Support Intel prefetchit0/t1

  Hi all,

We will take back the patches which add a new parameter on original
builtin_prefetch and implement instruction prefetch on that.

Also we consider that since we will only do that on specific backend,
no need to add a new rtl for that.

This patch will only support instructions prefetch for x86 backend.

Regtested on x86_64-pc-linux-gnu. Ok for trunk?

BRs,
Haochen

gcc/ChangeLog:

	* common/config/i386/cpuinfo.h (get_available_features):
	Detect PREFETCHI.
	* common/config/i386/i386-common.cc
	(OPTION_MASK_ISA2_PREFETCHI_SET,
	OPTION_MASK_ISA2_PREFETCHI_UNSET): New.
	(ix86_handle_option): Handle -mprefetchi.
	* common/config/i386/i386-cpuinfo.h
	(enum processor_features): Add FEATURE_PREFETCHI.
	* common/config/i386/i386-isas.h: Add ISA_NAME_TABLE_ENTRY
	for prefetchi.
	* config.gcc: Add prfchiintrin.h.
	* config/i386/cpuid.h (bit_PREFETCHI): New.
	* config/i386/i386-builtin-types.def:
	Add DEF_FUNCTION_TYPE (VOID, PCVOID, INT)
	and DEF_FUNCTION_TYPE (VOID, PCVOID, INT, INT, INT).
	* config/i386/i386-builtin.def (BDESC): Add new builtins.
	* config/i386/i386-c.cc (ix86_target_macros_internal):
	Define __PREFETCHI__.
	* config/i386/i386-expand.cc: Handle new builtins.
	* config/i386/i386-isa.def (PREFETCHI):
	Add DEF_PTA(PREFETCHI).
	* config/i386/i386-options.cc
	(ix86_valid_target_attribute_inner_p): Handle prefetchi.
	* config/i386/i386.md (prefetchi): New define_insn.
	* config/i386/i386.opt: Add option -mprefetchi.
	* config/i386/predicates.md (local_func_symbolic_operand):
	New predicates.
	* config/i386/x86gprintrin.h: Include prfchiintrin.h.
	* config/i386/xmmintrin.h (enum _mm_hint): New enum for
	prefetchi.
	(_mm_prefetch): Handle the highest bit of enum.
	* doc/extend.texi: Document prefetchi.
	* doc/invoke.texi: Document -mprefetchi.
	* doc/sourcebuild.texi: Document target prefetchi.
	* config/i386/prfchiintrin.h: New file.

gcc/testsuite/ChangeLog:

	* g++.dg/other/i386-2.C: Add -mprefetchi.
	* g++.dg/other/i386-3.C: Ditto.
	* gcc.target/i386/avx-1.c: Ditto.
	* gcc.target/i386/funcspec-56.inc: Add new target attribute.
	* gcc.target/i386/sse-13.c: Add -mprefetchi.
	* gcc.target/i386/sse-23.c: Ditto.
	* gcc.target/i386/x86gprintrin-1.c: Ditto.
	* gcc.target/i386/x86gprintrin-2.c: Ditto.
	* gcc.target/i386/x86gprintrin-3.c: Ditto.
	* gcc.target/i386/x86gprintrin-4.c: Ditto.
	* gcc.target/i386/x86gprintrin-5.c: Ditto.
	* gcc.target/i386/prefetchi-1.c: New test.
	* gcc.target/i386/prefetchi-2.c: Ditto.
	* gcc.target/i386/prefetchi-3.c: Ditto.
	* gcc.target/i386/prefetchi-4.c: Ditto.

Co-authored-by: Hongtao Liu <hongtao.liu@intel.com>
---
 gcc/common/config/i386/cpuinfo.h              |  2 +
 gcc/common/config/i386/i386-common.cc         | 15 ++++
 gcc/common/config/i386/i386-cpuinfo.h         |  1 +
 gcc/common/config/i386/i386-isas.h            |  1 +
 gcc/config.gcc                                |  2 +-
 gcc/config/i386/cpuid.h                       |  1 +
 gcc/config/i386/i386-builtin-types.def        |  4 +
 gcc/config/i386/i386-builtin.def              |  4 +
 gcc/config/i386/i386-c.cc                     |  2 +
 gcc/config/i386/i386-expand.cc                | 77 +++++++++++++++++++
 gcc/config/i386/i386-isa.def                  |  1 +
 gcc/config/i386/i386-options.cc               |  4 +-
 gcc/config/i386/i386.md                       | 23 ++++++
 gcc/config/i386/i386.opt                      |  4 +
 gcc/config/i386/predicates.md                 | 15 ++++
 gcc/config/i386/prfchiintrin.h                | 49 ++++++++++++
 gcc/config/i386/x86gprintrin.h                |  2 +
 gcc/config/i386/xmmintrin.h                   |  7 +-
 gcc/doc/extend.texi                           |  5 ++
 gcc/doc/invoke.texi                           | 10 ++-
 gcc/doc/sourcebuild.texi                      |  3 +
 gcc/testsuite/g++.dg/other/i386-2.C           |  2 +-
 gcc/testsuite/g++.dg/other/i386-3.C           |  2 +-
 gcc/testsuite/gcc.target/i386/avx-1.c         |  4 +-
 gcc/testsuite/gcc.target/i386/funcspec-56.inc |  2 +
 gcc/testsuite/gcc.target/i386/prefetchi-1.c   | 40 ++++++++++
 gcc/testsuite/gcc.target/i386/prefetchi-2.c   | 26 +++++++
 gcc/testsuite/gcc.target/i386/prefetchi-3.c   | 20 +++++
 gcc/testsuite/gcc.target/i386/prefetchi-4.c   | 19 +++++
 gcc/testsuite/gcc.target/i386/sse-13.c        |  4 +-
 gcc/testsuite/gcc.target/i386/sse-23.c        |  4 +-
 .../gcc.target/i386/x86gprintrin-1.c          |  2 +-
 .../gcc.target/i386/x86gprintrin-2.c          |  2 +-
 .../gcc.target/i386/x86gprintrin-3.c          |  2 +-
 .../gcc.target/i386/x86gprintrin-4.c          |  2 +-
 .../gcc.target/i386/x86gprintrin-5.c          |  2 +-
 36 files changed, 345 insertions(+), 20 deletions(-)
 create mode 100644 gcc/config/i386/prfchiintrin.h
 create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-4.c
  

On Fri, Nov 4, 2022 at 3:47 PM Haochen Jiang via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Hi all,
>
> We will take back the patches which add a new parameter on original
> builtin_prefetch and implement instruction prefetch on that.
>
> Also we consider that since we will only do that on specific backend,
> no need to add a new rtl for that.
>
> This patch will only support instructions prefetch for x86 backend.
>
> Regtested on x86_64-pc-linux-gnu. Ok for trunk?
Ok.
>
> BRs,
> Haochen
>
> gcc/ChangeLog:
>
>         * common/config/i386/cpuinfo.h (get_available_features):
>         Detect PREFETCHI.
>         * common/config/i386/i386-common.cc
>         (OPTION_MASK_ISA2_PREFETCHI_SET,
>         OPTION_MASK_ISA2_PREFETCHI_UNSET): New.
>         (ix86_handle_option): Handle -mprefetchi.
>         * common/config/i386/i386-cpuinfo.h
>         (enum processor_features): Add FEATURE_PREFETCHI.
>         * common/config/i386/i386-isas.h: Add ISA_NAME_TABLE_ENTRY
>         for prefetchi.
>         * config.gcc: Add prfchiintrin.h.
>         * config/i386/cpuid.h (bit_PREFETCHI): New.
>         * config/i386/i386-builtin-types.def:
>         Add DEF_FUNCTION_TYPE (VOID, PCVOID, INT)
>         and DEF_FUNCTION_TYPE (VOID, PCVOID, INT, INT, INT).
>         * config/i386/i386-builtin.def (BDESC): Add new builtins.
>         * config/i386/i386-c.cc (ix86_target_macros_internal):
>         Define __PREFETCHI__.
>         * config/i386/i386-expand.cc: Handle new builtins.
>         * config/i386/i386-isa.def (PREFETCHI):
>         Add DEF_PTA(PREFETCHI).
>         * config/i386/i386-options.cc
>         (ix86_valid_target_attribute_inner_p): Handle prefetchi.
>         * config/i386/i386.md (prefetchi): New define_insn.
>         * config/i386/i386.opt: Add option -mprefetchi.
>         * config/i386/predicates.md (local_func_symbolic_operand):
>         New predicates.
>         * config/i386/x86gprintrin.h: Include prfchiintrin.h.
>         * config/i386/xmmintrin.h (enum _mm_hint): New enum for
>         prefetchi.
>         (_mm_prefetch): Handle the highest bit of enum.
>         * doc/extend.texi: Document prefetchi.
>         * doc/invoke.texi: Document -mprefetchi.
>         * doc/sourcebuild.texi: Document target prefetchi.
>         * config/i386/prfchiintrin.h: New file.
>
> gcc/testsuite/ChangeLog:
>
>         * g++.dg/other/i386-2.C: Add -mprefetchi.
>         * g++.dg/other/i386-3.C: Ditto.
>         * gcc.target/i386/avx-1.c: Ditto.
>         * gcc.target/i386/funcspec-56.inc: Add new target attribute.
>         * gcc.target/i386/sse-13.c: Add -mprefetchi.
>         * gcc.target/i386/sse-23.c: Ditto.
>         * gcc.target/i386/x86gprintrin-1.c: Ditto.
>         * gcc.target/i386/x86gprintrin-2.c: Ditto.
>         * gcc.target/i386/x86gprintrin-3.c: Ditto.
>         * gcc.target/i386/x86gprintrin-4.c: Ditto.
>         * gcc.target/i386/x86gprintrin-5.c: Ditto.
>         * gcc.target/i386/prefetchi-1.c: New test.
>         * gcc.target/i386/prefetchi-2.c: Ditto.
>         * gcc.target/i386/prefetchi-3.c: Ditto.
>         * gcc.target/i386/prefetchi-4.c: Ditto.
>
> Co-authored-by: Hongtao Liu <hongtao.liu@intel.com>
> ---
>  gcc/common/config/i386/cpuinfo.h              |  2 +
>  gcc/common/config/i386/i386-common.cc         | 15 ++++
>  gcc/common/config/i386/i386-cpuinfo.h         |  1 +
>  gcc/common/config/i386/i386-isas.h            |  1 +
>  gcc/config.gcc                                |  2 +-
>  gcc/config/i386/cpuid.h                       |  1 +
>  gcc/config/i386/i386-builtin-types.def        |  4 +
>  gcc/config/i386/i386-builtin.def              |  4 +
>  gcc/config/i386/i386-c.cc                     |  2 +
>  gcc/config/i386/i386-expand.cc                | 77 +++++++++++++++++++
>  gcc/config/i386/i386-isa.def                  |  1 +
>  gcc/config/i386/i386-options.cc               |  4 +-
>  gcc/config/i386/i386.md                       | 23 ++++++
>  gcc/config/i386/i386.opt                      |  4 +
>  gcc/config/i386/predicates.md                 | 15 ++++
>  gcc/config/i386/prfchiintrin.h                | 49 ++++++++++++
>  gcc/config/i386/x86gprintrin.h                |  2 +
>  gcc/config/i386/xmmintrin.h                   |  7 +-
>  gcc/doc/extend.texi                           |  5 ++
>  gcc/doc/invoke.texi                           | 10 ++-
>  gcc/doc/sourcebuild.texi                      |  3 +
>  gcc/testsuite/g++.dg/other/i386-2.C           |  2 +-
>  gcc/testsuite/g++.dg/other/i386-3.C           |  2 +-
>  gcc/testsuite/gcc.target/i386/avx-1.c         |  4 +-
>  gcc/testsuite/gcc.target/i386/funcspec-56.inc |  2 +
>  gcc/testsuite/gcc.target/i386/prefetchi-1.c   | 40 ++++++++++
>  gcc/testsuite/gcc.target/i386/prefetchi-2.c   | 26 +++++++
>  gcc/testsuite/gcc.target/i386/prefetchi-3.c   | 20 +++++
>  gcc/testsuite/gcc.target/i386/prefetchi-4.c   | 19 +++++
>  gcc/testsuite/gcc.target/i386/sse-13.c        |  4 +-
>  gcc/testsuite/gcc.target/i386/sse-23.c        |  4 +-
>  .../gcc.target/i386/x86gprintrin-1.c          |  2 +-
>  .../gcc.target/i386/x86gprintrin-2.c          |  2 +-
>  .../gcc.target/i386/x86gprintrin-3.c          |  2 +-
>  .../gcc.target/i386/x86gprintrin-4.c          |  2 +-
>  .../gcc.target/i386/x86gprintrin-5.c          |  2 +-
>  36 files changed, 345 insertions(+), 20 deletions(-)
>  create mode 100644 gcc/config/i386/prfchiintrin.h
>  create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-1.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-2.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-3.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-4.c
>
> diff --git a/gcc/common/config/i386/cpuinfo.h b/gcc/common/config/i386/cpuinfo.h
> index a38c1b65602..ac7761699af 100644
> --- a/gcc/common/config/i386/cpuinfo.h
> +++ b/gcc/common/config/i386/cpuinfo.h
> @@ -839,6 +839,8 @@ get_available_features (struct __processor_model *cpu_model,
>         set_feature (FEATURE_HRESET);
>        if (eax & bit_CMPCCXADD)
>         set_feature(FEATURE_CMPCCXADD);
> +      if (edx & bit_PREFETCHI)
> +       set_feature (FEATURE_PREFETCHI);
>        if (avx_usable)
>         {
>           if (eax & bit_AVXVNNI)
> diff --git a/gcc/common/config/i386/i386-common.cc b/gcc/common/config/i386/i386-common.cc
> index a044e28d25f..9bcae020a00 100644
> --- a/gcc/common/config/i386/i386-common.cc
> +++ b/gcc/common/config/i386/i386-common.cc
> @@ -112,6 +112,7 @@ along with GCC; see the file COPYING3.  If not see
>  #define OPTION_MASK_ISA2_AVXNECONVERT_SET OPTION_MASK_ISA2_AVXNECONVERT
>  #define OPTION_MASK_ISA2_CMPCCXADD_SET OPTION_MASK_ISA2_CMPCCXADD
>  #define OPTION_MASK_ISA2_AMX_FP16_SET OPTION_MASK_ISA2_AMX_FP16
> +#define OPTION_MASK_ISA2_PREFETCHI_SET OPTION_MASK_ISA2_PREFETCHI
>
>  /* SSE4 includes both SSE4.1 and SSE4.2. -msse4 should be the same
>     as -msse4.2.  */
> @@ -287,6 +288,7 @@ along with GCC; see the file COPYING3.  If not see
>  #define OPTION_MASK_ISA2_AVXNECONVERT_UNSET OPTION_MASK_ISA2_AVXNECONVERT
>  #define OPTION_MASK_ISA2_CMPCCXADD_UNSET OPTION_MASK_ISA2_CMPCCXADD
>  #define OPTION_MASK_ISA2_AMX_FP16_UNSET OPTION_MASK_ISA2_AMX_FP16
> +#define OPTION_MASK_ISA2_PREFETCHI_UNSET OPTION_MASK_ISA2_PREFETCHI
>
>  /* SSE4 includes both SSE4.1 and SSE4.2.  -mno-sse4 should the same
>     as -mno-sse4.1. */
> @@ -1211,6 +1213,19 @@ ix86_handle_option (struct gcc_options *opts,
>         }
>        return true;
>
> +    case OPT_mprefetchi:
> +      if (value)
> +       {
> +         opts->x_ix86_isa_flags2 |= OPTION_MASK_ISA2_PREFETCHI_SET;
> +         opts->x_ix86_isa_flags2_explicit |= OPTION_MASK_ISA2_PREFETCHI_SET;
> +       }
> +      else
> +       {
> +         opts->x_ix86_isa_flags2 &= ~OPTION_MASK_ISA2_PREFETCHI_UNSET;
> +         opts->x_ix86_isa_flags2_explicit |= OPTION_MASK_ISA2_PREFETCHI_UNSET;
> +       }
> +      return true;
> +
>      case OPT_mfma:
>        if (value)
>         {
> diff --git a/gcc/common/config/i386/i386-cpuinfo.h b/gcc/common/config/i386/i386-cpuinfo.h
> index 014174e1856..68eda7a8696 100644
> --- a/gcc/common/config/i386/i386-cpuinfo.h
> +++ b/gcc/common/config/i386/i386-cpuinfo.h
> @@ -249,6 +249,7 @@ enum processor_features
>    FEATURE_AVXNECONVERT,
>    FEATURE_CMPCCXADD,
>    FEATURE_AMX_FP16,
> +  FEATURE_PREFETCHI,
>    CPU_FEATURE_MAX
>  };
>
> diff --git a/gcc/common/config/i386/i386-isas.h b/gcc/common/config/i386/i386-isas.h
> index 7c4a71413b5..8648ea6903c 100644
> --- a/gcc/common/config/i386/i386-isas.h
> +++ b/gcc/common/config/i386/i386-isas.h
> @@ -182,4 +182,5 @@ ISA_NAMES_TABLE_START
>                         P_NONE, "-mavxneconvert")
>    ISA_NAMES_TABLE_ENTRY("cmpccxadd", FEATURE_CMPCCXADD, P_NONE, "-mcmpccxadd")
>    ISA_NAMES_TABLE_ENTRY("amx-fp16", FEATURE_AMX_FP16, P_NONE, "-mamx-fp16")
> +  ISA_NAMES_TABLE_ENTRY("prefetchi", FEATURE_PREFETCHI, P_NONE, "-mprefetchi")
>  ISA_NAMES_TABLE_END
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index 1191a0df7b0..5c782b2f298 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -423,7 +423,7 @@ i[34567]86-*-* | x86_64-*-*)
>                        hresetintrin.h keylockerintrin.h avxvnniintrin.h
>                        mwaitintrin.h avx512fp16intrin.h avx512fp16vlintrin.h
>                        avxifmaintrin.h avxvnniint8intrin.h avxneconvertintrin.h
> -                      cmpccxaddintrin.h amxfp16intrin.h"
> +                      cmpccxaddintrin.h amxfp16intrin.h prfchiintrin.h"
>         ;;
>  ia64-*-*)
>         extra_headers=ia64intrin.h
> diff --git a/gcc/config/i386/cpuid.h b/gcc/config/i386/cpuid.h
> index 229c15c5950..92583261883 100644
> --- a/gcc/config/i386/cpuid.h
> +++ b/gcc/config/i386/cpuid.h
> @@ -54,6 +54,7 @@
>  #define bit_AVXVNNIINT8 (1 << 4)
>  #define bit_AVXNECONVERT (1 << 5)
>  #define bit_CMPXCHG8B  (1 << 8)
> +#define bit_PREFETCHI  (1 << 14)
>  #define bit_CMOV       (1 << 15)
>  #define bit_MMX                (1 << 23)
>  #define bit_FXSAVE     (1 << 24)
> diff --git a/gcc/config/i386/i386-builtin-types.def b/gcc/config/i386/i386-builtin-types.def
> index 2af66145d4b..d10de32643f 100644
> --- a/gcc/config/i386/i386-builtin-types.def
> +++ b/gcc/config/i386/i386-builtin-types.def
> @@ -1411,3 +1411,7 @@ DEF_FUNCTION_TYPE (V8SF, PCV16BF)
>  # CMPccXADD builtins
>  DEF_FUNCTION_TYPE (INT, PINT, INT, INT, INT)
>  DEF_FUNCTION_TYPE (LONGLONG, PLONGLONG, LONGLONG, LONGLONG, INT)
> +
> +# PREFETCHI builtins
> +DEF_FUNCTION_TYPE (VOID, PCVOID, INT)
> +DEF_FUNCTION_TYPE (VOID, PCVOID, INT, INT, INT)
> diff --git a/gcc/config/i386/i386-builtin.def b/gcc/config/i386/i386-builtin.def
> index c272c392d03..837007ada8e 100644
> --- a/gcc/config/i386/i386-builtin.def
> +++ b/gcc/config/i386/i386-builtin.def
> @@ -487,6 +487,10 @@ BDESC (0, OPTION_MASK_ISA2_WIDEKL, CODE_FOR_nothing, "__builtin_ia32_aesdecwide2
>  BDESC (0, OPTION_MASK_ISA2_WIDEKL, CODE_FOR_nothing, "__builtin_ia32_aesencwide128kl_u8", IX86_BUILTIN_AESENCWIDE128KLU8, UNKNOWN, (int) UINT8_FTYPE_PV2DI_PCV2DI_PCVOID)
>  BDESC (0, OPTION_MASK_ISA2_WIDEKL, CODE_FOR_nothing, "__builtin_ia32_aesencwide256kl_u8", IX86_BUILTIN_AESENCWIDE256KLU8, UNKNOWN, (int) UINT8_FTYPE_PV2DI_PCV2DI_PCVOID)
>
> +/* PREFETCHI */
> +BDESC (0, 0, CODE_FOR_prefetchi, "__builtin_ia32_prefetchi", IX86_BUILTIN_PREFETCHI, UNKNOWN, (int) VOID_FTYPE_PCVOID_INT)
> +BDESC (0, 0, CODE_FOR_nothing, "__builtin_ia32_prefetch", IX86_BUILTIN_PREFETCH, UNKNOWN, (int) VOID_FTYPE_PCVOID_INT_INT_INT)
> +
>  BDESC_END (SPECIAL_ARGS, PURE_ARGS)
>
>  /* AVX */
> diff --git a/gcc/config/i386/i386-c.cc b/gcc/config/i386/i386-c.cc
> index ac0087a4653..07ce0f8a5a7 100644
> --- a/gcc/config/i386/i386-c.cc
> +++ b/gcc/config/i386/i386-c.cc
> @@ -657,6 +657,8 @@ ix86_target_macros_internal (HOST_WIDE_INT isa_flag,
>      def_or_undef (parse_in, "__CMPCCXADD__");
>    if (isa_flag2 & OPTION_MASK_ISA2_AMX_FP16)
>      def_or_undef (parse_in, "__AMX_FP16__");
> +  if (isa_flag2 & OPTION_MASK_ISA2_PREFETCHI)
> +    def_or_undef (parse_in, "__PREFETCHI__");
>    if (TARGET_IAMCU)
>      {
>        def_or_undef (parse_in, "__iamcu");
> diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
> index a37fde307d1..2e0d12c0108 100644
> --- a/gcc/config/i386/i386-expand.cc
> +++ b/gcc/config/i386/i386-expand.cc
> @@ -13035,6 +13035,83 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
>         return target;
>        }
>
> +    case IX86_BUILTIN_PREFETCH:
> +      {
> +       arg0 = CALL_EXPR_ARG (exp, 0); // const void *
> +       arg1 = CALL_EXPR_ARG (exp, 1); // const int
> +       arg2 = CALL_EXPR_ARG (exp, 2); // const int
> +       arg3 = CALL_EXPR_ARG (exp, 3); // const int
> +
> +       op0 = expand_normal (arg0);
> +       op1 = expand_normal (arg1);
> +       op2 = expand_normal (arg2);
> +       op3 = expand_normal (arg3);
> +
> +       if (!CONST_INT_P (op1) || !CONST_INT_P (op2) || !CONST_INT_P (op3))
> +         {
> +           error ("second, third and fourth argument must be a const");
> +           return const0_rtx;
> +         }
> +
> +       if (INTVAL (op3) == 1)
> +         {
> +           if (TARGET_64BIT
> +               && local_func_symbolic_operand (op0, GET_MODE (op0)))
> +             emit_insn (gen_prefetchi (op0, op2));
> +           else
> +             {
> +               warning (0, "instruction prefetch applies when in 64-bit mode"
> +                           " with RIP-relative addressing and"
> +                           " option %<-mprefetchi%>;"
> +                           " they stay NOPs otherwise");
> +               emit_insn (gen_nop ());
> +             }
> +         }
> +       else
> +         {
> +           if (!address_operand (op0, VOIDmode))
> +             {
> +               op0 = convert_memory_address (Pmode, op0);
> +               op0 = copy_addr_to_reg (op0);
> +             }
> +           emit_insn (gen_prefetch (op0, op1, op2));
> +         }
> +
> +       return 0;
> +      }
> +
> +    case IX86_BUILTIN_PREFETCHI:
> +      {
> +       arg0 = CALL_EXPR_ARG (exp, 0); // const void *
> +       arg1 = CALL_EXPR_ARG (exp, 1); // const int
> +
> +       op0 = expand_normal (arg0);
> +       op1 = expand_normal (arg1);
> +
> +       if (!CONST_INT_P (op1))
> +         {
> +           error ("second argument must be a const");
> +           return const0_rtx;
> +         }
> +
> +       /* GOT/PLT_PIC should not be available for instruction prefetch.
> +          It must be real instruction address.  */
> +       if (TARGET_64BIT
> +           && local_func_symbolic_operand (op0, GET_MODE (op0)))
> +         emit_insn (gen_prefetchi (op0, op1));
> +       else
> +         {
> +           /* Ignore the hint.  */
> +           warning (0, "instruction prefetch applies when in 64-bit mode"
> +                       " with RIP-relative addressing and"
> +                       " option %<-mprefetchi%>;"
> +                       " they stay NOPs otherwise");
> +           emit_insn (gen_nop ());
> +         }
> +
> +       return 0;
> +      }
> +
>      case IX86_BUILTIN_VEC_INIT_V2SI:
>      case IX86_BUILTIN_VEC_INIT_V4HI:
>      case IX86_BUILTIN_VEC_INIT_V8QI:
> diff --git a/gcc/config/i386/i386-isa.def b/gcc/config/i386/i386-isa.def
> index 55b25763957..f234dcc37d7 100644
> --- a/gcc/config/i386/i386-isa.def
> +++ b/gcc/config/i386/i386-isa.def
> @@ -114,3 +114,4 @@ DEF_PTA(AVXVNNIINT8)
>  DEF_PTA(AVXNECONVERT)
>  DEF_PTA(CMPCCXADD)
>  DEF_PTA(AMX_FP16)
> +DEF_PTA(PREFETCHI)
> diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
> index bbb8307d0b0..625739658c9 100644
> --- a/gcc/config/i386/i386-options.cc
> +++ b/gcc/config/i386/i386-options.cc
> @@ -233,7 +233,8 @@ static struct ix86_target_opts isa2_opts[] =
>    { "-mavxvnniint8",   OPTION_MASK_ISA2_AVXVNNIINT8 },
>    { "-mavxneconvert",   OPTION_MASK_ISA2_AVXNECONVERT },
>    { "-mcmpccxadd",      OPTION_MASK_ISA2_CMPCCXADD },
> -  { "-mamx-fp16",       OPTION_MASK_ISA2_AMX_FP16 }
> +  { "-mamx-fp16",       OPTION_MASK_ISA2_AMX_FP16 },
> +  { "-mprefetchi",      OPTION_MASK_ISA2_PREFETCHI }
>  };
>  static struct ix86_target_opts isa_opts[] =
>  {
> @@ -1086,6 +1087,7 @@ ix86_valid_target_attribute_inner_p (tree fndecl, tree args, char *p_strings[],
>      IX86_ATTR_ISA ("avxneconvert", OPT_mavxneconvert),
>      IX86_ATTR_ISA ("cmpccxadd",   OPT_mcmpccxadd),
>      IX86_ATTR_ISA ("amx-fp16", OPT_mamx_fp16),
> +    IX86_ATTR_ISA ("prefetchi",   OPT_mprefetchi),
>
>      /* enum options */
>      IX86_ATTR_ENUM ("fpmath=", OPT_mfpmath_),
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> index 436eabb691a..a2b8f26714a 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -330,6 +330,9 @@
>
>    ;; For HRESET support
>    UNSPECV_HRESET
> +
> +  ;; For PREFETCHI support
> +  UNSPECV_PREFETCHI
>  ])
>
>  ;; Constants to represent rounding modes in the ROUND instruction
> @@ -23961,6 +23964,26 @@
>         (symbol_ref "memory_address_length (operands[0], false)"))
>     (set_attr "memory" "none")])
>
> +(define_insn "prefetchi"
> +  [(unspec_volatile [(match_operand 0 "local_func_symbolic_operand" "p")
> +                    (match_operand:SI 1 "const_int_operand")]
> +                   UNSPECV_PREFETCHI)]
> +  "TARGET_PREFETCHI && TARGET_64BIT"
> +{
> +  static const char * const patterns[2] = {
> +    "prefetchit1\t%0", "prefetchit0\t%0"
> +  };
> +
> +  int locality = INTVAL (operands[1]);
> +  gcc_assert (IN_RANGE (locality, 2, 3));
> +
> +  return patterns[locality - 2];
> +}
> +  [(set_attr "type" "sse")
> +   (set (attr "length_address")
> +       (symbol_ref "memory_address_length (operands[0], false)"))
> +   (set_attr "memory" "none")])
> +
>  (define_expand "stack_protect_set"
>    [(match_operand 0 "memory_operand")
>     (match_operand 1 "memory_operand")]
> diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
> index eaa43946341..1d91103cd54 100644
> --- a/gcc/config/i386/i386.opt
> +++ b/gcc/config/i386/i386.opt
> @@ -1238,3 +1238,7 @@ CMPCCXADD build-in functions and code generation.
>  mamx-fp16
>  Target Mask(ISA2_AMX_FP16) Var(ix86_isa_flags2) Save
>  Support AMX-FP16 built-in functions and code generation.
> +
> +mprefetchi
> +Target Mask(ISA2_PREFETCHI) Var(ix86_isa_flags2) Save
> +Support PREFETCHI built-in functions and code generation.
> diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
> index c4141a96735..2a3f07224cc 100644
> --- a/gcc/config/i386/predicates.md
> +++ b/gcc/config/i386/predicates.md
> @@ -610,6 +610,21 @@
>    return false;
>  })
>
> +(define_predicate "local_func_symbolic_operand"
> +  (match_operand 0 "local_symbolic_operand")
> +{
> +  if (GET_CODE (op) == CONST
> +      && GET_CODE (XEXP (op, 0)) == PLUS
> +      && CONST_INT_P (XEXP (XEXP (op, 0), 1)))
> +    op = XEXP (XEXP (op, 0), 0);
> +
> +  if (GET_CODE (op) == SYMBOL_REF
> +      && !SYMBOL_REF_FUNCTION_P (op))
> +    return false;
> +
> +  return true;
> +})
> +
>  ;; Test for a legitimate @GOTOFF operand.
>  ;;
>  ;; VxWorks does not impose a fixed gap between segments; the run-time
> diff --git a/gcc/config/i386/prfchiintrin.h b/gcc/config/i386/prfchiintrin.h
> new file mode 100644
> index 00000000000..06deef488ba
> --- /dev/null
> +++ b/gcc/config/i386/prfchiintrin.h
> @@ -0,0 +1,49 @@
> +/* Copyright (C) 2022 Free Software Foundation, Inc.
> +
> +   This file is part of GCC.
> +
> +   GCC is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3, or (at your option)
> +   any later version.
> +
> +   GCC is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   Under Section 7 of GPL version 3, you are granted additional
> +   permissions described in the GCC Runtime Library Exception, version
> +   3.1, as published by the Free Software Foundation.
> +
> +   You should have received a copy of the GNU General Public License and
> +   a copy of the GCC Runtime Library Exception along with this program;
> +   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#if !defined _X86GPRINTRIN_H_INCLUDED
> +# error "Never use <prfchiintrin.h> directly; include <x86gprintrin.h> instead."
> +#endif
> +
> +#ifndef _PRFCHIINTRIN_H_INCLUDED
> +#define _PRFCHIINTRIN_H_INCLUDED
> +
> +#ifdef __x86_64__
> +
> +extern __inline void
> +__attribute__((__gnu_inline__, __always_inline__, __artificial__))
> +_m_prefetchit0 (void* __P)
> +{
> +  __builtin_ia32_prefetchi (__P, 3);
> +}
> +
> +extern __inline void
> +__attribute__((__gnu_inline__, __always_inline__, __artificial__))
> +_m_prefetchit1 (void* __P)
> +{
> +  __builtin_ia32_prefetchi (__P, 2);
> +}
> +
> +#endif
> +
> +#endif /* _PRFCHIINTRIN_H_INCLUDED */
> diff --git a/gcc/config/i386/x86gprintrin.h b/gcc/config/i386/x86gprintrin.h
> index a84fbe9137d..abe8f487f03 100644
> --- a/gcc/config/i386/x86gprintrin.h
> +++ b/gcc/config/i386/x86gprintrin.h
> @@ -74,6 +74,8 @@
>
>  #include <pkuintrin.h>
>
> +#include <prfchiintrin.h>
> +
>  #include <rdseedintrin.h>
>
>  #include <rtmintrin.h>
> diff --git a/gcc/config/i386/xmmintrin.h b/gcc/config/i386/xmmintrin.h
> index 62659080601..ab65c430a97 100644
> --- a/gcc/config/i386/xmmintrin.h
> +++ b/gcc/config/i386/xmmintrin.h
> @@ -36,6 +36,8 @@
>  /* Constants for use with _mm_prefetch.  */
>  enum _mm_hint
>  {
> +  _MM_HINT_IT0 = 19,
> +  _MM_HINT_IT1 = 18,
>    /* _MM_HINT_ET is _MM_HINT_T with set 3rd bit.  */
>    _MM_HINT_ET0 = 7,
>    _MM_HINT_ET1 = 6,
> @@ -51,11 +53,12 @@ enum _mm_hint
>  extern __inline void __attribute__((__gnu_inline__, __always_inline__, __artificial__))
>  _mm_prefetch (const void *__P, enum _mm_hint __I)
>  {
> -  __builtin_prefetch (__P, (__I & 0x4) >> 2, __I & 0x3);
> +  __builtin_ia32_prefetch (__P, (__I & 0x4) >> 2,
> +                          __I & 0x3, (__I & 0x10) >> 4);
>  }
>  #else
>  #define _mm_prefetch(P, I) \
> -  __builtin_prefetch ((P), ((I & 0x4) >> 2), (I & 0x3))
> +  __builtin_ia32_prefetch ((P), ((I) & 0x4) >> 2, ((I) & 0x3), ((I) & 0x10) >> 4)
>  #endif
>
>  #ifndef __SSE__
> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
> index 8d4475fc615..ba1e12b4fa9 100644
> --- a/gcc/doc/extend.texi
> +++ b/gcc/doc/extend.texi
> @@ -7085,6 +7085,11 @@ Enable/disable the generation of the CMPccXADD instructions.
>  @cindex @code{target("amx-fp16")} function attribute, x86
>  Enable/disable the generation of the AMX-FP16 instructions.
>
> +@item prefetchi
> +@itemx no-prefetchi
> +@cindex @code{target("prefetchi")} function attribute, x86
> +Enable/disable the generation of the PREFETCHI instructions.
> +
>  @item cld
>  @itemx no-cld
>  @cindex @code{target("cld")} function attribute, x86
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index e9207a3a255..bb908f81ba9 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -1438,6 +1438,7 @@ See RS/6000 and PowerPC Options.
>  -mrdseed  -msgx -mavx512vp2intersect -mserialize -mtsxldtrk@gol
>  -mamx-tile  -mamx-int8  -mamx-bf16 -muintr -mhreset -mavxvnni@gol
>  -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16 @gol
> +-mprefetchi @gol
>  -mcldemote  -mms-bitfields  -mno-align-stringops  -minline-all-stringops @gol
>  -minline-stringops-dynamically  -mstringop-strategy=@var{alg} @gol
>  -mkl -mwidekl @gol
> @@ -32984,6 +32985,9 @@ preferred alignment to @option{-mpreferred-stack-boundary=2}.
>  @need 200
>  @itemx -mamx-fp16
>  @opindex mamx-fp16
> +@need 200
> +@itemx -mprefetchi
> +@opindex mprefetchi
>  These switches enable the use of instructions in the MMX, SSE,
>  SSE2, SSE3, SSSE3, SSE4, SSE4A, SSE4.1, SSE4.2, AVX, AVX2, AVX512F, AVX512PF,
>  AVX512ER, AVX512CD, AVX512VL, AVX512BW, AVX512DQ, AVX512IFMA, AVX512VBMI, SHA,
> @@ -32994,9 +32998,9 @@ XSAVEOPT, XSAVEC, XSAVES, RTM, HLE, TBM, MWAITX, CLZERO, PKU, AVX512VBMI2,
>  GFNI, VAES, WAITPKG, VPCLMULQDQ, AVX512BITALG, MOVDIRI, MOVDIR64B, AVX512BF16,
>  ENQCMD, AVX512VPOPCNTDQ, AVX5124FMAPS, AVX512VNNI, AVX5124VNNIW, SERIALIZE,
>  UINTR, HRESET, AMXTILE, AMXINT8, AMXBF16, KL, WIDEKL, AVXVNNI, AVX512FP16,
> -AVXIFMA, AVXVNNIINT8, AVXNECONVERT, CMPCCXADD, AMX-FP16 or CLDEMOTE extended
> -instruction sets. Each has a corresponding @option{-mno-} option to disable
> -use of these instructions.
> +AVXIFMA, AVXVNNIINT8, AVXNECONVERT, CMPCCXADD, AMX-FP16, PREFETCHI or CLDEMOTE
> +extended instruction sets. Each has a corresponding @option{-mno-} option to
> +disable use of these instructions.
>
>  These extensions are also available as built-in functions: see
>  @ref{x86 Built-in Functions}, for details of the functions enabled and
> diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
> index 5de5e9576d5..58adb6516ed 100644
> --- a/gcc/doc/sourcebuild.texi
> +++ b/gcc/doc/sourcebuild.texi
> @@ -2535,6 +2535,9 @@ Target does not require strict alignment.
>  @item pie_copyreloc
>  The x86-64 target linker supports PIE with copy reloc.
>
> +@item prefetchi
> +Target supports the execution of @code{prefetchi} instructions.
> +
>  @item rdrand
>  Target supports x86 @code{rdrand} instruction.
>
> diff --git a/gcc/testsuite/g++.dg/other/i386-2.C b/gcc/testsuite/g++.dg/other/i386-2.C
> index 79b84af0a75..ec3b1864ec0 100644
> --- a/gcc/testsuite/g++.dg/other/i386-2.C
> +++ b/gcc/testsuite/g++.dg/other/i386-2.C
> @@ -1,5 +1,5 @@
>  /* { dg-do compile { target i?86-*-* x86_64-*-* } } */
> -/* { dg-options "-O -pedantic-errors -march=k8 -msse4a -m3dnow -mavx -mavx2 -mfma4 -mxop -maes -mpclmul -mpopcnt -mabm -mlzcnt -mbmi -mbmi2 -mtbm -mlwp -mfsgsbase -mrdrnd -mf16c -mfma -mrtm -mrdseed -mprfchw -madx -mfxsr -mxsaveopt -mavx512f -mavx512er -mavx512cd -mavx512pf -msha -mprefetchwt1 -mxsavec -mxsaves -mclflushopt  -mavx512dq -mavx512bw -mavx512vl -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -mclwb -mmwaitx -mclzero -mpku -msgx -mrdpid -mgfni -mavx512bitalg -mpconfig -mwbnoinvd -mavx512bf16 -menqcmd -mavx512vp2intersect -mserialize -mtsxldtrk -mamx-tile -mamx-int8 -mamx-bf16 -mkl -mwidekl -mavxvnni -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16" } */
> +/* { dg-options "-O -pedantic-errors -march=k8 -msse4a -m3dnow -mavx -mavx2 -mfma4 -mxop -maes -mpclmul -mpopcnt -mabm -mlzcnt -mbmi -mbmi2 -mtbm -mlwp -mfsgsbase -mrdrnd -mf16c -mfma -mrtm -mrdseed -mprfchw -madx -mfxsr -mxsaveopt -mavx512f -mavx512er -mavx512cd -mavx512pf -msha -mprefetchwt1 -mxsavec -mxsaves -mclflushopt  -mavx512dq -mavx512bw -mavx512vl -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -mclwb -mmwaitx -mclzero -mpku -msgx -mrdpid -mgfni -mavx512bitalg -mpconfig -mwbnoinvd -mavx512bf16 -menqcmd -mavx512vp2intersect -mserialize -mtsxldtrk -mamx-tile -mamx-int8 -mamx-bf16 -mkl -mwidekl -mavxvnni -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16 -mprefetchi" } */
>
>  /* Test that {,x,e,p,t,s,w,a,b,i}mmintrin.h, mm3dnow.h, fma4intrin.h,
>     xopintrin.h, abmintrin.h, bmiintrin.h, tbmintrin.h, lwpintrin.h,
> diff --git a/gcc/testsuite/g++.dg/other/i386-3.C b/gcc/testsuite/g++.dg/other/i386-3.C
> index c811a4454bf..542275ca057 100644
> --- a/gcc/testsuite/g++.dg/other/i386-3.C
> +++ b/gcc/testsuite/g++.dg/other/i386-3.C
> @@ -1,5 +1,5 @@
>  /* { dg-do compile { target i?86-*-* x86_64-*-* } } */
> -/* { dg-options "-O -fkeep-inline-functions -march=k8 -msse4a -m3dnow -mavx -mavx2 -mfma4 -mxop -maes -mpclmul -mpopcnt -mabm -mlzcnt -mbmi -mbmi2 -mtbm -mlwp -mfsgsbase -mrdrnd -mf16c -mfma -mrtm -mrdseed -mprfchw -madx -mfxsr -mxsaveopt -mavx512f -mavx512er -mavx512cd -mavx512pf -msha -mprefetchwt1 -mxsavec -mxsaves -mclflushopt -mavx512dq -mavx512bw -mavx512vl -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -mclwb -mmwaitx -mclzero -mpku -msgx -mrdpid -mgfni -mavx512bitalg -mpconfig -mwbnoinvd -mavx512bf16 -menqcmd -mavx512vp2intersect -mserialize -mtsxldtrk -mamx-tile -mamx-int8 -mamx-bf16 -mkl -mwidekl -mavxvnni -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16" } */
> +/* { dg-options "-O -fkeep-inline-functions -march=k8 -msse4a -m3dnow -mavx -mavx2 -mfma4 -mxop -maes -mpclmul -mpopcnt -mabm -mlzcnt -mbmi -mbmi2 -mtbm -mlwp -mfsgsbase -mrdrnd -mf16c -mfma -mrtm -mrdseed -mprfchw -madx -mfxsr -mxsaveopt -mavx512f -mavx512er -mavx512cd -mavx512pf -msha -mprefetchwt1 -mxsavec -mxsaves -mclflushopt -mavx512dq -mavx512bw -mavx512vl -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -mclwb -mmwaitx -mclzero -mpku -msgx -mrdpid -mgfni -mavx512bitalg -mpconfig -mwbnoinvd -mavx512bf16 -menqcmd -mavx512vp2intersect -mserialize -mtsxldtrk -mamx-tile -mamx-int8 -mamx-bf16 -mkl -mwidekl -mavxvnni -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16 -mprefetchi" } */
>
>  /* Test that {,x,e,p,t,s,w,a,b,i}mmintrin.h, mm3dnow.h, fma4intrin.h,
>     xopintrin.h, abmintrin.h, bmiintrin.h, tbmintrin.h, lwpintrin.h,
> diff --git a/gcc/testsuite/gcc.target/i386/avx-1.c b/gcc/testsuite/gcc.target/i386/avx-1.c
> index 051a1b59b5b..0b2b68b678d 100644
> --- a/gcc/testsuite/gcc.target/i386/avx-1.c
> +++ b/gcc/testsuite/gcc.target/i386/avx-1.c
> @@ -1,5 +1,5 @@
>  /* { dg-do compile } */
> -/* { dg-options "-O2 -Werror-implicit-function-declaration -march=k8 -m3dnow -mavx -mavx2 -maes -mpclmul -mgfni -mavx512bw -mavx512fp16 -mavx512vl" } */
> +/* { dg-options "-O2 -Werror-implicit-function-declaration -march=k8 -m3dnow -mavx -mavx2 -maes -mpclmul -mgfni -mavx512bw -mavx512fp16 -mavx512vl -mprefetchi" } */
>  /* { dg-add-options bind_pic_locally } */
>
>  #include <mm_malloc.h>
> @@ -153,7 +153,7 @@
>  #define __builtin_ia32_shufpd(A, B, N) __builtin_ia32_shufpd(A, B, 0)
>
>  /* xmmintrin.h */
> -#define __builtin_prefetch(P, A, I) __builtin_prefetch(P, 0, _MM_HINT_NTA)
> +#define __builtin_ia32_prefetch(A, B, C, D) __builtin_ia32_prefetch(A, 0, 3, 0)
>  #define __builtin_ia32_pshufw(A, N) __builtin_ia32_pshufw(A, 0)
>  #define __builtin_ia32_vec_set_v4hi(A, D, N) \
>    __builtin_ia32_vec_set_v4hi(A, D, 0)
> diff --git a/gcc/testsuite/gcc.target/i386/funcspec-56.inc b/gcc/testsuite/gcc.target/i386/funcspec-56.inc
> index 71063235374..631d5c2b950 100644
> --- a/gcc/testsuite/gcc.target/i386/funcspec-56.inc
> +++ b/gcc/testsuite/gcc.target/i386/funcspec-56.inc
> @@ -85,6 +85,7 @@ extern void test_avxvnniint8 (void)           __attribute__((__target__("avxvnniint8")));
>  extern void test_avxneconvert (void)           __attribute__((__target__("avxneconvert")));
>  extern void test_cmpccxadd (void)              __attribute__((__target__("cmpccxadd")));
>  extern void test_amx_fp16 (void)               __attribute__((__target__("amx-fp16")));
> +extern void test_prefetchi (void)               __attribute__((__target__("prefetchi")));
>
>  extern void test_no_sgx (void)                 __attribute__((__target__("no-sgx")));
>  extern void test_no_avx5124fmaps(void)         __attribute__((__target__("no-avx5124fmaps")));
> @@ -171,6 +172,7 @@ extern void test_no_avxvnniint8 (void)              __attribute__((__target__("no-avxvnniint
>  extern void test_no_avxneconvert (void)                __attribute__((__target__("no-avxneconvert")));
>  extern void test_no_cmpccxadd (void)            __attribute__((__target__("no-cmpccxadd")));
>  extern void test_no_amx_fp16 (void)            __attribute__((__target__("no-amx-fp16")));
> +extern void test_no_prefetchi (void)            __attribute__((__target__("no-prefetchi")));
>
>  extern void test_arch_nocona (void)            __attribute__((__target__("arch=nocona")));
>  extern void test_arch_core2 (void)             __attribute__((__target__("arch=core2")));
> diff --git a/gcc/testsuite/gcc.target/i386/prefetchi-1.c b/gcc/testsuite/gcc.target/i386/prefetchi-1.c
> new file mode 100644
> index 00000000000..80f25e70e8e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/prefetchi-1.c
> @@ -0,0 +1,40 @@
> +/* { dg-do compile { target { ! ia32 } } } */
> +/* { dg-options "-mprefetchi -O2" } */
> +/* { dg-final { scan-assembler-times "\[ \\t\]+prefetchit0\[ \\t\]+" 2 } } */
> +/* { dg-final { scan-assembler-times "\[ \\t\]+prefetchit1\[ \\t\]+" 2 } } */
> +
> +#include <x86intrin.h>
> +
> +int
> +bar (int a)
> +{
> +  return a + 1;
> +}
> +
> +int
> +foo1 (int b)
> +{
> +  _mm_prefetch (bar, _MM_HINT_IT0);
> +  return bar (b) + 1;
> +}
> +
> +int
> +foo2 (int b)
> +{
> +  _mm_prefetch (bar, _MM_HINT_IT1);
> +  return bar (b) + 1;
> +}
> +
> +int
> +foo3 (int b)
> +{
> +  _m_prefetchit0 (bar);
> +  return bar (b) + 1;
> +}
> +
> +int
> +foo4 (int b)
> +{
> +  _m_prefetchit1 (bar);
> +  return bar (b) + 1;
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/prefetchi-2.c b/gcc/testsuite/gcc.target/i386/prefetchi-2.c
> new file mode 100644
> index 00000000000..e05ce9c733d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/prefetchi-2.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile { target { ia32 } } } */
> +/* { dg-options "-mprefetchi -O2" } */
> +/* { dg-final { scan-assembler-not "\[ \\t\]+prefetchit0" } } */
> +/* { dg-final { scan-assembler-not "\[ \\t\]+prefetchit1" } } */
> +
> +#include <x86intrin.h>
> +
> +int
> +bar (int a)
> +{
> +  return a + 1;
> +}
> +
> +int
> +foo1 (int b)
> +{
> +  __builtin_ia32_prefetch (bar, 0, 3, 1); /* { dg-warning "instruction prefetch applies when in 64-bit mode with RIP-relative addressing and option '-mprefetchi'; they stay NOPs otherwise" } */
> +  return bar (b) + 1;
> +}
> +
> +int
> +foo2 (int b)
> +{
> +  __builtin_ia32_prefetchi (bar, 2); /* { dg-warning "instruction prefetch applies when in 64-bit mode with RIP-relative addressing and option '-mprefetchi'; they stay NOPs otherwise" } */
> +  return bar (b) + 1;
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/prefetchi-3.c b/gcc/testsuite/gcc.target/i386/prefetchi-3.c
> new file mode 100644
> index 00000000000..f0a4173d2a6
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/prefetchi-3.c
> @@ -0,0 +1,20 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mprefetchi -O2" } */
> +/* { dg-final { scan-assembler-not "prefetchit0" } } */
> +/* { dg-final { scan-assembler-not "prefetchit1" } } */
> +
> +#include <x86intrin.h>
> +
> +void* p;
> +
> +void extern
> +prefetchi_test1 (void)
> +{
> +  __builtin_ia32_prefetchi (p, 2); /* { dg-warning "instruction prefetch applies when in 64-bit mode with RIP-relative addressing and option '-mprefetchi'; they stay NOPs otherwise" } */
> +}
> +
> +void extern
> +prefetchi_test2 (void)
> +{
> +  __builtin_ia32_prefetch (p, 0, 3, 1); /* { dg-warning "instruction prefetch applies when in 64-bit mode with RIP-relative addressing and option '-mprefetchi'; they stay NOPs otherwise" } */
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/prefetchi-4.c b/gcc/testsuite/gcc.target/i386/prefetchi-4.c
> new file mode 100644
> index 00000000000..73ae596d147
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/prefetchi-4.c
> @@ -0,0 +1,19 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O0" } */
> +
> +#include <x86intrin.h>
> +
> +void* p;
> +
> +void extern
> +prefetch_test (void)
> +{
> +  __builtin_ia32_prefetch (p, 0, 3, 0);
> +  __builtin_ia32_prefetch (p, 0, 2, 0);
> +  __builtin_ia32_prefetch (p, 0, 1, 0);
> +  __builtin_ia32_prefetch (p, 0, 0, 0);
> +  __builtin_ia32_prefetch (p, 1, 3, 0);
> +  __builtin_ia32_prefetch (p, 1, 2, 0);
> +  __builtin_ia32_prefetch (p, 1, 1, 0);
> +  __builtin_ia32_prefetch (p, 1, 0, 0);
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/sse-13.c b/gcc/testsuite/gcc.target/i386/sse-13.c
> index ca662f7bd47..f0d2d5b4975 100644
> --- a/gcc/testsuite/gcc.target/i386/sse-13.c
> +++ b/gcc/testsuite/gcc.target/i386/sse-13.c
> @@ -1,5 +1,5 @@
>  /* { dg-do compile } */
> -/* { dg-options "-O2 -Werror-implicit-function-declaration -march=k8 -msse4a -m3dnow -mavx -mavx2 -mfma4 -mxop -maes -mpclmul -mpopcnt -mabm -mlzcnt -mbmi -mbmi2 -mtbm -mlwp -mfsgsbase -mrdrnd -mf16c -mfma -mrtm -mrdseed -mprfchw -madx -mfxsr -mxsaveopt -mavx512f -mavx512er -mavx512cd -mavx512pf -msha -mprefetchwt1 -mxsavec -mxsaves -mclflushopt -mavx512vl -mavx512dq -mavx512bw -mavx512vbmi -mavx512vbmi2 -mavx512ifma -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -mavx512vp2intersect -mclwb -mmwaitx -mclzero -mpku -msgx -mrdpid -mgfni -mavx512bitalg -mpconfig -mwbnoinvd -mavx512bf16 -menqcmd -mserialize -mtsxldtrk -mamx-tile -mamx-int8 -mamx-bf16 -mkl -mwidekl -mavxvnni -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16" } */
> +/* { dg-options "-O2 -Werror-implicit-function-declaration -march=k8 -msse4a -m3dnow -mavx -mavx2 -mfma4 -mxop -maes -mpclmul -mpopcnt -mabm -mlzcnt -mbmi -mbmi2 -mtbm -mlwp -mfsgsbase -mrdrnd -mf16c -mfma -mrtm -mrdseed -mprfchw -madx -mfxsr -mxsaveopt -mavx512f -mavx512er -mavx512cd -mavx512pf -msha -mprefetchwt1 -mxsavec -mxsaves -mclflushopt -mavx512vl -mavx512dq -mavx512bw -mavx512vbmi -mavx512vbmi2 -mavx512ifma -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -mavx512vp2intersect -mclwb -mmwaitx -mclzero -mpku -msgx -mrdpid -mgfni -mavx512bitalg -mpconfig -mwbnoinvd -mavx512bf16 -menqcmd -mserialize -mtsxldtrk -mamx-tile -mamx-int8 -mamx-bf16 -mkl -mwidekl -mavxvnni -mavx512fp16 -mavxifma -mavxvnniint8 -mavxneconvert -mcmpccxadd -mamx-fp16 -mprefetchi" } */
>  /* { dg-add-options bind_pic_locally } */
>
>  #include <mm_malloc.h>
> @@ -125,7 +125,7 @@
>  #define __builtin_ia32_shufpd(A, B, N) __builtin_ia32_shufpd(A, B, 0)
>
>  /* xmmintrin.h */
> -#define __builtin_prefetch(P, A, I) __builtin_prefetch(P, 0, _MM_HINT_NTA)
> +#define __builtin_ia32_prefetch(A, B, C, D) __builtin_ia32_prefetch(A, 0, 3, 0)
>  #define __builtin_ia32_pshufw(A, N) __builtin_ia32_pshufw(A, 0)
>  #define __builtin_ia32_vec_set_v4hi(A, D, N) \
>    __builtin_ia32_vec_set_v4hi(A, D, 0)
> diff --git a/gcc/testsuite/gcc.target/i386/sse-23.c b/gcc/testsuite/gcc.target/i386/sse-23.c
> index ba1310f9f89..547e441c986 100644
> --- a/gcc/testsuite/gcc.target/i386/sse-23.c
> +++ b/gcc/testsuite/gcc.target/i386/sse-23.c
> @@ -94,7 +94,7 @@
>  #define __builtin_ia32_shufpd(A, B, N) __builtin_ia32_shufpd(A, B, 0)
>
>  /* xmmintrin.h */
> -#define __builtin_prefetch(P, A, I) __builtin_prefetch(P, 0, _MM_HINT_NTA)
> +#define __builtin_ia32_prefetch(A, B, C, D) __builtin_ia32_prefetch(A, 0, 3, 0)
>  #define __builtin_ia32_pshufw(A, N) __builtin_ia32_pshufw(A, 0)
>  #define __builtin_ia32_vec_set_v4hi(A, D, N) \
>    __builtin_ia32_vec_set_v4hi(A, D, 0)
> @@ -847,6 +847,6 @@
>  #define __builtin_ia32_cmpccxadd(A, B, C, D) __builtin_ia32_cmpccxadd(A, B, C, 1)
>  #define __builtin_ia32_cmpccxadd64(A, B, C, D) __builtin_ia32_cmpccxadd64(A, B, C, 1)
>
> -#pragma GCC target ("sse4a,3dnow,avx,avx2,fma4,xop,aes,pclmul,popcnt,abm,lzcnt,bmi,bmi2,tbm,lwp,fsgsbase,rdrnd,f16c,fma,rtm,rdseed,prfchw,adx,fxsr,xsaveopt,avx512f,avx512er,avx512cd,avx512pf,sha,prefetchwt1,xsavec,xsaves,clflushopt,avx512bw,avx512dq,avx512vl,avx512vbmi,avx512ifma,avx5124fmaps,avx5124vnniw,avx512vpopcntdq,clwb,mwaitx,clzero,pku,sgx,rdpid,gfni,avx512vbmi2,vpclmulqdq,avx512bitalg,pconfig,wbnoinvd,avx512bf16,enqcmd,avx512vp2intersect,serialize,tsxldtrk,amx-tile,amx-int8,amx-bf16,kl,widekl,avxvnni,avx512fp16,avxifma,avxvnniint8,avxneconvert,cmpccxadd,amx-fp16")
> +#pragma GCC target ("sse4a,3dnow,avx,avx2,fma4,xop,aes,pclmul,popcnt,abm,lzcnt,bmi,bmi2,tbm,lwp,fsgsbase,rdrnd,f16c,fma,rtm,rdseed,prfchw,adx,fxsr,xsaveopt,avx512f,avx512er,avx512cd,avx512pf,sha,prefetchwt1,xsavec,xsaves,clflushopt,avx512bw,avx512dq,avx512vl,avx512vbmi,avx512ifma,avx5124fmaps,avx5124vnniw,avx512vpopcntdq,clwb,mwaitx,clzero,pku,sgx,rdpid,gfni,avx512vbmi2,vpclmulqdq,avx512bitalg,pconfig,wbnoinvd,avx512bf16,enqcmd,avx512vp2intersect,serialize,tsxldtrk,amx-tile,amx-int8,amx-bf16,kl,widekl,avxvnni,avx512fp16,avxifma,avxvnniint8,avxneconvert,cmpccxadd,amx-fp16,prefetchi")
>
>  #include <x86intrin.h>
> diff --git a/gcc/testsuite/gcc.target/i386/x86gprintrin-1.c b/gcc/testsuite/gcc.target/i386/x86gprintrin-1.c
> index 76de89d0cb7..3be40d41b37 100644
> --- a/gcc/testsuite/gcc.target/i386/x86gprintrin-1.c
> +++ b/gcc/testsuite/gcc.target/i386/x86gprintrin-1.c
> @@ -1,7 +1,7 @@
>  /* Test that <x86gprintrin.h> is usable with -O -std=c89 -pedantic-errors.  */
>  /* { dg-do compile } */
>  /* { dg-options "-O -std=c89 -pedantic-errors -march=x86-64 -madx -mbmi -mbmi2 -mcldemote -mclflushopt -mclwb -mclzero -menqcmd -mfsgsbase -mfxsr -mhreset -mlzcnt -mlwp -mmovdiri -mmwaitx -mpconfig -mpopcnt -mpku -mptwrite -mrdpid -mrdrnd -mrdseed -mrtm -mserialize -msgx -mshstk -mtbm -mtsxldtrk -mwaitpkg -mwbnoinvd -mxsave -mxsavec -mxsaveopt -mxsaves -mno-sse -mno-mmx" } */
> -/* { dg-additional-options "-mcmpccxadd -muintr" { target { ! ia32 } } }  */
> +/* { dg-additional-options "-mcmpccxadd -mprefetchi -muintr" { target { ! ia32 } } }  */
>
>  #include <x86gprintrin.h>
>
> diff --git a/gcc/testsuite/gcc.target/i386/x86gprintrin-2.c b/gcc/testsuite/gcc.target/i386/x86gprintrin-2.c
> index aefad77f864..5eaeab6edf0 100644
> --- a/gcc/testsuite/gcc.target/i386/x86gprintrin-2.c
> +++ b/gcc/testsuite/gcc.target/i386/x86gprintrin-2.c
> @@ -1,7 +1,7 @@
>  /* { dg-do compile } */
>  /* { dg-options "-O2 -Werror-implicit-function-declaration -march=x86-64 -madx -mbmi -mbmi2 -mcldemote -mclflushopt -mclwb -mclzero -menqcmd -mfsgsbase -mfxsr -mhreset -mlzcnt -mlwp -mmovdiri -mmwaitx -mpconfig -mpopcnt -mpku -mptwrite -mrdpid -mrdrnd -mrdseed -mrtm -mserialize -msgx -mshstk -mtbm -mtsxldtrk -mwaitpkg -mwbnoinvd -mxsave -mxsavec -mxsaveopt -mxsaves -mno-sse -mno-mmx" } */
>  /* { dg-add-options bind_pic_locally } */
> -/* { dg-additional-options "-mcmpccxadd -muintr" { target { ! ia32 } } }  */
> +/* { dg-additional-options "-mcmpccxadd -mprefetchi -muintr" { target { ! ia32 } } }  */
>
>  /* Test that the intrinsics in <x86gprintrin.h> compile with optimization.
>     All of them are defined as inline functions that reference the proper
> diff --git a/gcc/testsuite/gcc.target/i386/x86gprintrin-3.c b/gcc/testsuite/gcc.target/i386/x86gprintrin-3.c
> index 261c9180aa0..03967f80445 100644
> --- a/gcc/testsuite/gcc.target/i386/x86gprintrin-3.c
> +++ b/gcc/testsuite/gcc.target/i386/x86gprintrin-3.c
> @@ -1,7 +1,7 @@
>  /* { dg-do compile } */
>  /* { dg-options "-O0 -Werror-implicit-function-declaration -march=x86-64 -madx -mbmi -mbmi2 -mcldemote -mclflushopt -mclwb -mclzero -menqcmd -mfsgsbase -mfxsr -mhreset -mlzcnt -mlwp -mmovdiri -mmwaitx -mpconfig -mpopcnt -mpku -mptwrite -mrdpid -mrdrnd -mrdseed -mrtm -mserialize -msgx -mshstk -mtbm -mtsxldtrk -mwaitpkg -mwbnoinvd -mxsave -mxsavec -mxsaveopt -mxsaves -mno-sse -mno-mmx" } */
>  /* { dg-add-options bind_pic_locally } */
> -/* { dg-additional-options "-mcmpccxadd -muintr" { target { ! ia32 } } }  */
> +/* { dg-additional-options "-mcmpccxadd -mprefetchi -muintr" { target { ! ia32 } } }  */
>
>  /* Test that the intrinsics in <x86gprintrin.h> compile without optimization.
>     All of them are defined as inline functions that reference the proper
> diff --git a/gcc/testsuite/gcc.target/i386/x86gprintrin-4.c b/gcc/testsuite/gcc.target/i386/x86gprintrin-4.c
> index 7f76b870934..64fc337da60 100644
> --- a/gcc/testsuite/gcc.target/i386/x86gprintrin-4.c
> +++ b/gcc/testsuite/gcc.target/i386/x86gprintrin-4.c
> @@ -15,7 +15,7 @@
>
>  #ifndef DIFFERENT_PRAGMAS
>  #ifdef __x86_64__
> -#pragma GCC target ("adx,bmi,bmi2,cmpccxadd,fsgsbase,fxsr,hreset,lwp,lzcnt,popcnt,rdrnd,rdseed,tbm,rtm,serialize,tsxldtrk,uintr,xsaveopt")
> +#pragma GCC target ("adx,bmi,bmi2,cmpccxadd,fsgsbase,fxsr,hreset,lwp,lzcnt,popcnt,prefetchi,rdrnd,rdseed,tbm,rtm,serialize,tsxldtrk,uintr,xsaveopt")
>  #else
>  #pragma GCC target ("adx,bmi,bmi2,fsgsbase,fxsr,hreset,lwp,lzcnt,popcnt,rdrnd,rdseed,tbm,rtm,serialize,tsxldtrk,xsaveopt")
>  #endif
> diff --git a/gcc/testsuite/gcc.target/i386/x86gprintrin-5.c b/gcc/testsuite/gcc.target/i386/x86gprintrin-5.c
> index 54d826c4f46..8937f55e7ee 100644
> --- a/gcc/testsuite/gcc.target/i386/x86gprintrin-5.c
> +++ b/gcc/testsuite/gcc.target/i386/x86gprintrin-5.c
> @@ -32,7 +32,7 @@
>  #define __builtin_ia32_cmpccxadd64(A, B, C, D) __builtin_ia32_cmpccxadd64(A, B, C, 1)
>
>  #ifdef __x86_64__
> -#pragma GCC target ("adx,bmi,bmi2,clflushopt,clwb,clzero,cmpccxadd,enqcmd,fsgsbase,fxsr,hreset,lwp,lzcnt,mwaitx,pconfig,pku,popcnt,rdpid,rdrnd,rdseed,tbm,rtm,serialize,sgx,tsxldtrk,uintr,xsavec,xsaveopt,xsaves,wbnoinvd")
> +#pragma GCC target ("adx,bmi,bmi2,clflushopt,clwb,clzero,cmpccxadd,enqcmd,fsgsbase,fxsr,hreset,lwp,lzcnt,mwaitx,pconfig,pku,popcnt,prefetchi,rdpid,rdrnd,rdseed,tbm,rtm,serialize,sgx,tsxldtrk,uintr,xsavec,xsaveopt,xsaves,wbnoinvd")
>  #else
>  #pragma GCC target ("adx,bmi,bmi2,clflushopt,clwb,clzero,enqcmd,fsgsbase,fxsr,hreset,lwp,lzcnt,mwaitx,pconfig,pku,popcnt,rdpid,rdrnd,rdseed,tbm,rtm,serialize,sgx,tsxldtrk,xsavec,xsaveopt,xsaves,wbnoinvd")
>  #endif
> --
> 2.18.1
>
  

On Fri, Nov 04, 2022 at 03:46:32PM +0800, Haochen Jiang via Gcc-patches wrote:
> We will take back the patches which add a new parameter on original
> builtin_prefetch and implement instruction prefetch on that.
> 
> Also we consider that since we will only do that on specific backend,
> no need to add a new rtl for that.
> 
> This patch will only support instructions prefetch for x86 backend.
> 
> Regtested on x86_64-pc-linux-gnu. Ok for trunk?

The gcc.target/i386/prefetchi-4.c testcase ICEs for me on i686-linux.
Can be reproduced even on x86_64, with:
./cc1 -quiet -m32 -march=pentiumpro prefetchi-4.c -isystem include/
during RTL pass: expand
prefetchi-4.c: In function ‘prefetch_test’:
prefetchi-4.c:11:3: internal compiler error: in gen_prefetch, at config/i386/i386.md:23913
   11 |   __builtin_ia32_prefetch (p, 0, 3, 0);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0x1b92416 gen_prefetch(rtx_def*, rtx_def*, rtx_def*)
	../../gcc/config/i386/i386.md:23913
0x141dcf3 ix86_expand_builtin(tree_node*, rtx_def*, rtx_def*, machine_mode, int)
	../../gcc/config/i386/i386-expand.cc:13077
0x60deb4 expand_builtin(tree_node*, rtx_def*, rtx_def*, machine_mode, int)
	../../gcc/builtins.cc:7321
0x80803d expand_expr_real_1(tree_node*, rtx_def*, machine_mode, expand_modifier, rtx_def**, bool)
	../../gcc/expr.cc:11865
0x7fa4d5 expand_expr_real(tree_node*, rtx_def*, machine_mode, expand_modifier, rtx_def**, bool)
	../../gcc/expr.cc:9000
0x648c12 expand_expr
	../../gcc/expr.h:310
0x651c17 expand_call_stmt
	../../gcc/cfgexpand.cc:2831
0x655709 expand_gimple_stmt_1
	../../gcc/cfgexpand.cc:3880
0x655d93 expand_gimple_stmt
	../../gcc/cfgexpand.cc:4044
0x65e061 expand_gimple_basic_block
	../../gcc/cfgexpand.cc:6096
0x660575 execute
	../../gcc/cfgexpand.cc:6822
Please submit a full bug report, with preprocessed source (by using -freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

The ICE is on
          gcc_assert (TARGET_3DNOW);
          operands[2] = GEN_INT (3);
The expander has
  "TARGET_3DNOW || TARGET_PREFETCH_SSE || TARGET_PRFCHW || TARGET_PREFETCHWT1"
condition and for write handles all those different ISAs, so gcc_assert (TARGET_3DNOW);
at the end only asserts the obvious that the expander condition had to be
satisfied.  But for !write, it only has:
      if (TARGET_PREFETCH_SSE)
        ;
      else
        {
          gcc_assert (TARGET_3DNOW);
          operands[2] = GEN_INT (3);
        }
and here I don't understand how it can work, because if
!TARGET_3DNOW && !TARGET_PREFETCH_SSE, but
TARGET_PRFCHW || TARGET_PREFETCHWT1
then it clearly ICEs.  Both of the latter ISAs can be enabled/disabled
individually without dependencies.

It is unclear what exactly changed though, because the prefetch pattern
has not changed, but it didn't ICE before that commit.

	Jakub
  

On Tue, Nov 8, 2022 at 6:07 PM Jakub Jelinek via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Fri, Nov 04, 2022 at 03:46:32PM +0800, Haochen Jiang via Gcc-patches wrote:
> > We will take back the patches which add a new parameter on original
> > builtin_prefetch and implement instruction prefetch on that.
> >
> > Also we consider that since we will only do that on specific backend,
> > no need to add a new rtl for that.
> >
> > This patch will only support instructions prefetch for x86 backend.
> >
> > Regtested on x86_64-pc-linux-gnu. Ok for trunk?
>
> The gcc.target/i386/prefetchi-4.c testcase ICEs for me on i686-linux.
> Can be reproduced even on x86_64, with:
> ./cc1 -quiet -m32 -march=pentiumpro prefetchi-4.c -isystem include/
> during RTL pass: expand
> prefetchi-4.c: In function ‘prefetch_test’:
> prefetchi-4.c:11:3: internal compiler error: in gen_prefetch, at config/i386/i386.md:23913
>    11 |   __builtin_ia32_prefetch (p, 0, 3, 0);
>       |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 0x1b92416 gen_prefetch(rtx_def*, rtx_def*, rtx_def*)
>         ../../gcc/config/i386/i386.md:23913
> 0x141dcf3 ix86_expand_builtin(tree_node*, rtx_def*, rtx_def*, machine_mode, int)
>         ../../gcc/config/i386/i386-expand.cc:13077
> 0x60deb4 expand_builtin(tree_node*, rtx_def*, rtx_def*, machine_mode, int)
>         ../../gcc/builtins.cc:7321
> 0x80803d expand_expr_real_1(tree_node*, rtx_def*, machine_mode, expand_modifier, rtx_def**, bool)
>         ../../gcc/expr.cc:11865
> 0x7fa4d5 expand_expr_real(tree_node*, rtx_def*, machine_mode, expand_modifier, rtx_def**, bool)
>         ../../gcc/expr.cc:9000
> 0x648c12 expand_expr
>         ../../gcc/expr.h:310
> 0x651c17 expand_call_stmt
>         ../../gcc/cfgexpand.cc:2831
> 0x655709 expand_gimple_stmt_1
>         ../../gcc/cfgexpand.cc:3880
> 0x655d93 expand_gimple_stmt
>         ../../gcc/cfgexpand.cc:4044
> 0x65e061 expand_gimple_basic_block
>         ../../gcc/cfgexpand.cc:6096
> 0x660575 execute
>         ../../gcc/cfgexpand.cc:6822
> Please submit a full bug report, with preprocessed source (by using -freport-bug).
> Please include the complete backtrace with any bug report.
> See <https://gcc.gnu.org/bugs/> for instructions.
>
> The ICE is on
>           gcc_assert (TARGET_3DNOW);
>           operands[2] = GEN_INT (3);
> The expander has
>   "TARGET_3DNOW || TARGET_PREFETCH_SSE || TARGET_PRFCHW || TARGET_PREFETCHWT1"
> condition and for write handles all those different ISAs, so gcc_assert (TARGET_3DNOW);
> at the end only asserts the obvious that the expander condition had to be
> satisfied.  But for !write, it only has:
>       if (TARGET_PREFETCH_SSE)
>         ;
>       else
>         {
>           gcc_assert (TARGET_3DNOW);
>           operands[2] = GEN_INT (3);
>         }
> and here I don't understand how it can work, because if
> !TARGET_3DNOW && !TARGET_PREFETCH_SSE, but
> TARGET_PRFCHW || TARGET_PREFETCHWT1
> then it clearly ICEs.  Both of the latter ISAs can be enabled/disabled
> individually without dependencies.
>
> It is unclear what exactly changed though, because the prefetch pattern
> has not changed, but it didn't ICE before that commit.
We need to check the expander condition before gen_prefetch.
>
>         Jakub
>