2; 0x02
2ff6: 29 81 ldd r18, Y+1; 0x01
//}
2ff8: ec cf rjmp.-40; 0x2fd2
<_Z9deepSleepj+0x44>
//{ what the hell here? where such calculations in C code?
2ffa: f9 01 movwr30, r18
2ffc: ef 2f mov r30, r31
2ffe: ff 27 eor r31, r31
3000: e6 95 lsr r30
3002: 60 e0 ldi r22, 0x00 ; 0
3004: 7e ef ldi r23, 0xFE ; 254
3006: e6 9f mul r30, r22
3008: c0 01 movwr24, r0
300a: e7 9f mul r30, r23
300c: 90 0d add r25, r0
300e: f6 9f mul r31, r22
3010: 90 0d add r25, r0
3012: 11 24 eor r1, r1
3014: 82 0f add r24, r18
3016: 93 1f adc r25, r19
//}
sleep_periods -= 512;
}
if (sleep_periods & 256) narcoleptic_sleep_down(WDTO_4S);
3018: 90 ff sbrsr25, 0
301a: 0d c0 rjmp.+26; 0x3036
<_Z9deepSleepj+0xa8>
301c: 88 e0 ldi r24, 0x08 ; 8
}
//{ optimization on size but GCC generates 2nd epilogue to escape tail
recursion while simple CALL takes less memory
301e: 0f 90 pop r0
3020: 0f 90 pop r0
3022: 0f 90 pop r0
3024: 0f 90 pop r0
3026: df 91 pop r29
3028: cf 91 pop r28
302a: ff 90 pop r15
302c: ef 90 pop r14
302e: df 90 pop r13
3030: cf 90 pop r12
while (sleep_periods >= 512) {
narcoleptic_sleep_down(WDTO_8S);
sle
