* [PATCH] drm/i915: Use __is_constexpr()
@ 2019-03-20 15:40 Chris Wilson
2019-03-20 16:05 ` Randy Dunlap
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Chris Wilson @ 2019-03-20 15:40 UTC (permalink / raw)
To: intel-gfx; +Cc: Jani Nikula, Randy Dunlap
gcc-4.8 and older dislike the use of __builtin_constant_p() within a
constant expression context, and so we must use the magical
__is_constexpr() instead.
For example, with gcc-4.8.5:
../drivers/gpu/drm/i915/i915_reg.h:167:27: error: first argument to ‘__builtin_choose_expr’ not a constant
../include/linux/build_bug.h:16:45: error: bit-field ‘<anonymous>’ width not an integer constant
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: baa09e7d2f42 ("drm/i915: use REG_FIELD_PREP() to define register bitfield values")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
---
drivers/gpu/drm/i915/i915_reg.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 85e8d1a1f70b..50d0b2ae89eb 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -161,10 +161,10 @@
*/
#define REG_FIELD_PREP(__mask, __val) \
((u32)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \
- BUILD_BUG_ON_ZERO(!__builtin_constant_p(__mask)) + \
+ BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \
BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \
BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \
- BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
+ BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
/**
* REG_FIELD_GET() - Extract a u32 bitfield value
--
2.20.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] drm/i915: Use __is_constexpr()
2019-03-20 15:40 [PATCH] drm/i915: Use __is_constexpr() Chris Wilson
@ 2019-03-20 16:05 ` Randy Dunlap
2019-03-20 17:20 ` ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
2019-03-21 9:50 ` [PATCH] " Jani Nikula
2 siblings, 0 replies; 5+ messages in thread
From: Randy Dunlap @ 2019-03-20 16:05 UTC (permalink / raw)
To: Chris Wilson, intel-gfx; +Cc: Jani Nikula
On 3/20/19 8:40 AM, Chris Wilson wrote:
> gcc-4.8 and older dislike the use of __builtin_constant_p() within a
> constant expression context, and so we must use the magical
> __is_constexpr() instead.
>
> For example, with gcc-4.8.5:
> ../drivers/gpu/drm/i915/i915_reg.h:167:27: error: first argument to ‘__builtin_choose_expr’ not a constant
> ../include/linux/build_bug.h:16:45: error: bit-field ‘<anonymous>’ width not an integer constant
>
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Fixes: baa09e7d2f42 ("drm/i915: use REG_FIELD_PREP() to define register bitfield values")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Thanks.
> ---
> drivers/gpu/drm/i915/i915_reg.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 85e8d1a1f70b..50d0b2ae89eb 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -161,10 +161,10 @@
> */
> #define REG_FIELD_PREP(__mask, __val) \
> ((u32)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \
> - BUILD_BUG_ON_ZERO(!__builtin_constant_p(__mask)) + \
> + BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \
> BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \
> BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \
> - BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
> + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
>
> /**
> * REG_FIELD_GET() - Extract a u32 bitfield value
>
--
~Randy
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^ permalink raw reply [flat|nested] 5+ messages in thread* ✗ Fi.CI.CHECKPATCH: warning for drm/i915: Use __is_constexpr()
2019-03-20 15:40 [PATCH] drm/i915: Use __is_constexpr() Chris Wilson
2019-03-20 16:05 ` Randy Dunlap
@ 2019-03-20 17:20 ` Patchwork
2019-03-21 9:50 ` [PATCH] " Jani Nikula
2 siblings, 0 replies; 5+ messages in thread
From: Patchwork @ 2019-03-20 17:20 UTC (permalink / raw)
To: Chris Wilson; +Cc: intel-gfx
== Series Details ==
Series: drm/i915: Use __is_constexpr()
URL : https://patchwork.freedesktop.org/series/58278/
State : warning
== Summary ==
$ dim checkpatch origin/drm-tip
3ae1e5b1f498 drm/i915: Use __is_constexpr()
-:38: WARNING:LONG_LINE: line over 100 characters
#38: FILE: drivers/gpu/drm/i915/i915_reg.h:167:
+ BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
total: 0 errors, 1 warnings, 0 checks, 12 lines checked
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] drm/i915: Use __is_constexpr()
2019-03-20 15:40 [PATCH] drm/i915: Use __is_constexpr() Chris Wilson
2019-03-20 16:05 ` Randy Dunlap
2019-03-20 17:20 ` ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
@ 2019-03-21 9:50 ` Jani Nikula
2019-03-21 10:00 ` Chris Wilson
2 siblings, 1 reply; 5+ messages in thread
From: Jani Nikula @ 2019-03-21 9:50 UTC (permalink / raw)
To: Chris Wilson, intel-gfx; +Cc: Randy Dunlap
On Wed, 20 Mar 2019, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> gcc-4.8 and older dislike the use of __builtin_constant_p() within a
> constant expression context, and so we must use the magical
> __is_constexpr() instead.
>
> For example, with gcc-4.8.5:
> ../drivers/gpu/drm/i915/i915_reg.h:167:27: error: first argument to ‘__builtin_choose_expr’ not a constant
> ../include/linux/build_bug.h:16:45: error: bit-field ‘<anonymous>’ width not an integer constant
>
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Fixes: baa09e7d2f42 ("drm/i915: use REG_FIELD_PREP() to define register bitfield values")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Randy Dunlap <rdunlap@infradead.org>
Thanks, Uma reported this too and confirmed __is_constexpr works.
Reported-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 85e8d1a1f70b..50d0b2ae89eb 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -161,10 +161,10 @@
> */
> #define REG_FIELD_PREP(__mask, __val) \
> ((u32)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \
> - BUILD_BUG_ON_ZERO(!__builtin_constant_p(__mask)) + \
> + BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \
> BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \
> BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \
> - BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
> + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
>
> /**
> * REG_FIELD_GET() - Extract a u32 bitfield value
--
Jani Nikula, Intel Open Source Graphics Center
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] drm/i915: Use __is_constexpr()
2019-03-21 9:50 ` [PATCH] " Jani Nikula
@ 2019-03-21 10:00 ` Chris Wilson
0 siblings, 0 replies; 5+ messages in thread
From: Chris Wilson @ 2019-03-21 10:00 UTC (permalink / raw)
To: Jani Nikula, intel-gfx; +Cc: Randy Dunlap
Quoting Jani Nikula (2019-03-21 09:50:25)
> On Wed, 20 Mar 2019, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > gcc-4.8 and older dislike the use of __builtin_constant_p() within a
> > constant expression context, and so we must use the magical
> > __is_constexpr() instead.
> >
> > For example, with gcc-4.8.5:
> > ../drivers/gpu/drm/i915/i915_reg.h:167:27: error: first argument to ‘__builtin_choose_expr’ not a constant
> > ../include/linux/build_bug.h:16:45: error: bit-field ‘<anonymous>’ width not an integer constant
> >
> > Reported-by: Randy Dunlap <rdunlap@infradead.org>
> > Fixes: baa09e7d2f42 ("drm/i915: use REG_FIELD_PREP() to define register bitfield values")
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> > Cc: Jani Nikula <jani.nikula@intel.com>
> > Cc: Imre Deak <imre.deak@intel.com>
> > Cc: Randy Dunlap <rdunlap@infradead.org>
>
> Thanks, Uma reported this too and confirmed __is_constexpr works.
>
> Reported-by: Uma Shankar <uma.shankar@intel.com>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
And pushed for a quieter tomorrow. Thanks everyone for reporting!
-Chris
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-03-21 10:02 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2019-03-20 15:40 [PATCH] drm/i915: Use __is_constexpr() Chris Wilson
2019-03-20 16:05 ` Randy Dunlap
2019-03-20 17:20 ` ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
2019-03-21 9:50 ` [PATCH] " Jani Nikula
2019-03-21 10:00 ` Chris Wilson
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