On Wed, May 15, 2024 at 9:43 AM Kong, Lingling <lingling.k...@intel.com> wrote:
>
> From: Hongyu Wang <hongyu.w...@intel.com>
>
> APX NF(no flags) feature implements suppresses the update of status flags for
> arithmetic operations.
>
> For NF add, it is not clear whether NF add can be faster than lea. If so, the
> pattern needs to be adjusted to prefer LEA generation.
>
> gcc/ChangeLog:
>
> * config/i386/i386-opts.h (enum apx_features): Add nf
> enumeration.
> * config/i386/i386.h (TARGET_APX_NF): New.
> * config/i386/i386.md (*add<mode>_1_nf): New define_insn.
> * config/i386/i386.opt: Add apx_nf enumeration.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/apx-ndd.c: Fixed test.
> * gcc.target/i386/apx-nf.c: New test.
>
> Co-authored-by: Lingling Kong <lingling.k...@intel.com>
>
> Bootstrapped and regtested on x86_64-linux-gnu. And Supported SPEC 2017 run
> normally on Intel software development emulator.
> Ok for trunk?
>
> ---
> gcc/config/i386/i386-opts.h | 3 +-
> gcc/config/i386/i386.h | 1 +
> gcc/config/i386/i386.md | 42 +++++++++++++++++++++++++
> gcc/config/i386/i386.opt | 3 ++
> gcc/testsuite/gcc.target/i386/apx-ndd.c | 2 +-
> gcc/testsuite/gcc.target/i386/apx-nf.c | 6 ++++
> 6 files changed, 55 insertions(+), 2 deletions(-) create mode 100644
> gcc/testsuite/gcc.target/i386/apx-nf.c
>
> diff --git a/gcc/config/i386/i386-opts.h b/gcc/config/i386/i386-opts.h index
> ef2825803b3..60176ce609f 100644
> --- a/gcc/config/i386/i386-opts.h
> +++ b/gcc/config/i386/i386-opts.h
> @@ -140,7 +140,8 @@ enum apx_features {
> apx_push2pop2 = 1 << 1,
> apx_ndd = 1 << 2,
> apx_ppx = 1 << 3,
> - apx_all = apx_egpr | apx_push2pop2 | apx_ndd | apx_ppx,
> + apx_nf = 1<< 4,
> + apx_all = apx_egpr | apx_push2pop2 | apx_ndd | apx_ppx | apx_nf,
> };
>
> #endif
> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index
> 529edff93a4..f20ae4726da 100644
> --- a/gcc/config/i386/i386.h
> +++ b/gcc/config/i386/i386.h
> @@ -55,6 +55,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.
> If not, see #define TARGET_APX_PUSH2POP2 (ix86_apx_features & apx_push2pop2)
> #define TARGET_APX_NDD (ix86_apx_features & apx_ndd) #define TARGET_APX_PPX
> (ix86_apx_features & apx_ppx)
> +#define TARGET_APX_NF (ix86_apx_features & apx_nf)
>
> #include "config/vxworks-dummy.h"
>
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index
> 764bfe20ff2..4a9e35c4990 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -6233,6 +6233,48 @@
> }
> })
>
>
> +;; NF instructions.
> +
> +(define_insn "*add<mode>_1_nf"
> + [(set (match_operand:SWI 0 "nonimmediate_operand" "=rm,rje,r,r,r,r,r,r")
> + (plus:SWI
> + (match_operand:SWI 1 "nonimmediate_operand" "%0,0,0,r,r,rje,jM,r")
> + (match_operand:SWI 2 "x86_64_general_operand"
> +"r,e,BM,0,le,r,e,BM")))]
> + "TARGET_APX_NF &&
> + ix86_binary_operator_ok (PLUS, <MODE>mode, operands,
> + TARGET_APX_NDD)"
I wonder if we can use "define_subst" to conditionally add flags
clobber for !TARGET_APX_NF targets. Even the example for "Define
Subst" uses the insn w/ and w/o the clobber, so I think it is worth
considering this approach.
Uros.
