[PATCH next v2 06/11] minmax: Remove 'constexpr' check from __careful_clamp()

David Laight
2024-02-25T16:52:27Z

Nothing requires that clamp() return a constant expression.
The logic to do so significantly increases the .i file.
Remove the check and directly expand __clamp_once() from clamp_t()
since the type check can't fail.

Signed-off-by: David Laight <david.laight@aculab.com>
---
include/linux/minmax.h | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

Changes for v2:
- Typographical and spelling corrections to the commit messages.
Patches unchanged.

diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index 111c52a14fe5..5c7fce76abe5 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -141,12 +141,10 @@
"clamp() low limit " #lo " greater than high limit " #hi); \
__clamp(__val_##uniq, __lo_##uniq, __hi_##uniq); })

-#define __careful_clamp(val, lo, hi, uniq) \
- __builtin_choose_expr(__is_constexpr((val) - (lo) + (hi)), \
- __clamp(val, lo, hi), \
- ({ _Static_assert(__types_ok(val, lo), "clamp() 'lo' signedness error"); \
- _Static_assert(__types_ok(val, hi), "clamp() 'hi' signedness error"); \
- __clamp_once(val, lo, hi, uniq); }))
+#define __careful_clamp(val, lo, hi, uniq) ({ \
+ _Static_assert(__types_ok(val, lo), "clamp() 'lo' signedness error"); \
+ _Static_assert(__types_ok(val, hi), "clamp() 'hi' signedness error"); \
+ __clamp_once(val, lo, hi, uniq); })

/**
* clamp - return a value clamped to a given range with strict typechecking
@@ -168,7 +166,9 @@
* This macro does no typechecking and uses temporary variables of type
* @type to make all the comparisons.
*/
-#define clamp_t(type, val, lo, hi) clamp((type)(val), (type)(lo), (type)(hi))
+#define __clamp_t(type, val, lo, hi, uniq) \
+ __clamp_once((type)(val), (type)(lo), (type)(hi), uniq)
+#define clamp_t(type, val, lo, hi) __clamp_t(type, val, lo, hi, __COUNTER__)

/**
* clamp_val - return a value clamped to a given range using val's type