[PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Jani Nikula]

The kernel has plenty of ternary operators to choose between constant
strings, such as condition ? "yes" : "no", as well as value == 1 ? "" :
"s":

$ git grep '? "yes" : "no"' | wc -l
258
$ git grep '? "on" : "off"' | wc -l
204
$ git grep '? "enabled" : "disabled"' | wc -l
196
$ git grep '? "" : "s"' | wc -l
25

Additionally, there are some occurences of the same in reverse order,
split to multiple lines, or otherwise not caught by the simple grep.

Add helpers to return the constant strings. Remove existing equivalent
and conflicting functions in i915, cxgb4, and USB core. Further
conversion can be done incrementally.

The main goal here is to abstract recurring patterns, and slightly clean
up the code base by not open coding the ternary operators.

Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: Vishal Kulkarni <vishal@chelsio.com>
Cc: netdev@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

v2: add string-choice.[ch] to not clutter kernel.h and to actually save
space on string constants.

v3: back to static inlines based on Rasmus' feedback

v4: Massaged commit message about space savings to make it less fluffy
based on Rasmus' feedback.

Example of further cleanup possibilities are at [1], to be done
incrementally afterwards.

[1] http://lore.kernel.org/r/20190903133731.2094-2-jani.nikula@intel.com
---
 drivers/gpu/drm/i915/i915_utils.h             | 16 +---------
 .../ethernet/chelsio/cxgb4/cxgb4_debugfs.c    | 12 +------
 drivers/usb/core/config.c                     |  6 +---
 drivers/usb/core/generic.c                    |  6 +---
 include/linux/string-choice.h                 | 31 +++++++++++++++++++
 5 files changed, 35 insertions(+), 36 deletions(-)
 create mode 100644 include/linux/string-choice.h

diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
index 562f756da421..794f02a90efe 100644
--- a/drivers/gpu/drm/i915/i915_utils.h
+++ b/drivers/gpu/drm/i915/i915_utils.h
@@ -28,6 +28,7 @@
 #include <linux/list.h>
 #include <linux/overflow.h>
 #include <linux/sched.h>
+#include <linux/string-choice.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
@@ -395,21 +396,6 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 #define MBps(x) KBps(1000 * (x))
 #define GBps(x) ((u64)1000 * MBps((x)))
 
-static inline const char *yesno(bool v)
-{
-	return v ? "yes" : "no";
-}
-
-static inline const char *onoff(bool v)
-{
-	return v ? "on" : "off";
-}
-
-static inline const char *enableddisabled(bool v)
-{
-	return v ? "enabled" : "disabled";
-}
-
 static inline void add_taint_for_CI(unsigned int taint)
 {
 	/*
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
index ae6a47dd7dc9..d9123dae1d00 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
@@ -35,6 +35,7 @@
 #include <linux/seq_file.h>
 #include <linux/debugfs.h>
 #include <linux/string_helpers.h>
+#include <linux/string-choice.h>
 #include <linux/sort.h>
 #include <linux/ctype.h>
 
@@ -2023,17 +2024,6 @@ static const struct file_operations rss_debugfs_fops = {
 /* RSS Configuration.
  */
 
-/* Small utility function to return the strings "yes" or "no" if the supplied
- * argument is non-zero.
- */
-static const char *yesno(int x)
-{
-	static const char *yes = "yes";
-	static const char *no = "no";
-
-	return x ? yes : no;
-}
-
 static int rss_config_show(struct seq_file *seq, void *v)
 {
 	struct adapter *adapter = seq->private;
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 151a74a54386..52cee9067eb4 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <linux/string-choice.h>
 #include <asm/byteorder.h>
 #include "usb.h"
 
@@ -19,11 +20,6 @@
 #define USB_MAXCONFIG			8	/* Arbitrary limit */
 
 
-static inline const char *plural(int n)
-{
-	return (n == 1 ? "" : "s");
-}
-
 static int find_next_descriptor(unsigned char *buffer, int size,
     int dt1, int dt2, int *num_skipped)
 {
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index 38f8b3e31762..a784a09794d6 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -21,14 +21,10 @@
 
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
+#include <linux/string-choice.h>
 #include <uapi/linux/usb/audio.h>
 #include "usb.h"
 
-static inline const char *plural(int n)
-{
-	return (n == 1 ? "" : "s");
-}
-
 static int is_rndis(struct usb_interface_descriptor *desc)
 {
 	return desc->bInterfaceClass == USB_CLASS_COMM
diff --git a/include/linux/string-choice.h b/include/linux/string-choice.h
new file mode 100644
index 000000000000..320b598bd8f0
--- /dev/null
+++ b/include/linux/string-choice.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef __STRING_CHOICE_H__
+#define __STRING_CHOICE_H__
+
+#include <linux/types.h>
+
+static inline const char *yesno(bool v)
+{
+	return v ? "yes" : "no";
+}
+
+static inline const char *onoff(bool v)
+{
+	return v ? "on" : "off";
+}
+
+static inline const char *enableddisabled(bool v)
+{
+	return v ? "enabled" : "disabled";
+}
+
+static inline const char *plural(long v)
+{
+	return v == 1 ? "" : "s";
+}
+
+#endif /* __STRING_CHOICE_H__ */
-- 
2.20.1

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Rasmus Villemoes]

On 23/10/2019 15.13, Jani Nikula wrote:
> The kernel has plenty of ternary operators to choose between constant
> strings, such as condition ? "yes" : "no", as well as value == 1 ? "" :
> "s":
> 
> 
> v4: Massaged commit message about space savings to make it less fluffy
> based on Rasmus' feedback.

Thanks, it looks good to me. FWIW,

Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Jani Nikula]

On Wed, 23 Oct 2019, Rasmus Villemoes <linux@rasmusvillemoes.dk> wrote:
> On 23/10/2019 15.13, Jani Nikula wrote:
>> The kernel has plenty of ternary operators to choose between constant
>> strings, such as condition ? "yes" : "no", as well as value == 1 ? "" :
>> "s":
>> 
>> 
>> v4: Massaged commit message about space savings to make it less fluffy
>> based on Rasmus' feedback.
>
> Thanks, it looks good to me. FWIW,
>
> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>

Thanks.

I think the question is, which tree to apply this to, who's going to
pick it up? I'm fine with any route.

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Andrew Morton]

On Wed, 23 Oct 2019 16:13:08 +0300 Jani Nikula <jani.nikula@intel.com> wrote:

> The kernel has plenty of ternary operators to choose between constant
> strings, such as condition ? "yes" : "no", as well as value == 1 ? "" :
> "s":
> 
> $ git grep '? "yes" : "no"' | wc -l
> 258
> $ git grep '? "on" : "off"' | wc -l
> 204
> $ git grep '? "enabled" : "disabled"' | wc -l
> 196
> $ git grep '? "" : "s"' | wc -l
> 25
> 
> Additionally, there are some occurences of the same in reverse order,
> split to multiple lines, or otherwise not caught by the simple grep.
> 
> Add helpers to return the constant strings. Remove existing equivalent
> and conflicting functions in i915, cxgb4, and USB core. Further
> conversion can be done incrementally.
> 
> The main goal here is to abstract recurring patterns, and slightly clean
> up the code base by not open coding the ternary operators.

Fair enough.

> --- /dev/null
> +++ b/include/linux/string-choice.h
> @@ -0,0 +1,31 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2019 Intel Corporation
> + */
> +
> +#ifndef __STRING_CHOICE_H__
> +#define __STRING_CHOICE_H__
> +
> +#include <linux/types.h>
> +
> +static inline const char *yesno(bool v)
> +{
> +	return v ? "yes" : "no";
> +}
> +
> +static inline const char *onoff(bool v)
> +{
> +	return v ? "on" : "off";
> +}
> +
> +static inline const char *enableddisabled(bool v)
> +{
> +	return v ? "enabled" : "disabled";
> +}
> +
> +static inline const char *plural(long v)
> +{
> +	return v == 1 ? "" : "s";
> +}
> +
> +#endif /* __STRING_CHOICE_H__ */

These aren't very good function names.  Better to create a kernel-style
namespace such as "choice_" and then add the expected underscores:

choice_yes_no()
choice_enabled_disabled()
choice_plural()

(Example: note that slabinfo.c already has an "onoff()").


Also, I worry that making these functions inline means that each .o
file will contain its own copy of the strings ("yes", "no", "enabled",
etc) if the .c file calls the relevant helper.  I'm not sure if the
linker is smart enough (yet) to fix this up.  If not, we will end up
with a smaller kernel by uninlining these functions. 
lib/string-choice.c would suit.

And doing this will cause additional savings: calling a single-arg
out-of-line function generates less .text than calling yesno().  When I
did this: 

--- a/include/linux/string-choice.h~string-choice-add-yesno-onoff-enableddisabled-plural-helpers-fix
+++ a/include/linux/string-choice.h
@@ -8,10 +8,7 @@
 
 #include <linux/types.h>
 
-static inline const char *yesno(bool v)
-{
-	return v ? "yes" : "no";
-}
+const char *yesno(bool v);
 
 static inline const char *onoff(bool v)
 {

The text segment of drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.o
(78 callsites) shrunk by 118 bytes.

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Joe Perches]

On Wed, 2019-10-23 at 15:56 -0700, Andrew Morton wrote:
> And doing this will cause additional savings: calling a single-arg
> out-of-line function generates less .text than calling yesno().

I get no change in size at all with any of
	extern
	static __always_inline
with either of bool or int argument.

gcc 8.3, defconfig with CONFIG_CHELSIO_T4

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Jani Nikula]

On Wed, 23 Oct 2019, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Wed, 23 Oct 2019 16:13:08 +0300 Jani Nikula <jani.nikula@intel.com> wrote:
>
>> The kernel has plenty of ternary operators to choose between constant
>> strings, such as condition ? "yes" : "no", as well as value == 1 ? "" :
>> "s":
>> 
>> $ git grep '? "yes" : "no"' | wc -l
>> 258
>> $ git grep '? "on" : "off"' | wc -l
>> 204
>> $ git grep '? "enabled" : "disabled"' | wc -l
>> 196
>> $ git grep '? "" : "s"' | wc -l
>> 25
>> 
>> Additionally, there are some occurences of the same in reverse order,
>> split to multiple lines, or otherwise not caught by the simple grep.
>> 
>> Add helpers to return the constant strings. Remove existing equivalent
>> and conflicting functions in i915, cxgb4, and USB core. Further
>> conversion can be done incrementally.
>> 
>> The main goal here is to abstract recurring patterns, and slightly clean
>> up the code base by not open coding the ternary operators.
>
> Fair enough.
>
>> --- /dev/null
>> +++ b/include/linux/string-choice.h
>> @@ -0,0 +1,31 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/*
>> + * Copyright © 2019 Intel Corporation
>> + */
>> +
>> +#ifndef __STRING_CHOICE_H__
>> +#define __STRING_CHOICE_H__
>> +
>> +#include <linux/types.h>
>> +
>> +static inline const char *yesno(bool v)
>> +{
>> +	return v ? "yes" : "no";
>> +}
>> +
>> +static inline const char *onoff(bool v)
>> +{
>> +	return v ? "on" : "off";
>> +}
>> +
>> +static inline const char *enableddisabled(bool v)
>> +{
>> +	return v ? "enabled" : "disabled";
>> +}
>> +
>> +static inline const char *plural(long v)
>> +{
>> +	return v == 1 ? "" : "s";
>> +}
>> +
>> +#endif /* __STRING_CHOICE_H__ */
>
> These aren't very good function names.  Better to create a kernel-style
> namespace such as "choice_" and then add the expected underscores:
>
> choice_yes_no()
> choice_enabled_disabled()
> choice_plural()

I was merely using existing function names used in several drivers in
the kernel. But I can rename no problem.

Are your suggestions the names we can settle on now, or should I expect
to receive more opinions, but only after I send v5?

> (Example: note that slabinfo.c already has an "onoff()").

Under tools/ though? I did mean to address all conflicts in this patch.

> Also, I worry that making these functions inline means that each .o
> file will contain its own copy of the strings ("yes", "no", "enabled",
> etc) if the .c file calls the relevant helper.  I'm not sure if the
> linker is smart enough (yet) to fix this up.  If not, we will end up
> with a smaller kernel by uninlining these functions. 
> lib/string-choice.c would suit.
>
> And doing this will cause additional savings: calling a single-arg
> out-of-line function generates less .text than calling yesno().  When I
> did this: 
>
> --- a/include/linux/string-choice.h~string-choice-add-yesno-onoff-enableddisabled-plural-helpers-fix
> +++ a/include/linux/string-choice.h
> @@ -8,10 +8,7 @@
>  
>  #include <linux/types.h>
>  
> -static inline const char *yesno(bool v)
> -{
> -	return v ? "yes" : "no";
> -}
> +const char *yesno(bool v);
>  
>  static inline const char *onoff(bool v)
>  {
>
> The text segment of drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.o
> (78 callsites) shrunk by 118 bytes.

So we've already been back and forth on that particular topic in the
history of this patch. v2 had lib/string-choice.c and no inlines [1].

In the end, starting to use functions, inline or not, will let us rework
the implementation as we see fit, without touching the callers.

Again, it's no problem to go back to lib/string-choice.c, *once* more,
and the effort is trivial, but the ping-pong is getting old.


BR,
Jani.


[1] http://lore.kernel.org/r/20190930141842.15075-1-jani.nikula@intel.com

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Rasmus Villemoes]

On 24/10/2019 00.56, Andrew Morton wrote:
> On Wed, 23 Oct 2019 16:13:08 +0300 Jani Nikula <jani.nikula@intel.com> wrote:
> 
>> +
>> +static inline const char *yesno(bool v)
>> +{
>> +	return v ? "yes" : "no";
>> +}
>> +
>> +static inline const char *onoff(bool v)
>> +{
>> +	return v ? "on" : "off";
>> +}
>> +
>> +static inline const char *enableddisabled(bool v)
>> +{
>> +	return v ? "enabled" : "disabled";
>> +}
>> +
>> +static inline const char *plural(long v)
>> +{
>> +	return v == 1 ? "" : "s";
>> +}
>> +
>> +#endif /* __STRING_CHOICE_H__ */
> 
> These aren't very good function names.  Better to create a kernel-style
> namespace such as "choice_" and then add the expected underscores:
> 
> choice_yes_no()
> choice_enabled_disabled()
> choice_plural()

I think I prefer the short names (no choice_ prefix), it's rather
obvious what they do. I also asked for underscores, especially for the
enableddisabled case, but Jani didn't want to change existing callers.
But I'll keep out of the naming discussion from now on.
> Also, I worry that making these functions inline means that each .o
> file will contain its own copy of the strings 

They will, in .rodata.str1.1

("yes", "no", "enabled",
> etc) if the .c file calls the relevant helper.  I'm not sure if the
> linker is smart enough (yet) to fix this up. 

AFAIK, that's an optimization the linker has done forever - the whole
reason the SHF_MERGE | SHF_STRINGS (the MS in readelf -S output) flags
exist (and AFAICT they have been part of the ELF spec since forever) is
so the linker can do that trick. So no, do not make them ool.

> And doing this will cause additional savings: calling a single-arg
> out-of-line function generates less .text than calling yesno().  When I
> did this: 
> 
> --- a/include/linux/string-choice.h~string-choice-add-yesno-onoff-enableddisabled-plural-helpers-fix
> +++ a/include/linux/string-choice.h
> @@ -8,10 +8,7 @@
>  
>  #include <linux/types.h>
>  
> -static inline const char *yesno(bool v)
> -{
> -	return v ? "yes" : "no";
> -}
> +const char *yesno(bool v);
>  
>  static inline const char *onoff(bool v)
>  {
> 
> The text segment of drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.o
> (78 callsites) shrunk by 118 bytes.
> 

Interesting, and not at all what I see. Mind dumping rss_config_show
before/after? Even better, cxgb4_debugfs.s before/after. Here's what I get:

static inline yesno:

     cbb:       49 c7 c4 00 00 00 00    mov    $0x0,%r12        cbe:
R_X86_64_32S       .rodata.str1.1+0x197
     cc2:       44 89 ea                mov    %r13d,%edx
     cc5:       48 c7 c6 00 00 00 00    mov    $0x0,%rsi        cc8:
R_X86_64_32S       .rodata.str1.1+0x1b7
     ccc:       48 c7 c5 00 00 00 00    mov    $0x0,%rbp        ccf:
R_X86_64_32S       .rodata.str1.1+0x19b

Load "yes" into %12 and "no" into %rbp (or vice versa).

     cd3:       4d 89 e7                mov    %r12,%r15
     cd6:       e8 00 00 00 00          callq  cdb
<rss_config_show+0x3b>       cd7: R_X86_64_PC32      seq_printf-0x4
     cdb:       45 85 ed                test   %r13d,%r13d
     cde:       4c 89 e2                mov    %r12,%rdx
     ce1:       48 89 df                mov    %rbx,%rdi
     ce4:       48 0f 49 d5             cmovns %rbp,%rdx
     ce8:       48 c7 c6 00 00 00 00    mov    $0x0,%rsi        ceb:
R_X86_64_32S       .rodata.str1.1+0x1cb
     cef:       e8 00 00 00 00          callq  cf4
<rss_config_show+0x54>       cf0: R_X86_64_PC32      seq_printf-0x4
     cf4:       41 f7 c5 00 00 00 40    test   $0x40000000,%r13d
     cfb:       4c 89 e2                mov    %r12,%rdx
     cfe:       48 89 df                mov    %rbx,%rdi
     d01:       48 0f 44 d5             cmove  %rbp,%rdx
     d05:       48 c7 c6 00 00 00 00    mov    $0x0,%rsi        d08:
R_X86_64_32S       .rodata.str1.1+0x1e1
     d0c:       e8 00 00 00 00          callq  d11
<rss_config_show+0x71>       d0d: R_X86_64_PC32      seq_printf-0x4

Test a bit, move "yes" into %rdx, conditionally move "no" into %rdx
instead, call seq_printf.

     d11:       41 f7 c5 00 00 00 20    test   $0x20000000,%r13d
     d18:       4c 89 e2                mov    %r12,%rdx
     d1b:       48 89 df                mov    %rbx,%rdi
     d1e:       48 0f 44 d5             cmove  %rbp,%rdx
     d22:       48 c7 c6 00 00 00 00    mov    $0x0,%rsi        d25:
R_X86_64_32S       .rodata.str1.1+0x1f7
     d29:       e8 00 00 00 00          callq  d2e
<rss_config_show+0x8e>       d2a: R_X86_64_PC32      seq_printf-0x4

etc. That's a marginal (i.e., after the preamble storing "yes" and "no"
in callee-saved registers) cost of six instructions/29 bytes per
seq_printf, three of which are to implement the yesno() call.

extern const char *yesno():

   64e7:       48 c7 c6 00 00 00 00    mov    $0x0,%rsi        64ea:
R_X86_64_32S      .rodata.str1.1+0x8e4
    64ee:       89 ea                   mov    %ebp,%edx
    64f0:       41 89 ed                mov    %ebp,%r13d
    64f3:       e8 00 00 00 00          callq  64f8
<rss_config_show+0x28>      64f4: R_X86_64_PC32     seq_printf-0x4
    64f8:       89 ef                   mov    %ebp,%edi
    64fa:       c1 ef 1f                shr    $0x1f,%edi
    64fd:       e8 00 00 00 00          callq  6502
<rss_config_show+0x32>      64fe: R_X86_64_PC32     yesno-0x4

Three instructions to prepare the argument to yesno and call it.

    6502:       48 c7 c6 00 00 00 00    mov    $0x0,%rsi        6505:
R_X86_64_32S      .rodata.str1.1+0x8f8
    6509:       48 89 c2                mov    %rax,%rdx

One more to put the return from yesno in the right register.

    650c:       48 89 df                mov    %rbx,%rdi
    650f:       e8 00 00 00 00          callq  6514
<rss_config_show+0x44>      6510: R_X86_64_PC32     seq_printf-0x4

So not a lot, but still one more instruction, for a total of 31 bytes.
bloat-o-meter says

$ scripts/bloat-o-meter
drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.o.{1,2}
add/remove: 0/0 grow/shrink: 3/0 up/down: 301/0 (301)
Function                                     old     new   delta
rss_config_show                             2343    2482    +139
rss_vf_config_show                           263     363    +100
rss_pf_config_show                           342     404     +62

which is more then 2*78, but I haven't looked at the code patterns in
the other functions.

Did you use size(1) to compare when you say "text segment"? That would
include .rodata (and, more importantly, .rodata.strX.Y) in its text
column. Maybe your compiler doesn't do string literal merging (since the
linker does it anyway), so your .rodata.str1.1 might contain several
copies of "yes" and "no", but they shouldn't really be counted.

Rasmus

Re: [PATCH v4] string-choice: add yesno(), onoff(), enableddisabled(), plural() helpers

[Rasmus Villemoes]

On 24/10/2019 09.40, Rasmus Villemoes wrote:

> column. Maybe your compiler doesn't do string literal merging (since the
> linker does it anyway), so your .rodata.str1.1 might contain several
> copies of "yes" and "no", but they shouldn't really be counted.

Sorry, that's of course nonsense - the strings only appear once in the
TU (inside the static inline function), so gcc must treat them all as
the same object - as opposed to the case where the implementation was

#define yesno(x) ((x) ? "yes" : "no")

So that can't explain why you saw a smaller text segment using the OOL
version.

Rasmus