diff mbox series

rs6000: Some builtins require IBM-128 long double format (PR103623)

Message ID 3bde7975-4753-f6b0-1b90-5a6bca315ebf@linux.ibm.com
State New
Headers
Series rs6000: Some builtins require IBM-128 long double format (PR103623) |

Commit Message

Li, Pan2 via Gcc-patches Dec. 13, 2021, 3:55 p.m. UTC 
  Hi!

PR103623 shows that we ICE if __builtin_pack_longdouble or __builtin_unpack_longdouble
is used when long double is not defined to be the IBM-128 (double-double) format.
To solve this, I introduce a new built-in function attribute "ibmld" that enforces
this requirement.

Tested the fix on a powerpc-e300c3-linux-gnu cross.  Bootstrapped and tested on
powerpc64le-linux-gnu with no regressions.  Is this okay for trunk?

Thanks!
Bill


2021-12-13  Bill Schmidt  <wschmidt@linux.ibm.com>

gcc/
	PR target/103623
	* config/rs6000/rs6000-builtin-new.def (__builtin_pack_longdouble): Add
	ibmld attribute.
	(__builtin_unpack_longdouble): Likewise.
	* config/rs6000/rs6000-call.c (rs6000_expand_new_builtin): Add special
	handling for ibmld attribute.
	* config/rs6000/rs6000-gen-builtins.c (attrinfo): Add isibmld.
	(parse_bif_attrs): Handle ibmld.
	(write_decls): Likewise.
	(write_bif_static_init): Likewise.
---
 gcc/config/rs6000/rs6000-builtin-new.def | 11 +++--------
 gcc/config/rs6000/rs6000-call.c          |  7 +++++++
 gcc/config/rs6000/rs6000-gen-builtins.c  | 13 +++++++++++--
 3 files changed, 21 insertions(+), 10 deletions(-)

Comments

Martin Sebor Dec. 13, 2021, 8:15 p.m. UTC | #1 
On 12/13/21 8:55 AM, Bill Schmidt via Gcc-patches wrote:
> Hi!
> 
> PR103623 shows that we ICE if __builtin_pack_longdouble or __builtin_unpack_longdouble
> is used when long double is not defined to be the IBM-128 (double-double) format.
> To solve this, I introduce a new built-in function attribute "ibmld" that enforces
> this requirement.
> 
> Tested the fix on a powerpc-e300c3-linux-gnu cross.  Bootstrapped and tested on
> powerpc64le-linux-gnu with no regressions.  Is this okay for trunk?

Just a minor note about the format of the new error message
below:

...
> diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
> index d9736eaf21c..b6f0c6c4c08 100644
> --- a/gcc/config/rs6000/rs6000-call.c
> +++ b/gcc/config/rs6000/rs6000-call.c
> @@ -15741,6 +15741,13 @@ rs6000_expand_new_builtin (tree exp, rtx target,
>         return const0_rtx;
>       }
>   
> +  if (bif_is_ibmld (*bifaddr) && !FLOAT128_2REG_P (TFmode))
> +    {
> +      error ("%<%s%> requires long double to be IBM 128-bit format",

as a keyword long double should be quoted in the message.

Martin
Li, Pan2 via Gcc-patches Dec. 13, 2021, 8:40 p.m. UTC | #2 
Hi!

On 12/13/21 2:15 PM, Martin Sebor wrote:
> On 12/13/21 8:55 AM, Bill Schmidt via Gcc-patches wrote:
>> Hi!
>>
>> PR103623 shows that we ICE if __builtin_pack_longdouble or __builtin_unpack_longdouble
>> is used when long double is not defined to be the IBM-128 (double-double) format.
>> To solve this, I introduce a new built-in function attribute "ibmld" that enforces
>> this requirement.
>>
>> Tested the fix on a powerpc-e300c3-linux-gnu cross.  Bootstrapped and tested on
>> powerpc64le-linux-gnu with no regressions.  Is this okay for trunk?
>
> Just a minor note about the format of the new error message
> below:
>
> ...
>> diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
>> index d9736eaf21c..b6f0c6c4c08 100644
>> --- a/gcc/config/rs6000/rs6000-call.c
>> +++ b/gcc/config/rs6000/rs6000-call.c
>> @@ -15741,6 +15741,13 @@ rs6000_expand_new_builtin (tree exp, rtx target,
>>         return const0_rtx;
>>       }
>>   +  if (bif_is_ibmld (*bifaddr) && !FLOAT128_2REG_P (TFmode))
>> +    {
>> +      error ("%<%s%> requires long double to be IBM 128-bit format",
>
> as a keyword long double should be quoted in the message.

Thanks, Martin, good point.  Sorry for overlooking that!

Bill
>
> Martin
Segher Boessenkool Dec. 14, 2021, 1:22 a.m. UTC | #3 
Hi!

On Mon, Dec 13, 2021 at 09:55:17AM -0600, Bill Schmidt wrote:
> PR103623 shows that we ICE if __builtin_pack_longdouble or __builtin_unpack_longdouble
> is used when long double is not defined to be the IBM-128 (double-double) format.
> To solve this, I introduce a new built-in function attribute "ibmld" that enforces
> this requirement.

Good call.

> @@ -215,13 +216,8 @@
>    double __builtin_mffsl ();
>      MFFSL rs6000_mffsl {}
>  
> -; This thing really assumes long double == __ibm128, and I'm told it has
> -; been used as such within libgcc.  Given that __builtin_pack_ibm128
> -; exists for the same purpose, this should really not be used at all.
> -; TODO: Consider adding special handling for this to warn whenever
> -; long double is not __ibm128.
>    const long double __builtin_pack_longdouble (double, double);
> -    PACK_TF packtf {}
> +    PACK_TF packtf {ibmld}

You removed a bit much of the comment.  Please retain the part about
__builtin_pack_ibm128 being better to use, less antiquated.

> -; See above comments for __builtin_pack_longdouble.
>    const double __builtin_unpack_longdouble (long double, const int<1>);
> -    UNPACK_TF unpacktf {}
> +    UNPACK_TF unpacktf {ibmld}

And that comment :-)  (Or just copy the short comment from there).

Okay for trunk with that tweaked (and Martin's quoting thing taken care
of).  Thanks!


Segher
diff mbox series

Patch

diff --git a/gcc/config/rs6000/rs6000-builtin-new.def b/gcc/config/rs6000/rs6000-builtin-new.def
index 2becd96a36c..a020dbbe2fb 100644
--- a/gcc/config/rs6000/rs6000-builtin-new.def
+++ b/gcc/config/rs6000/rs6000-builtin-new.def
@@ -137,6 +137,7 @@ 
 ;   lxvrse   Needs special handling for load-rightmost, sign-extended
 ;   lxvrze   Needs special handling for load-rightmost, zero-extended
 ;   endian   Needs special handling for endianness
+;   ibmld    Restrict usage to the case when TFmode is IBM-128
 ;
 ; Each attribute corresponds to extra processing required when
 ; the built-in is expanded.  All such special processing should
@@ -215,13 +216,8 @@ 
   double __builtin_mffsl ();
     MFFSL rs6000_mffsl {}
 
-; This thing really assumes long double == __ibm128, and I'm told it has
-; been used as such within libgcc.  Given that __builtin_pack_ibm128
-; exists for the same purpose, this should really not be used at all.
-; TODO: Consider adding special handling for this to warn whenever
-; long double is not __ibm128.
   const long double __builtin_pack_longdouble (double, double);
-    PACK_TF packtf {}
+    PACK_TF packtf {ibmld}
 
   unsigned long __builtin_ppc_mftb ();
     MFTB rs6000_mftb_di {32bit}
@@ -244,9 +240,8 @@ 
   const double __builtin_unpack_ibm128 (__ibm128, const int<1>);
     UNPACK_IF unpackif {}
 
-; See above comments for __builtin_pack_longdouble.
   const double __builtin_unpack_longdouble (long double, const int<1>);
-    UNPACK_TF unpacktf {}
+    UNPACK_TF unpacktf {ibmld}
 
 
 ; Builtins that have been around just about forever, but not quite.
diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index d9736eaf21c..b6f0c6c4c08 100644
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -15741,6 +15741,13 @@  rs6000_expand_new_builtin (tree exp, rtx target,
       return const0_rtx;
     }
 
+  if (bif_is_ibmld (*bifaddr) && !FLOAT128_2REG_P (TFmode))
+    {
+      error ("%<%s%> requires long double to be IBM 128-bit format",
+	     bifaddr->bifname);
+      return const0_rtx;
+    }
+
   if (bif_is_cpu (*bifaddr))
     return new_cpu_expand_builtin (fcode, exp, target);
 
diff --git a/gcc/config/rs6000/rs6000-gen-builtins.c b/gcc/config/rs6000/rs6000-gen-builtins.c
index d2e9c4ce547..ababe83895c 100644
--- a/gcc/config/rs6000/rs6000-gen-builtins.c
+++ b/gcc/config/rs6000/rs6000-gen-builtins.c
@@ -92,6 +92,7 @@  along with GCC; see the file COPYING3.  If not see
      lxvrse   Needs special handling for load-rightmost, sign-extended
      lxvrze   Needs special handling for load-rightmost, zero-extended
      endian   Needs special handling for endianness
+     ibmld    Restrict usage to the case when TFmode is IBM-128
 
    An example stanza might look like this:
 
@@ -390,6 +391,7 @@  struct attrinfo
   bool islxvrse;
   bool islxvrze;
   bool isendian;
+  bool isibmld;
 };
 
 /* Fields associated with a function prototype (bif or overload).  */
@@ -1435,6 +1437,8 @@  parse_bif_attrs (attrinfo *attrptr)
 	  attrptr->islxvrze = 1;
 	else if (!strcmp (attrname, "endian"))
 	  attrptr->isendian = 1;
+	else if (!strcmp (attrname, "ibmld"))
+	  attrptr->isibmld = 1;
 	else
 	  {
 	    diag (oldpos, "unknown attribute.\n");
@@ -1468,14 +1472,14 @@  parse_bif_attrs (attrinfo *attrptr)
 	"ldvec = %d, stvec = %d, reve = %d, pred = %d, htm = %d, "
 	"htmspr = %d, htmcr = %d, mma = %d, quad = %d, pair = %d, "
 	"mmaint = %d, no32bit = %d, 32bit = %d, cpu = %d, ldstmask = %d, "
-	"lxvrse = %d, lxvrze = %d, endian = %d.\n",
+	"lxvrse = %d, lxvrze = %d, endian = %d, ibmdld= %d.\n",
 	attrptr->isinit, attrptr->isset, attrptr->isextract,
 	attrptr->isnosoft, attrptr->isldvec, attrptr->isstvec,
 	attrptr->isreve, attrptr->ispred, attrptr->ishtm, attrptr->ishtmspr,
 	attrptr->ishtmcr, attrptr->ismma, attrptr->isquad, attrptr->ispair,
 	attrptr->ismmaint, attrptr->isno32bit, attrptr->is32bit,
 	attrptr->iscpu, attrptr->isldstmask, attrptr->islxvrse,
-	attrptr->islxvrze, attrptr->isendian);
+	attrptr->islxvrze, attrptr->isendian, attrptr->isibmld);
 #endif
 
   return PC_OK;
@@ -2289,6 +2293,7 @@  write_decls (void)
   fprintf (header_file, "#define bif_lxvrse_bit\t\t(0x00080000)\n");
   fprintf (header_file, "#define bif_lxvrze_bit\t\t(0x00100000)\n");
   fprintf (header_file, "#define bif_endian_bit\t\t(0x00200000)\n");
+  fprintf (header_file, "#define bif_ibmld_bit\t\t(0x00400000)\n");
   fprintf (header_file, "\n");
   fprintf (header_file,
 	   "#define bif_is_init(x)\t\t((x).bifattrs & bif_init_bit)\n");
@@ -2334,6 +2339,8 @@  write_decls (void)
 	   "#define bif_is_lxvrze(x)\t((x).bifattrs & bif_lxvrze_bit)\n");
   fprintf (header_file,
 	   "#define bif_is_endian(x)\t((x).bifattrs & bif_endian_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_ibmld(x)\t((x).bifattrs & bif_ibmld_bit)\n");
   fprintf (header_file, "\n");
 
   /* #### Note that the _x is added for now to avoid conflict with
@@ -2568,6 +2575,8 @@  write_bif_static_init (void)
 	fprintf (init_file, " | bif_lxvrze_bit");
       if (bifp->attrs.isendian)
 	fprintf (init_file, " | bif_endian_bit");
+      if (bifp->attrs.isibmld)
+	fprintf (init_file, " | bif_ibmld_bit");
       fprintf (init_file, ",\n");
       fprintf (init_file, "      /* restr_opnd */\t{%d, %d, %d},\n",
 	       bifp->proto.restr_opnd[0], bifp->proto.restr_opnd[1],