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author | Roland McGrath <roland@hack.frob.com> | 2012-08-08 13:57:50 -0700 |
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committer | Roland McGrath <roland@hack.frob.com> | 2012-08-08 13:57:50 -0700 |
commit | 69a14aa48712cf436b3f31c59b3f9fcc71b5dbb4 (patch) | |
tree | 6bec1f3c38ed919c1862ff45002ade384ac0e39a /ports/sysdeps/unix | |
parent | 7f3e1ad05f1af9954e3daf605a79e624da715f5e (diff) | |
download | glibc-69a14aa48712cf436b3f31c59b3f9fcc71b5dbb4.tar.gz glibc-69a14aa48712cf436b3f31c59b3f9fcc71b5dbb4.tar.xz glibc-69a14aa48712cf436b3f31c59b3f9fcc71b5dbb4.zip |
Fiddle ARM atomic.h to avoid -Wvolatile-register-var warnings.
Diffstat (limited to 'ports/sysdeps/unix')
-rw-r--r-- | ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h b/ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h index 4e810a28d6..c9ad50d135 100644 --- a/ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h +++ b/ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h @@ -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. 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 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__ /* Thumb-2 has ldrex/strex. However it does not have barrier instructions, so we still need to use the kernel helper. */ #define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ - ({ register __typeof (oldval) a_oldval asm ("r0"); \ - register __typeof (oldval) a_newval asm ("r1") = (newval); \ + ({ union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\ + 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 (oldval) a_tmp asm ("r3"); \ - register __typeof (oldval) a_oldval2 asm ("r4") = (oldval); \ + register uint32_t a_tmp asm ("r3"); \ + register uint32_t a_oldval2 asm ("r4") = oldval_arg.v; \ __asm__ __volatile__ \ ("0:\tldr\t%[tmp],[%[ptr]]\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), \ [old2] "r" (a_oldval2) \ : "ip", "lr", "cc", "memory"); \ - a_tmp; }) + (__typeof (oldval)) a_tmp; }) #else -#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ - ({ register __typeof (oldval) a_oldval asm ("r0"); \ - register __typeof (oldval) a_newval asm ("r1") = (newval); \ +#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ + ({ union { __typeof (oldval) a; uint32_t v; } oldval_arg = { .a = (oldval) };\ + 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 (oldval) a_tmp asm ("r3"); \ - register __typeof (oldval) a_oldval2 asm ("r4") = (oldval); \ + register uint32_t a_tmp asm ("r3"); \ + register uint32_t a_oldval2 asm ("r4") = oldval_arg.v; \ __asm__ __volatile__ \ ("0:\tldr\t%[tmp],[%[ptr]]\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), \ [old2] "r" (a_oldval2) \ : "ip", "lr", "cc", "memory"); \ - a_tmp; }) + (__typeof (oldval)) a_tmp; }) #endif #define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \ |