Re: [musl] add loongarch64 port v9.

[Hongliang Wang <wanghongliang@loongson.cn>]

在 2023/11/17 上午12:10, Rich Felker 写道:
> On Thu, Nov 16, 2023 at 10:54:44AM +0800, Hongliang Wang wrote:
>> Hi,
>>
>> Thank you for your suggestion, I have modified the dynamic linker
>> name according to the basic ABI types are specified in the ABI
>> document of the LoongArch, and post 0001-add-loongarch64-port-v9.patch,
>> as shown in the attachment.
>>
>> Based on 0001-add-loongarch64-port-v8.patch,the modifications for
>> 0001-add-loongarch64-port-v9.patch are as follows:
>>
>> ---
>>   arch/loongarch64/reloc.h | 10 ++++++----
>>   configure                |  4 +++-
>>   2 files changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/loongarch64/reloc.h b/arch/loongarch64/reloc.h
>> index a4482b48..6907de8e 100644
>> --- a/arch/loongarch64/reloc.h
>> +++ b/arch/loongarch64/reloc.h
>> @@ -1,7 +1,9 @@
>> -#ifdef __loongarch_soft_float
>> -#define FP_SUFFIX "-sf"
>> -#else
>> -#define FP_SUFFIX ""
>> +#if defined __loongarch_double_float
>> +#define FP_SUFFIX "-lp64d"
>> +#elif defined __loongarch_single_float
>> +#define FP_SUFFIX "-lp64f"
>> +#elif defined __loongarch_soft_float
>> +#define FP_SUFFIX "-lp64s"
>>   #endif
>>
>>   #define LDSO_ARCH "loongarch64"  FP_SUFFIX
>> diff --git a/configure b/configure
>> index 55d179f1..93b06287 100755
>> --- a/configure
>> +++ b/configure
>> @@ -673,7 +673,9 @@ trycppif __AARCH64EB__ "$t" && SUBARCH=${SUBARCH}_be
>>   fi
>>
>>   if test "$ARCH" = "loongarch64" ; then
>> -trycppif __loongarch_soft_float "$t" && SUBARCH=${SUBARCH}-sf
>> +trycppif __loongarch_double_float "$t" && SUBARCH=${SUBARCH}-lp64d
>> +trycppif __loongarch_single_float "$t" && SUBARCH=${SUBARCH}-lp64f
>> +trycppif __loongarch_soft_float "$t" && SUBARCH=${SUBARCH}-lp64s
>>   printf "checking whether compiler support FCSRs... "
>>   echo "__asm__(\"movfcsr2gr \$t0,\$fcsr0\");" > "$tmpc"
>>   if $CC -c -o /dev/null "$tmpc" >/dev/null 2>&1 ; then
>> -- 
>>
>> Please review again, and point them out if any questions need to be
>> modified, thanks.
> 
> Why are you changing the ABI name for the existing one to something
> different rather than just adding the missing ones, and doing it with
> a name that's less descriptive ("-sf" is widely recognized as a
> softfloat suffix, -lp64s not so much) and adding a redundant "lp64"
> part to each one that does not seem to be part of distinguishing the
> float ABI?
> 
> Rich
> 
We change the ABI name based on the LoongArch ELF ABI specification,
which can be seen:
https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html
(Table 7. Base ABI Types.)
The specification defines lp64d, lp64s, lp64f:
lp64d indicates uses 64-bit FPRs, d indicates double float.
lp64s indicates uses 32-bit FPRs, s indicates single float.
lp64f indicates uses no FPRs,  f indicates soft float.

The specification does not define sf, so I removed it.
The define in musl is also consistent with gcc.