Re: [PATCH][AArch64] Fix PR79041

[James Greenhalgh]

On Fri, Jul 21, 2017 at 12:22:00PM +0100, Wilco Dijkstra wrote:
> 
>     
> ping
> 
>     
> As described in PR79041, -mcmodel=large -mpc-relative-literal-loads
> may be used to avoid generating ADRP/ADD or ADRP/LDR.  However both
> trunk and GCC7 may still emit ADRP for some constant pool literals.
> Fix this by adding a aarch64_pcrelative_literal_loads check.
> 
> OK for trunk/GCC7 backport?

OK. Either like this, or with the conditions swapped around as Yvan
suggested to make backporting easier.

Thanks,
James

> 
> ChangeLog:
> 2017-06-27  Wilco Dijkstra  
> 
>     PR target/79041
>     * config/aarch64/aarch64.c (aarch64_classify_symbol):
>     Avoid SYMBOL_SMALL_ABSOLUTE .
>     * testsuite/gcc.target/aarch64/pr79041-2.c: New test.
> --
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 
> 060cd8476d2954119daac495ecb059c9be73edbe..329d244e9cf16dbdf849e5dd02b3999caf0cd5a7
>  100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -10042,7 +10042,7 @@ aarch64_classify_symbol (rtx x, rtx offset)
>    /* This is alright even in PIC code as the constant
>   pool reference is always PC relative and within
>   the same translation unit.  */
> - if (CONSTANT_POOL_ADDRESS_P (x))
> + if (CONSTANT_POOL_ADDRESS_P (x) && 
> !aarch64_pcrelative_literal_loads)
>  return SYMBOL_SMALL_ABSOLUTE;
>    else
>  return SYMBOL_FORCE_TO_MEM;
> diff --git a/gcc/testsuite/gcc.target/aarch64/pr79041-2.c 
> b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
> new file mode 100644
> index 
> ..e7899725bad2b770f8488a07f99792113275bdf2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mcmodel=large -mpc-relative-literal-loads" } */
> +
> +__int128
> +t (void)
> +{
> +  return (__int128)1 << 80;
> +}
> +
> +/* { dg-final { scan-assembler "adr" } } */
>     

Re: [PATCH][AArch64] Fix PR79041

[Wilco Dijkstra]

    
ping

    
As described in PR79041, -mcmodel=large -mpc-relative-literal-loads
may be used to avoid generating ADRP/ADD or ADRP/LDR.  However both
trunk and GCC7 may still emit ADRP for some constant pool literals.
Fix this by adding a aarch64_pcrelative_literal_loads check.

OK for trunk/GCC7 backport?

ChangeLog:
2017-06-27  Wilco Dijkstra  

    PR target/79041
    * config/aarch64/aarch64.c (aarch64_classify_symbol):
    Avoid SYMBOL_SMALL_ABSOLUTE .
    * testsuite/gcc.target/aarch64/pr79041-2.c: New test.
--
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 
060cd8476d2954119daac495ecb059c9be73edbe..329d244e9cf16dbdf849e5dd02b3999caf0cd5a7
 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -10042,7 +10042,7 @@ aarch64_classify_symbol (rtx x, rtx offset)
   /* This is alright even in PIC code as the constant
  pool reference is always PC relative and within
  the same translation unit.  */
- if (CONSTANT_POOL_ADDRESS_P (x))
+ if (CONSTANT_POOL_ADDRESS_P (x) && !aarch64_pcrelative_literal_loads)
 return SYMBOL_SMALL_ABSOLUTE;
   else
 return SYMBOL_FORCE_TO_MEM;
diff --git a/gcc/testsuite/gcc.target/aarch64/pr79041-2.c 
b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
new file mode 100644
index 
..e7899725bad2b770f8488a07f99792113275bdf2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcmodel=large -mpc-relative-literal-loads" } */
+
+__int128
+t (void)
+{
+  return (__int128)1 << 80;
+}
+
+/* { dg-final { scan-assembler "adr" } } */
    

Re: [PATCH][AArch64] Fix PR79041

[Wilco Dijkstra]

ping

    
As described in PR79041, -mcmodel=large -mpc-relative-literal-loads
may be used to avoid generating ADRP/ADD or ADRP/LDR.  However both
trunk and GCC7 may still emit ADRP for some constant pool literals.
Fix this by adding a aarch64_pcrelative_literal_loads check.

OK for trunk/GCC7 backport?

ChangeLog:
2017-06-27  Wilco Dijkstra  

    PR target/79041
    * config/aarch64/aarch64.c (aarch64_classify_symbol):
    Avoid SYMBOL_SMALL_ABSOLUTE .
    * testsuite/gcc.target/aarch64/pr79041-2.c: New test.
--
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 
060cd8476d2954119daac495ecb059c9be73edbe..329d244e9cf16dbdf849e5dd02b3999caf0cd5a7
 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -10042,7 +10042,7 @@ aarch64_classify_symbol (rtx x, rtx offset)
   /* This is alright even in PIC code as the constant
  pool reference is always PC relative and within
  the same translation unit.  */
- if (CONSTANT_POOL_ADDRESS_P (x))
+ if (CONSTANT_POOL_ADDRESS_P (x) && !aarch64_pcrelative_literal_loads)
 return SYMBOL_SMALL_ABSOLUTE;
   else
 return SYMBOL_FORCE_TO_MEM;
diff --git a/gcc/testsuite/gcc.target/aarch64/pr79041-2.c 
b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
new file mode 100644
index 
..e7899725bad2b770f8488a07f99792113275bdf2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcmodel=large -mpc-relative-literal-loads" } */
+
+__int128
+t (void)
+{
+  return (__int128)1 << 80;
+}
+
+/* { dg-final { scan-assembler "adr" } } */

Re: [PATCH][AArch64] Fix PR79041

[Yvan Roux]

On 27 June 2017 at 16:55, Yvan Roux  wrote:
> Hi
>
> On 27 June 2017 at 16:49, Wilco Dijkstra  wrote:
>> As described in PR79041, -mcmodel=large -mpc-relative-literal-loads
>> may be used to avoid generating ADRP/ADD or ADRP/LDR.  However both
>> trunk and GCC7 may still emit ADRP for some constant pool literals.
>> Fix this by adding a aarch64_pcrelative_literal_loads check.
>>
>> OK for trunk/GCC7 backport?
>
> I can't approve it, but the patch is ok for me, I've built and
> regtested the very same patch for aarch64-linux-gnu,
> aarch64-none-elf and aarch64_be-none-elf targets :)
>
> Yvan
>
>> ChangeLog:
>> 2017-06-27  Wilco Dijkstra  
>>
>> PR target/79041
>> * config/aarch64/aarch64.c (aarch64_classify_symbol):
>> Avoid SYMBOL_SMALL_ABSOLUTE .
>> * testsuite/gcc.target/aarch64/pr79041-2.c: New test.
>> --
>> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
>> index 
>> 060cd8476d2954119daac495ecb059c9be73edbe..329d244e9cf16dbdf849e5dd02b3999caf0cd5a7
>>  100644
>> --- a/gcc/config/aarch64/aarch64.c
>> +++ b/gcc/config/aarch64/aarch64.c
>> @@ -10042,7 +10042,7 @@ aarch64_classify_symbol (rtx x, rtx offset)
>>   /* This is alright even in PIC code as the constant
>>  pool reference is always PC relative and within
>>  the same translation unit.  */
>> - if (CONSTANT_POOL_ADDRESS_P (x))
>> + if (CONSTANT_POOL_ADDRESS_P (x) && 
>> !aarch64_pcrelative_literal_loads)

maybe just a small note here, in my backport patch on gcc-6-branch a
kept the existing order in the condition:

- if (nopcrelative_literal_loads
+ if (!aarch64_pcrelative_literal_loads
  && CONSTANT_POOL_ADDRESS_P (x))

Can we keep it, or maybe I should wait for your patch to be committed
on trunk, and include its backport in my patch for GCC 6.


>> return SYMBOL_SMALL_ABSOLUTE;
>>   else
>> return SYMBOL_FORCE_TO_MEM;
>> diff --git a/gcc/testsuite/gcc.target/aarch64/pr79041-2.c 
>> b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
>> new file mode 100644
>> index 
>> ..e7899725bad2b770f8488a07f99792113275bdf2
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
>> @@ -0,0 +1,10 @@
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2 -mcmodel=large -mpc-relative-literal-loads" } */
>> +
>> +__int128
>> +t (void)
>> +{
>> +  return (__int128)1 << 80;
>> +}
>> +
>> +/* { dg-final { scan-assembler "adr" } } */

Re: [PATCH][AArch64] Fix PR79041

[Yvan Roux]

Hi

On 27 June 2017 at 16:49, Wilco Dijkstra  wrote:
> As described in PR79041, -mcmodel=large -mpc-relative-literal-loads
> may be used to avoid generating ADRP/ADD or ADRP/LDR.  However both
> trunk and GCC7 may still emit ADRP for some constant pool literals.
> Fix this by adding a aarch64_pcrelative_literal_loads check.
>
> OK for trunk/GCC7 backport?

I can't approve it, but the patch is ok for me, I've built and
regtested the very same patch for aarch64-linux-gnu,
aarch64-none-elf and aarch64_be-none-elf targets :)

Yvan

> ChangeLog:
> 2017-06-27  Wilco Dijkstra  
>
> PR target/79041
> * config/aarch64/aarch64.c (aarch64_classify_symbol):
> Avoid SYMBOL_SMALL_ABSOLUTE .
> * testsuite/gcc.target/aarch64/pr79041-2.c: New test.
> --
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 
> 060cd8476d2954119daac495ecb059c9be73edbe..329d244e9cf16dbdf849e5dd02b3999caf0cd5a7
>  100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -10042,7 +10042,7 @@ aarch64_classify_symbol (rtx x, rtx offset)
>   /* This is alright even in PIC code as the constant
>  pool reference is always PC relative and within
>  the same translation unit.  */
> - if (CONSTANT_POOL_ADDRESS_P (x))
> + if (CONSTANT_POOL_ADDRESS_P (x) && 
> !aarch64_pcrelative_literal_loads)
> return SYMBOL_SMALL_ABSOLUTE;
>   else
> return SYMBOL_FORCE_TO_MEM;
> diff --git a/gcc/testsuite/gcc.target/aarch64/pr79041-2.c 
> b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
> new file mode 100644
> index 
> ..e7899725bad2b770f8488a07f99792113275bdf2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mcmodel=large -mpc-relative-literal-loads" } */
> +
> +__int128
> +t (void)
> +{
> +  return (__int128)1 << 80;
> +}
> +
> +/* { dg-final { scan-assembler "adr" } } */

[PATCH][AArch64] Fix PR79041

[Wilco Dijkstra]

As described in PR79041, -mcmodel=large -mpc-relative-literal-loads
may be used to avoid generating ADRP/ADD or ADRP/LDR.  However both
trunk and GCC7 may still emit ADRP for some constant pool literals.
Fix this by adding a aarch64_pcrelative_literal_loads check.

OK for trunk/GCC7 backport?

ChangeLog:
2017-06-27  Wilco Dijkstra  

PR target/79041
* config/aarch64/aarch64.c (aarch64_classify_symbol):
Avoid SYMBOL_SMALL_ABSOLUTE .
* testsuite/gcc.target/aarch64/pr79041-2.c: New test.
--
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 
060cd8476d2954119daac495ecb059c9be73edbe..329d244e9cf16dbdf849e5dd02b3999caf0cd5a7
 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -10042,7 +10042,7 @@ aarch64_classify_symbol (rtx x, rtx offset)
  /* This is alright even in PIC code as the constant
 pool reference is always PC relative and within
 the same translation unit.  */
- if (CONSTANT_POOL_ADDRESS_P (x))
+ if (CONSTANT_POOL_ADDRESS_P (x) && !aarch64_pcrelative_literal_loads)
return SYMBOL_SMALL_ABSOLUTE;
  else
return SYMBOL_FORCE_TO_MEM;
diff --git a/gcc/testsuite/gcc.target/aarch64/pr79041-2.c 
b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
new file mode 100644
index 
..e7899725bad2b770f8488a07f99792113275bdf2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr79041-2.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcmodel=large -mpc-relative-literal-loads" } */
+
+__int128
+t (void)
+{
+  return (__int128)1 << 80;
+}
+
+/* { dg-final { scan-assembler "adr" } } */