diff mbox

string/stratcliff.c: Replace int with size_t [BZ #21982]

Message ID CAMe9rOppYs6+kPif2++WrF3sAcphhWgw_bf04EVDp7r5fqO_Lg@mail.gmail.com
State New, archived
Headers

Commit Message

H.J. Lu Aug. 22, 2017, 12:43 p.m. UTC 
  On Tue, Aug 22, 2017 at 5:07 AM, Stefan Liebler <stli@linux.vnet.ibm.com> wrote:
> On 08/22/2017 01:05 AM, H.J. Lu wrote:
>>
>> On Mon, Aug 21, 2017 at 8:41 AM, Stefan Liebler <stli@linux.vnet.ibm.com>
>> wrote:
>>>
>>> On 08/21/2017 04:53 PM, H.J. Lu wrote:
>>>>
>>>>
>>>> On Mon, Aug 21, 2017 at 6:48 AM, Stefan Liebler
>>>> <stli@linux.vnet.ibm.com>
>>>> wrote:
>>>>>
>>>>>
>>>>> On 08/20/2017 07:17 PM, H.J. Lu wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> Fix GCC 7 errors when string/stratcliff.c is compiled with -O3:
>>>>>>
>>>>>> stratcliff.c: In function ‘do_test’:
>>>>>> cc1: error: assuming signed overflow does not occur when assuming that
>>>>>> (X
>>>>>> - c) <= X is always true [-Werror=strict-overflow]
>>>>>>
>>>>>> OK for master?
>>>>>>
>>>>>> H.J.
>>>>>> ---
>>>>>>           [BZ #21982]
>>>>>>           * string/stratcliff.c (do_test): Declare size, nchars,
>>>>>> inner,
>>>>>>           middle and outer with size_t instead of int.  Repleace %d
>>>>>> with
>>>>>>           %Zd in printf.
>>>>>> ---
>>>>>>     string/stratcliff.c | 72
>>>>>> ++++++++++++++++++++++++++---------------------------
>>>>>>     1 file changed, 36 insertions(+), 36 deletions(-)
>>>>>>
>>>>>> diff --git a/string/stratcliff.c b/string/stratcliff.c
>>>>>> index e28b0c5058..ae780379cb 100644
>>>>>> --- a/string/stratcliff.c
>>>>>> +++ b/string/stratcliff.c
>>>>>> @@ -58,8 +58,8 @@
>>>>>>     int
>>>>>>     do_test (void)
>>>>>>     {
>>>>>> -  int size = sysconf (_SC_PAGESIZE);
>>>>>> -  int nchars = size / sizeof (CHAR);
>>>>>> +  size_t size = sysconf (_SC_PAGESIZE);
>>>>>> +  size_t nchars = size / sizeof (CHAR);
>>>>>>       CHAR *adr;
>>>>>>       CHAR *dest;
>>>>>>       int result = 0;
>>>>>> @@ -80,7 +80,7 @@ do_test (void)
>>>>>>         }
>>>>>>       else
>>>>>>         {
>>>>>> -      int inner, middle, outer;
>>>>>> +      size_t inner, middle, outer;
>>>>>>
>>>>>>           mprotect (adr, size, PROT_NONE);
>>>>>>           mprotect (adr + 2 * nchars, size, PROT_NONE);
>>>>>> @@ -101,7 +101,7 @@ do_test (void)
>>>>>>
>>>>>>                 if (STRLEN (&adr[outer]) != (size_t) (inner - outer))
>>>>>>                   {
>>>>>> -                 printf ("%s flunked for outer = %d, inner = %d\n",
>>>>>> +                 printf ("%s flunked for outer = %Zd, inner = %Zd\n",
>>>>>>                             STRINGIFY (STRLEN), outer, inner);
>>>>>>                     result = 1;
>>>>>>                   }
>>>>>>                   {
>>>>>> -                 printf ("%s flunked for outer = %d, middle = %d\n",
>>>>>> +                 printf ("%s flunked for outer = %Zd, middle =
>>>>>> %Zd\n",
>>>>>>                             STRINGIFY (rawmemchr), outer, middle);
>>>>>>                     result = 1;
>>>>>>                   }
>>>>>> Hi H.J. Lu,
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> I've applied your patch and the warnings does not occur anymore on
>>>>> s390.
>>>>
>>>>
>>>>
>>>> Great.
>>>>
>>>>> The outer loops of the string tests are all using the following:
>>>>> size_t nchars, outer;
>>>>> for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
>>>>>
>>>>> I think we can assume, that nchars is always > 128 as it is derived by
>>>>> the
>>>>> pagesize.
>>>>> But if nchars would be equal to 128, this would result in an infinite
>>>>> loop
>>>>> (outer >= 0)?
>>>>> If nchars would be less than 128, the tests would be skipped.
>>>>>
>>>>> Should we add a check that nchars > 128 at the beginning and replace
>>>>> the
>>>>> "MAX (0, nchars - 128)" with only "nchars - 128"?
>>>>
>>>>
>>>>
>>>> This is a separate issue beyond BZ #21982.
>>>>
>>>>
>>> Your patch is introducing this behaviour.
>>> Before your patch, nchars and outer was an int and the for-loop-condition
>>> "outer >= MAX (0, nchars - 128)" does not lead to an infinite loop or to
>>> skipping the test if nchars <= 128.
>>>
>>
>> How about this patch?
>>
> This solves the cases if nchars < 128.
> But if nchars == 128, then the condition of the for-loop is "size_t outer >=
> 0", which is always true.
>
> Could we check once if nchars > 128 and exit the test with an error if
> nchars is <= 128?
> Are there architectures where the page size is < 4096?
> Or where wchar_t > 4byte?
>

Here is the updated patch.  I added

 if (outer == 0)
   break;

at the end of loop.

Comments

Stefan Liebler Aug. 22, 2017, 2:56 p.m. UTC | #1 
On 08/22/2017 02:43 PM, H.J. Lu wrote:
> On Tue, Aug 22, 2017 at 5:07 AM, Stefan Liebler <stli@linux.vnet.ibm.com> wrote:
>> On 08/22/2017 01:05 AM, H.J. Lu wrote:
>>>
>>> On Mon, Aug 21, 2017 at 8:41 AM, Stefan Liebler <stli@linux.vnet.ibm.com>
>>> wrote:
>>>>
>>>> On 08/21/2017 04:53 PM, H.J. Lu wrote:
>>>>>
>>>>>
>>>>> On Mon, Aug 21, 2017 at 6:48 AM, Stefan Liebler
>>>>> <stli@linux.vnet.ibm.com>
>>>>> wrote:
>>>>>>
>>>>>>
>>>>>> On 08/20/2017 07:17 PM, H.J. Lu wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Fix GCC 7 errors when string/stratcliff.c is compiled with -O3:
>>>>>>>
>>>>>>> stratcliff.c: In function ‘do_test’:
>>>>>>> cc1: error: assuming signed overflow does not occur when assuming that
>>>>>>> (X
>>>>>>> - c) <= X is always true [-Werror=strict-overflow]
>>>>>>>
>>>>>>> OK for master?
>>>>>>>
>>>>>>> H.J.
>>>>>>> ---
>>>>>>>            [BZ #21982]
>>>>>>>            * string/stratcliff.c (do_test): Declare size, nchars,
>>>>>>> inner,
>>>>>>>            middle and outer with size_t instead of int.  Repleace %d
>>>>>>> with
>>>>>>>            %Zd in printf.
>>>>>>> ---
>>>>>>>      string/stratcliff.c | 72
>>>>>>> ++++++++++++++++++++++++++---------------------------
>>>>>>>      1 file changed, 36 insertions(+), 36 deletions(-)
>>>>>>>
>>>>>>> diff --git a/string/stratcliff.c b/string/stratcliff.c
>>>>>>> index e28b0c5058..ae780379cb 100644
>>>>>>> --- a/string/stratcliff.c
>>>>>>> +++ b/string/stratcliff.c
>>>>>>> @@ -58,8 +58,8 @@
>>>>>>>      int
>>>>>>>      do_test (void)
>>>>>>>      {
>>>>>>> -  int size = sysconf (_SC_PAGESIZE);
>>>>>>> -  int nchars = size / sizeof (CHAR);
>>>>>>> +  size_t size = sysconf (_SC_PAGESIZE);
>>>>>>> +  size_t nchars = size / sizeof (CHAR);
>>>>>>>        CHAR *adr;
>>>>>>>        CHAR *dest;
>>>>>>>        int result = 0;
>>>>>>> @@ -80,7 +80,7 @@ do_test (void)
>>>>>>>          }
>>>>>>>        else
>>>>>>>          {
>>>>>>> -      int inner, middle, outer;
>>>>>>> +      size_t inner, middle, outer;
>>>>>>>
>>>>>>>            mprotect (adr, size, PROT_NONE);
>>>>>>>            mprotect (adr + 2 * nchars, size, PROT_NONE);
>>>>>>> @@ -101,7 +101,7 @@ do_test (void)
>>>>>>>
>>>>>>>                  if (STRLEN (&adr[outer]) != (size_t) (inner - outer))
>>>>>>>                    {
>>>>>>> -                 printf ("%s flunked for outer = %d, inner = %d\n",
>>>>>>> +                 printf ("%s flunked for outer = %Zd, inner = %Zd\n",
>>>>>>>                              STRINGIFY (STRLEN), outer, inner);
>>>>>>>                      result = 1;
>>>>>>>                    }
>>>>>>>                    {
>>>>>>> -                 printf ("%s flunked for outer = %d, middle = %d\n",
>>>>>>> +                 printf ("%s flunked for outer = %Zd, middle =
>>>>>>> %Zd\n",
>>>>>>>                              STRINGIFY (rawmemchr), outer, middle);
>>>>>>>                      result = 1;
>>>>>>>                    }
>>>>>>> Hi H.J. Lu,
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> I've applied your patch and the warnings does not occur anymore on
>>>>>> s390.
>>>>>
>>>>>
>>>>>
>>>>> Great.
>>>>>
>>>>>> The outer loops of the string tests are all using the following:
>>>>>> size_t nchars, outer;
>>>>>> for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
>>>>>>
>>>>>> I think we can assume, that nchars is always > 128 as it is derived by
>>>>>> the
>>>>>> pagesize.
>>>>>> But if nchars would be equal to 128, this would result in an infinite
>>>>>> loop
>>>>>> (outer >= 0)?
>>>>>> If nchars would be less than 128, the tests would be skipped.
>>>>>>
>>>>>> Should we add a check that nchars > 128 at the beginning and replace
>>>>>> the
>>>>>> "MAX (0, nchars - 128)" with only "nchars - 128"?
>>>>>
>>>>>
>>>>>
>>>>> This is a separate issue beyond BZ #21982.
>>>>>
>>>>>
>>>> Your patch is introducing this behaviour.
>>>> Before your patch, nchars and outer was an int and the for-loop-condition
>>>> "outer >= MAX (0, nchars - 128)" does not lead to an infinite loop or to
>>>> skipping the test if nchars <= 128.
>>>>
>>>
>>> How about this patch?
>>>
>> This solves the cases if nchars < 128.
>> But if nchars == 128, then the condition of the for-loop is "size_t outer >=
>> 0", which is always true.
>>
>> Could we check once if nchars > 128 and exit the test with an error if
>> nchars is <= 128?
>> Are there architectures where the page size is < 4096?
>> Or where wchar_t > 4byte?
>>
> 
> Here is the updated patch.  I added
> 
>   if (outer == 0)
>     break;
> 
> at the end of loop.
> 

Okay. This fixes the case nchars == 128.
I've retested this patch on s390x with gcc 7 -O3 and the warnings does 
not occur anymore.

Thanks.
Stefan
H.J. Lu Aug. 23, 2017, 2:49 p.m. UTC | #2 
On Tue, Aug 22, 2017 at 7:56 AM, Stefan Liebler <stli@linux.vnet.ibm.com> wrote:
> On 08/22/2017 02:43 PM, H.J. Lu wrote:
>>
>> On Tue, Aug 22, 2017 at 5:07 AM, Stefan Liebler <stli@linux.vnet.ibm.com>
>> wrote:
>>>
>>> On 08/22/2017 01:05 AM, H.J. Lu wrote:
>>>>
>>>>
>>>> On Mon, Aug 21, 2017 at 8:41 AM, Stefan Liebler
>>>> <stli@linux.vnet.ibm.com>
>>>> wrote:
>>>>>
>>>>>
>>>>> On 08/21/2017 04:53 PM, H.J. Lu wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Mon, Aug 21, 2017 at 6:48 AM, Stefan Liebler
>>>>>> <stli@linux.vnet.ibm.com>
>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 08/20/2017 07:17 PM, H.J. Lu wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Fix GCC 7 errors when string/stratcliff.c is compiled with -O3:
>>>>>>>>
>>>>>>>> stratcliff.c: In function ‘do_test’:
>>>>>>>> cc1: error: assuming signed overflow does not occur when assuming
>>>>>>>> that
>>>>>>>> (X
>>>>>>>> - c) <= X is always true [-Werror=strict-overflow]
>>>>>>>>
>>>>>>>> OK for master?
>>>>>>>>
>>>>>>>> H.J.
>>>>>>>> ---
>>>>>>>>            [BZ #21982]
>>>>>>>>            * string/stratcliff.c (do_test): Declare size, nchars,
>>>>>>>> inner,
>>>>>>>>            middle and outer with size_t instead of int.  Repleace %d
>>>>>>>> with
>>>>>>>>            %Zd in printf.
>>>>>>>> ---
>>>>>>>>      string/stratcliff.c | 72
>>>>>>>> ++++++++++++++++++++++++++---------------------------
>>>>>>>>      1 file changed, 36 insertions(+), 36 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/string/stratcliff.c b/string/stratcliff.c
>>>>>>>> index e28b0c5058..ae780379cb 100644
>>>>>>>> --- a/string/stratcliff.c
>>>>>>>> +++ b/string/stratcliff.c
>>>>>>>> @@ -58,8 +58,8 @@
>>>>>>>>      int
>>>>>>>>      do_test (void)
>>>>>>>>      {
>>>>>>>> -  int size = sysconf (_SC_PAGESIZE);
>>>>>>>> -  int nchars = size / sizeof (CHAR);
>>>>>>>> +  size_t size = sysconf (_SC_PAGESIZE);
>>>>>>>> +  size_t nchars = size / sizeof (CHAR);
>>>>>>>>        CHAR *adr;
>>>>>>>>        CHAR *dest;
>>>>>>>>        int result = 0;
>>>>>>>> @@ -80,7 +80,7 @@ do_test (void)
>>>>>>>>          }
>>>>>>>>        else
>>>>>>>>          {
>>>>>>>> -      int inner, middle, outer;
>>>>>>>> +      size_t inner, middle, outer;
>>>>>>>>
>>>>>>>>            mprotect (adr, size, PROT_NONE);
>>>>>>>>            mprotect (adr + 2 * nchars, size, PROT_NONE);
>>>>>>>> @@ -101,7 +101,7 @@ do_test (void)
>>>>>>>>
>>>>>>>>                  if (STRLEN (&adr[outer]) != (size_t) (inner -
>>>>>>>> outer))
>>>>>>>>                    {
>>>>>>>> -                 printf ("%s flunked for outer = %d, inner = %d\n",
>>>>>>>> +                 printf ("%s flunked for outer = %Zd, inner =
>>>>>>>> %Zd\n",
>>>>>>>>                              STRINGIFY (STRLEN), outer, inner);
>>>>>>>>                      result = 1;
>>>>>>>>                    }
>>>>>>>>                    {
>>>>>>>> -                 printf ("%s flunked for outer = %d, middle =
>>>>>>>> %d\n",
>>>>>>>> +                 printf ("%s flunked for outer = %Zd, middle =
>>>>>>>> %Zd\n",
>>>>>>>>                              STRINGIFY (rawmemchr), outer, middle);
>>>>>>>>                      result = 1;
>>>>>>>>                    }
>>>>>>>> Hi H.J. Lu,
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> I've applied your patch and the warnings does not occur anymore on
>>>>>>> s390.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Great.
>>>>>>
>>>>>>> The outer loops of the string tests are all using the following:
>>>>>>> size_t nchars, outer;
>>>>>>> for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
>>>>>>>
>>>>>>> I think we can assume, that nchars is always > 128 as it is derived
>>>>>>> by
>>>>>>> the
>>>>>>> pagesize.
>>>>>>> But if nchars would be equal to 128, this would result in an infinite
>>>>>>> loop
>>>>>>> (outer >= 0)?
>>>>>>> If nchars would be less than 128, the tests would be skipped.
>>>>>>>
>>>>>>> Should we add a check that nchars > 128 at the beginning and replace
>>>>>>> the
>>>>>>> "MAX (0, nchars - 128)" with only "nchars - 128"?
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> This is a separate issue beyond BZ #21982.
>>>>>>
>>>>>>
>>>>> Your patch is introducing this behaviour.
>>>>> Before your patch, nchars and outer was an int and the
>>>>> for-loop-condition
>>>>> "outer >= MAX (0, nchars - 128)" does not lead to an infinite loop or
>>>>> to
>>>>> skipping the test if nchars <= 128.
>>>>>
>>>>
>>>> How about this patch?
>>>>
>>> This solves the cases if nchars < 128.
>>> But if nchars == 128, then the condition of the for-loop is "size_t outer
>>> >=
>>> 0", which is always true.
>>>
>>> Could we check once if nchars > 128 and exit the test with an error if
>>> nchars is <= 128?
>>> Are there architectures where the page size is < 4096?
>>> Or where wchar_t > 4byte?
>>>
>>
>> Here is the updated patch.  I added
>>
>>   if (outer == 0)
>>     break;
>>
>> at the end of loop.
>>
>
> Okay. This fixes the case nchars == 128.
> I've retested this patch on s390x with gcc 7 -O3 and the warnings does not
> occur anymore.

I am checking it in shortly.

Thanks.
H.J. Lu Sept. 7, 2017, 4:20 p.m. UTC | #3 
On Wed, Aug 23, 2017 at 7:49 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Aug 22, 2017 at 7:56 AM, Stefan Liebler <stli@linux.vnet.ibm.com> wrote:
>> On 08/22/2017 02:43 PM, H.J. Lu wrote:
>>>
>>> On Tue, Aug 22, 2017 at 5:07 AM, Stefan Liebler <stli@linux.vnet.ibm.com>
>>> wrote:
>>>>
>>>> On 08/22/2017 01:05 AM, H.J. Lu wrote:
>>>>>
>>>>>
>>>>> On Mon, Aug 21, 2017 at 8:41 AM, Stefan Liebler
>>>>> <stli@linux.vnet.ibm.com>
>>>>> wrote:
>>>>>>
>>>>>>
>>>>>> On 08/21/2017 04:53 PM, H.J. Lu wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Mon, Aug 21, 2017 at 6:48 AM, Stefan Liebler
>>>>>>> <stli@linux.vnet.ibm.com>
>>>>>>> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On 08/20/2017 07:17 PM, H.J. Lu wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Fix GCC 7 errors when string/stratcliff.c is compiled with -O3:
>>>>>>>>>
>>>>>>>>> stratcliff.c: In function ‘do_test’:
>>>>>>>>> cc1: error: assuming signed overflow does not occur when assuming
>>>>>>>>> that
>>>>>>>>> (X
>>>>>>>>> - c) <= X is always true [-Werror=strict-overflow]
>>>>>>>>>
>>>>>>>>> OK for master?
>>>>>>>>>
>>>>>>>>> H.J.
>>>>>>>>> ---
>>>>>>>>>            [BZ #21982]
>>>>>>>>>            * string/stratcliff.c (do_test): Declare size, nchars,
>>>>>>>>> inner,
>>>>>>>>>            middle and outer with size_t instead of int.  Repleace %d
>>>>>>>>> with
>>>>>>>>>            %Zd in printf.
>>>>>>>>> ---
>>>>>>>>>      string/stratcliff.c | 72
>>>>>>>>> ++++++++++++++++++++++++++---------------------------
>>>>>>>>>      1 file changed, 36 insertions(+), 36 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/string/stratcliff.c b/string/stratcliff.c
>>>>>>>>> index e28b0c5058..ae780379cb 100644
>>>>>>>>> --- a/string/stratcliff.c
>>>>>>>>> +++ b/string/stratcliff.c
>>>>>>>>> @@ -58,8 +58,8 @@
>>>>>>>>>      int
>>>>>>>>>      do_test (void)
>>>>>>>>>      {
>>>>>>>>> -  int size = sysconf (_SC_PAGESIZE);
>>>>>>>>> -  int nchars = size / sizeof (CHAR);
>>>>>>>>> +  size_t size = sysconf (_SC_PAGESIZE);
>>>>>>>>> +  size_t nchars = size / sizeof (CHAR);
>>>>>>>>>        CHAR *adr;
>>>>>>>>>        CHAR *dest;
>>>>>>>>>        int result = 0;
>>>>>>>>> @@ -80,7 +80,7 @@ do_test (void)
>>>>>>>>>          }
>>>>>>>>>        else
>>>>>>>>>          {
>>>>>>>>> -      int inner, middle, outer;
>>>>>>>>> +      size_t inner, middle, outer;
>>>>>>>>>
>>>>>>>>>            mprotect (adr, size, PROT_NONE);
>>>>>>>>>            mprotect (adr + 2 * nchars, size, PROT_NONE);
>>>>>>>>> @@ -101,7 +101,7 @@ do_test (void)
>>>>>>>>>
>>>>>>>>>                  if (STRLEN (&adr[outer]) != (size_t) (inner -
>>>>>>>>> outer))
>>>>>>>>>                    {
>>>>>>>>> -                 printf ("%s flunked for outer = %d, inner = %d\n",
>>>>>>>>> +                 printf ("%s flunked for outer = %Zd, inner =
>>>>>>>>> %Zd\n",
>>>>>>>>>                              STRINGIFY (STRLEN), outer, inner);
>>>>>>>>>                      result = 1;
>>>>>>>>>                    }
>>>>>>>>>                    {
>>>>>>>>> -                 printf ("%s flunked for outer = %d, middle =
>>>>>>>>> %d\n",
>>>>>>>>> +                 printf ("%s flunked for outer = %Zd, middle =
>>>>>>>>> %Zd\n",
>>>>>>>>>                              STRINGIFY (rawmemchr), outer, middle);
>>>>>>>>>                      result = 1;
>>>>>>>>>                    }
>>>>>>>>> Hi H.J. Lu,
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> I've applied your patch and the warnings does not occur anymore on
>>>>>>>> s390.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Great.
>>>>>>>
>>>>>>>> The outer loops of the string tests are all using the following:
>>>>>>>> size_t nchars, outer;
>>>>>>>> for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
>>>>>>>>
>>>>>>>> I think we can assume, that nchars is always > 128 as it is derived
>>>>>>>> by
>>>>>>>> the
>>>>>>>> pagesize.
>>>>>>>> But if nchars would be equal to 128, this would result in an infinite
>>>>>>>> loop
>>>>>>>> (outer >= 0)?
>>>>>>>> If nchars would be less than 128, the tests would be skipped.
>>>>>>>>
>>>>>>>> Should we add a check that nchars > 128 at the beginning and replace
>>>>>>>> the
>>>>>>>> "MAX (0, nchars - 128)" with only "nchars - 128"?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> This is a separate issue beyond BZ #21982.
>>>>>>>
>>>>>>>
>>>>>> Your patch is introducing this behaviour.
>>>>>> Before your patch, nchars and outer was an int and the
>>>>>> for-loop-condition
>>>>>> "outer >= MAX (0, nchars - 128)" does not lead to an infinite loop or
>>>>>> to
>>>>>> skipping the test if nchars <= 128.
>>>>>>
>>>>>
>>>>> How about this patch?
>>>>>
>>>> This solves the cases if nchars < 128.
>>>> But if nchars == 128, then the condition of the for-loop is "size_t outer
>>>> >=
>>>> 0", which is always true.
>>>>
>>>> Could we check once if nchars > 128 and exit the test with an error if
>>>> nchars is <= 128?
>>>> Are there architectures where the page size is < 4096?
>>>> Or where wchar_t > 4byte?
>>>>
>>>
>>> Here is the updated patch.  I added
>>>
>>>   if (outer == 0)
>>>     break;
>>>
>>> at the end of loop.
>>>
>>
>> Okay. This fixes the case nchars == 128.
>> I've retested this patch on s390x with gcc 7 -O3 and the warnings does not
>> occur anymore.
>
> I am checking it in shortly.
>

I'd like to backport it to 2.25 and 2.26 branches.   Any comments?
H.J. Lu Sept. 11, 2017, 3:46 p.m. UTC | #4 
On Thu, Sep 7, 2017 at 9:20 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Wed, Aug 23, 2017 at 7:49 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Tue, Aug 22, 2017 at 7:56 AM, Stefan Liebler <stli@linux.vnet.ibm.com> wrote:
>>> On 08/22/2017 02:43 PM, H.J. Lu wrote:
>>>>
>>>> On Tue, Aug 22, 2017 at 5:07 AM, Stefan Liebler <stli@linux.vnet.ibm.com>
>>>> wrote:
>>>>>
>>>>> On 08/22/2017 01:05 AM, H.J. Lu wrote:
>>>>>>
>>>>>>
>>>>>> On Mon, Aug 21, 2017 at 8:41 AM, Stefan Liebler
>>>>>> <stli@linux.vnet.ibm.com>
>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>> On 08/21/2017 04:53 PM, H.J. Lu wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Mon, Aug 21, 2017 at 6:48 AM, Stefan Liebler
>>>>>>>> <stli@linux.vnet.ibm.com>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 08/20/2017 07:17 PM, H.J. Lu wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Fix GCC 7 errors when string/stratcliff.c is compiled with -O3:
>>>>>>>>>>
>>>>>>>>>> stratcliff.c: In function ‘do_test’:
>>>>>>>>>> cc1: error: assuming signed overflow does not occur when assuming
>>>>>>>>>> that
>>>>>>>>>> (X
>>>>>>>>>> - c) <= X is always true [-Werror=strict-overflow]
>>>>>>>>>>
>>>>>>>>>> OK for master?
>>>>>>>>>>
>>>>>>>>>> H.J.
>>>>>>>>>> ---
>>>>>>>>>>            [BZ #21982]
>>>>>>>>>>            * string/stratcliff.c (do_test): Declare size, nchars,
>>>>>>>>>> inner,
>>>>>>>>>>            middle and outer with size_t instead of int.  Repleace %d
>>>>>>>>>> with
>>>>>>>>>>            %Zd in printf.
>>>>>>>>>> ---
>>>>>>>>>>      string/stratcliff.c | 72
>>>>>>>>>> ++++++++++++++++++++++++++---------------------------
>>>>>>>>>>      1 file changed, 36 insertions(+), 36 deletions(-)
>>>>>>>>>>
>>>>>>>>>> diff --git a/string/stratcliff.c b/string/stratcliff.c
>>>>>>>>>> index e28b0c5058..ae780379cb 100644
>>>>>>>>>> --- a/string/stratcliff.c
>>>>>>>>>> +++ b/string/stratcliff.c
>>>>>>>>>> @@ -58,8 +58,8 @@
>>>>>>>>>>      int
>>>>>>>>>>      do_test (void)
>>>>>>>>>>      {
>>>>>>>>>> -  int size = sysconf (_SC_PAGESIZE);
>>>>>>>>>> -  int nchars = size / sizeof (CHAR);
>>>>>>>>>> +  size_t size = sysconf (_SC_PAGESIZE);
>>>>>>>>>> +  size_t nchars = size / sizeof (CHAR);
>>>>>>>>>>        CHAR *adr;
>>>>>>>>>>        CHAR *dest;
>>>>>>>>>>        int result = 0;
>>>>>>>>>> @@ -80,7 +80,7 @@ do_test (void)
>>>>>>>>>>          }
>>>>>>>>>>        else
>>>>>>>>>>          {
>>>>>>>>>> -      int inner, middle, outer;
>>>>>>>>>> +      size_t inner, middle, outer;
>>>>>>>>>>
>>>>>>>>>>            mprotect (adr, size, PROT_NONE);
>>>>>>>>>>            mprotect (adr + 2 * nchars, size, PROT_NONE);
>>>>>>>>>> @@ -101,7 +101,7 @@ do_test (void)
>>>>>>>>>>
>>>>>>>>>>                  if (STRLEN (&adr[outer]) != (size_t) (inner -
>>>>>>>>>> outer))
>>>>>>>>>>                    {
>>>>>>>>>> -                 printf ("%s flunked for outer = %d, inner = %d\n",
>>>>>>>>>> +                 printf ("%s flunked for outer = %Zd, inner =
>>>>>>>>>> %Zd\n",
>>>>>>>>>>                              STRINGIFY (STRLEN), outer, inner);
>>>>>>>>>>                      result = 1;
>>>>>>>>>>                    }
>>>>>>>>>>                    {
>>>>>>>>>> -                 printf ("%s flunked for outer = %d, middle =
>>>>>>>>>> %d\n",
>>>>>>>>>> +                 printf ("%s flunked for outer = %Zd, middle =
>>>>>>>>>> %Zd\n",
>>>>>>>>>>                              STRINGIFY (rawmemchr), outer, middle);
>>>>>>>>>>                      result = 1;
>>>>>>>>>>                    }
>>>>>>>>>> Hi H.J. Lu,
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I've applied your patch and the warnings does not occur anymore on
>>>>>>>>> s390.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Great.
>>>>>>>>
>>>>>>>>> The outer loops of the string tests are all using the following:
>>>>>>>>> size_t nchars, outer;
>>>>>>>>> for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
>>>>>>>>>
>>>>>>>>> I think we can assume, that nchars is always > 128 as it is derived
>>>>>>>>> by
>>>>>>>>> the
>>>>>>>>> pagesize.
>>>>>>>>> But if nchars would be equal to 128, this would result in an infinite
>>>>>>>>> loop
>>>>>>>>> (outer >= 0)?
>>>>>>>>> If nchars would be less than 128, the tests would be skipped.
>>>>>>>>>
>>>>>>>>> Should we add a check that nchars > 128 at the beginning and replace
>>>>>>>>> the
>>>>>>>>> "MAX (0, nchars - 128)" with only "nchars - 128"?
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> This is a separate issue beyond BZ #21982.
>>>>>>>>
>>>>>>>>
>>>>>>> Your patch is introducing this behaviour.
>>>>>>> Before your patch, nchars and outer was an int and the
>>>>>>> for-loop-condition
>>>>>>> "outer >= MAX (0, nchars - 128)" does not lead to an infinite loop or
>>>>>>> to
>>>>>>> skipping the test if nchars <= 128.
>>>>>>>
>>>>>>
>>>>>> How about this patch?
>>>>>>
>>>>> This solves the cases if nchars < 128.
>>>>> But if nchars == 128, then the condition of the for-loop is "size_t outer
>>>>> >=
>>>>> 0", which is always true.
>>>>>
>>>>> Could we check once if nchars > 128 and exit the test with an error if
>>>>> nchars is <= 128?
>>>>> Are there architectures where the page size is < 4096?
>>>>> Or where wchar_t > 4byte?
>>>>>
>>>>
>>>> Here is the updated patch.  I added
>>>>
>>>>   if (outer == 0)
>>>>     break;
>>>>
>>>> at the end of loop.
>>>>
>>>
>>> Okay. This fixes the case nchars == 128.
>>> I've retested this patch on s390x with gcc 7 -O3 and the warnings does not
>>> occur anymore.
>>
>> I am checking it in shortly.
>>
>
> I'd like to backport it to 2.25 and 2.26 branches.   Any comments?
>

I am checking it in now.
diff mbox

Patch

From f951e4aa927efdf3112be92006b11d31cb75ef2b Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sun, 20 Aug 2017 10:11:38 -0700
Subject: [PATCH] string/stratcliff.c: Replace int with size_t [BZ #21982]
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fix GCC 7 errors when string/stratcliff.c is compiled with -O3:

stratcliff.c: In function ‘do_test’:
cc1: error: assuming signed overflow does not occur when assuming that (X - c) <= X is always true [-Werror=strict-overflow]

	[BZ #21982]
	* string/stratcliff.c (do_test): Declare size, nchars, inner,
	middle and outer with size_t instead of int.  Repleace %d and
	%Zd with %zu in printf.  Update "MAX (0, nchars - 128)" and
	"MAX (outer, nchars - 64)" to support unsigned outer and
	nchars.  Also exit loop when outer == 0.
---
 string/stratcliff.c | 276 +++++++++++++++++++++++++++++++---------------------
 1 file changed, 167 insertions(+), 109 deletions(-)

diff --git a/string/stratcliff.c b/string/stratcliff.c
index e28b0c5058..4320336c9a 100644
--- a/string/stratcliff.c
+++ b/string/stratcliff.c
@@ -58,8 +58,8 @@ 
 int
 do_test (void)
 {
-  int size = sysconf (_SC_PAGESIZE);
-  int nchars = size / sizeof (CHAR);
+  size_t size = sysconf (_SC_PAGESIZE);
+  size_t nchars = size / sizeof (CHAR);
   CHAR *adr;
   CHAR *dest;
   int result = 0;
@@ -80,7 +80,17 @@  do_test (void)
     }
   else
     {
-      int inner, middle, outer;
+      size_t inner, middle, outer, nchars64, max128;
+
+      if (nchars > 64)
+	nchars64 = nchars - 64;
+      else
+	nchars64 = 0;
+
+      if (nchars > 128)
+	max128 = nchars - 128;
+      else
+	max128 = 0;
 
       mprotect (adr, size, PROT_NONE);
       mprotect (adr + 2 * nchars, size, PROT_NONE);
@@ -93,59 +103,65 @@  do_test (void)
       MEMSET (adr, L('T'), nchars);
 
       /* strlen/wcslen test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (inner = MAX (outer, nchars - 64); inner < nchars; ++inner)
+	  for (inner = MAX (outer, nchars64); inner < nchars; ++inner)
 	    {
 	      adr[inner] = L('\0');
 
 	      if (STRLEN (&adr[outer]) != (size_t) (inner - outer))
 		{
-		  printf ("%s flunked for outer = %d, inner = %d\n",
+		  printf ("%s flunked for outer = %zu, inner = %zu\n",
 			  STRINGIFY (STRLEN), outer, inner);
 		  result = 1;
 		}
 
 	      adr[inner] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* strnlen/wcsnlen test */
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= max128; --outer)
 	{
-	  for (inner = MAX (outer, nchars - 64); inner < nchars; ++inner)
+	  for (inner = MAX (outer, nchars64); inner < nchars; ++inner)
 	    {
 	      adr[inner] = L('\0');
 
 	      if (STRNLEN (&adr[outer], inner - outer + 1)
 		  != (size_t) (inner - outer))
 		{
-		  printf ("%s flunked for outer = %d, inner = %d\n",
+		  printf ("%s flunked for outer = %zu, inner = %zu\n",
 			  STRINGIFY (STRNLEN), outer, inner);
 		  result = 1;
 		}
 
 	      adr[inner] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= max128; --outer)
 	{
-	  for (inner = MAX (outer, nchars - 64); inner <= nchars; ++inner)
+	  for (inner = MAX (outer, nchars64); inner <= nchars; ++inner)
 	    {
 	      if (STRNLEN (&adr[outer], inner - outer)
 		  != (size_t) (inner - outer))
 		{
-		  printf ("%s flunked bounded for outer = %d, inner = %d\n",
+		  printf ("%s flunked bounded for outer = %zu, inner = %zu\n",
 			  STRINGIFY (STRNLEN), outer, inner);
 		  result = 1;
 		}
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* strchr/wcschr test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
+	  for (middle = MAX (outer, nchars64); middle < nchars; ++middle)
 	    {
 	      for (inner = middle; inner < nchars; ++inner)
 		{
@@ -158,8 +174,8 @@  do_test (void)
 		      || (inner != middle
 			  && (cp - &adr[outer]) != middle - outer))
 		    {
-		      printf ("%s flunked for outer = %d, middle = %d, "
-			      "inner = %d\n",
+		      printf ("%s flunked for outer = %zu, middle = %zu, "
+			      "inner = %zu\n",
 			      STRINGIFY (STRCHR), outer, middle, inner);
 		      result = 1;
 		    }
@@ -168,6 +184,8 @@  do_test (void)
 		  adr[middle] = L('T');
 		}
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* Special test.  */
@@ -180,9 +198,9 @@  do_test (void)
 	}
 
       /* strrchr/wcsrchr test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
+	  for (middle = MAX (outer, nchars64); middle < nchars; ++middle)
 	    {
 	      for (inner = middle; inner < nchars; ++inner)
 		{
@@ -195,8 +213,8 @@  do_test (void)
 		      || (inner != middle
 			  && (cp - &adr[outer]) != middle - outer))
 		    {
-		      printf ("%s flunked for outer = %d, middle = %d, "
-			      "inner = %d\n",
+		      printf ("%s flunked for outer = %zu, middle = %zu, "
+			      "inner = %zu\n",
 			      STRINGIFY (STRRCHR), outer, middle, inner);
 		      result = 1;
 		    }
@@ -205,12 +223,14 @@  do_test (void)
 		  adr[middle] = L('T');
 		}
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* memchr test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
+	  for (middle = MAX (outer, nchars64); middle < nchars; ++middle)
 	    {
 	      adr[middle] = L('V');
 
@@ -218,32 +238,36 @@  do_test (void)
 
 	      if (cp - &adr[outer] != middle - outer)
 		{
-		  printf ("%s flunked for outer = %d, middle = %d\n",
+		  printf ("%s flunked for outer = %zu, middle = %zu\n",
 			  STRINGIFY (MEMCHR), outer, middle);
 		  result = 1;
 		}
 
 	      adr[middle] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= max128; --outer)
 	{
 	  CHAR *cp = MEMCHR (&adr[outer], L('V'), nchars - outer);
 
 	  if (cp != NULL)
 	    {
-	      printf ("%s flunked for outer = %d\n",
+	      printf ("%s flunked for outer = %zu\n",
 		      STRINGIFY (MEMCHR), outer);
 	      result = 1;
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* These functions only exist for single-byte characters.  */
 #ifndef WCSTEST
       /* rawmemchr test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
+	  for (middle = MAX (outer, nchars64); middle < nchars; ++middle)
 	    {
 	      adr[middle] = L('V');
 
@@ -251,19 +275,21 @@  do_test (void)
 
 	      if (cp - &adr[outer] != middle - outer)
 		{
-		  printf ("%s flunked for outer = %d, middle = %d\n",
+		  printf ("%s flunked for outer = %zu, middle = %zu\n",
 			  STRINGIFY (rawmemchr), outer, middle);
 		  result = 1;
 		}
 
 	      adr[middle] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* memrchr test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
+	  for (middle = MAX (outer, nchars64); middle < nchars; ++middle)
 	    {
 	      adr[middle] = L('V');
 
@@ -271,44 +297,50 @@  do_test (void)
 
 	      if (cp - &adr[outer] != middle - outer)
 		{
-		  printf ("%s flunked for outer = %d, middle = %d\n",
+		  printf ("%s flunked for outer = %zu, middle = %zu\n",
 			  STRINGIFY (memrchr), outer, middle);
 		  result = 1;
 		}
 
 	      adr[middle] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= max128; --outer)
 	{
 	  CHAR *cp = memrchr (&adr[outer], L('V'), nchars - outer);
 
 	  if (cp != NULL)
 	    {
-	      printf ("%s flunked for outer = %d\n",
+	      printf ("%s flunked for outer = %zu\n",
 		      STRINGIFY (memrchr), outer);
 	      result = 1;
 	    }
+	  if (outer == 0)
+	    break;
 	}
 #endif
 
       /* strcpy/wcscpy test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (inner = MAX (outer, nchars - 64); inner < nchars; ++inner)
+	  for (inner = MAX (outer, nchars64); inner < nchars; ++inner)
 	    {
 	      adr[inner] = L('\0');
 
 	      if (STRCPY (dest, &adr[outer]) != dest
 		  || STRLEN (dest) != (size_t) (inner - outer))
 		{
-		  printf ("%s flunked for outer = %d, inner = %d\n",
+		  printf ("%s flunked for outer = %zu, inner = %zu\n",
 			  STRINGIFY (STRCPY), outer, inner);
 		  result = 1;
 		}
 
 	      adr[inner] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* strcmp/wcscmp tests */
@@ -322,14 +354,14 @@  do_test (void)
 
 	    if (STRCMP (adr + middle, dest + nchars - outer) <= 0)
 	      {
-		printf ("%s 1 flunked for outer = %d, middle = %d\n",
+		printf ("%s 1 flunked for outer = %zu, middle = %zu\n",
 			STRINGIFY (STRCMP), outer, middle);
 		result = 1;
 	      }
 
 	    if (STRCMP (dest + nchars - outer, adr + middle) >= 0)
 	      {
-		printf ("%s 2 flunked for outer = %d, middle = %d\n",
+		printf ("%s 2 flunked for outer = %zu, middle = %zu\n",
 			STRINGIFY (STRCMP), outer, middle);
 		result = 1;
 	      }
@@ -348,16 +380,16 @@  do_test (void)
 	      {
 		if (STRNCMP (adr + middle, dest + nchars - outer, inner) != 0)
 		  {
-		    printf ("%s 1 flunked for outer = %d, middle = %d, "
-			    "inner = %d\n",
+		    printf ("%s 1 flunked for outer = %zu, middle = %zu, "
+			    "inner = %zu\n",
 			    STRINGIFY (STRNCMP), outer, middle, inner);
 		    result = 1;
 		  }
 
 		if (STRNCMP (dest + nchars - outer, adr + middle, inner) != 0)
 		  {
-		    printf ("%s 2 flunked for outer = %d, middle = %d, "
-			    "inner = %d\n",
+		    printf ("%s 2 flunked for outer = %zu, middle = %zu, "
+			    "inner = %zu\n",
 			    STRINGIFY (STRNCMP), outer, middle, inner);
 		    result = 1;
 		  }
@@ -365,14 +397,14 @@  do_test (void)
 
 	    if (STRNCMP (adr + middle, dest + nchars - outer, outer) >= 0)
 	      {
-		printf ("%s 1 flunked for outer = %d, middle = %d, full\n",
+		printf ("%s 1 flunked for outer = %zu, middle = %zu, full\n",
 			STRINGIFY (STRNCMP), outer, middle);
 		result = 1;
 	      }
 
 	    if (STRNCMP (dest + nchars - outer, adr + middle, outer) <= 0)
 	      {
-		printf ("%s 2 flunked for outer = %d, middle = %d, full\n",
+		printf ("%s 2 flunked for outer = %zu, middle = %zu, full\n",
 			STRINGIFY (STRNCMP), outer, middle);
 		result = 1;
 	      }
@@ -380,7 +412,7 @@  do_test (void)
 
       /* strncpy/wcsncpy tests */
       adr[nchars - 1] = L('T');
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= max128; --outer)
 	{
 	  size_t len;
 
@@ -389,17 +421,19 @@  do_test (void)
 	      if (STRNCPY (dest, &adr[outer], len) != dest
 		  || MEMCMP (dest, &adr[outer], len) != 0)
 		{
-		  printf ("outer %s flunked for outer = %d, len = %Zd\n",
+		  printf ("outer %s flunked for outer = %zu, len = %zu\n",
 			  STRINGIFY (STRNCPY), outer, len);
 		  result = 1;
 		}
 	    }
+	  if (outer == 0)
+	    break;
 	}
       adr[nchars - 1] = L('\0');
 
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (inner = MAX (outer, nchars - 64); inner < nchars; ++inner)
+	  for (inner = MAX (outer, nchars64); inner < nchars; ++inner)
 	    {
 	      size_t len;
 
@@ -413,8 +447,8 @@  do_test (void)
 		      || (inner - outer < len
 			  && STRLEN (dest) != (inner - outer)))
 		    {
-		      printf ("%s flunked for outer = %d, inner = %d, "
-			      "len = %Zd\n",
+		      printf ("%s flunked for outer = %zu, inner = %zu, "
+			      "len = %zu\n",
 			      STRINGIFY (STRNCPY), outer, inner, len);
 		      result = 1;
 		    }
@@ -424,8 +458,8 @@  do_test (void)
 		      || (inner - outer < len
 			  && STRLEN (dest + 1) != (inner - outer)))
 		    {
-		      printf ("%s+1 flunked for outer = %d, inner = %d, "
-			      "len = %Zd\n",
+		      printf ("%s+1 flunked for outer = %zu, inner = %zu, "
+			      "len = %zu\n",
 			      STRINGIFY (STRNCPY), outer, inner, len);
 		      result = 1;
 		    }
@@ -433,29 +467,33 @@  do_test (void)
 
 	      adr[inner] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* stpcpy/wcpcpy test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (inner = MAX (outer, nchars - 64); inner < nchars; ++inner)
+	  for (inner = MAX (outer, nchars64); inner < nchars; ++inner)
 	    {
 	      adr[inner] = L('\0');
 
 	      if ((STPCPY (dest, &adr[outer]) - dest) != inner - outer)
 		{
-		  printf ("%s flunked for outer = %d, inner = %d\n",
+		  printf ("%s flunked for outer = %zu, inner = %zu\n",
 			  STRINGIFY (STPCPY), outer, inner);
 		  result = 1;
 		}
 
 	      adr[inner] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* stpncpy/wcpncpy test */
       adr[nchars - 1] = L('T');
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= max128; --outer)
 	{
 	  size_t len;
 
@@ -464,17 +502,19 @@  do_test (void)
 	      if (STPNCPY (dest, &adr[outer], len) != dest + len
 		  || MEMCMP (dest, &adr[outer], len) != 0)
 		{
-		  printf ("outer %s flunked for outer = %d, len = %Zd\n",
+		  printf ("outer %s flunked for outer = %zu, len = %zu\n",
 			  STRINGIFY (STPNCPY), outer, len);
 		  result = 1;
 		}
 	    }
+	  if (outer == 0)
+	    break;
 	}
       adr[nchars - 1] = L('\0');
 
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars - 1; outer >= max128; --outer)
 	{
-	  for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
+	  for (middle = MAX (outer, nchars64); middle < nchars; ++middle)
 	    {
 	      adr[middle] = L('\0');
 
@@ -483,8 +523,8 @@  do_test (void)
 		  if ((STPNCPY (dest, &adr[outer], inner) - dest)
 		      != MIN (inner, middle - outer))
 		    {
-		      printf ("%s flunked for outer = %d, middle = %d, "
-			      "inner = %d\n",
+		      printf ("%s flunked for outer = %zu, middle = %zu, "
+			      "inner = %zu\n",
 			      STRINGIFY (STPNCPY), outer, middle, inner);
 		      result = 1;
 		    }
@@ -492,66 +532,84 @@  do_test (void)
 
 	      adr[middle] = L('T');
 	    }
+	  if (outer == 0)
+	    break;
 	}
 
       /* memcpy/wmemcpy test */
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
-	for (inner = 0; inner < nchars - outer; ++inner)
-	  if (MEMCPY (dest, &adr[outer], inner) !=  dest)
-	    {
-	      printf ("%s flunked for outer = %d, inner = %d\n",
-		      STRINGIFY (MEMCPY), outer, inner);
-	      result = 1;
-	    }
+      for (outer = nchars; outer >= max128; --outer)
+	{
+	  for (inner = 0; inner < nchars - outer; ++inner)
+	    if (MEMCPY (dest, &adr[outer], inner) !=  dest)
+	      {
+		printf ("%s flunked for outer = %zu, inner = %zu\n",
+			STRINGIFY (MEMCPY), outer, inner);
+		result = 1;
+	      }
+	  if (outer == 0)
+	    break;
+	}
 
       /* mempcpy/wmempcpy test */
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
-	for (inner = 0; inner < nchars - outer; ++inner)
-	  if (MEMPCPY (dest, &adr[outer], inner) !=  dest + inner)
-	    {
-	      printf ("%s flunked for outer = %d, inner = %d\n",
-		      STRINGIFY (MEMPCPY), outer, inner);
-	      result = 1;
-	    }
+      for (outer = nchars; outer >= max128; --outer)
+	{
+	  for (inner = 0; inner < nchars - outer; ++inner)
+	    if (MEMPCPY (dest, &adr[outer], inner) !=  dest + inner)
+	      {
+		printf ("%s flunked for outer = %zu, inner = %zu\n",
+			STRINGIFY (MEMPCPY), outer, inner);
+		result = 1;
+	      }
+	  if (outer == 0)
+	    break;
+	}
 
       /* This function only exists for single-byte characters.  */
 #ifndef WCSTEST
       /* memccpy test */
       memset (adr, '\0', nchars);
-      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
-	for (inner = 0; inner < nchars - outer; ++inner)
-	  if (memccpy (dest, &adr[outer], L('\1'), inner) != NULL)
-	    {
-	      printf ("memccpy flunked full copy for outer = %d, inner = %d\n",
-		      outer, inner);
-	      result = 1;
-	    }
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
-	for (middle = 0; middle < nchars - outer; ++middle)
-	  {
-	    memset (dest, L('\2'), middle + 1);
-	    for (inner = 0; inner < middle; ++inner)
+      for (outer = nchars; outer >= max128; --outer)
+	{
+	  for (inner = 0; inner < nchars - outer; ++inner)
+	    if (memccpy (dest, &adr[outer], L('\1'), inner) != NULL)
 	      {
-		adr[outer + inner] = L('\1');
-
-		if (memccpy (dest, &adr[outer], '\1', middle + 128)
-		    !=  dest + inner + 1)
-		  {
-		    printf ("\
-memccpy flunked partial copy for outer = %d, middle = %d, inner = %d\n",
-			    outer, middle, inner);
-		    result = 1;
-		  }
-		else if (dest[inner + 1] != L('\2'))
-		  {
-		    printf ("\
-memccpy copied too much for outer = %d, middle = %d, inner = %d\n",
-			    outer, middle, inner);
-		    result = 1;
-		  }
-		adr[outer + inner] = L('\0');
+		printf ("memccpy flunked full copy for outer = %zu, inner = %zu\n",
+			outer, inner);
+		result = 1;
 	      }
-	  }
+	  if (outer == 0)
+	    break;
+	}
+      for (outer = nchars - 1; outer >= max128; --outer)
+	{
+	  for (middle = 0; middle < nchars - outer; ++middle)
+	    {
+	      memset (dest, L('\2'), middle + 1);
+	      for (inner = 0; inner < middle; ++inner)
+		{
+		  adr[outer + inner] = L('\1');
+
+		  if (memccpy (dest, &adr[outer], '\1', middle + 128)
+		      !=  dest + inner + 1)
+		    {
+		      printf ("\
+			      memccpy flunked partial copy for outer = %zu, middle = %zu, inner = %zu\n",
+			      outer, middle, inner);
+		      result = 1;
+		    }
+		  else if (dest[inner + 1] != L('\2'))
+		    {
+		      printf ("\
+			      memccpy copied too much for outer = %zu, middle = %zu, inner = %zu\n",
+			      outer, middle, inner);
+		      result = 1;
+		    }
+		  adr[outer + inner] = L('\0');
+		}
+	    }
+	  if (outer == 0)
+	    break;
+	}
 #endif
     }
 
-- 
2.13.5