使用arm none eabi gcc编译时不考虑优化标志
我想使用该项目编译一个带有使用arm none eabi gcc编译时不考虑优化标志,c,makefile,arm,compiler-optimization,libopencm3,C,Makefile,Arm,Compiler Optimization,Libopencm3,我想使用该项目编译一个带有arm none eabi gcc 9.2.1的程序，并在arm Cortex-M4处理器上运行它。我的程序由两个文件组成：main.c #include "../common/stm32wrapper.h" #include "test.h" #include <stdio.h> #include <string.h> typedef unsigned char u8; typedef unsigned int u32; typedef u
arm none eabi gcc 9.2.1main.c#include "../common/stm32wrapper.h"
#include "test.h"
#include <stdio.h>
#include <string.h>
typedef unsigned char u8;
typedef unsigned int u32;
typedef unsigned long long u64;
int main(void)
{
clock_setup();
gpio_setup();
usart_setup(115200);
flash_setup();
SCS_DEMCR |= SCS_DEMCR_TRCENA;
DWT_CYCCNT = 0;
DWT_CTRL |= DWT_CTRL_CYCCNTENA;
u32 oldcount, newcount;
u32 a = 0x75;
u32 b = 0x14;
char buffer[36];
oldcount = DWT_CYCCNT;
u32 c = test(a,b);
newcount = DWT_CYCCNT-oldcount;
sprintf(buffer, "cycles: %d, %08x", newcount, c);
send_USART_str(buffer);
return 0;
}
.PHONY: all clean
PREFIX ?= arm-none-eabi
CC = $(PREFIX)-gcc -v
LD = $(PREFIX)-gcc -v
OBJCOPY = $(PREFIX)-objcopy
OBJDUMP = $(PREFIX)-objdump
GDB = $(PREFIX)-gdb
OPENCM3DIR = ../libopencm3
ARMNONEEABIDIR = /usr/arm-none-eabi
COMMONDIR = ../common
all: test_m4.bin
test_m4.%: ARCH_FLAGS = -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16
test_m4.o: CFLAGS += -DSTM32F4
$(COMMONDIR)/stm32f4_wrapper.o: CFLAGS += -DSTM32F4
test_m4.elf: LDSCRIPT = $(COMMONDIR)/stm32f4-discovery.ld
test_m4.elf: LDFLAGS += -L$(OPENCM3DIR)/lib/ -lopencm3_stm32f4
test_m4.elf: OBJS += $(COMMONDIR)/stm32f4_wrapper.o
test_m4.elf: $(COMMONDIR)/stm32f4_wrapper.o $(OPENCM3DIR)/lib/libopencm3_stm32f4.a
CFLAGS += -O3 \
-Wall -Wextra -Wimplicit-function-declaration \
-Wredundant-decls -Wmissing-prototypes -Wstrict-prototypes \
-Wundef -Wshadow \
-I$(ARMNONEEABIDIR)/include -I$(OPENCM3DIR)/include \
-fno-common $(ARCH_FLAGS) -MD \
-ftime-report
LDFLAGS += --static -Wl,--start-group -lc -lgcc -lnosys -Wl,--end-group \
-T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections,--no-print-gc-sections \
$(ARCH_FLAGS)
OBJS += test.c
%.bin: %.elf
$(OBJCOPY) -Obinary $^ $@
%.elf: %.o $(OBJS) $(LDSCRIPT)
$(LD) -o $@ $< $(OBJS) $(LDFLAGS)
test%.o: main.c
$(CC) $(CFLAGS) -o $@ -c $^
%.o: %.c
$(CC) $(CFLAGS) -o $@ -c $^
clean:
rm -f *.o *.d *.elf *.bin
循环：196645000063080001ac <main>:
80001ac: b570 push {r4, r5, r6, lr}
80001ae: b08a sub sp, #40 ; 0x28
80001b0: f006 fc06 bl 80069c0 <clock_setup>
80001b4: f006 fc1c bl 80069f0 <gpio_setup>
80001b8: f44f 30e1 mov.w r0, #115200 ; 0x1c200
80001bc: f006 fc32 bl 8006a24 <usart_setup>
80001c0: f006 fc52 bl 8006a68 <flash_setup>
80001c4: 490e ldr r1, [pc, #56] ; (8000200 <main+0x54>)
80001c6: 4c0f ldr r4, [pc, #60] ; (8000204 <main+0x58>)
80001c8: 680b ldr r3, [r1, #0]
80001ca: 4a0f ldr r2, [pc, #60] ; (8000208 <main+0x5c>)
80001cc: 2500 movs r5, #0
80001ce: f043 7380 orr.w r3, r3, #16777216 ; 0x1000000
80001d2: 600b str r3, [r1, #0]
80001d4: 6025 str r5, [r4, #0]
80001d6: 6813 ldr r3, [r2, #0]
80001d8: f043 0301 orr.w r3, r3, #1
80001dc: 6013 str r3, [r2, #0]
80001de: 6826 ldr r6, [r4, #0]
80001e0: f000 f816 bl 8000210 <test>
80001e4: 6822 ldr r2, [r4, #0]
80001e6: 4909 ldr r1, [pc, #36] ; (800020c <main+0x60>)
80001e8: 4603 mov r3, r0
80001ea: 1b92 subs r2, r2, r6
80001ec: a801 add r0, sp, #4
80001ee: f006 fca5 bl 8006b3c <sprintf>
80001f2: a801 add r0, sp, #4
80001f4: f006 fc48 bl 8006a88 <send_USART_str>
80001f8: 4628 mov r0, r5
80001fa: b00a add sp, #40 ; 0x28
80001fc: bd70 pop {r4, r5, r6, pc}
80001fe: bf00 nop
8000200: e000edfc .word 0xe000edfc
8000204: e0001004 .word 0xe0001004
8000208: e0001000 .word 0xe0001000
800020c: 0800c1e8 .word 0x0800c1e8
08000210 <test>:
8000210: b480 push {r7}
8000212: b087 sub sp, #28
8000214: af00 add r7, sp, #0
8000216: 2375 movs r3, #117 ; 0x75
8000218: 60fb str r3, [r7, #12]
800021a: 2314 movs r3, #20
800021c: 60bb str r3, [r7, #8]
800021e: 2300 movs r3, #0
8000220: 613b str r3, [r7, #16]
8000222: e020 b.n 8000266 <test+0x56>
8000224: 68fb ldr r3, [r7, #12]
8000226: b2db uxtb r3, r3
8000228: 607b str r3, [r7, #4]
800022a: 68bb ldr r3, [r7, #8]
800022c: b2db uxtb r3, r3
800022e: 603b str r3, [r7, #0]
8000230: 687a ldr r2, [r7, #4]
8000232: 683b ldr r3, [r7, #0]
8000234: 405a eors r2, r3
8000236: 693b ldr r3, [r7, #16]
8000238: 2b00 cmp r3, #0
800023a: da01 bge.n 8000240 <test+0x30>
800023c: f203 13ff addw r3, r3, #511 ; 0x1ff
8000240: 125b asrs r3, r3, #9
8000242: 4619 mov r1, r3
8000244: 68fb ldr r3, [r7, #12]
8000246: 40cb lsrs r3, r1
8000248: 405a eors r2, r3
800024a: 693b ldr r3, [r7, #16]
800024c: 2b00 cmp r3, #0
800024e: da01 bge.n 8000254 <test+0x44>
8000250: f203 33ff addw r3, r3, #1023 ; 0x3ff
8000254: 129b asrs r3, r3, #10
8000256: 4619 mov r1, r3
8000258: 68bb ldr r3, [r7, #8]
800025a: 40cb lsrs r3, r1
800025c: 4053 eors r3, r2
800025e: 617b str r3, [r7, #20]
8000260: 693b ldr r3, [r7, #16]
8000262: 3301 adds r3, #1
8000264: 613b str r3, [r7, #16]
8000266: 693b ldr r3, [r7, #16]
8000268: f5b3 5f80 cmp.w r3, #4096 ; 0x1000
800026c: dbda blt.n 8000224 <test+0x14>
800026e: 697b ldr r3, [r7, #20]
8000270: 4618 mov r0, r3
8000272: 371c adds r7, #28
8000274: 46bd mov sp, r7
8000276: f85d 7b04 ldr.w r7, [sp], #4
800027a: 4770 bx lr
080001ac:
80001ac:b570推力{r4，r5，r6，lr}
80001ae:b08a子sp，#40；0x28
80001b0:f006 fc06 bl 80069c0
80001b4:f006 fc1c bl 80069f0
80001b8:f44f 30e1移动带r0，#115200；0x1c200
80001bc:f006 fc32 bl 8006a24
80001c0:f006 fc52 bl 8006a68
80001c4:490e ldr r1，[pc，#56]；(8000200 )
80001c6:4c0f ldr r4，[pc，#60]；(8000204 )
80001c8:680b ldr r3[r1，#0]
80001ca:4a0f ldr r2，[pc，#60]；(8000208 )
80001cc:2500 movs r5，#0
80001ce:f043 7380或w r3，r3，#16777216；0x1000000
80001d2:600b str r3[r1，#0]
80001d4:6025 str r5[r4，#0]
80001d6:6813 ldr r3[r2，#0]
80001d8:f043 0301或w r3，r3，#1
80001dc:6013街r3[r2，#0]
80001de:6826 ldr r6[r4，#0]
80001e0:f000 f816 bl 8000210
80001e4:6822 ldr r2[r4，#0]
80001e6:4909 ldr r1，[pc，#36]；（800020c）
80001e8:4603 mov r3，r0
80001ea:1b92接头r2、r2、r6
80001ec:a801添加r0，sp，#4
80001ee:f006 fca5 bl 8006b3c
80001f2:a801添加r0，sp，#4
80001f4:f006 fc48 bl 8006a88
80001f8:4628 mov r0，r5
80001fa:b00a添加sp，#40；0x28
80001fc:bd70 pop{r4，r5，r6，pc}
80001fe:bf00 nop
8000200:e000edfc。字0xe000edfc
8000204:e0001004.字0xe0001004
8000208:e0001000.字0xe0001000
800020c:0800c1e8.字0x0800c1e8
08000210 :
8000210:b480推送{r7}
8000212:b087子sp，#28
8000214:af00添加r7，sp，#0
8000216:2375 movs r3，#117；0x75
8000218:60fb街r3[r7，#12]
800021a:2314 movs r3，#20
800021c:60bb str r3[r7，#8]
800021e:2300 movs r3，#0
8000220:613b街r3[r7，#16]
8000222:e020 b.n 8000266
8000224:68fb ldr r3[r7，#12]
8000226:b2db uxtb r3，r3
8000228:607b str r3[r7，#4]
800022a:68bb ldr r3[r7，#8]
800022c:b2db uxtb r3，r3
800022e:603b str r3[r7，#0]
8000230:687a ldr r2[r7，#4]
8000232:683b ldr r3[r7，#0]
8000234:405a提高采收率r2，r3
8000236:693b ldr r3[r7，#16]
8000238:2b00 cmp r3，#0
800023a:da01 bge.n 8000240
800023c:f203 13ff地址r3，r3，#511；0x1ff
8000240:125b asrs r3，r3，#9
8000242:4619 mov r1，r3
8000244:68fb ldr r3[r7，#12]
8000246:40cb LSR r3、r1
8000248:405a提高采收率r2，r3
800024a:693b ldr r3[r7，#16]
800024c:2b00 cmp r3，#0
800024e:da01 bge.n 8000254
8000250:f203第33层增补r3、r3、#1023；0x3ff
8000254:129b asrs r3，r3，#10
8000256:4619 mov r1，r3
8000258:68bb ldr r3[r7，#8]
800025a:40cb LSR r3、r1
800025c:4053提高采收率r3，r2
800025e:617b str r3[r7，#20]
8000260:693b ldr r3[r7，#16]
8000262:3301加上r3，#1
8000264:613b街r3[r7，#16]
8000266:693b ldr r3[r7，#16]
8000268:f5b3 5f80 cmp.w r3，#4096；0x1000
800026c:dbda blt.n 8000224
800026e:697b ldr r3[r7，#20]
8000270:4618 mov r0，r3
8000272:371c加上r7，#28
8000274:46bd mov sp，r7
8000276:f85d 7b04 ldr.w r7[sp]，#4
800027a:4770 bx lr
uxtbeortypedef unsigned int uint32_t;
uint32_t test(uint32_t a, uint32_t b) {
uint32_t tmp0, tmp1;
uint32_t c;
for(int i = 0; i< 4096; i++) {
tmp0 = a & 0xff;
tmp1 = b & 0xff;
c = tmp0 ^ tmp1 ^ (a>>(i/512)) ^ (b >> (i/1024));
}
return c;
}
unsigned int hello ( void )
{
return(test(0x75,0x14));
}
arm none eabi gcc-O0 so.c-c-mthumb-mcpu=cortex-m4-o so.o
第节的分解。正文：
00000000 :
0:b480推送{r7}
2:b087子sp，#28
4:af00加上r7，sp，#0
6:6078 str r0，[r7，#4]
8:6039 str r1[r7，#0]
a:2300 movs r3，#0
c:613b str r3[r7，#16]
e:e020 b.n.52
10:687b ldr r3[r7，#4]
12:b2db uxtb r3，r3
14:60fb str r3[r7，#12]
16:683b ldr r3[r7，#0]
18:b2db uxtb r3，r3
1a:60bb str r3[r7，#8]
1c:68fa ldr r2，[r7，#12]
1e:68bb ldr r3，[r7，#8]
20:405a提高采收率r2，r3
22:693b ldr r3[r7，#16]
24:200立方厘米r3，#0
26:da01 bge.n 2c
28:f203 13ff地址r3，r3，#511；0x1ff
2c:125b asrs r3，r3，#9
2e:4619 mov r1，r3
30:687b ldr r3，[r7，#4]
32:40 CB LSR r3，r1
34:405a提高采收率r2，r3
36:693b ldr r3[r7，#16]
38:2b00 cmp r3，#0
3a:da01 bge.n 40
3c:f203第33段增补r3，r3，#1023；0x3ff
40:129b asrs r3，r3，#10
42:4619 mov r1，r3
44:683b ldr r3[r7，#0]
46:40 CB LSR r3，r1
48:4053 e
080001ac <main>:
80001ac: b570 push {r4, r5, r6, lr}
80001ae: b08a sub sp, #40 ; 0x28
80001b0: f006 fc06 bl 80069c0 <clock_setup>
80001b4: f006 fc1c bl 80069f0 <gpio_setup>
80001b8: f44f 30e1 mov.w r0, #115200 ; 0x1c200
80001bc: f006 fc32 bl 8006a24 <usart_setup>
80001c0: f006 fc52 bl 8006a68 <flash_setup>
80001c4: 490e ldr r1, [pc, #56] ; (8000200 <main+0x54>)
80001c6: 4c0f ldr r4, [pc, #60] ; (8000204 <main+0x58>)
80001c8: 680b ldr r3, [r1, #0]
80001ca: 4a0f ldr r2, [pc, #60] ; (8000208 <main+0x5c>)
80001cc: 2500 movs r5, #0
80001ce: f043 7380 orr.w r3, r3, #16777216 ; 0x1000000
80001d2: 600b str r3, [r1, #0]
80001d4: 6025 str r5, [r4, #0]
80001d6: 6813 ldr r3, [r2, #0]
80001d8: f043 0301 orr.w r3, r3, #1
80001dc: 6013 str r3, [r2, #0]
80001de: 6826 ldr r6, [r4, #0]
80001e0: f000 f816 bl 8000210 <test>
80001e4: 6822 ldr r2, [r4, #0]
80001e6: 4909 ldr r1, [pc, #36] ; (800020c <main+0x60>)
80001e8: 4603 mov r3, r0
80001ea: 1b92 subs r2, r2, r6
80001ec: a801 add r0, sp, #4
80001ee: f006 fca5 bl 8006b3c <sprintf>
80001f2: a801 add r0, sp, #4
80001f4: f006 fc48 bl 8006a88 <send_USART_str>
80001f8: 4628 mov r0, r5
80001fa: b00a add sp, #40 ; 0x28
80001fc: bd70 pop {r4, r5, r6, pc}
80001fe: bf00 nop
8000200: e000edfc .word 0xe000edfc
8000204: e0001004 .word 0xe0001004
8000208: e0001000 .word 0xe0001000
800020c: 0800c1e8 .word 0x0800c1e8
08000210 <test>:
8000210: b480 push {r7}
8000212: b087 sub sp, #28
8000214: af00 add r7, sp, #0
8000216: 2375 movs r3, #117 ; 0x75
8000218: 60fb str r3, [r7, #12]
800021a: 2314 movs r3, #20
800021c: 60bb str r3, [r7, #8]
800021e: 2300 movs r3, #0
8000220: 613b str r3, [r7, #16]
8000222: e020 b.n 8000266 <test+0x56>
8000224: 68fb ldr r3, [r7, #12]
8000226: b2db uxtb r3, r3
8000228: 607b str r3, [r7, #4]
800022a: 68bb ldr r3, [r7, #8]
800022c: b2db uxtb r3, r3
800022e: 603b str r3, [r7, #0]
8000230: 687a ldr r2, [r7, #4]
8000232: 683b ldr r3, [r7, #0]
8000234: 405a eors r2, r3
8000236: 693b ldr r3, [r7, #16]
8000238: 2b00 cmp r3, #0
800023a: da01 bge.n 8000240 <test+0x30>
800023c: f203 13ff addw r3, r3, #511 ; 0x1ff
8000240: 125b asrs r3, r3, #9
8000242: 4619 mov r1, r3
8000244: 68fb ldr r3, [r7, #12]
8000246: 40cb lsrs r3, r1
8000248: 405a eors r2, r3
800024a: 693b ldr r3, [r7, #16]
800024c: 2b00 cmp r3, #0
800024e: da01 bge.n 8000254 <test+0x44>
8000250: f203 33ff addw r3, r3, #1023 ; 0x3ff
8000254: 129b asrs r3, r3, #10
8000256: 4619 mov r1, r3
8000258: 68bb ldr r3, [r7, #8]
800025a: 40cb lsrs r3, r1
800025c: 4053 eors r3, r2
800025e: 617b str r3, [r7, #20]
8000260: 693b ldr r3, [r7, #16]
8000262: 3301 adds r3, #1
8000264: 613b str r3, [r7, #16]
8000266: 693b ldr r3, [r7, #16]
8000268: f5b3 5f80 cmp.w r3, #4096 ; 0x1000
800026c: dbda blt.n 8000224 <test+0x14>
800026e: 697b ldr r3, [r7, #20]
8000270: 4618 mov r0, r3
8000272: 371c adds r7, #28
8000274: 46bd mov sp, r7
8000276: f85d 7b04 ldr.w r7, [sp], #4
800027a: 4770 bx lr
typedef unsigned int uint32_t;
uint32_t test(uint32_t a, uint32_t b) {
uint32_t tmp0, tmp1;
uint32_t c;
for(int i = 0; i< 4096; i++) {
tmp0 = a & 0xff;
tmp1 = b & 0xff;
c = tmp0 ^ tmp1 ^ (a>>(i/512)) ^ (b >> (i/1024));
}
return c;
}
unsigned int hello ( void )
{
return(test(0x75,0x14));
}
arm-none-eabi-gcc --version
arm-none-eabi-gcc (GCC) 9.3.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
arm-none-eabi-gcc -O0 so.c -c -mthumb -mcpu=cortex-m4 -o so.o
Disassembly of section .text:
00000000 <test>:
0: b480 push {r7}
2: b087 sub sp, #28
4: af00 add r7, sp, #0
6: 6078 str r0, [r7, #4]
8: 6039 str r1, [r7, #0]
a: 2300 movs r3, #0
c: 613b str r3, [r7, #16]
e: e020 b.n 52 <test+0x52>
10: 687b ldr r3, [r7, #4]
12: b2db uxtb r3, r3
14: 60fb str r3, [r7, #12]
16: 683b ldr r3, [r7, #0]
18: b2db uxtb r3, r3
1a: 60bb str r3, [r7, #8]
1c: 68fa ldr r2, [r7, #12]
1e: 68bb ldr r3, [r7, #8]
20: 405a eors r2, r3
22: 693b ldr r3, [r7, #16]
24: 2b00 cmp r3, #0
26: da01 bge.n 2c <test+0x2c>
28: f203 13ff addw r3, r3, #511 ; 0x1ff
2c: 125b asrs r3, r3, #9
2e: 4619 mov r1, r3
30: 687b ldr r3, [r7, #4]
32: 40cb lsrs r3, r1
34: 405a eors r2, r3
36: 693b ldr r3, [r7, #16]
38: 2b00 cmp r3, #0
3a: da01 bge.n 40 <test+0x40>
3c: f203 33ff addw r3, r3, #1023 ; 0x3ff
40: 129b asrs r3, r3, #10
42: 4619 mov r1, r3
44: 683b ldr r3, [r7, #0]
46: 40cb lsrs r3, r1
48: 4053 eors r3, r2
4a: 617b str r3, [r7, #20]
4c: 693b ldr r3, [r7, #16]
4e: 3301 adds r3, #1
50: 613b str r3, [r7, #16]
52: 693b ldr r3, [r7, #16]
54: f5b3 5f80 cmp.w r3, #4096 ; 0x1000
58: dbda blt.n 10 <test+0x10>
5a: 697b ldr r3, [r7, #20]
5c: 4618 mov r0, r3
5e: 371c adds r7, #28
60: 46bd mov sp, r7
62: bc80 pop {r7}
64: 4770 bx lr
00000066 <hello>:
66: b580 push {r7, lr}
68: af00 add r7, sp, #0
6a: 2114 movs r1, #20
6c: 2075 movs r0, #117 ; 0x75
6e: f7ff fffe bl 0 <test>
72: 4603 mov r3, r0
74: 4618 mov r0, r3
76: bd80 pop {r7, pc}
arm-none-eabi-gcc -O1 so.c -c -mthumb -mcpu=cortex-m4 -o so.o
arm-none-eabi-objdump -D so.o
so.o: file format elf32-littlearm
Disassembly of section .text:
00000000 <test>:
0: f44f 5380 mov.w r3, #4096 ; 0x1000
4: 3b01 subs r3, #1
6: d1fd bne.n 4 <test+0x4>
8: 08ca lsrs r2, r1, #3
a: ea82 12d0 eor.w r2, r2, r0, lsr #7
e: ea80 0301 eor.w r3, r0, r1
12: b2db uxtb r3, r3
14: ea82 0003 eor.w r0, r2, r3
18: 4770 bx lr
0000001a <hello>:
1a: b508 push {r3, lr}
1c: 2114 movs r1, #20
1e: 2075 movs r0, #117 ; 0x75
20: f7ff fffe bl 0 <test>
24: bd08 pop {r3, pc}
Disassembly of section .text:
00000000 <test>:
0: ea80 0301 eor.w r3, r0, r1
4: 08ca lsrs r2, r1, #3
6: ea82 10d0 eor.w r0, r2, r0, lsr #7
a: b2db uxtb r3, r3
c: 4058 eors r0, r3
e: 4770 bx lr
00000010 <hello>:
10: 2063 movs r0, #99 ; 0x63
12: 4770 bx lr
00000000 <test>:
0: ea80 0301 eor.w r3, r0, r1
4: 08ca lsrs r2, r1, #3
6: ea82 10d0 eor.w r0, r2, r0, lsr #7
a: b2db uxtb r3, r3
c: 4058 eors r0, r3
e: 4770 bx lr
00000010 <hello>:
10: 2063 movs r0, #99 ; 0x63
12: 4770 bx lr
00000000 <test>:
0: 08cb lsrs r3, r1, #3
2: ea83 13d0 eor.w r3, r3, r0, lsr #7
6: 4048 eors r0, r1
8: b2c0 uxtb r0, r0
a: 4058 eors r0, r3
c: 4770 bx lr
0000000e <hello>:
e: 2114 movs r1, #20
10: 2075 movs r0, #117 ; 0x75
12: f7ff bffe b.w 0 <test>