http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49515
Summary: [4.7 Regression] gcc.dg/torture/tls/thr-init-2.c -O2
-fpic execution test failure
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: ubiz...@gmail.com
CC: r...@gcc.gnu.org
Target: alpha-linux-gnu
gcc.dg/torture/tls/thr-init-2.c -O2 -fpic testcase fails on
alphaev68-pc-linux-gnu due to clobbering of $16 register.
The problematic function in the testcase compiles to (-O2 -fpic):
$test_code..ng:
ldq $27,__tls_get_addr($29) !literal!1
lda $30,-16($30)
stq $26,0($30)
stq $9,8($30)
.prologue 1
mov $16,$9
lda $16,fstat($29) !tlsldm!1
jsr $26,($27),__tls_get_addr !lituse_tlsldm!1
ldah $29,0($26) !gpdisp!3
ldah $1,fstat($0) !dtprelhi
ldq $26,0($30)
lda $29,0($29) !gpdisp!3
>>> ldl $16,fstat($1) !dtprello
>>> addl $16,$9,$16
ldq $9,8($30)
addl $31,$16,$0
>>> stl $16,fstat($1) !dtprello
lda $30,16($30)
ret $31,($26),1
$ ./a.out
a=2 fstat=33554434
Aborted
The difference to working code from gcc-4.4.5 is:
@@ -26,17 +26,18 @@
ldah $1,fstat($0) !dtprelhi
ldq $26,0($30)
lda $29,0($29) !gpdisp!3
- ldl $0,fstat($1) !dtprello
- addl $0,$9,$0
+ ldl $16,fstat($1) !dtprello
+ addl $16,$9,$16
ldq $9,8($30)
- stl $0,fstat($1) !dtprello
+ addl $31,$16,$0
+ stl $16,fstat($1) !dtprello
lda $30,16($30)
ret $31,($26),1
Please note that $0 is used instead (extra addl is just a move from $16 to $0).
Does !dtprello relocation need live $16 register? The relevant patterns in
alpha.md do not model that dependancy.
