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[#162] Fix 64bit atomic api issues for 32bit system-part2 #423

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[#162] Fix 64bit atomic api issues for 32bit system-part2 #423

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83 changes: 74 additions & 9 deletions include/click/atomic.hh
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Original file line number Diff line number Diff line change
Expand Up @@ -858,10 +858,34 @@ atomic_uint64_t::operator+=(int64_t delta)
#elif CLICK_ATOMIC_BUILTINS
__atomic_add_fetch(&_val, delta, CLICK_ATOMIC_MEMORDER);
#elif CLICK_ATOMIC_X86
asm volatile (CLICK_ATOMIC_LOCK "addq %1,%0"
#if defined(__x86_64__)
asm volatile (CLICK_ATOMIC_LOCK "addq %1,%0"
: "=m" (CLICK_ATOMIC_VAL)
: "r" (delta), "m" (CLICK_ATOMIC_VAL)
: "cc");
#else
uint32_t dlow = static_cast<uint32_t>(delta & 0xFFFFFFFF);
int32_t dhigh = static_cast<int32_t>(delta >> 32);

asm volatile (
"movl %%ebx, %%esi\n\t" // Save EBX (needed for PIC)
"1:\n\t"
"movl (%[addr]), %%eax\n\t" // EAX = old low
"movl 4(%[addr]), %%edx\n\t" // EDX = old high
"movl %%eax, %%ebx\n\t" // EBX = expected low
"movl %%edx, %%ecx\n\t" // ECX = expected high
"addl %[delta_low], %%ebx\n\t" // EBX = new low
"adcl %[delta_high], %%ecx\n\t" // ECX = new high (+ carry)
CLICK_ATOMIC_LOCK "cmpxchg8b (%[addr])\n\t" // Atomically compare and exchange
"jnz 1b\n\t" // Retry if comparison failed
"movl %%esi, %%ebx\n\t" // Restore EBX
:
: [addr] "r" (&_val),
[delta_low] "m" (dlow),
[delta_high] "m" (dhigh) // sign-extend high part
: "eax", "edx", "ecx", "esi", "memory"
);
#endif
#else
CLICK_ATOMIC_VAL += delta;
#endif
Expand All @@ -877,10 +901,32 @@ atomic_uint64_t::add(volatile uint64_t &x, uint64_t delta)
#elif CLICK_ATOMIC_BUILTINS
__atomic_add_fetch(&x, delta, CLICK_ATOMIC_MEMORDER);
#elif CLICK_ATOMIC_X86
asm volatile (CLICK_ATOMIC_LOCK "addq %1,%0"
: "=m" (x)
: "r" (delta), "m" (x)
: "cc");
#if defined(__x86_64__)
asm volatile (CLICK_ATOMIC_LOCK "addq %1,%0"
: "=m" (x)
: "r" (delta), "m" (x)
: "cc");
#else
uint32_t dlow = static_cast<uint32_t>(delta & 0xFFFFFFFF);
uint32_t dhigh = static_cast<uint32_t>(delta >> 32);
asm volatile (
"movl %%ebx, %%esi\n\t" // Save EBX
"1:\n\t"
"movl (%[addr]), %%eax\n\t" // EAX = old low
"movl 4(%[addr]), %%edx\n\t" // EDX = old high
"movl %%eax, %%ebx\n\t" // EBX = expected low
"movl %%edx, %%ecx\n\t" // ECX = expected high
"addl %[delta_low], %%ebx\n\t" // EBX = new low
"adcl %[delta_high], %%ecx\n\t" // ECX = new high (+ carry)
CLICK_ATOMIC_LOCK "cmpxchg8b (%[addr])\n\t" // Try to atomically swap
"jnz 1b\n\t" // Retry if failed
"movl %%esi, %%ebx\n\t" // Restore EBX
:
: [addr] "r" (&x),
[delta_low] "m" (dlow),
[delta_high] "m" (dhigh)
: "eax", "edx", "ecx", "esi", "memory");
#endif
#else
x += delta;
#endif
Expand All @@ -895,10 +941,29 @@ atomic_uint64_t::operator-=(int64_t delta)
#elif CLICK_ATOMIC_BUILTINS
__atomic_sub_fetch(&CLICK_ATOMIC_VAL, delta, CLICK_ATOMIC_MEMORDER);
#elif CLICK_ATOMIC_X86
asm volatile (CLICK_ATOMIC_LOCK "subq %1,%0"
: "=m" (CLICK_ATOMIC_VAL)
: "r" (delta), "m" (CLICK_ATOMIC_VAL)
: "cc");
#if defined(__x86_64__)
asm volatile (CLICK_ATOMIC_LOCK "subq %1,%0"
: "=m" (CLICK_ATOMIC_VAL)
: "r" (delta), "m" (CLICK_ATOMIC_VAL)
: "cc");
#else
uint32_t dlow = static_cast<uint32_t>(delta & 0xFFFFFFFF);
int32_t dhigh = static_cast<int32_t>(delta >> 32);
asm volatile("1:\n\t"
"movl (%[addr]), %%eax\n\t" // EAX = old low
"movl 4(%[addr]), %%edx\n\t" // EDX = old high
"movl %%eax, %%ebx\n\t" // EBX = old low
"movl %%edx, %%ecx\n\t" // ECX = old high
"subl %[vlo], %%ebx\n\t" // EBX -= value low
"sbbl %[vhi], %%ecx\n\t" // ECX -= value high + borrow
CLICK_ATOMIC_LOCK "cmpxchg8b (%[addr])\n\t" // Attempt atomic CAS
"jnz 1b\n\t" // Retry if it failed
:
: [addr] "r" (&_val),
[vlo] "m" (dlow),
[vhi] "m" (dhigh)
: "eax", "ebx", "ecx", "edx", "memory");
#endif
#else
CLICK_ATOMIC_VAL -= delta;
#endif
Expand Down