https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100622
Thomas Koenig <tkoenig at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|SUSPENDED |UNCONFIRMED
Ever confirmed|1 |0
--- Comment #2 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
So, with recent trunk now.
[tkoenig@gcc135 tmp]$ gcc -v
Es werden eingebaute Spezifikationen verwendet.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/home/tkoenig/libexec/gcc/powerpc64le-unknown-linux-gnu/12.0.0/lto-wrapper
Ziel: powerpc64le-unknown-linux-gnu
Konfiguriert mit: ../trunk/configure --prefix=/home/tkoenig
--enable-languages=c,c++,fortran
Thread-Modell: posix
Unterstützte LTO-Kompressionsalgorithmen: zlib
gcc-Version 12.0.0 20210516 (experimental) (GCC)
[tkoenig@gcc135 tmp]$ cat add.c
unsigned int foo(unsigned int *a, int n)
{
int i;
unsigned int res = 0;
for (i=0; i<n; i++)
res += a[i];
return res;
}
unsigned int foo2 (unsigned int *a, int n)
{
int i;
unsigned long res = 0;
for (i=0; i<n; i++)
res += a[i];
return res;
}
[tkoenig@gcc135 tmp]$ gcc -O -c add.c && objdump --disassemble add.o
add.o: file format elf64-powerpcle
Disassembly of section .text:
0000000000000000 <foo>:
0: 00 00 04 2c cmpwi r4,0
4: 30 00 81 40 ble 34 <foo+0x34>
8: 20 00 89 78 clrldi r9,r4,32
c: fc ff 43 39 addi r10,r3,-4
10: 00 00 60 38 li r3,0
14: a6 03 29 7d mtctr r9
18: 04 00 0a 85 lwzu r8,4(r10)
1c: 14 1a 68 7c add r3,r8,r3
20: 20 00 63 78 clrldi r3,r3,32
24: ff ff 29 39 addi r9,r9,-1
28: 20 00 29 79 clrldi r9,r9,32
2c: ec ff 00 42 bdnz 18 <foo+0x18>
30: 20 00 80 4e blr
34: 00 00 60 38 li r3,0
38: 20 00 80 4e blr
...
0000000000000048 <foo2>:
48: 00 00 04 2c cmpwi r4,0
4c: 30 00 81 40 ble 7c <foo2+0x34>
50: 20 00 89 78 clrldi r9,r4,32
54: fc ff 43 39 addi r10,r3,-4
58: 00 00 60 38 li r3,0
5c: a6 03 29 7d mtctr r9
60: 04 00 0a 85 lwzu r8,4(r10)
64: 14 42 63 7c add r3,r3,r8
68: ff ff 29 39 addi r9,r9,-1
6c: 20 00 29 79 clrldi r9,r9,32
70: f0 ff 00 42 bdnz 60 <foo2+0x18>
74: 20 00 63 78 clrldi r3,r3,32
78: 20 00 80 4e blr
7c: 00 00 60 38 li r3,0
80: f4 ff ff 4b b 74 <foo2+0x2c>
With -O2 -fno-unroll-loops (foo only):
0000000000000000 <foo>:
0: 00 00 04 2c cmpwi r4,0
4: 3c 00 81 40 ble 40 <foo+0x40>
8: 20 00 8a 78 clrldi r10,r4,32
c: fc ff 23 39 addi r9,r3,-4
10: a6 03 49 7d mtctr r10
14: 00 00 60 38 li r3,0
18: 00 00 00 60 nop
1c: 00 00 42 60 ori r2,r2,0
20: 04 00 49 85 lwzu r10,4(r9)
24: 14 1a 6a 7c add r3,r10,r3
28: 20 00 63 78 clrldi r3,r3,32
2c: f4 ff 00 42 bdnz 20 <foo+0x20>
30: 20 00 80 4e blr
34: 00 00 00 60 nop
38: 00 00 00 60 nop
3c: 00 00 42 60 ori r2,r2,0
40: 00 00 60 38 li r3,0
44: 20 00 80 4e blr
...
54: 00 00 00 60 nop
58: 00 00 00 60 nop
5c: 00 00 42 60 ori r2,r2,0
The clrldi is still in there.
