https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100491
Bug ID: 100491
Summary: Code generation get worse when including function
prototype on ARM
Product: gcc
Version: 11.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: [email protected]
Target Milestone: ---
Created attachment 50779
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50779&action=edit
sym.c
New in arm-none-eabi-gcc-11.1.0 I found that code generated when including a
function prototype was getting worse. I've in the past tested gcc 4-10, and
these didn't show this behavior.
Attach example from CSiBE Flex.
(Code was getting +17% size both with -O2 and -Os.)
Target: arm-none-eabi, cortex-m3, softfloat
GCC-10.2.0
00000000 <addsym.constprop.0.isra.0>:
0: e92d 43f8 stmdb sp!, {r3, r4, r5, r6, r7, r8, r9, lr}
4: 4689 mov r9, r1
6: 2165 movs r1, #101 ; 0x65
8: 461c mov r4, r3
a: 4607 mov r7, r0
c: 4690 mov r8, r2
e: f7ff fffe bl 0 <hashfunct>
12: 4605 mov r5, r0
14: f854 6020 ldr.w r6, [r4, r0, lsl #2]
18: b98e cbnz r6, 3e <addsym.constprop.0.isra.0+0x3e>
1a: 2014 movs r0, #20
1c: f7ff fffe bl 0 <flex_alloc>
20: f854 3025 ldr.w r3, [r4, r5, lsl #2]
24: b19b cbz r3, 4e <addsym.constprop.0.isra.0+0x4e>
26: 6043 str r3, [r0, #4]
28: 6018 str r0, [r3, #0]
2a: 2300 movs r3, #0
2c: e9c0 7902 strd r7, r9, [r0, #8]
30: 6003 str r3, [r0, #0]
32: f8c0 8010 str.w r8, [r0, #16]
36: f844 0025 str.w r0, [r4, r5, lsl #2]
3a: e8bd 83f8 ldmia.w sp!, {r3, r4, r5, r6, r7, r8, r9, pc}
3e: 4638 mov r0, r7
40: 68b1 ldr r1, [r6, #8]
42: f7ff fffe bl 0 <strcmp>
46: 2800 cmp r0, #0
48: d0f7 beq.n 3a <addsym.constprop.0.isra.0+0x3a>
4a: 6876 ldr r6, [r6, #4]
4c: e7e4 b.n 18 <addsym.constprop.0.isra.0+0x18>
4e: 6046 str r6, [r0, #4]
50: e7eb b.n 2a <addsym.constprop.0.isra.0+0x2a>
00000052 <cclinstal>:
52: b510 push {r4, lr}
54: 460c mov r4, r1
56: f7ff fffe bl 0 <copy_unsigned_string>
5a: 4622 mov r2, r4
5c: e8bd 4010 ldmia.w sp!, {r4, lr}
60: 2100 movs r1, #0
62: 4b01 ldr r3, [pc, #4] ; (68 <cclinstal+0x16>)
64: e7cc b.n 0 <addsym.constprop.0.isra.0>
66: bf00 nop
68: 00000000 .word 0x00000000
0000006c <ndinstal>:
6c: b570 push {r4, r5, r6, lr}
6e: 460d mov r5, r1
70: f7ff fffe bl 0 <copy_string>
74: 4604 mov r4, r0
76: 4628 mov r0, r5
78: f7ff fffe bl 0 <copy_unsigned_string>
7c: 2200 movs r2, #0
7e: 4601 mov r1, r0
80: 4b02 ldr r3, [pc, #8] ; (8c <ndinstal+0x20>)
82: 4620 mov r0, r4
84: e8bd 4070 ldmia.w sp!, {r4, r5, r6, lr}
88: e7ba b.n 0 <addsym.constprop.0.isra.0>
8a: bf00 nop
8c: 00000194 .word 0x00000194
GCC-11.1.0
00000000 <addsym.constprop.0>:
0: e92d 47f0 stmdb sp!, {r4, r5, r6, r7, r8, r9, sl, lr}
4: 4689 mov r9, r1
6: 2165 movs r1, #101 ; 0x65
8: 461d mov r5, r3
a: 4607 mov r7, r0
c: 4690 mov r8, r2
e: f7ff fffe bl 0 <hashfunct>
12: 4606 mov r6, r0
14: f855 a020 ldr.w sl, [r5, r0, lsl #2]
18: f1ba 0f00 cmp.w sl, #0
1c: d112 bne.n 44 <addsym.constprop.0+0x44>
1e: 2014 movs r0, #20
20: f7ff fffe bl 0 <flex_alloc>
24: f855 3026 ldr.w r3, [r5, r6, lsl #2]
28: 4604 mov r4, r0
2a: b1a3 cbz r3, 56 <addsym.constprop.0+0x56>
2c: 6043 str r3, [r0, #4]
2e: 6018 str r0, [r3, #0]
30: 2000 movs r0, #0
32: e9c4 7902 strd r7, r9, [r4, #8]
36: 6020 str r0, [r4, #0]
38: f8c4 8010 str.w r8, [r4, #16]
3c: f845 4026 str.w r4, [r5, r6, lsl #2]
40: e8bd 87f0 ldmia.w sp!, {r4, r5, r6, r7, r8, r9, sl, pc}
44: 4638 mov r0, r7
46: f8da 1008 ldr.w r1, [sl, #8]
4a: f7ff fffe bl 0 <strcmp>
4e: b128 cbz r0, 5c <addsym.constprop.0+0x5c>
50: f8da a004 ldr.w sl, [sl, #4]
54: e7e0 b.n 18 <addsym.constprop.0+0x18>
56: f8c0 a004 str.w sl, [r0, #4]
5a: e7e9 b.n 30 <addsym.constprop.0+0x30>
5c: f04f 30ff mov.w r0, #4294967295 ; 0xffffffff
60: e7ee b.n 40 <addsym.constprop.0+0x40>
00000062 <cclinstal>:
62: b513 push {r0, r1, r4, lr}
64: 460c mov r4, r1
66: f7ff fffe bl 0 <copy_unsigned_string>
6a: 2365 movs r3, #101 ; 0x65
6c: 4622 mov r2, r4
6e: 9300 str r3, [sp, #0]
70: 2100 movs r1, #0
72: 4b02 ldr r3, [pc, #8] ; (7c <cclinstal+0x1a>)
74: f7ff ffc4 bl 0 <addsym.constprop.0>
78: b002 add sp, #8
7a: bd10 pop {r4, pc}
7c: 00000000 .word 0x00000000
00000080 <ndinstal>:
80: b537 push {r0, r1, r2, r4, r5, lr}
82: 460d mov r5, r1
84: f7ff fffe bl 0 <copy_string>
88: 4604 mov r4, r0
8a: 4628 mov r0, r5
8c: f7ff fffe bl 0 <copy_unsigned_string>
90: 2365 movs r3, #101 ; 0x65
92: 4601 mov r1, r0
94: 9300 str r3, [sp, #0]
96: 2200 movs r2, #0
98: 4620 mov r0, r4
9a: 4b02 ldr r3, [pc, #8] ; (a4 <ndinstal+0x24>)
9c: f7ff ffb0 bl 0 <addsym.constprop.0>
a0: b003 add sp, #12
a2: bd30 pop {r4, r5, pc}
a4: 00000194 .word 0x00000194
