Re: Re: [NOT CODE REVIEW] [PATCH v3 1/1] [RISC-V] Add support for _Bfloat16

[Xiao Zeng]

2024-05-16 16:55  Kito Cheng  wrote:
>
>Hi Xiao Zeng:
>
>Just wondering why use _Bfloat16 rather than __bf16? you mention
>__bf16 in comment, but implementation use _Bfloat16?
Obviously, this is a mistake.
This patch has spanned a considerable amount of time locally.

I will submit a new patch to correct it.
> I would like to use __bf16 to make it consistent between LLVM and psABI if 
> possible :)
Thanks Kito for pointing out this point. Meanwhile, due to my issue, I did not 
see
Andreas Schwab's email. He had already sent me an email earlier, pointing out 
the existing issues.


By the way, if I don't reply to the email in a timely manner, it must be my 
problem.
Please send me another email to remind me.
I will reset the email to avoid missing any emails

Thanks
Xiao Zeng

Re: [NOT CODE REVIEW] [PATCH v3 1/1] [RISC-V] Add support for _Bfloat16

[Kito Cheng]

Hi Xiao Zeng:

Just wondering why use _Bfloat16 rather than __bf16? you mention
__bf16 in comment, but implementation use _Bfloat16? I would like to
use __bf16 to make it consistent between LLVM and psABI if possible :)

Re: [NOT CODE REVIEW] [PATCH v3 1/1] [RISC-V] Add support for _Bfloat16

[Andreas Schwab]

This breaks libstdc++-abi/abi_check.

3 incompatible symbols 
0
_ZTIPKDF16b
typeinfo for std::bfloat16_t const*
version status: incompatible
CXXABI_1.3.14
type: object
type size: 32
status: added


1
_ZTIPDF16b
typeinfo for std::bfloat16_t*
version status: incompatible
CXXABI_1.3.14
type: object
type size: 32
status: added


2
_ZTIDF16b
typeinfo for std::bfloat16_t
version status: incompatible
CXXABI_1.3.14
type: object
type size: 16
status: added

-- 
Andreas Schwab, SUSE Labs, sch...@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

Re: [NOT CODE REVIEW] [PATCH v3 1/1] [RISC-V] Add support for _Bfloat16

[Jeff Law]

On 5/5/24 6:38 PM, Xiao Zeng wrote:

1 At point ,
   BF16 has already been completed "post public review".

2 LLVM has also added support for RISCV BF16 in
    and
   .

3 According to the discussion 
,
   this use __bf16 and use DF16b in riscv_mangle_type like x86.

Below test are passed for this patch
 * The riscv fully regression test.

gcc/ChangeLog:

* config/riscv/iterators.md: New mode iterator HFBF.
* config/riscv/riscv-builtins.cc (riscv_init_builtin_types):
Initialize data type _Bfloat16.
* config/riscv/riscv-modes.def (FLOAT_MODE): New.
(ADJUST_FLOAT_FORMAT): New.
* config/riscv/riscv.cc (riscv_mangle_type): Support for BFmode.
(riscv_scalar_mode_supported_p): Ditto.
(riscv_libgcc_floating_mode_supported_p): Ditto.
(riscv_init_libfuncs): Set the conversion method for BFmode and
HFmode.
(riscv_block_arith_comp_libfuncs_for_mode): Set the arithmetic
and comparison libfuncs for the mode.
* config/riscv/riscv.md (mode" ): Add BF.
(movhf): Support for BFmode.
(mov): Ditto.
(*movhf_softfloat): Ditto.
(*mov_softfloat): Ditto.

libgcc/ChangeLog:

* config/riscv/sfp-machine.h (_FP_NANFRAC_B): New.
(_FP_NANSIGN_B): Ditto.
* config/riscv/t-softfp32: Add support for BF16 libfuncs.
* config/riscv/t-softfp64: Ditto.
* soft-fp/floatsibf.c: For si -> bf16.
* soft-fp/floatunsibf.c: For unsi -> bf16.

gcc/testsuite/ChangeLog:

* gcc.target/riscv/bf16_arithmetic.c: New test.
* gcc.target/riscv/bf16_call.c: New test.
* gcc.target/riscv/bf16_comparison.c: New test.
* gcc.target/riscv/bf16_float_libcall_convert.c: New test.
* gcc.target/riscv/bf16_integer_libcall_convert.c: New test.
Given we were only looking to have the CI system check the formatting 
nit and that has passed.  I've pushed this to the trunk.


jeff

[NOT CODE REVIEW] [PATCH v3 1/1] [RISC-V] Add support for _Bfloat16

[Xiao Zeng]

1 At point ,
  BF16 has already been completed "post public review".

2 LLVM has also added support for RISCV BF16 in
   and
  .

3 According to the discussion 
,
  this use __bf16 and use DF16b in riscv_mangle_type like x86.

Below test are passed for this patch
* The riscv fully regression test.

gcc/ChangeLog:

* config/riscv/iterators.md: New mode iterator HFBF.
* config/riscv/riscv-builtins.cc (riscv_init_builtin_types):
Initialize data type _Bfloat16.
* config/riscv/riscv-modes.def (FLOAT_MODE): New.
(ADJUST_FLOAT_FORMAT): New.
* config/riscv/riscv.cc (riscv_mangle_type): Support for BFmode.
(riscv_scalar_mode_supported_p): Ditto.
(riscv_libgcc_floating_mode_supported_p): Ditto.
(riscv_init_libfuncs): Set the conversion method for BFmode and
HFmode.
(riscv_block_arith_comp_libfuncs_for_mode): Set the arithmetic
and comparison libfuncs for the mode.
* config/riscv/riscv.md (mode" ): Add BF.
(movhf): Support for BFmode.
(mov): Ditto.
(*movhf_softfloat): Ditto.
(*mov_softfloat): Ditto.

libgcc/ChangeLog:

* config/riscv/sfp-machine.h (_FP_NANFRAC_B): New.
(_FP_NANSIGN_B): Ditto.
* config/riscv/t-softfp32: Add support for BF16 libfuncs.
* config/riscv/t-softfp64: Ditto.
* soft-fp/floatsibf.c: For si -> bf16.
* soft-fp/floatunsibf.c: For unsi -> bf16.

gcc/testsuite/ChangeLog:

* gcc.target/riscv/bf16_arithmetic.c: New test.
* gcc.target/riscv/bf16_call.c: New test.
* gcc.target/riscv/bf16_comparison.c: New test.
* gcc.target/riscv/bf16_float_libcall_convert.c: New test.
* gcc.target/riscv/bf16_integer_libcall_convert.c: New test.

Co-authored-by: Jin Ma 
---
 gcc/config/riscv/iterators.md |  2 +
 gcc/config/riscv/riscv-builtins.cc| 16 
 gcc/config/riscv/riscv-modes.def  |  3 +
 gcc/config/riscv/riscv.cc | 64 ++-
 gcc/config/riscv/riscv.md | 24 +++---
 .../gcc.target/riscv/bf16_arithmetic.c| 42 ++
 gcc/testsuite/gcc.target/riscv/bf16_call.c| 12 +++
 .../gcc.target/riscv/bf16_comparison.c| 36 +
 .../riscv/bf16_float_libcall_convert.c| 57 +
 .../riscv/bf16_integer_libcall_convert.c  | 81 +++
 libgcc/config/riscv/sfp-machine.h |  3 +
 libgcc/config/riscv/t-softfp32| 10 ++-
 libgcc/config/riscv/t-softfp64|  3 +-
 libgcc/soft-fp/floatsibf.c| 45 +++
 libgcc/soft-fp/floatunsibf.c  | 45 +++
 15 files changed, 407 insertions(+), 36 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/bf16_arithmetic.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/bf16_call.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/bf16_comparison.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/bf16_float_libcall_convert.c
 create mode 100644 
gcc/testsuite/gcc.target/riscv/bf16_integer_libcall_convert.c
 create mode 100644 libgcc/soft-fp/floatsibf.c
 create mode 100644 libgcc/soft-fp/floatunsibf.c

diff --git a/gcc/config/riscv/iterators.md b/gcc/config/riscv/iterators.md
index 75e119e407a..32e1b140305 100644
--- a/gcc/config/riscv/iterators.md
+++ b/gcc/config/riscv/iterators.md
@@ -75,6 +75,8 @@
 ;; Iterator for floating-point modes that can be loaded into X registers.
 (define_mode_iterator SOFTF [SF (DF "TARGET_64BIT") (HF "TARGET_ZFHMIN")])
 
+;; Iterator for floating-point modes of BF16
+(define_mode_iterator HFBF [HF BF])
 
 ;; ---
 ;; Mode attributes
diff --git a/gcc/config/riscv/riscv-builtins.cc 
b/gcc/config/riscv/riscv-builtins.cc
index d457e306dd1..4c08834288a 100644
--- a/gcc/config/riscv/riscv-builtins.cc
+++ b/gcc/config/riscv/riscv-builtins.cc
@@ -230,6 +230,7 @@ static GTY(()) int riscv_builtin_decl_index[NUM_INSN_CODES];
   riscv_builtin_decls[riscv_builtin_decl_index[(CODE)]]
 
 tree riscv_float16_type_node = NULL_TREE;
+tree riscv_bfloat16_type_node = NULL_TREE;
 
 /* Return the function type associated with function prototype TYPE.  */
 
@@ -273,6 +274,21 @@ riscv_init_builtin_types (void)
   if (!maybe_get_identifier ("_Float16"))
 lang_hooks.types.register_builtin_type (riscv_float16_type_node,
"_Float16");
+
+  /* Provide the _Bfloat16 type and bfloat16_type_node if needed.  */
+  if (!bfloat16_type_node)
+{
+  riscv_bfloat16_type_node = make_node (REAL_TYPE);
+  TYPE_PRECISION (riscv_bfloat16_type_node) = 16;
+  SET_TYPE_MODE (riscv_bfloat16_type_node, BFmode);
+  layout_type (riscv_bfloat16_type_node);
+