[PATCH v2 0/6] Implement FEAT_FPRCVT in cpu_max

[PATCH v2 0/6] Implement FEAT_FPRCVT in cpu_max

[Jim MacArthur]

This introduces new forms of FCVTXX instructions which convert floating
point to integer but place the results in SIMD & FP registers, and
forms of the [SU]CVTF instructions which convert from integer to FP
with a source in SIMD & FP registers. The logic for conversion and test
values are otherwise the same as the versions which use general-purpose
registers.

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
Changes in v2:
- New instructions are gated on FPRCVT flag
- do_cvtf_simd removed; changes folded into do_cvtf_f
- Some vector forms of instructions are now allowed in streaming mode (new patch)
- Tests restructured to avoid the duplication of fcvt.ref
- docs/system/arm/emulation.rst updated to indicate FPRCVT support
- linux-user/aarch64/elfload.c now reports FPRCVT
- Link to v1: https://lore.kernel.org/qemu-devel/20260618-jmac-fprcvt-v1-0-1b4475bacf51@linaro.org

---
Jim MacArthur (6):
      target/arm/tcg: Implement new instructions for FPRCVT
      target/arm/tcg: Allow vector FP conversions with FPRCVT
      target/arm/tcg/cpu64.c: Add FEAT_FPRCVT to cpu_max
      linux-user/aarch64/elfload.c: Add FPRCVT
      docs/system/arm: Add FEAT_FPRCVT to A-profile support
      tests/tcg/arm: Tests for new FPRCVT instructions

 docs/system/arm/emulation.rst     |  1 +
 linux-user/aarch64/elfload.c      |  1 +
 target/arm/cpu-features.h         |  5 +++
 target/arm/tcg/a64.decode         | 15 +++++++
 target/arm/tcg/cpu64.c            |  1 +
 target/arm/tcg/translate-a64.c    | 89 ++++++++++++++++++++++++++++++++++-----
 tests/tcg/aarch64/Makefile.target | 14 +++++-
 tests/tcg/arm/fcvt.c              |  7 +++
 8 files changed, 122 insertions(+), 11 deletions(-)
---
base-commit: b83371668192a705b878e909c5ae9c1233cbd5fb
change-id: 20260618-jmac-fprcvt-1554d4c80bc8

Best regards,
-- 
Jim MacArthur <jim.macarthur@linaro.org>

[PATCH v2 1/6] target/arm/tcg: Implement new instructions for FPRCVT

[Jim MacArthur]

Adds the opcode format for the SIMD versions of FCVTXX and [US]CVTF.
These use very similar logic to the FP-to-general and general-to-FP
register versions which exist, but use another SIMD/FP register
as source or destination. The source and destination size rules are
slightly different.

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
 target/arm/cpu-features.h      |  5 +++
 target/arm/tcg/a64.decode      | 15 +++++++++
 target/arm/tcg/translate-a64.c | 71 +++++++++++++++++++++++++++++++++++++-----
 3 files changed, 83 insertions(+), 8 deletions(-)

diff --git a/target/arm/cpu-features.h b/target/arm/cpu-features.h
index a80b251589..aba95f4253 100644
--- a/target/arm/cpu-features.h
+++ b/target/arm/cpu-features.h
@@ -1665,6 +1665,11 @@ static inline bool isar_feature_aa64_f8mm4(const ARMISARegisters *id)
     return FIELD_EX64_IDREG(id, ID_AA64FPFR0, F8MM4);
 }
 
+static inline bool isar_feature_aa64_fprcvt(const ARMISARegisters *id)
+{
+    return FIELD_EX64_IDREG(id, ID_AA64ISAR3, FPRCVT);
+}
+
 /*
  * Combinations of feature tests, for ease of use with TRANS_FEAT.
  */
diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
index 28cd1faf61..5b6f156d08 100644
--- a/target/arm/tcg/a64.decode
+++ b/target/arm/tcg/a64.decode
@@ -1456,6 +1456,21 @@ FCVTZU_g        . 0011110 .. 111001 000000 ..... .....  @icvt
 FCVTAS_g        . 0011110 .. 100100 000000 ..... .....  @icvt
 FCVTAU_g        . 0011110 .. 100101 000000 ..... .....  @icvt
 
+# Conversion between floating-point and integer (SIMD & FP)
+SCVTF_simd      . 0011110 .. 111100 000000 ..... .....  @icvt
+UCVTF_simd      . 0011110 .. 111101 000000 ..... .....  @icvt
+
+FCVTAS_g_simd   . 0011110 .. 111010 000000 ..... .....  @icvt
+FCVTAU_g_simd   . 0011110 .. 111011 000000 ..... .....  @icvt
+FCVTMS_g_simd   . 0011110 .. 110100 000000 ..... .....  @icvt
+FCVTMU_g_simd   . 0011110 .. 110101 000000 ..... .....  @icvt
+FCVTNS_g_simd   . 0011110 .. 101010 000000 ..... .....  @icvt
+FCVTNU_g_simd   . 0011110 .. 101011 000000 ..... .....  @icvt
+FCVTPS_g_simd   . 0011110 .. 110010 000000 ..... .....  @icvt
+FCVTPU_g_simd   . 0011110 .. 110011 000000 ..... .....  @icvt
+FCVTZS_g_simd   . 0011110 .. 110110 000000 ..... .....  @icvt
+FCVTZU_g_simd   . 0011110 .. 110111 000000 ..... .....  @icvt
+
 FJCVTZS         0 0011110 01 111110 000000 ..... .....  @rr
 
 FMOV_ws         0 0011110 00 100110 000000 ..... .....  @rr
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 227719ef25..07f985a5f0 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -9905,12 +9905,14 @@ TRANS(SCVTF_g, do_cvtf_g, a, true)
 TRANS(UCVTF_g, do_cvtf_g, a, false)
 
 /*
- * [US]CVTF (vector), scalar version.
- * Which sounds weird, but really just means input from fp register
+ * [US]CVTF (vector), scalar or SIMD version.
+ * Which sounds weird, but really just means input from FP/SIMD register
  * instead of input from general register.  Input and output element
- * size are always equal.
+ * size are always equal for the scalar version and different for the
+ * SIMD version.
  */
-static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, bool is_signed)
+static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, MemOp src_mop_int,
+                      bool is_signed)
 {
     TCGv_i64 tcg_int;
     int check = fp_access_check_scalar_hsd(s, a->esz);
@@ -9918,14 +9920,18 @@ static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, bool is_signed)
     if (check <= 0) {
         return check == 0;
     }
-
     tcg_int = tcg_temp_new_i64();
-    read_vec_element(s, tcg_int, a->rn, 0, a->esz | (is_signed ? MO_SIGN : 0));
+    read_vec_element(s, tcg_int, a->rn, 0,
+                     src_mop_int | (is_signed ? MO_SIGN : 0));
     return do_cvtf_scalar(s, a->esz, a->rd, a->shift, tcg_int, is_signed);
 }
 
-TRANS(SCVTF_f, do_cvtf_f, a, true)
-TRANS(UCVTF_f, do_cvtf_f, a, false)
+TRANS(SCVTF_f, do_cvtf_f, a, a->esz, true)
+TRANS(UCVTF_f, do_cvtf_f, a, a->esz, false)
+TRANS_FEAT(SCVTF_simd, aa64_fprcvt, do_cvtf_f, a,
+           a->sf ? MO_64 : MO_32, true)
+TRANS_FEAT(UCVTF_simd, aa64_fprcvt, do_cvtf_f, a,
+           a->sf ? MO_64 : MO_32, false)
 
 static void do_fcvt_scalar(DisasContext *s, MemOp out, MemOp esz,
                            TCGv_i64 tcg_out, int shift, int rn,
@@ -10044,6 +10050,34 @@ static bool do_fcvt_g(DisasContext *s, arg_fcvt *a,
     return true;
 }
 
+/*
+ * Floating point to int conversion, but puts the result
+ * in a SIMD register.
+ */
+static bool do_fcvt_simd(DisasContext *s, arg_fcvt *a,
+                      ARMFPRounding rmode, bool is_signed)
+{
+    TCGv_i64 tcg_int;
+    int check = fp_access_check_scalar_hsd(s, a->esz);
+
+    if (check <= 0) {
+        return check == 0;
+    }
+    /*
+     * a->sf should specify destination size (64 bit or 32 bit)
+     * a->esz specifies source size
+     */
+    tcg_int = tcg_temp_new_i64();
+    do_fcvt_scalar(s, (a->sf ? MO_64 : MO_32) | (is_signed ? MO_SIGN : 0),
+                   a->esz, tcg_int, a->shift, a->rn, rmode);
+
+    if (!s->fpcr_nep) {
+        clear_vec(s, a->rd);
+    }
+    write_vec_element(s, tcg_int, a->rd, 0, (a->sf ? MO_64 : MO_32));
+    return true;
+}
+
 TRANS(FCVTNS_g, do_fcvt_g, a, FPROUNDING_TIEEVEN, true)
 TRANS(FCVTNU_g, do_fcvt_g, a, FPROUNDING_TIEEVEN, false)
 TRANS(FCVTPS_g, do_fcvt_g, a, FPROUNDING_POSINF, true)
@@ -10055,6 +10089,27 @@ TRANS(FCVTZU_g, do_fcvt_g, a, FPROUNDING_ZERO, false)
 TRANS(FCVTAS_g, do_fcvt_g, a, FPROUNDING_TIEAWAY, true)
 TRANS(FCVTAU_g, do_fcvt_g, a, FPROUNDING_TIEAWAY, false)
 
+TRANS_FEAT(FCVTNS_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_TIEEVEN, true)
+TRANS_FEAT(FCVTNU_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_TIEEVEN, false)
+TRANS_FEAT(FCVTPS_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_POSINF, true)
+TRANS_FEAT(FCVTPU_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_POSINF, false)
+TRANS_FEAT(FCVTMS_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_NEGINF, true)
+TRANS_FEAT(FCVTMU_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_NEGINF, false)
+TRANS_FEAT(FCVTZS_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_ZERO, true)
+TRANS_FEAT(FCVTZU_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_ZERO, false)
+TRANS_FEAT(FCVTAS_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_TIEAWAY, true)
+TRANS_FEAT(FCVTAU_g_simd, aa64_fprcvt, do_fcvt_simd, a,
+           FPROUNDING_TIEAWAY, false)
+
 /*
  * FCVT* (vector), scalar version.
  * Which sounds weird, but really just means output to fp register

-- 
2.43.0

Re: [PATCH v2 1/6] target/arm/tcg: Implement new instructions for FPRCVT

[Richard Henderson]

On 6/24/26 06:37, Jim MacArthur wrote:
>   /*
> - * [US]CVTF (vector), scalar version.
> - * Which sounds weird, but really just means input from fp register
> + * [US]CVTF (vector), scalar or SIMD version.
> + * Which sounds weird, but really just means input from FP/SIMD register
>    * instead of input from general register.  Input and output element
> - * size are always equal.
> + * size are always equal for the scalar version and different for the
> + * SIMD version.
>    */
> -static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, bool is_signed)
> +static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, MemOp src_mop_int,
> +                      bool is_signed)
>   {
>       TCGv_i64 tcg_int;
>       int check = fp_access_check_scalar_hsd(s, a->esz);
> @@ -9918,14 +9920,18 @@ static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, bool is_signed)
>       if (check <= 0) {
>           return check == 0;
>       }
> -
>       tcg_int = tcg_temp_new_i64();
> -    read_vec_element(s, tcg_int, a->rn, 0, a->esz | (is_signed ? MO_SIGN : 0));
> +    read_vec_element(s, tcg_int, a->rn, 0,
> +                     src_mop_int | (is_signed ? MO_SIGN : 0));
>       return do_cvtf_scalar(s, a->esz, a->rd, a->shift, tcg_int, is_signed);
>   }
>   
> -TRANS(SCVTF_f, do_cvtf_f, a, true)
> -TRANS(UCVTF_f, do_cvtf_f, a, false)
> +TRANS(SCVTF_f, do_cvtf_f, a, a->esz, true)
> +TRANS(UCVTF_f, do_cvtf_f, a, a->esz, false)
> +TRANS_FEAT(SCVTF_simd, aa64_fprcvt, do_cvtf_f, a,
> +           a->sf ? MO_64 : MO_32, true)
> +TRANS_FEAT(UCVTF_simd, aa64_fprcvt, do_cvtf_f, a,
> +           a->sf ? MO_64 : MO_32, false)

Good, thanks.

> +/*
> + * Floating point to int conversion, but puts the result
> + * in a SIMD register.
> + */
> +static bool do_fcvt_simd(DisasContext *s, arg_fcvt *a,
> +                      ARMFPRounding rmode, bool is_signed)
> +{
> +    TCGv_i64 tcg_int;
> +    int check = fp_access_check_scalar_hsd(s, a->esz);
> +
> +    if (check <= 0) {
> +        return check == 0;
> +    }
> +    /*
> +     * a->sf should specify destination size (64 bit or 32 bit)
> +     * a->esz specifies source size
> +     */
> +    tcg_int = tcg_temp_new_i64();
> +    do_fcvt_scalar(s, (a->sf ? MO_64 : MO_32) | (is_signed ? MO_SIGN : 0),
> +                   a->esz, tcg_int, a->shift, a->rn, rmode);
> +
> +    if (!s->fpcr_nep) {
> +        clear_vec(s, a->rd);
> +    }
> +    write_vec_element(s, tcg_int, a->rd, 0, (a->sf ? MO_64 : MO_32));
> +    return true;
> +}

I had suggested that the same MemOp change be done to do_fcvt_f, for the destination.


r~

[PATCH v2 2/6] target/arm/tcg: Allow vector FP conversions with FPRCVT

[Jim MacArthur]

FEAT_FPRCVT allows the vector forms of FCVTXX and [US]CVTF in streaming
mode which would otherwise only be available in nonstreaming mode.

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
 target/arm/tcg/translate-a64.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 07f985a5f0..1a0868eaf0 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -9915,7 +9915,14 @@ static bool do_cvtf_f(DisasContext *s, arg_fcvt *a, MemOp src_mop_int,
                       bool is_signed)
 {
     TCGv_i64 tcg_int;
-    int check = fp_access_check_scalar_hsd(s, a->esz);
+    int check;
+
+    /* FEAT_FPRCVT allows vector forms in streaming mode */
+    if (dc_isar_feature(aa64_fprcvt, s)) {
+        s->is_nonstreaming = false;
+    }
+
+    check = fp_access_check_scalar_hsd(s, a->esz);
 
     if (check <= 0) {
         return check == 0;
@@ -10120,7 +10127,14 @@ static bool do_fcvt_f(DisasContext *s, arg_fcvt *a,
                       ARMFPRounding rmode, bool is_signed)
 {
     TCGv_i64 tcg_int;
-    int check = fp_access_check_scalar_hsd(s, a->esz);
+    int check;
+
+    /* FEAT_FPRCVT allows vector forms in streaming mode */
+    if (dc_isar_feature(aa64_fprcvt, s)) {
+        s->is_nonstreaming = false;
+    }
+
+    check = fp_access_check_scalar_hsd(s, a->esz);
 
     if (check <= 0) {
         return check == 0;

-- 
2.43.0

Re: [PATCH v2 2/6] target/arm/tcg: Allow vector FP conversions with FPRCVT

[Richard Henderson]

On 6/24/26 06:37, Jim MacArthur wrote:
> FEAT_FPRCVT allows the vector forms of FCVTXX and [US]CVTF in streaming
> mode which would otherwise only be available in nonstreaming mode.
> 
> Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
> ---
>   target/arm/tcg/translate-a64.c | 18 ++++++++++++++++--

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

Re: [PATCH v2 2/6] target/arm/tcg: Allow vector FP conversions with FPRCVT

[Alex Bennée]

Jim MacArthur <jim.macarthur@linaro.org> writes:

> FEAT_FPRCVT allows the vector forms of FCVTXX and [US]CVTF in streaming
> mode which would otherwise only be available in nonstreaming mode.
>
> Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

<snip>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

[PATCH v2 3/6] target/arm/tcg/cpu64.c: Add FEAT_FPRCVT to cpu_max

[Jim MacArthur]

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
 target/arm/tcg/cpu64.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/arm/tcg/cpu64.c b/target/arm/tcg/cpu64.c
index f7a920a202..f259e82dd3 100644
--- a/target/arm/tcg/cpu64.c
+++ b/target/arm/tcg/cpu64.c
@@ -1269,6 +1269,7 @@ void aarch64_max_tcg_initfn(Object *obj)
 
     t = GET_IDREG(isar, ID_AA64ISAR3);
     t = FIELD_DP64(t, ID_AA64ISAR3, FAMINMAX, 1); /* FEAT_FAMINMAX */
+    t = FIELD_DP64(t, ID_AA64ISAR3, FPRCVT, 1);   /* FEAT_FPRCVT */
     SET_IDREG(isar, ID_AA64ISAR3, t);
 
     t = GET_IDREG(isar, ID_AA64PFR0);

-- 
2.43.0

Re: [PATCH v2 3/6] target/arm/tcg/cpu64.c: Add FEAT_FPRCVT to cpu_max

[Richard Henderson]

On 6/24/26 06:37, Jim MacArthur wrote:
> Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
> ---
>   target/arm/tcg/cpu64.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/target/arm/tcg/cpu64.c b/target/arm/tcg/cpu64.c
> index f7a920a202..f259e82dd3 100644
> --- a/target/arm/tcg/cpu64.c
> +++ b/target/arm/tcg/cpu64.c
> @@ -1269,6 +1269,7 @@ void aarch64_max_tcg_initfn(Object *obj)
>   
>       t = GET_IDREG(isar, ID_AA64ISAR3);
>       t = FIELD_DP64(t, ID_AA64ISAR3, FAMINMAX, 1); /* FEAT_FAMINMAX */
> +    t = FIELD_DP64(t, ID_AA64ISAR3, FPRCVT, 1);   /* FEAT_FPRCVT */
>       SET_IDREG(isar, ID_AA64ISAR3, t);
>   
>       t = GET_IDREG(isar, ID_AA64PFR0);
> 

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH v2 4/6] linux-user/aarch64/elfload.c: Add FPRCVT

[Jim MacArthur]

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
 linux-user/aarch64/elfload.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/linux-user/aarch64/elfload.c b/linux-user/aarch64/elfload.c
index 4887a3a7b7..4487d047bb 100644
--- a/linux-user/aarch64/elfload.c
+++ b/linux-user/aarch64/elfload.c
@@ -173,6 +173,7 @@ abi_ulong get_elf_hwcap(CPUState *cs)
     GET_FEATURE_ID(aa64_cmpbr, ARM_HWCAP_A64_CMPBR);
     GET_FEATURE_ID(aa64_f8mm8, ARM_HWCAP_A64_F8MM8);
     GET_FEATURE_ID(aa64_f8mm4, ARM_HWCAP_A64_F8MM4);
+    GET_FEATURE_ID(aa64_fprcvt, ARM_HWCAP_A64_FPRCVT);
 
     return hwcaps;
 }

-- 
2.43.0

Re: [PATCH v2 4/6] linux-user/aarch64/elfload.c: Add FPRCVT

[Richard Henderson]

On 6/24/26 06:37, Jim MacArthur wrote:
> Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
> ---
>   linux-user/aarch64/elfload.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/linux-user/aarch64/elfload.c b/linux-user/aarch64/elfload.c
> index 4887a3a7b7..4487d047bb 100644
> --- a/linux-user/aarch64/elfload.c
> +++ b/linux-user/aarch64/elfload.c
> @@ -173,6 +173,7 @@ abi_ulong get_elf_hwcap(CPUState *cs)
>       GET_FEATURE_ID(aa64_cmpbr, ARM_HWCAP_A64_CMPBR);
>       GET_FEATURE_ID(aa64_f8mm8, ARM_HWCAP_A64_F8MM8);
>       GET_FEATURE_ID(aa64_f8mm4, ARM_HWCAP_A64_F8MM4);
> +    GET_FEATURE_ID(aa64_fprcvt, ARM_HWCAP_A64_FPRCVT);
>   
>       return hwcaps;
>   }
> 


Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

[PATCH v2 5/6] docs/system/arm: Add FEAT_FPRCVT to A-profile support

[Jim MacArthur]

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
 docs/system/arm/emulation.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index a8072ddb67..98c028f6a6 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -85,6 +85,7 @@ the following architecture extensions:
 - FEAT_FPACCOMBINE (Faulting on combined pointer authentication instructions)
 - FEAT_FPACC_SPEC (Speculative behavior of combined pointer authentication instructions)
 - FEAT_FPMR (Floating-point Mode Register)
+- FEAT_FPRCVT (Floating-Point to/from Integer in Scalar FP register)
 - FEAT_FRINTTS (Floating-point to integer instructions)
 - FEAT_FlagM (Flag manipulation instructions v2)
 - FEAT_FlagM2 (Enhancements to flag manipulation instructions)

-- 
2.43.0

Re: [PATCH v2 5/6] docs/system/arm: Add FEAT_FPRCVT to A-profile support

[Richard Henderson]

On 6/24/26 06:37, Jim MacArthur wrote:
> Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
> ---
>   docs/system/arm/emulation.rst | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
> index a8072ddb67..98c028f6a6 100644
> --- a/docs/system/arm/emulation.rst
> +++ b/docs/system/arm/emulation.rst
> @@ -85,6 +85,7 @@ the following architecture extensions:
>   - FEAT_FPACCOMBINE (Faulting on combined pointer authentication instructions)
>   - FEAT_FPACC_SPEC (Speculative behavior of combined pointer authentication instructions)
>   - FEAT_FPMR (Floating-point Mode Register)
> +- FEAT_FPRCVT (Floating-Point to/from Integer in Scalar FP register)
>   - FEAT_FRINTTS (Floating-point to integer instructions)
>   - FEAT_FlagM (Flag manipulation instructions v2)
>   - FEAT_FlagM2 (Enhancements to flag manipulation instructions)
> 

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH v2 6/6] tests/tcg/arm: Tests for new FPRCVT instructions

[Jim MacArthur]

We autodetect the presence of FPRCVT in the test cross compiler,
which is a recent feature in GCC and not supported by many distros
yet. If this is in place, we compile the existing fcvt.c test with
an extra compiler flag which uses the new SIMD instructions; the
output from the test is unchanged.

The existing [US]CVTF instructions do not have a test, so no new
tests are added for the SIMD versions. They have been tested manually
to check the new SIMD versions produce the same numerical results as
the existing versions.

Signed-off-by: Jim MacArthur <jim.macarthur@linaro.org>
---
 tests/tcg/aarch64/Makefile.target | 14 +++++++++++++-
 tests/tcg/arm/fcvt.c              |  7 +++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target
index 6203ac9b51..32f2689273 100644
--- a/tests/tcg/aarch64/Makefile.target
+++ b/tests/tcg/aarch64/Makefile.target
@@ -28,9 +28,21 @@ config-cc.mak: Makefile
 	    $(call cc-option,-march=armv8.5-a,              CROSS_CC_HAS_ARMV8_5); \
 	    $(call cc-option,-mbranch-protection=standard,  CROSS_CC_HAS_ARMV8_BTI); \
 	    $(call cc-option,-march=armv8.5-a+memtag,       CROSS_CC_HAS_ARMV8_MTE); \
-	    $(call cc-option,-Wa$(COMMA)-march=armv9-a+sme $$fnia, CROSS_AS_HAS_ARMV9_SME)) 3> config-cc.mak
+	    $(call cc-option,-Wa$(COMMA)-march=armv9-a+sme $$fnia, CROSS_AS_HAS_ARMV9_SME); \
+	    $(call cc-option,-march=armv9-a+fprcvt,         CROSS_CC_HAS_ARMV9_FPRCVT)) 3> config-cc.mak
 -include config-cc.mak
 
+ifneq ($(CROSS_CC_HAS_ARMV9_FPRCVT),)
+AARCH64_TESTS += fcvt-fprcvt
+fcvt-fprcvt: LDFLAGS += -lm
+fcvt-fprcvt: CFLAGS += $(CROSS_CC_HAS_ARMV9_FPRCVT) -DFPRCVT
+fcvt-fprcvt: fcvt.c
+	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) $< -o $@ $(LDFLAGS)
+run-fcvt-fprcvt: fcvt-fprcvt
+	$(call run-test,$<,$(QEMU) $<)
+	$(call diff-out,$<,$(AARCH64_SRC)/fcvt.ref)
+endif
+
 ifneq ($(CROSS_CC_HAS_ARMV8_2),)
 AARCH64_TESTS += dcpop
 dcpop: CFLAGS += $(CROSS_CC_HAS_ARMV8_2)
diff --git a/tests/tcg/arm/fcvt.c b/tests/tcg/arm/fcvt.c
index ecebbb0247..7c0cc4367e 100644
--- a/tests/tcg/arm/fcvt.c
+++ b/tests/tcg/arm/fcvt.c
@@ -171,8 +171,14 @@ static void convert_single_to_integer(void)
 #if defined(__arm__)
         /* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
         output = input;
+#else
+#ifdef FPRCVT
+        asm("fcvtzs d0, %s1\r\n"
+            "fmov %0, d0" :
+            "=r" (output) : "w" (input));
 #else
         asm("fcvtzs %0, %s1" : "=r" (output) : "w" (input));
+#endif
 #endif
         print_int64(i, output);
     }
@@ -425,6 +431,7 @@ int main(int argc, char *argv[argc])
     convert_double_to_integer();
     convert_half_to_integer();
 
+
     /* And now with ARM alternative FP16 */
 #if defined(__arm__)
     asm("vmrs r1, fpscr\n\t"

-- 
2.43.0

Re: [PATCH v2 6/6] tests/tcg/arm: Tests for new FPRCVT instructions

[Richard Henderson]

On 6/24/26 06:37, Jim MacArthur wrote:
> +#ifdef FPRCVT
> +        asm("fcvtzs d0, %s1\r\n"
> +            "fmov %0, d0" :
> +            "=r" (output) : "w" (input));
>   #else

Missing d0 clobber, but better as

   asm("fcvtzs %d0, %s0" : "=w"(output) : "w"(input))


r~