diff options
author | Ivan Maidanski <ivmai@mail.ru> | 2022-08-10 11:51:43 +0300 |
---|---|---|
committer | Ivan Maidanski <ivmai@mail.ru> | 2022-08-10 11:51:43 +0300 |
commit | 124c97a9ab14735334850e57379e08d0d2c089d8 (patch) | |
tree | fd01d2eaaf14f7fbaacd1cda3c8770271108b1b3 | |
parent | 620ae9dd25faf62e96063c5440a0be648ae29d46 (diff) | |
download | libatomic_ops-124c97a9ab14735334850e57379e08d0d2c089d8.tar.gz |
Fix AO_compare_and_swap_full asm code for clang on sparc
Issue #52 (libatomic_ops).
The issue (SIGSEGV in test_malloc) is observed with clang-13, at least.
The workaround is to simplify asm code of AO_compare_and_swap_full
(moving the comparison of CAS result and old value to C code).
* src/atomic_ops/sysdeps/gcc/sparc.h [(!(AO_GNUC_PREREQ(12,0)
|| AO_CLANG_PREREQ(13,0)) || AO_DISABLE_GCC_ATOMICS) && !AO_NO_SPARC_V9
&& !AO_GENERALIZE_ASM_BOOL_CAS] (AO_compare_and_swap_full): Remove ret
local variable; remove cmp, be, mov, clr instructions from asm block
(to match that of AO_fetch_compare_and_swap_full); remove cc from asm
block clobbers; change specifier for old input operand of asm block
(from "0" to "r"); return new_val==old instead of ret.
-rw-r--r-- | src/atomic_ops/sysdeps/gcc/sparc.h | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/src/atomic_ops/sysdeps/gcc/sparc.h b/src/atomic_ops/sysdeps/gcc/sparc.h index 1d52be7..3f107d8 100644 --- a/src/atomic_ops/sysdeps/gcc/sparc.h +++ b/src/atomic_ops/sysdeps/gcc/sparc.h @@ -48,23 +48,17 @@ AO_test_and_set_full(volatile AO_TS_t *addr) { /* Returns nonzero if the comparison succeeded. */ AO_INLINE int AO_compare_and_swap_full(volatile AO_t *addr, AO_t old, AO_t new_val) { - AO_t ret; __asm__ __volatile__ ("membar #StoreLoad | #LoadLoad\n\t" # if defined(__arch64__) - "casx [%2],%0,%1\n\t" + "casx [%1],%2,%0\n\t" # else - "cas [%2],%0,%1\n\t" /* 32-bit version */ + "cas [%1],%2,%0\n\t" /* 32-bit version */ # endif "membar #StoreLoad | #StoreStore\n\t" - "cmp %0,%1\n\t" - "be,a 0f\n\t" - "mov 1,%0\n\t"/* one insn after branch always executed */ - "clr %0\n\t" - "0:\n\t" - : "=r" (ret), "+r" (new_val) - : "r" (addr), "0" (old) - : "memory", "cc"); - return (int)ret; + : "+r" (new_val) + : "r" (addr), "r" (old) + : "memory"); + return new_val == old; } # define AO_HAVE_compare_and_swap_full # endif /* !AO_GENERALIZE_ASM_BOOL_CAS */ |