From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Force __builtin_constant_p to evaluate whether the argument to atomic_add
& atomic_sub is constant in the front-end before optimisations which
can lead GCC to output a call to __bad_increment_for_ia64_fetch_and_add().
See GCC bugzilla 83653.
Signed-off-by: Jakub Jelinek <jakub@xxxxxxxxxx>
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
Linus: Willy isn't pining for the old days working on ia64. He
has some patches to generic code that he can't push because this
compiler issue breaks the ia64 build with his new stuff applied.
arch/ia64/include/asm/atomic.h | 37 +++++++++++++++++++------------------
1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h
index 28e02c99be6d..762eeb0fcc1d 100644
--- a/arch/ia64/include/asm/atomic.h
+++ b/arch/ia64/include/asm/atomic.h
@@ -65,29 +65,30 @@ ia64_atomic_fetch_##op (int i, atomic_t *v) \
ATOMIC_OPS(add, +)
ATOMIC_OPS(sub, -)
-#define atomic_add_return(i,v) \
+#ifdef __OPTIMIZE__
+#define __ia64_atomic_const(i) __builtin_constant_p(i) ? \
+ ((i) == 1 || (i) == 4 || (i) == 8 || (i) == 16 || \
+ (i) == -1 || (i) == -4 || (i) == -8 || (i) == -16) : 0
+
+#define atomic_add_return(i, v) \
({ \
- int __ia64_aar_i = (i); \
- (__builtin_constant_p(i) \
- && ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
- || (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
- || (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
- || (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
- ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
- : ia64_atomic_add(__ia64_aar_i, v); \
+ int __i = (i); \
+ static const int __ia64_atomic_p = __ia64_atomic_const(i); \
+ __ia64_atomic_p ? ia64_fetch_and_add(__i, &(v)->counter) : \
+ ia64_atomic_add(__i, v); \
})
-#define atomic_sub_return(i,v) \
+#define atomic_sub_return(i, v) \
({ \
- int __ia64_asr_i = (i); \
- (__builtin_constant_p(i) \
- && ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
- || (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
- || (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
- || (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
- ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
- : ia64_atomic_sub(__ia64_asr_i, v); \
+ int __i = (i); \
+ static const int __ia64_atomic_p = __ia64_atomic_const(i); \
+ __ia64_atomic_p ? ia64_fetch_and_add(-__i, &(v)->counter) : \
+ ia64_atomic_sub(__i, v); \
})
+#else
+#define atomic_add_return(i, v) ia64_atomic_add(i, v)
+#define atomic_sub_return(i, v) ia64_atomic_sub(i, v)
+#endif
#define atomic_fetch_add(i,v) \
({ \
--
2.14.1
--
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