https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110093
--- Comment #2 from Georg-Johann Lay <gjl at gcc dot gnu.org> ---
Meanwhile (2023-08-22) the generated code from above got worse once again and
even pops a frame:
long add (long aa, long bb, long cc)
{
if (cc < 0)
return aa - cc;
return aa + bb;
}
> avr-gcc -Os -S -dp
add:
push r4 ; 83 [c=4 l=1] pushqi1/0
push r5 ; 84 [c=4 l=1] pushqi1/0
push r6 ; 85 [c=4 l=1] pushqi1/0
push r7 ; 86 [c=4 l=1] pushqi1/0
push r8 ; 87 [c=4 l=1] pushqi1/0
push r9 ; 88 [c=4 l=1] pushqi1/0
push r10 ; 89 [c=4 l=1] pushqi1/0
push r11 ; 90 [c=4 l=1] pushqi1/0
push r14 ; 91 [c=4 l=1] pushqi1/0
push r15 ; 92 [c=4 l=1] pushqi1/0
push r16 ; 93 [c=4 l=1] pushqi1/0
push r17 ; 94 [c=4 l=1] pushqi1/0
push r28 ; 95 [c=4 l=1] pushqi1/0
push r29 ; 96 [c=4 l=1] pushqi1/0
; SP -= 4 ; 100 [c=4 l=2] *addhi3_sp
rcall .
rcall .
in r28,__SP_L__ ; 126 [c=4 l=2] *movhi/7
in r29,__SP_H__
/* prologue: function */
/* frame size = 4 */
/* stack size = 18 */
.L__stack_usage = 18
mov r8,r22 ; 69 [c=4 l=1] movqi_insn/0
mov r9,r23 ; 70 [c=4 l=1] movqi_insn/0
mov r10,r24 ; 71 [c=4 l=1] movqi_insn/0
mov r11,r25 ; 72 [c=4 l=1] movqi_insn/0
std Y+1,r18 ; 73 [c=4 l=1] movqi_insn/2
std Y+2,r19 ; 74 [c=4 l=1] movqi_insn/2
std Y+3,r20 ; 75 [c=4 l=1] movqi_insn/2
std Y+4,r21 ; 76 [c=4 l=1] movqi_insn/2
mov r4,r14 ; 77 [c=4 l=1] movqi_insn/0
mov r5,r15 ; 78 [c=4 l=1] movqi_insn/0
mov r6,r16 ; 79 [c=4 l=1] movqi_insn/0
mov r7,r17 ; 80 [c=4 l=1] movqi_insn/0
sbrs r7,7 ; 123 [c=4 l=2] *sbrx_branchhi
rjmp .L2
mov r25,r11 ; 67 [c=4 l=4] *movsi/0
mov r24,r10
mov r23,r9
mov r22,r8
sub r22,r4 ; 68 [c=16 l=4] *subsi3/0
sbc r23,r5
sbc r24,r6
sbc r25,r7
.L1:
/* epilogue start */
; SP += 4 ; 106 [c=4 l=4] *addhi3_sp
pop __tmp_reg__
pop __tmp_reg__
pop __tmp_reg__
pop __tmp_reg__
pop r29 ; 107 [c=4 l=1] popqi
pop r28 ; 108 [c=4 l=1] popqi
pop r17 ; 109 [c=4 l=1] popqi
pop r16 ; 110 [c=4 l=1] popqi
pop r15 ; 111 [c=4 l=1] popqi
pop r14 ; 112 [c=4 l=1] popqi
pop r11 ; 113 [c=4 l=1] popqi
pop r10 ; 114 [c=4 l=1] popqi
pop r9 ; 115 [c=4 l=1] popqi
pop r8 ; 116 [c=4 l=1] popqi
pop r7 ; 117 [c=4 l=1] popqi
pop r6 ; 118 [c=4 l=1] popqi
pop r5 ; 119 [c=4 l=1] popqi
pop r4 ; 120 [c=4 l=1] popqi
ret ; 121 [c=0 l=1] return_from_epilogue
.L2:
ldd r22,Y+1 ; 65 [c=16 l=4] *movsi/2
ldd r23,Y+2
ldd r24,Y+3
ldd r25,Y+4
add r22,r8 ; 66 [c=16 l=4] *addsi3/0
adc r23,r9
adc r24,r10
adc r25,r11
rjmp .L1 ; 124 [c=4 l=1] jump
.ident "GCC: (GNU) 14.0.0 20230822 (experimental)"
