[PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

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Hi,

while testing, I've got the following werror on s390x when build with 
gcc 6.1 (or current gcc head) and -O3:
../sysdeps/ieee754/dbl-64/k_rem_pio2.c: In function ‘__kernel_rem_pio2’:
../sysdeps/ieee754/dbl-64/k_rem_pio2.c:254:18: error: array subscript is 
below array bounds [-Werror=array-bounds]
     for (k = 1; iq[jk - k] == 0; k++)
                 ~~^~~~~~~~

I get the same error with sysdeps/ieee754/flt-32/k_rem_pio2f.c.

Does anybody else get this warning on another architecture, too?

This patch adds a check so that the index is always >= 0.
Afterwards glibc builds/tests fine with gcc 6.1 and -O3.

Okay to commit?
Before or after release?

Bye
Stefan

ChangeLog:

	* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
	Add test to ensure that array-index is >= 0.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
	Likewise.

[-- Attachment #2: 20160707_k_rem_pio2_warraybounds.patch --]
[-- Type: text/x-patch, Size: 1105 bytes --]

diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
index e58c9e8..4fe14de 100644
--- a/sysdeps/ieee754/dbl-64/k_rem_pio2.c
+++ b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
@@ -251,7 +251,7 @@ recompute:
 	j |= iq[i];
       if (j == 0)      /* need recomputation */
 	{
-	  for (k = 1; iq[jk - k] == 0; k++)
+	  for (k = 1; k <= jk && iq[jk - k] == 0; k++)
 	    ;                               /* k = no. of terms needed */
 
 	  for (i = jz + 1; i <= jz + k; i++) /* add q[jz+1] to q[jz+k] */
diff --git a/sysdeps/ieee754/flt-32/k_rem_pio2f.c b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
index 392afdb..805f487 100644
--- a/sysdeps/ieee754/flt-32/k_rem_pio2f.c
+++ b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
@@ -122,7 +122,8 @@ recompute:
 	    j = 0;
 	    for (i=jz-1;i>=jk;i--) j |= iq[i];
 	    if(j==0) { /* need recomputation */
-		for(k=1;iq[jk-k]==0;k++);   /* k = no. of terms needed */
+		for (k = 1; k <= jk && iq[jk - k] == 0; k++)
+		  ;    /* k = no. of terms needed */
 
 		for(i=jz+1;i<=jz+k;i++) {   /* add q[jz+1] to q[jz+k] */
 		    f[jx+i] = (float) ipio2[jv+i];

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

PING

On 07/07/2016 10:22 AM, Stefan Liebler wrote:
> Hi,
>
> while testing, I've got the following werror on s390x when build with
> gcc 6.1 (or current gcc head) and -O3:
> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c: In function ‘__kernel_rem_pio2’:
> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c:254:18: error: array subscript is
> below array bounds [-Werror=array-bounds]
>      for (k = 1; iq[jk - k] == 0; k++)
>                  ~~^~~~~~~~
>
> I get the same error with sysdeps/ieee754/flt-32/k_rem_pio2f.c.
>
> Does anybody else get this warning on another architecture, too?
>
> This patch adds a check so that the index is always >= 0.
> Afterwards glibc builds/tests fine with gcc 6.1 and -O3.
>
> Okay to commit?
> Before or after release?
>
> Bye
> Stefan
>
> ChangeLog:
>
>      * sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
>      Add test to ensure that array-index is >= 0.
>      * sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
>      Likewise.

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

PING

On 07/13/2016 12:25 PM, Stefan Liebler wrote:
> PING
>
> On 07/07/2016 10:22 AM, Stefan Liebler wrote:
>> Hi,
>>
>> while testing, I've got the following werror on s390x when build with
>> gcc 6.1 (or current gcc head) and -O3:
>> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c: In function ‘__kernel_rem_pio2’:
>> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c:254:18: error: array subscript is
>> below array bounds [-Werror=array-bounds]
>>      for (k = 1; iq[jk - k] == 0; k++)
>>                  ~~^~~~~~~~
>>
>> I get the same error with sysdeps/ieee754/flt-32/k_rem_pio2f.c.
>>
>> Does anybody else get this warning on another architecture, too?
>>
>> This patch adds a check so that the index is always >= 0.
>> Afterwards glibc builds/tests fine with gcc 6.1 and -O3.
>>
>> Okay to commit?
>> Before or after release?
>>
>> Bye
>> Stefan
>>
>> ChangeLog:
>>
>>      * sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
>>      Add test to ensure that array-index is >= 0.
>>      * sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
>>      Likewise.
>
>

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Joseph Myers]

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On Thu, 7 Jul 2016, Stefan Liebler wrote:

> Hi,
> 
> while testing, I've got the following werror on s390x when build with gcc 6.1
> (or current gcc head) and -O3:
> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c: In function ‘__kernel_rem_pio2’:
> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c:254:18: error: array subscript is below
> array bounds [-Werror=array-bounds]
>     for (k = 1; iq[jk - k] == 0; k++)
>                 ~~^~~~~~~~
> 
> I get the same error with sysdeps/ieee754/flt-32/k_rem_pio2f.c.
> 
> Does anybody else get this warning on another architecture, too?
> 
> This patch adds a check so that the index is always >= 0.

Such an unnecessary check is not how we deal with bogus warnings.  
Rather, use the DIAG_*_NEEDS_COMMENT macros from include/libc-internal.h, 
with a detailed comment explaining what the warning is and why it is a 
false positive.

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

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On 07/20/2016 06:33 PM, Joseph Myers wrote:
> On Thu, 7 Jul 2016, Stefan Liebler wrote:
>
>> Hi,
>>
>> while testing, I've got the following werror on s390x when build with gcc 6.1
>> (or current gcc head) and -O3:
>> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c: In function ‘__kernel_rem_pio2’:
>> ../sysdeps/ieee754/dbl-64/k_rem_pio2.c:254:18: error: array subscript is below
>> array bounds [-Werror=array-bounds]
>>      for (k = 1; iq[jk - k] == 0; k++)
>>                  ~~^~~~~~~~
>>
>> I get the same error with sysdeps/ieee754/flt-32/k_rem_pio2f.c.
>>
>> Does anybody else get this warning on another architecture, too?
>>
>> This patch adds a check so that the index is always >= 0.
>
> Such an unnecessary check is not how we deal with bogus warnings.
> Rather, use the DIAG_*_NEEDS_COMMENT macros from include/libc-internal.h,
> with a detailed comment explaining what the warning is and why it is a
> false positive.
>

Sorry for the delay. Here is the updated patch with DIAG_* macros.
Is this okay?

Bye Stefan

ChangeLog:


ChangeLog:

	* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
	Use DIAG_*_NEEDS_COMMENT macro to get rid of array-bounds
	warning.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
	Likewise.

[-- Attachment #2: 20160725_k_rem_pio2_warraybounds.patch --]
[-- Type: text/x-patch, Size: 2412 bytes --]

diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
index e58c9e8..4fa05b9 100644
--- a/sysdeps/ieee754/dbl-64/k_rem_pio2.c
+++ b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
@@ -132,6 +132,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2.c,v 1.7 1995/05/10 20:46:25 jtc Exp $
 
 #include <math.h>
 #include <math_private.h>
+#include <libc-internal.h>
 
 static const int init_jk[] = {2,3,4,6}; /* initial value for jk */
 
@@ -251,8 +252,16 @@ recompute:
 	j |= iq[i];
       if (j == 0)      /* need recomputation */
 	{
+	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
+	     array bounds [-Werror=array-bounds]". Only __ieee754_rem_pio2l()
+	     calls __kernel_rem_pio2f() for normal numbers and |x| > 3pi/4. Thus
+	     x can't be zero and ipio2 is not zero, too. Thus not all iq[]
+	     values can't be zero.  */
+	  DIAG_PUSH_NEEDS_COMMENT;
+	  DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds");
 	  for (k = 1; iq[jk - k] == 0; k++)
 	    ;                               /* k = no. of terms needed */
+	  DIAG_POP_NEEDS_COMMENT;
 
 	  for (i = jz + 1; i <= jz + k; i++) /* add q[jz+1] to q[jz+k] */
 	    {
diff --git a/sysdeps/ieee754/flt-32/k_rem_pio2f.c b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
index 392afdb..83d3214 100644
--- a/sysdeps/ieee754/flt-32/k_rem_pio2f.c
+++ b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
@@ -19,6 +19,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2f.c,v 1.4 1995/05/10 20:46:28 jtc Exp
 
 #include <math.h>
 #include <math_private.h>
+#include <libc-internal.h>
 
 /* In the float version, the input parameter x contains 8 bit
    integers, not 24 bit integers.  113 bit precision is not supported.  */
@@ -122,7 +123,15 @@ recompute:
 	    j = 0;
 	    for (i=jz-1;i>=jk;i--) j |= iq[i];
 	    if(j==0) { /* need recomputation */
+		/* On s390x gcc 6.1 -O3 produces the warning "array subscript is
+		   below array bounds [-Werror=array-bounds]". Only
+		   __ieee754_rem_pio2f() calls __kernel_rem_pio2f() for normal
+		   numbers and |x| ~> 2^7*(pi/2). Thus x can't be zero and ipio2
+		   is not zero, too. Thus not all iq[] values can't be zero.  */
+		DIAG_PUSH_NEEDS_COMMENT;
+		DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds");
 		for(k=1;iq[jk-k]==0;k++);   /* k = no. of terms needed */
+		DIAG_POP_NEEDS_COMMENT;
 
 		for(i=jz+1;i<=jz+k;i++) {   /* add q[jz+1] to q[jz+k] */
 		    f[jx+i] = (float) ipio2[jv+i];

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Mike Frysinger]

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On 25 Jul 2016 17:55, Stefan Liebler wrote:
> +	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
> +	     array bounds [-Werror=array-bounds]". Only __ieee754_rem_pio2l()
> +	     calls __kernel_rem_pio2f() for normal numbers and |x| > 3pi/4. Thus
> +	     x can't be zero and ipio2 is not zero, too. Thus not all iq[]
> +	     values can't be zero.  */

GNU style puts two spaces after the period
-mike

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Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

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On 08/01/2016 04:12 PM, Mike Frysinger wrote:
> On 25 Jul 2016 17:55, Stefan Liebler wrote:
>> +	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
>> +	     array bounds [-Werror=array-bounds]". Only __ieee754_rem_pio2l()
>> +	     calls __kernel_rem_pio2f() for normal numbers and |x| > 3pi/4. Thus
>> +	     x can't be zero and ipio2 is not zero, too. Thus not all iq[]
>> +	     values can't be zero.  */
>
> GNU style puts two spaces after the period
> -mike
>
Oops. I missed that.
Here is an update.
Thanks.
Stefan

[-- Attachment #2: 20160802_k_rem_pio2_warraybounds.patch --]
[-- Type: text/x-patch, Size: 2423 bytes --]

diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
index e58c9e8..db0a657 100644
--- a/sysdeps/ieee754/dbl-64/k_rem_pio2.c
+++ b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
@@ -132,6 +132,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2.c,v 1.7 1995/05/10 20:46:25 jtc Exp $
 
 #include <math.h>
 #include <math_private.h>
+#include <libc-internal.h>
 
 static const int init_jk[] = {2,3,4,6}; /* initial value for jk */
 
@@ -251,8 +252,16 @@ recompute:
 	j |= iq[i];
       if (j == 0)      /* need recomputation */
 	{
+	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
+	     array bounds [-Werror=array-bounds]".  Only __ieee754_rem_pio2l()
+	     calls __kernel_rem_pio2f() for normal numbers and |x| > 3pi/4.
+	     Thus x can't be zero and ipio2 is not zero, too.  Thus not all iq[]
+	     values can't be zero.  */
+	  DIAG_PUSH_NEEDS_COMMENT;
+	  DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds");
 	  for (k = 1; iq[jk - k] == 0; k++)
 	    ;                               /* k = no. of terms needed */
+	  DIAG_POP_NEEDS_COMMENT;
 
 	  for (i = jz + 1; i <= jz + k; i++) /* add q[jz+1] to q[jz+k] */
 	    {
diff --git a/sysdeps/ieee754/flt-32/k_rem_pio2f.c b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
index 392afdb..cca20aa 100644
--- a/sysdeps/ieee754/flt-32/k_rem_pio2f.c
+++ b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
@@ -19,6 +19,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2f.c,v 1.4 1995/05/10 20:46:28 jtc Exp
 
 #include <math.h>
 #include <math_private.h>
+#include <libc-internal.h>
 
 /* In the float version, the input parameter x contains 8 bit
    integers, not 24 bit integers.  113 bit precision is not supported.  */
@@ -122,7 +123,16 @@ recompute:
 	    j = 0;
 	    for (i=jz-1;i>=jk;i--) j |= iq[i];
 	    if(j==0) { /* need recomputation */
+		/* On s390x gcc 6.1 -O3 produces the warning "array subscript is
+		   below array bounds [-Werror=array-bounds]".  Only
+		   __ieee754_rem_pio2f() calls __kernel_rem_pio2f() for normal
+		   numbers and |x| ~> 2^7*(pi/2).  Thus x can't be zero and
+		   ipio2 is not zero, too.  Thus not all iq[] values can't be
+		   zero.  */
+		DIAG_PUSH_NEEDS_COMMENT;
+		DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds");
 		for(k=1;iq[jk-k]==0;k++);   /* k = no. of terms needed */
+		DIAG_POP_NEEDS_COMMENT;
 
 		for(i=jz+1;i<=jz+k;i++) {   /* add q[jz+1] to q[jz+k] */
 		    f[jx+i] = (float) ipio2[jv+i];

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

PING

On 08/02/2016 10:37 AM, Stefan Liebler wrote:
> On 08/01/2016 04:12 PM, Mike Frysinger wrote:
>> On 25 Jul 2016 17:55, Stefan Liebler wrote:
>>> +      /* On s390x gcc 6.1 -O3 produces the warning "array subscript
>>> is below
>>> +         array bounds [-Werror=array-bounds]". Only
>>> __ieee754_rem_pio2l()
>>> +         calls __kernel_rem_pio2f() for normal numbers and |x| >
>>> 3pi/4. Thus
>>> +         x can't be zero and ipio2 is not zero, too. Thus not all iq[]
>>> +         values can't be zero.  */
>>
>> GNU style puts two spaces after the period
>> -mike
>>
> Oops. I missed that.
> Here is an update.
> Thanks.
> Stefan

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Joseph Myers]

On Tue, 2 Aug 2016, Stefan Liebler wrote:

> diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c

> +	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
> +	     array bounds [-Werror=array-bounds]".  Only __ieee754_rem_pio2l()
> +	     calls __kernel_rem_pio2f() for normal numbers and |x| > 3pi/4.

__kernel_rem_pio2f seems like the wrong function to reference in a comment 
in this file.  Please review the actual call sequences in each case to 
make sure the right functions are referenced.  Also, the GNU Coding 
Standards say not to use () after a function name when referencing the 
function:

    Please do not write @samp{()} after a function name just to indicate
    it is a function.  @code{foo ()} is not a function, it is a function
    call with no arguments.

> +		/* On s390x gcc 6.1 -O3 produces the warning "array subscript is
> +		   below array bounds [-Werror=array-bounds]".  Only
> +		   __ieee754_rem_pio2f() calls __kernel_rem_pio2f() for normal

Likewise, don't use () after the function name.

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

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On 08/10/2016 01:38 PM, Joseph Myers wrote:
> On Tue, 2 Aug 2016, Stefan Liebler wrote:
>
>> diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
>
>> +	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
>> +	     array bounds [-Werror=array-bounds]".  Only __ieee754_rem_pio2l()
>> +	     calls __kernel_rem_pio2f() for normal numbers and |x| > 3pi/4.
>
> __kernel_rem_pio2f seems like the wrong function to reference in a comment
> in this file.  Please review the actual call sequences in each case to
> make sure the right functions are referenced.  Also, the GNU Coding
> Standards say not to use () after a function name when referencing the
> function:
>
>     Please do not write @samp{()} after a function name just to indicate
>     it is a function.  @code{foo ()} is not a function, it is a function
>     call with no arguments.
>
>> +		/* On s390x gcc 6.1 -O3 produces the warning "array subscript is
>> +		   below array bounds [-Werror=array-bounds]".  Only
>> +		   __ieee754_rem_pio2f() calls __kernel_rem_pio2f() for normal
>
> Likewise, don't use () after the function name.
>
I've reviewed the call sequences and adjusted the comment and removed 
the () after the function names.
Here is the updated patch.

Okay to commit?

Bye
Stefan

ChangeLog:

	* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
	Use DIAG_*_NEEDS_COMMENT macro to get rid of array-bounds
	warning.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
	Likewise.

[-- Attachment #2: 20160817_k_rem_pio2_warraybounds.patch --]
[-- Type: text/x-patch, Size: 2480 bytes --]

diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
index e58c9e8..d853b65 100644
--- a/sysdeps/ieee754/dbl-64/k_rem_pio2.c
+++ b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
@@ -132,6 +132,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2.c,v 1.7 1995/05/10 20:46:25 jtc Exp $
 
 #include <math.h>
 #include <math_private.h>
+#include <libc-internal.h>
 
 static const int init_jk[] = {2,3,4,6}; /* initial value for jk */
 
@@ -251,8 +252,17 @@ recompute:
 	j |= iq[i];
       if (j == 0)      /* need recomputation */
 	{
+	  /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below
+	     array bounds [-Werror=array-bounds]".  Only __ieee754_rem_pio2l
+	     calls __kernel_rem_pio2 for normal numbers and |x| > pi/4 in case
+	     of ldbl-96 and |x| > 3pi/4 in case of ldbl-128[ibm].
+	     Thus x can't be zero and ipio2 is not zero, too.  Thus not all iq[]
+	     values can't be zero.  */
+	  DIAG_PUSH_NEEDS_COMMENT;
+	  DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds");
 	  for (k = 1; iq[jk - k] == 0; k++)
 	    ;                               /* k = no. of terms needed */
+	  DIAG_POP_NEEDS_COMMENT;
 
 	  for (i = jz + 1; i <= jz + k; i++) /* add q[jz+1] to q[jz+k] */
 	    {
diff --git a/sysdeps/ieee754/flt-32/k_rem_pio2f.c b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
index 392afdb..52ffb09 100644
--- a/sysdeps/ieee754/flt-32/k_rem_pio2f.c
+++ b/sysdeps/ieee754/flt-32/k_rem_pio2f.c
@@ -19,6 +19,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2f.c,v 1.4 1995/05/10 20:46:28 jtc Exp
 
 #include <math.h>
 #include <math_private.h>
+#include <libc-internal.h>
 
 /* In the float version, the input parameter x contains 8 bit
    integers, not 24 bit integers.  113 bit precision is not supported.  */
@@ -122,7 +123,16 @@ recompute:
 	    j = 0;
 	    for (i=jz-1;i>=jk;i--) j |= iq[i];
 	    if(j==0) { /* need recomputation */
+		/* On s390x gcc 6.1 -O3 produces the warning "array subscript is
+		   below array bounds [-Werror=array-bounds]".  Only
+		   __ieee754_rem_pio2f calls __kernel_rem_pio2f for normal
+		   numbers and |x| ~> 2^7*(pi/2).  Thus x can't be zero and
+		   ipio2 is not zero, too.  Thus not all iq[] values can't be
+		   zero.  */
+		DIAG_PUSH_NEEDS_COMMENT;
+		DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds");
 		for(k=1;iq[jk-k]==0;k++);   /* k = no. of terms needed */
+		DIAG_POP_NEEDS_COMMENT;
 
 		for(i=jz+1;i<=jz+k;i++) {   /* add q[jz+1] to q[jz+k] */
 		    f[jx+i] = (float) ipio2[jv+i];

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Joseph Myers]

On Wed, 17 Aug 2016, Stefan Liebler wrote:

> I've reviewed the call sequences and adjusted the comment and removed the ()
> after the function names.
> Here is the updated patch.
> 
> Okay to commit?

OK.

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [PATCH] Get rid of array-bounds warning in __kernel_rem_pio2[f] with gcc 6.1 -O3.

[Stefan Liebler]

On 08/17/2016 05:32 PM, Joseph Myers wrote:
> On Wed, 17 Aug 2016, Stefan Liebler wrote:
>
>> I've reviewed the call sequences and adjusted the comment and removed the ()
>> after the function names.
>> Here is the updated patch.
>>
>> Okay to commit?
>
> OK.
>
Commited.