http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59710
Bug ID: 59710
Summary: Nios2: Missing gprel optimization
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: sebastian.hu...@embedded-brains.de
The compiler doesn't generate gprel load/store operations for variables
external to the translation unit (this is unlike the PowerPC target for
example). Consider the following test case:
gprel-ok.c:
int iii;
int jjj = 456;
void gprel_ok(void)
{
iii = 123;
jjj = 789;
}
gprel-not-ok.c:
extern int iii;
extern int jjj;
void gprel_not_ok(void)
{
iii = 123;
jjj = 789;
}
nios2-elf-gcc -O2 -fno-common -S gprel-ok.c
nios2-elf-gcc -O2 -fno-common -S gprel-not-ok.c
gprel-ok.s:
.file "gprel-ok.c"
.section .text
.align 2
.global gprel_ok
.type gprel_ok, @function
gprel_ok:
movi r2, 123
stw r2, %gprel(iii)(gp)
movi r2, 789
stw r2, %gprel(jjj)(gp)
ret
.size gprel_ok, .-gprel_ok
.global jjj
.section .sdata,"aws",@progbits
.align 2
.type jjj, @object
.size jjj, 4
jjj:
.long 456
.global iii
.section .sbss,"aws",@nobits
.align 2
.type iii, @object
.size iii, 4
iii:
.zero 4
.ident "GCC: (GNU) 4.9.0 20140103 (experimental)"
gprel-not-ok.s:
.file "gprel-not-ok.c"
.section .text
.align 2
.global gprel_not_ok
.type gprel_not_ok, @function
gprel_not_ok:
movi r3, 123
movhi r2, %hiadj(iii)
addi r2, r2, %lo(iii)
stw r3, 0(r2)
movi r3, 789
movhi r2, %hiadj(jjj)
addi r2, r2, %lo(jjj)
stw r3, 0(r2)
ret
.size gprel_not_ok, .-gprel_not_ok
.ident "GCC: (GNU) 4.9.0 20140103 (experimental)"
