Messages in this thread Patch in this message | | | Date | Wed, 13 Apr 2011 00:00:45 +0300 | From | Alexey Dobriyan <> | Subject | [PATCH] remove abs64() |
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We don't need no stinking abs64() given some GCC extensions (especially __builtin_choose_expr()).
One abs() implementation is better than two abs() implementations.
New abs() doesn't expand type needlessly.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> ---
drivers/gpu/drm/drm_irq.c | 4 ++-- include/linux/kernel.h | 43 +++++++++++++++++++++---------------------- lib/div64.c | 2 +- 3 files changed, 24 insertions(+), 25 deletions(-)
--- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -154,7 +154,7 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc) * available. In that case we can't account for this and just * hope for the best. */ - if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) { + if ((vblrc > 0) && (abs(diff_ns) > 1000000)) { atomic_inc(&dev->_vblank_count[crtc]); smp_mb__after_atomic_inc(); } @@ -1290,7 +1290,7 @@ bool drm_handle_vblank(struct drm_device *dev, int crtc) * e.g., due to spurious vblank interrupts. We need to * ignore those for accounting. */ - if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) { + if (abs(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) { /* Store new timestamp in ringbuffer. */ vblanktimestamp(dev, crtc, vblcount + 1) = tvblank; --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -143,28 +143,27 @@ extern int _cond_resched(void); #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) -/* - * abs() handles unsigned and signed longs, ints, shorts and chars. For all - * input types abs() returns a signed long. - * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() - * for those. - */ -#define abs(x) ({ \ - long ret; \ - if (sizeof(x) == sizeof(long)) { \ - long __x = (x); \ - ret = (__x < 0) ? -__x : __x; \ - } else { \ - int __x = (x); \ - ret = (__x < 0) ? -__x : __x; \ - } \ - ret; \ - }) - -#define abs64(x) ({ \ - s64 __x = (x); \ - (__x < 0) ? -__x : __x; \ - }) +#define abs(x) \ +({ \ + typeof(x) _x = (x); \ + \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(_x), signed char), \ + (unsigned char)({ _x < 0 ? -_x : _x; }), \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(_x), short), \ + (unsigned short)({ _x < 0 ? -_x : _x; }), \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(_x), int), \ + (unsigned int)({ _x < 0 ? -_x : _x; }), \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(_x), long), \ + (unsigned long)({ _x < 0 ? -_x : _x; }), \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(_x), long long), \ + (unsigned long long)({ _x < 0 ? -_x : _x; }), \ + _x))))); \ +}) #ifdef CONFIG_PROVE_LOCKING void might_fault(void); --- a/lib/div64.c +++ b/lib/div64.c @@ -121,7 +121,7 @@ s64 div64_s64(s64 dividend, s64 divisor) { s64 quot, t; - quot = div64_u64(abs64(dividend), abs64(divisor)); + quot = div64_u64(abs(dividend), abs(divisor)); t = (dividend ^ divisor) >> 63; return (quot ^ t) - t;
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