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Fiddle ARM atomic.h to avoid -Wvolatile-register-var warnings.

This commit is contained in:
Roland McGrath 2012-08-08 13:57:50 -07:00
parent 7f3e1ad05f
commit 69a14aa487
2 changed files with 27 additions and 13 deletions
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5
ports/ChangeLog.arm
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@ -1,5 +1,10 @@
2012-08-08 Roland McGrath <roland@hack.frob.com> 2012-08-08 Roland McGrath <roland@hack.frob.com>
* sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h
[!__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4]
(__arch_compare_and_exchange_val_32_acq): Use uint32_t rather than
__typeof (...) for non-pointer variables derived from the arguments.
* sysdeps/arm/dl-irel.h: Include <ldsodefs.h>. * sysdeps/arm/dl-irel.h: Include <ldsodefs.h>.
* sysdeps/arm/dl-machine.h (elf_machine_load_address): Use proper type * sysdeps/arm/dl-machine.h (elf_machine_load_address): Use proper type

35
ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h
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@ -1,4 +1,4 @@
/* Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. /* Copyright (C) 2002-2012 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
@ -74,17 +74,24 @@ void __arm_link_error (void);
/* It doesn't matter what register is used for a_oldval2, but we must /* It doesn't matter what register is used for a_oldval2, but we must
specify one to work around GCC PR rtl-optimization/21223. Otherwise specify one to work around GCC PR rtl-optimization/21223. Otherwise
it may cause a_oldval or a_tmp to be moved to a different register. */ it may cause a_oldval or a_tmp to be moved to a different register.
We use the union trick rather than simply using __typeof (...) in the
declarations of A_OLDVAL et al because when NEWVAL or OLDVAL is of the
form *PTR and PTR has a 'volatile ... *' type, then __typeof (*PTR) has
a 'volatile ...' type and this triggers -Wvolatile-register-var to
complain about 'register volatile ... asm ("reg")'. */
#elif defined __thumb2__ #elif defined __thumb2__
/* Thumb-2 has ldrex/strex. However it does not have barrier instructions, /* Thumb-2 has ldrex/strex. However it does not have barrier instructions,
so we still need to use the kernel helper. */ so we still need to use the kernel helper. */
#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ #define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
({ register __typeof (oldval) a_oldval asm ("r0"); \ ({ union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\
register __typeof (oldval) a_newval asm ("r1") = (newval); \ union { __typeof (newval) a; uint32_t v; } newval_arg = { .a = (newval) };\
register uint32_t a_oldval asm ("r0"); \
register uint32_t a_newval asm ("r1") = newval_arg.v; \
register __typeof (mem) a_ptr asm ("r2") = (mem); \ register __typeof (mem) a_ptr asm ("r2") = (mem); \
register __typeof (oldval) a_tmp asm ("r3"); \ register uint32_t a_tmp asm ("r3"); \
register __typeof (oldval) a_oldval2 asm ("r4") = (oldval); \ register uint32_t a_oldval2 asm ("r4") = oldval_arg.v; \
__asm__ __volatile__ \ __asm__ __volatile__ \
("0:\tldr\t%[tmp],[%[ptr]]\n\t" \ ("0:\tldr\t%[tmp],[%[ptr]]\n\t" \
"cmp\t%[tmp], %[old2]\n\t" \ "cmp\t%[tmp], %[old2]\n\t" \
@ -100,14 +107,16 @@ void __arm_link_error (void);
: [new] "r" (a_newval), [ptr] "r" (a_ptr), \ : [new] "r" (a_newval), [ptr] "r" (a_ptr), \
[old2] "r" (a_oldval2) \ [old2] "r" (a_oldval2) \
: "ip", "lr", "cc", "memory"); \ : "ip", "lr", "cc", "memory"); \
a_tmp; }) (__typeof (oldval)) a_tmp; })
#else #else
#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ #define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
({ register __typeof (oldval) a_oldval asm ("r0"); \ ({ union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\
register __typeof (oldval) a_newval asm ("r1") = (newval); \ union { __typeof (newval) a; uint32_t v; } newval_arg = { .a = (newval) };\
register uint32_t a_oldval asm ("r0"); \
register uint32_t a_newval asm ("r1") = newval_arg.v; \
register __typeof (mem) a_ptr asm ("r2") = (mem); \ register __typeof (mem) a_ptr asm ("r2") = (mem); \
register __typeof (oldval) a_tmp asm ("r3"); \ register uint32_t a_tmp asm ("r3"); \
register __typeof (oldval) a_oldval2 asm ("r4") = (oldval); \ register uint32_t a_oldval2 asm ("r4") = oldval_arg.v; \
__asm__ __volatile__ \ __asm__ __volatile__ \
("0:\tldr\t%[tmp],[%[ptr]]\n\t" \ ("0:\tldr\t%[tmp],[%[ptr]]\n\t" \
"cmp\t%[tmp], %[old2]\n\t" \ "cmp\t%[tmp], %[old2]\n\t" \
@ -123,7 +132,7 @@ void __arm_link_error (void);
: [new] "r" (a_newval), [ptr] "r" (a_ptr), \ : [new] "r" (a_newval), [ptr] "r" (a_ptr), \
[old2] "r" (a_oldval2) \ [old2] "r" (a_oldval2) \
: "ip", "lr", "cc", "memory"); \ : "ip", "lr", "cc", "memory"); \
a_tmp; }) (__typeof (oldval)) a_tmp; })
#endif #endif
#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \ #define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \