[v3,1/3] RISC-V: Add support for XCVelw extension in CV32E40P

Message ID 20231128131615.3986922-2-mary.bennett@embecosm.com
State Superseded
Delegated to: Kito Cheng
Headers
Series RISC-V: Support CORE-V XCVELW and XCVBI extensions |

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Commit Message

Mary Bennett Nov. 28, 2023, 1:16 p.m. UTC
  Spec: github.com/openhwgroup/core-v-sw/blob/master/specifications/corev-builtin-spec.md

Contributors:
  Mary Bennett <mary.bennett@embecosm.com>
  Nandni Jamnadas <nandni.jamnadas@embecosm.com>
  Pietra Ferreira <pietra.ferreira@embecosm.com>
  Charlie Keaney
  Jessica Mills
  Craig Blackmore <craig.blackmore@embecosm.com>
  Simon Cook <simon.cook@embecosm.com>
  Jeremy Bennett <jeremy.bennett@embecosm.com>
  Helene Chelin <helene.chelin@embecosm.com>

gcc/ChangeLog:
	* common/config/riscv/riscv-common.cc: Add XCVelw.
	* config/riscv/corev.def: Likewise.
	* config/riscv/corev.md: Likewise.
	* config/riscv/riscv-builtins.cc (AVAIL): Likewise.
	* config/riscv/riscv-ftypes.def: Likewise.
	* config/riscv/riscv.opt: Likewise.
	* doc/extend.texi: Add XCVelw builtin documentation.
	* doc/sourcebuild.texi: Likewise.

gcc/testsuite/ChangeLog:
	* gcc.target/riscv/cv-elw-compile-1.c: Create test for cv.elw.
	* testsuite/lib/target-supports.exp: Add proc for the XCVelw extension.
---
 gcc/common/config/riscv/riscv-common.cc           |  2 ++
 gcc/config/riscv/corev.def                        |  3 +++
 gcc/config/riscv/corev.md                         | 15 +++++++++++++++
 gcc/config/riscv/riscv-builtins.cc                |  2 ++
 gcc/config/riscv/riscv-ftypes.def                 |  1 +
 gcc/config/riscv/riscv.opt                        |  2 ++
 gcc/doc/extend.texi                               |  8 ++++++++
 gcc/doc/sourcebuild.texi                          |  3 +++
 .../gcc.target/riscv/cv-elw-elw-compile-1.c       | 11 +++++++++++
 gcc/testsuite/lib/target-supports.exp             | 13 +++++++++++++
 10 files changed, 60 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c
  

Comments

Kito Cheng Dec. 5, 2023, 3:11 p.m. UTC | #1
LGTM

On Tue, Nov 28, 2023 at 9:17 PM Mary Bennett <mary.bennett@embecosm.com> wrote:
>
> Spec: github.com/openhwgroup/core-v-sw/blob/master/specifications/corev-builtin-spec.md
>
> Contributors:
>   Mary Bennett <mary.bennett@embecosm.com>
>   Nandni Jamnadas <nandni.jamnadas@embecosm.com>
>   Pietra Ferreira <pietra.ferreira@embecosm.com>
>   Charlie Keaney
>   Jessica Mills
>   Craig Blackmore <craig.blackmore@embecosm.com>
>   Simon Cook <simon.cook@embecosm.com>
>   Jeremy Bennett <jeremy.bennett@embecosm.com>
>   Helene Chelin <helene.chelin@embecosm.com>
>
> gcc/ChangeLog:
>         * common/config/riscv/riscv-common.cc: Add XCVelw.
>         * config/riscv/corev.def: Likewise.
>         * config/riscv/corev.md: Likewise.
>         * config/riscv/riscv-builtins.cc (AVAIL): Likewise.
>         * config/riscv/riscv-ftypes.def: Likewise.
>         * config/riscv/riscv.opt: Likewise.
>         * doc/extend.texi: Add XCVelw builtin documentation.
>         * doc/sourcebuild.texi: Likewise.
>
> gcc/testsuite/ChangeLog:
>         * gcc.target/riscv/cv-elw-compile-1.c: Create test for cv.elw.
>         * testsuite/lib/target-supports.exp: Add proc for the XCVelw extension.
> ---
>  gcc/common/config/riscv/riscv-common.cc           |  2 ++
>  gcc/config/riscv/corev.def                        |  3 +++
>  gcc/config/riscv/corev.md                         | 15 +++++++++++++++
>  gcc/config/riscv/riscv-builtins.cc                |  2 ++
>  gcc/config/riscv/riscv-ftypes.def                 |  1 +
>  gcc/config/riscv/riscv.opt                        |  2 ++
>  gcc/doc/extend.texi                               |  8 ++++++++
>  gcc/doc/sourcebuild.texi                          |  3 +++
>  .../gcc.target/riscv/cv-elw-elw-compile-1.c       | 11 +++++++++++
>  gcc/testsuite/lib/target-supports.exp             | 13 +++++++++++++
>  10 files changed, 60 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c
>
> diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
> index 5111626157b..c8c0d0a2252 100644
> --- a/gcc/common/config/riscv/riscv-common.cc
> +++ b/gcc/common/config/riscv/riscv-common.cc
> @@ -312,6 +312,7 @@ static const struct riscv_ext_version riscv_ext_version_table[] =
>
>    {"xcvmac", ISA_SPEC_CLASS_NONE, 1, 0},
>    {"xcvalu", ISA_SPEC_CLASS_NONE, 1, 0},
> +  {"xcvelw", ISA_SPEC_CLASS_NONE, 1, 0},
>
>    {"xtheadba", ISA_SPEC_CLASS_NONE, 1, 0},
>    {"xtheadbb", ISA_SPEC_CLASS_NONE, 1, 0},
> @@ -1676,6 +1677,7 @@ static const riscv_ext_flag_table_t riscv_ext_flag_table[] =
>
>    {"xcvmac",        &gcc_options::x_riscv_xcv_subext, MASK_XCVMAC},
>    {"xcvalu",        &gcc_options::x_riscv_xcv_subext, MASK_XCVALU},
> +  {"xcvelw",        &gcc_options::x_riscv_xcv_subext, MASK_XCVELW},
>
>    {"xtheadba",      &gcc_options::x_riscv_xthead_subext, MASK_XTHEADBA},
>    {"xtheadbb",      &gcc_options::x_riscv_xthead_subext, MASK_XTHEADBB},
> diff --git a/gcc/config/riscv/corev.def b/gcc/config/riscv/corev.def
> index 17580df3c41..3b9ec029d06 100644
> --- a/gcc/config/riscv/corev.def
> +++ b/gcc/config/riscv/corev.def
> @@ -41,3 +41,6 @@ RISCV_BUILTIN (cv_alu_subN,     "cv_alu_subN", RISCV_BUILTIN_DIRECT, RISCV_SI_FT
>  RISCV_BUILTIN (cv_alu_subuN,    "cv_alu_subuN", RISCV_BUILTIN_DIRECT, RISCV_USI_FTYPE_USI_USI_UQI,  cvalu),
>  RISCV_BUILTIN (cv_alu_subRN,    "cv_alu_subRN", RISCV_BUILTIN_DIRECT, RISCV_SI_FTYPE_SI_SI_UQI, cvalu),
>  RISCV_BUILTIN (cv_alu_subuRN,   "cv_alu_subuRN",RISCV_BUILTIN_DIRECT, RISCV_USI_FTYPE_USI_USI_UQI,  cvalu),
> +
> +// XCVELW
> +RISCV_BUILTIN (cv_elw_elw_si, "cv_elw_elw", RISCV_BUILTIN_DIRECT, RISCV_USI_FTYPE_VOID_PTR, cvelw),
> diff --git a/gcc/config/riscv/corev.md b/gcc/config/riscv/corev.md
> index 1350bd4b81e..c7a2ba07bcc 100644
> --- a/gcc/config/riscv/corev.md
> +++ b/gcc/config/riscv/corev.md
> @@ -24,6 +24,9 @@
>    UNSPEC_CV_ALU_CLIPR
>    UNSPEC_CV_ALU_CLIPU
>    UNSPEC_CV_ALU_CLIPUR
> +
> +  ;;CORE-V EVENT LOAD
> +  UNSPECV_CV_ELW
>  ])
>
>  ;; XCVMAC extension.
> @@ -691,3 +694,15 @@
>    cv.suburnr\t%0,%2,%3"
>    [(set_attr "type" "arith")
>    (set_attr "mode" "SI")])
> +
> +;; XCVELW builtins
> +(define_insn "riscv_cv_elw_elw_si"
> +  [(set (match_operand:SI 0 "register_operand" "=r")
> +   (unspec_volatile [(match_operand:SI 1 "move_operand" "p")]
> +     UNSPECV_CV_ELW))]
> +
> +  "TARGET_XCVELW && !TARGET_64BIT"
> +  "cv.elw\t%0,%a1"
> +
> +  [(set_attr "type" "load")
> +  (set_attr "mode" "SI")])
> diff --git a/gcc/config/riscv/riscv-builtins.cc b/gcc/config/riscv/riscv-builtins.cc
> index fc3976f3ba1..5ee11ebe3bc 100644
> --- a/gcc/config/riscv/riscv-builtins.cc
> +++ b/gcc/config/riscv/riscv-builtins.cc
> @@ -128,6 +128,7 @@ AVAIL (hint_pause, (!0))
>  // CORE-V AVAIL
>  AVAIL (cvmac, TARGET_XCVMAC && !TARGET_64BIT)
>  AVAIL (cvalu, TARGET_XCVALU && !TARGET_64BIT)
> +AVAIL (cvelw, TARGET_XCVELW && !TARGET_64BIT)
>
>  /* Construct a riscv_builtin_description from the given arguments.
>
> @@ -168,6 +169,7 @@ AVAIL (cvalu, TARGET_XCVALU && !TARGET_64BIT)
>  #define RISCV_ATYPE_HI intHI_type_node
>  #define RISCV_ATYPE_SI intSI_type_node
>  #define RISCV_ATYPE_VOID_PTR ptr_type_node
> +#define RISCV_ATYPE_INT_PTR integer_ptr_type_node
>
>  /* RISCV_FTYPE_ATYPESN takes N RISCV_FTYPES-like type codes and lists
>     their associated RISCV_ATYPEs.  */
> diff --git a/gcc/config/riscv/riscv-ftypes.def b/gcc/config/riscv/riscv-ftypes.def
> index 0d1e4dd061e..3e7d5c69503 100644
> --- a/gcc/config/riscv/riscv-ftypes.def
> +++ b/gcc/config/riscv/riscv-ftypes.def
> @@ -30,6 +30,7 @@ DEF_RISCV_FTYPE (0, (USI))
>  DEF_RISCV_FTYPE (0, (VOID))
>  DEF_RISCV_FTYPE (1, (VOID, USI))
>  DEF_RISCV_FTYPE (1, (VOID, VOID_PTR))
> +DEF_RISCV_FTYPE (1, (USI, VOID_PTR))
>  DEF_RISCV_FTYPE (1, (USI, USI))
>  DEF_RISCV_FTYPE (1, (UDI, UDI))
>  DEF_RISCV_FTYPE (1, (USI, UQI))
> diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
> index 11526f9cc2a..bfa0945daca 100644
> --- a/gcc/config/riscv/riscv.opt
> +++ b/gcc/config/riscv/riscv.opt
> @@ -411,6 +411,8 @@ Mask(XCVMAC) Var(riscv_xcv_subext)
>
>  Mask(XCVALU) Var(riscv_xcv_subext)
>
> +Mask(XCVELW) Var(riscv_xcv_subext)
> +
>  TargetVariable
>  int riscv_xthead_subext
>
> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
> index 9474e9398bb..b89aa915b7e 100644
> --- a/gcc/doc/extend.texi
> +++ b/gcc/doc/extend.texi
> @@ -22084,6 +22084,14 @@ Generated assembler @code{cv.subuRN} if the uint8_t operand is a constant and in
>  Generated assembler @code{cv.subuRNr} if  the it is a register.
>  @end deftypefn
>
> +These built-in functions are available for the CORE-V Event Load machine
> +architecture. For more information on CORE-V ELW builtins, please see
> +@uref{https://github.com/openhwgroup/core-v-sw/blob/master/specifications/corev-builtin-spec.md#listing-of-event-load-word-builtins-xcvelw}
> +
> +@deftypefn {Built-in Function} {uint32_t} __builtin_riscv_cv_elw_elw (uint32_t *)
> +Generated assembler @code{cv.elw}
> +@end deftypefn
> +
>  @node RX Built-in Functions
>  @subsection RX Built-in Functions
>  GCC supports some of the RX instructions which cannot be expressed in
> diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
> index e27e0fa606c..d63b11d245c 100644
> --- a/gcc/doc/sourcebuild.texi
> +++ b/gcc/doc/sourcebuild.texi
> @@ -2481,6 +2481,9 @@ Test system has support for the CORE-V MAC extension.
>  @item cv_alu
>  Test system has support for the CORE-V ALU extension.
>
> +@item cv_elw
> +Test system has support for the CORE-V ELW extension.
> +
>  @end table
>
>  @subsubsection Other hardware attributes
> diff --git a/gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c b/gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c
> new file mode 100644
> index 00000000000..30f951c3f0a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target cv_elw } */
> +/* { dg-options "-march=rv32i_xcvelw -mabi=ilp32" } */
> +
> +int
> +foo (void* b)
> +{
> +    return __builtin_riscv_cv_elw_elw (b + 8);
> +}
> +
> +/* { dg-final { scan-assembler-times "cv\\.elw\t\[a-z\]\[0-99\],\[0-99\]\\(\[a-z\]\[0-99\]\\)" 1 } } */
> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> index 87b2ae58720..c324a7898fc 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -13147,6 +13147,19 @@ proc check_effective_target_cv_alu { } {
>      } "-march=rv32i_xcvalu" ]
>  }
>
> +# Return 1 if the CORE-V ELW extension is available.
> +proc check_effective_target_cv_elw { } {
> +    if { !([istarget riscv*-*-*]) } {
> +         return 0
> +     }
> +    return [check_no_compiler_messages cv_elw object {
> +        void foo (void)
> +        {
> +          asm ("cv.elw x0, 0(x0)");
> +        }
> +    } "-march=rv32i_xcvelw" ]
> +}
> +
>  proc check_effective_target_loongarch_sx { } {
>      return [check_no_compiler_messages loongarch_lsx assembly {
>         #if !defined(__loongarch_sx)
> --
> 2.34.1
>
  

Patch

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 5111626157b..c8c0d0a2252 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -312,6 +312,7 @@  static const struct riscv_ext_version riscv_ext_version_table[] =
 
   {"xcvmac", ISA_SPEC_CLASS_NONE, 1, 0},
   {"xcvalu", ISA_SPEC_CLASS_NONE, 1, 0},
+  {"xcvelw", ISA_SPEC_CLASS_NONE, 1, 0},
 
   {"xtheadba", ISA_SPEC_CLASS_NONE, 1, 0},
   {"xtheadbb", ISA_SPEC_CLASS_NONE, 1, 0},
@@ -1676,6 +1677,7 @@  static const riscv_ext_flag_table_t riscv_ext_flag_table[] =
 
   {"xcvmac",        &gcc_options::x_riscv_xcv_subext, MASK_XCVMAC},
   {"xcvalu",        &gcc_options::x_riscv_xcv_subext, MASK_XCVALU},
+  {"xcvelw",        &gcc_options::x_riscv_xcv_subext, MASK_XCVELW},
 
   {"xtheadba",      &gcc_options::x_riscv_xthead_subext, MASK_XTHEADBA},
   {"xtheadbb",      &gcc_options::x_riscv_xthead_subext, MASK_XTHEADBB},
diff --git a/gcc/config/riscv/corev.def b/gcc/config/riscv/corev.def
index 17580df3c41..3b9ec029d06 100644
--- a/gcc/config/riscv/corev.def
+++ b/gcc/config/riscv/corev.def
@@ -41,3 +41,6 @@  RISCV_BUILTIN (cv_alu_subN,     "cv_alu_subN", RISCV_BUILTIN_DIRECT, RISCV_SI_FT
 RISCV_BUILTIN (cv_alu_subuN,    "cv_alu_subuN", RISCV_BUILTIN_DIRECT, RISCV_USI_FTYPE_USI_USI_UQI,  cvalu),
 RISCV_BUILTIN (cv_alu_subRN,    "cv_alu_subRN", RISCV_BUILTIN_DIRECT, RISCV_SI_FTYPE_SI_SI_UQI, cvalu),
 RISCV_BUILTIN (cv_alu_subuRN,   "cv_alu_subuRN",RISCV_BUILTIN_DIRECT, RISCV_USI_FTYPE_USI_USI_UQI,  cvalu),
+
+// XCVELW
+RISCV_BUILTIN (cv_elw_elw_si, "cv_elw_elw", RISCV_BUILTIN_DIRECT, RISCV_USI_FTYPE_VOID_PTR, cvelw),
diff --git a/gcc/config/riscv/corev.md b/gcc/config/riscv/corev.md
index 1350bd4b81e..c7a2ba07bcc 100644
--- a/gcc/config/riscv/corev.md
+++ b/gcc/config/riscv/corev.md
@@ -24,6 +24,9 @@ 
   UNSPEC_CV_ALU_CLIPR
   UNSPEC_CV_ALU_CLIPU
   UNSPEC_CV_ALU_CLIPUR
+
+  ;;CORE-V EVENT LOAD
+  UNSPECV_CV_ELW
 ])
 
 ;; XCVMAC extension.
@@ -691,3 +694,15 @@ 
   cv.suburnr\t%0,%2,%3"
   [(set_attr "type" "arith")
   (set_attr "mode" "SI")])
+
+;; XCVELW builtins
+(define_insn "riscv_cv_elw_elw_si"
+  [(set (match_operand:SI 0 "register_operand" "=r")
+   (unspec_volatile [(match_operand:SI 1 "move_operand" "p")]
+     UNSPECV_CV_ELW))]
+
+  "TARGET_XCVELW && !TARGET_64BIT"
+  "cv.elw\t%0,%a1"
+
+  [(set_attr "type" "load")
+  (set_attr "mode" "SI")])
diff --git a/gcc/config/riscv/riscv-builtins.cc b/gcc/config/riscv/riscv-builtins.cc
index fc3976f3ba1..5ee11ebe3bc 100644
--- a/gcc/config/riscv/riscv-builtins.cc
+++ b/gcc/config/riscv/riscv-builtins.cc
@@ -128,6 +128,7 @@  AVAIL (hint_pause, (!0))
 // CORE-V AVAIL
 AVAIL (cvmac, TARGET_XCVMAC && !TARGET_64BIT)
 AVAIL (cvalu, TARGET_XCVALU && !TARGET_64BIT)
+AVAIL (cvelw, TARGET_XCVELW && !TARGET_64BIT)
 
 /* Construct a riscv_builtin_description from the given arguments.
 
@@ -168,6 +169,7 @@  AVAIL (cvalu, TARGET_XCVALU && !TARGET_64BIT)
 #define RISCV_ATYPE_HI intHI_type_node
 #define RISCV_ATYPE_SI intSI_type_node
 #define RISCV_ATYPE_VOID_PTR ptr_type_node
+#define RISCV_ATYPE_INT_PTR integer_ptr_type_node
 
 /* RISCV_FTYPE_ATYPESN takes N RISCV_FTYPES-like type codes and lists
    their associated RISCV_ATYPEs.  */
diff --git a/gcc/config/riscv/riscv-ftypes.def b/gcc/config/riscv/riscv-ftypes.def
index 0d1e4dd061e..3e7d5c69503 100644
--- a/gcc/config/riscv/riscv-ftypes.def
+++ b/gcc/config/riscv/riscv-ftypes.def
@@ -30,6 +30,7 @@  DEF_RISCV_FTYPE (0, (USI))
 DEF_RISCV_FTYPE (0, (VOID))
 DEF_RISCV_FTYPE (1, (VOID, USI))
 DEF_RISCV_FTYPE (1, (VOID, VOID_PTR))
+DEF_RISCV_FTYPE (1, (USI, VOID_PTR))
 DEF_RISCV_FTYPE (1, (USI, USI))
 DEF_RISCV_FTYPE (1, (UDI, UDI))
 DEF_RISCV_FTYPE (1, (USI, UQI))
diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
index 11526f9cc2a..bfa0945daca 100644
--- a/gcc/config/riscv/riscv.opt
+++ b/gcc/config/riscv/riscv.opt
@@ -411,6 +411,8 @@  Mask(XCVMAC) Var(riscv_xcv_subext)
 
 Mask(XCVALU) Var(riscv_xcv_subext)
 
+Mask(XCVELW) Var(riscv_xcv_subext)
+
 TargetVariable
 int riscv_xthead_subext
 
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 9474e9398bb..b89aa915b7e 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -22084,6 +22084,14 @@  Generated assembler @code{cv.subuRN} if the uint8_t operand is a constant and in
 Generated assembler @code{cv.subuRNr} if  the it is a register.
 @end deftypefn
 
+These built-in functions are available for the CORE-V Event Load machine
+architecture. For more information on CORE-V ELW builtins, please see
+@uref{https://github.com/openhwgroup/core-v-sw/blob/master/specifications/corev-builtin-spec.md#listing-of-event-load-word-builtins-xcvelw}
+
+@deftypefn {Built-in Function} {uint32_t} __builtin_riscv_cv_elw_elw (uint32_t *)
+Generated assembler @code{cv.elw}
+@end deftypefn
+
 @node RX Built-in Functions
 @subsection RX Built-in Functions
 GCC supports some of the RX instructions which cannot be expressed in
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index e27e0fa606c..d63b11d245c 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2481,6 +2481,9 @@  Test system has support for the CORE-V MAC extension.
 @item cv_alu
 Test system has support for the CORE-V ALU extension.
 
+@item cv_elw
+Test system has support for the CORE-V ELW extension.
+
 @end table
 
 @subsubsection Other hardware attributes
diff --git a/gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c b/gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c
new file mode 100644
index 00000000000..30f951c3f0a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/cv-elw-elw-compile-1.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target cv_elw } */
+/* { dg-options "-march=rv32i_xcvelw -mabi=ilp32" } */
+
+int
+foo (void* b)
+{
+    return __builtin_riscv_cv_elw_elw (b + 8);
+}
+
+/* { dg-final { scan-assembler-times "cv\\.elw\t\[a-z\]\[0-99\],\[0-99\]\\(\[a-z\]\[0-99\]\\)" 1 } } */
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 87b2ae58720..c324a7898fc 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -13147,6 +13147,19 @@  proc check_effective_target_cv_alu { } {
     } "-march=rv32i_xcvalu" ]
 }
 
+# Return 1 if the CORE-V ELW extension is available.
+proc check_effective_target_cv_elw { } {
+    if { !([istarget riscv*-*-*]) } {
+         return 0
+     }
+    return [check_no_compiler_messages cv_elw object {
+        void foo (void)
+        {
+          asm ("cv.elw x0, 0(x0)");
+        }
+    } "-march=rv32i_xcvelw" ]
+}
+
 proc check_effective_target_loongarch_sx { } {
     return [check_no_compiler_messages loongarch_lsx assembly {
        #if !defined(__loongarch_sx)