See the test case for an example:
(sorry if it's still a bit much, but I tried to strip everything
that's not relevant.
I spent a lot of time on it, and it's a fraction of the original code.)
In this case NOT inlining generates more then 5 times as much
instructions than inlining!
*/
#define extIntSetEnable_gcc_4_3_3_aail_workaround
//#define extIntSetEnable_gcc_4_3_3_aail_workaround
__attribute__((always_inline))
#include <avr/io.h>
#include <avr/interrupt.h>
#define BIT(x) (0x01 << (x))
#define bit_set(p,b) ((p) |= BIT(b))
#define bit_clear(p,b) ((p) &= ~BIT(b))
//#define bit_write(p,b,c) (c ? bit_set(p,b) : bit_clear(p,b))
#define bit_write(p,b,c) if (c) { bit_set(p,b);}else bit_clear(p,b)
static inline
void extIntSetEnable_gcc_4_3_3_aail_workaround extIntSetEnable(char
channel, char enabled)
{
switch (channel) { /// enable / disable int
case 0: {
bit_write(GICR,INT0,enabled);
} break;
case 1: {
bit_write(GICR,INT1,enabled);
} break;
case 2: {
bit_write(GICR,INT2,enabled);
} break;
}
}
int main (void)
{
extIntSetEnable(0,0);
///...
extIntSetEnable(0,1);
for (;;)
{
}
}
/**
avr-gcc (GCC) 3.4.6
avr-gcc -c -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=16000000UL
-DBOOTSIZE=1024 -Os -funsigned-char -funsigned-bitfields
-fpack-struct -fshort-enums -fno-strict-aliasing -Wall -Winline
-Wstrict-prototypes -Wa,-adhlns=test_il.lst -ID:/Lib/ -std=gnu99 -MD
-MP -MF .dep/test_il.o.d test_il.c -o test_il.o
avr-gcc -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=16000000UL
-DBOOTSIZE=1024 -Os -funsigned-char -funsigned-bitfields
-fpack-struct -fshort-enums -fno-strict-aliasing -Wall -Winline
-Wstrict-prototypes -Wa,-adhlns=test_il.o -ID:/Lib/ -std=gnu99 -MD -MP
-MF .dep/test_il.elf.d test_il.o --output test_il.elf
-Wl,-Map=test_il.map,--cref -lm
-Wl,--section-start=.bootloader=0x3800
Size after:
.text 184 0
00000054 <__ctors_end>:
58: cf e5 ldi r28, 0x5F ; 95
5a: d4 e0 ldi r29, 0x04 ; 4
5c: de bf out 0x3e, r29 ; 62
5e: cd bf out 0x3d, r28 ; 61
...
0000008e <main>:
8e: cf e5 ldi r28, 0x5F ; 95 <<< again? ... gcc 3.4.6
has
it's own faults
90: d4 e0 ldi r29, 0x04 ; 4
92: de bf out 0x3e, r29 ; 62
94: cd bf out 0x3d, r28 ; 61
extIntSetEnable(0,0);
96: 8b b7 in r24, 0x3b ; 59
98: 8f 7b andi r24, 0xBF ; 191
9a: 8b bf out 0x3b, r24 ; 59
extIntSetEnable(0,1);
9c: 8b b7 in r24, 0x3b ; 59
9e: 80 64 ori r24, 0x40 ; 64
a0: 8b bf out 0x3b, r24 ; 59
*/
/**
avr-gcc (WinAVR 20090313) 4.3.2
avr-gcc -c -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=16000000UL
-DBOOTSIZE=1024 -Os -funsigned-char -funsigned-bitfields
-fpack-struct -fshort-enums -fno-strict-aliasing
-fno-inline-small-functions -save-temps -Wall -Winline
-Wstrict-prototypes -Wa,-adhlns=test_il.lst -ID:/Lib/ -std=gnu99 -MD
-MP -MF .dep/test_il.o.d test_il.c -o test_il.o
avr-gcc -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=16000000UL
-DBOOTSIZE=1024 -Os -funsigned-char -funsigned-bitfields
-fpack-struct -fshort-enums -fno-strict-aliasing
-fno-inline-small-functions -save-temps -Wall -Winline
-Wstrict-prototypes -Wa,-adhlns=test_il.o -ID:/Lib/ -std=gnu99 -MD -MP
-MF .dep/test_il.elf.d test_il.o --output test_il.elf
-Wl,-Map=test_il.map,--cref -lm
-Wl,--section-start=.bootloader=0x3800
Size after:
.text 146 0
0000006c <main>:
bit_write(GICR,INT0,enabled);
6c: 8b b7 in r24, 0x3b ; 59
6e: 8f 7b andi r24, 0xBF ; 191
70: 8b bf out 0x3b, r24 ; 59
72: 8b b7 in r24, 0x3b ; 59
74: 80 64 ori r24, 0x40 ; 64
76: 8b bf out 0x3b, r24 ; 59
*/
/**
avr-gcc (WinAVR 20100110) 4.3.3
avr-gcc -c -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=16000000UL
-DBOOTSIZE=1024 -Os -funsigned-char -funsigned-bitfields
-fpack-struct -fshort-enums -fno-strict-aliasing
-fno-inline-small-functions -save-temps -Wall -Winline
-Wstrict-prototypes -Wa,-adhlns=test_il.lst -ID:/Lib/ -std=gnu99 -MD
-MP -MF .dep/test_il.o.d test_il.c -o test_il.o
test_il.c: In function 'main':
test_il.c:32: warning: inlining failed in call to 'extIntSetEnable':
optimizing for size and code size would grow
test_il.c:49: warning: called from here
test_il.c:32: warning: inlining failed in call to 'extIntSetEnable':
optimizing for size and code size would grow
test_il.c:54: warning: called from here
avr-gcc -mmcu=atmega16 -I. -gdwarf-2 -DF_CPU=16000000UL
-DBOOTSIZE=1024 -Os -funsigned-char -funsigned-bitfields
-fpack-struct -fshort-enums -fno-strict-aliasing
-fno-inline-small-functions -save-temps -Wall -Winline
-Wstrict-prototypes -Wa,-adhlns=test_il.o -ID:/Lib/ -std=gnu99 -MD -MP
-MF .dep/test_il.elf.d test_il.o --output test_il.elf
-Wl,-Map=test_il.map,--cref -lm
-Wl,--section-start=.bootloader=0x3800
Size after:
.text 216 0
0000006c <extIntSetEnable>:
switch (channel) { /// enable / disable int
6c: 81 30 cpi r24, 0x01 ; 1
6e: 69 f0 breq .+26 ; 0x8a <extIntSetEnable+0x1e>
70: 81 30 cpi r24, 0x01 ; 1
72: 18 f0 brcs .+6 ; 0x7a <extIntSetEnable+0xe>
74: 82 30 cpi r24, 0x02 ; 2
76: e1 f4 brne .+56 ; 0xb0 <extIntSetEnable+0x44>
78: 10 c0 rjmp .+32 ; 0x9a <extIntSetEnable+0x2e>
case 0: {
bit_write(GICR,INT0,enabled);
7a: 66 23 and r22, r22
7c: 19 f0 breq .+6 ; 0x84 <extIntSetEnable+0x18>
7e: 8b b7 in r24, 0x3b ; 59
80: 80 64 ori r24, 0x40 ; 64
82: 0f c0 rjmp .+30 ; 0xa2 <extIntSetEnable+0x36>
84: 8b b7 in r24, 0x3b ; 59
86: 8f 7b andi r24, 0xBF ; 191
88: 0c c0 rjmp .+24 ; 0xa2 <extIntSetEnable+0x36>
} break;
case 1: {
bit_write(GICR,INT1,enabled);
8a: 66 23 and r22, r22
8c: 19 f0 breq .+6 ; 0x94 <extIntSetEnable+0x28>
8e: 8b b7 in r24, 0x3b ; 59
90: 80 68 ori r24, 0x80 ; 128
92: 07 c0 rjmp .+14 ; 0xa2 <extIntSetEnable+0x36>
94: 8b b7 in r24, 0x3b ; 59
96: 8f 77 andi r24, 0x7F ; 127
98: 04 c0 rjmp .+8 ; 0xa2 <extIntSetEnable+0x36>
} break;
case 2: {
bit_write(GICR,INT2,enabled);
9a: 66 23 and r22, r22
9c: 21 f0 breq .+8 ; 0xa6 <extIntSetEnable+0x3a>
9e: 8b b7 in r24, 0x3b ; 59
a0: 80 62 ori r24, 0x20 ; 32
a2: 8b bf out 0x3b, r24 ; 59
a4: 08 95 ret
a6: 8b b7 in r24, 0x3b ; 59
a8: 8f 7d andi r24, 0xDF ; 223
aa: 8b bf out 0x3b, r24 ; 59
ac: 08 95 ret
000000ae <main>:
extIntSetEnable(0,0);
ae: 80 e0 ldi r24, 0x00 ; 0
b0: 60 e0 ldi r22, 0x00 ; 0
b2: 0e 94 36 00 call 0x6c ; 0x6c <extIntSetEnable>
extIntSetEnable(0,1);
b6: 80 e0 ldi r24, 0x00 ; 0
b8: 61 e0 ldi r22, 0x01 ; 1
ba: 0e 94 36 00 call 0x6c ; 0x6c <extIntSetEnable>
*/
SIGNAL(SIG_INTERRUPT0)
{
}
