[for-6.2,51/53] target/arm: Implement MVE VCVT between single and half precision

Message ID 20210729111512.16541-52-peter.maydell@linaro.org
State Superseded
Headers show
Series
  • target/arm: MVE slices 3 and 4
Related show

Commit Message

Peter Maydell July 29, 2021, 11:15 a.m.
Implement the MVE VCVT instruction which converts between single
and half precision floating point.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

---
 target/arm/helper-mve.h    |  5 +++
 target/arm/mve.decode      |  8 +++++
 target/arm/mve_helper.c    | 71 ++++++++++++++++++++++++++++++++++++++
 target/arm/translate-mve.c | 14 ++++++++
 4 files changed, 98 insertions(+)

-- 
2.20.1

Comments

Richard Henderson July 30, 2021, 8:33 p.m. | #1
On 7/29/21 1:15 AM, Peter Maydell wrote:
> +/*

> + * VCVT between halfprec and singleprec. As usual for halfprec

> + * conversions, FZ16 is ignored and AHP is observed.

> + */

> +#define DO_VCVT_SH(OP, TOP)                                             \

> +    void HELPER(glue(mve_, OP))(CPUARMState *env, void *vd, void *vm)   \


These might be easier to read as a local function with an extra "top" argument, rather 
than as a macro, since you're not passing in anything complicated.

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


r~

Patch

diff --git a/target/arm/helper-mve.h b/target/arm/helper-mve.h
index 6d4052a5269..f6345c7abbe 100644
--- a/target/arm/helper-mve.h
+++ b/target/arm/helper-mve.h
@@ -182,6 +182,11 @@  DEF_HELPER_FLAGS_4(mve_vcvt_rm_uh, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(mve_vcvt_rm_ss, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(mve_vcvt_rm_us, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
 
+DEF_HELPER_FLAGS_3(mve_vcvtb_sh, TCG_CALL_NO_WG, void, env, ptr, ptr)
+DEF_HELPER_FLAGS_3(mve_vcvtt_sh, TCG_CALL_NO_WG, void, env, ptr, ptr)
+DEF_HELPER_FLAGS_3(mve_vcvtb_hs, TCG_CALL_NO_WG, void, env, ptr, ptr)
+DEF_HELPER_FLAGS_3(mve_vcvtt_hs, TCG_CALL_NO_WG, void, env, ptr, ptr)
+
 DEF_HELPER_FLAGS_3(mve_vmovnbb, TCG_CALL_NO_WG, void, env, ptr, ptr)
 DEF_HELPER_FLAGS_3(mve_vmovnbh, TCG_CALL_NO_WG, void, env, ptr, ptr)
 DEF_HELPER_FLAGS_3(mve_vmovntb, TCG_CALL_NO_WG, void, env, ptr, ptr)
diff --git a/target/arm/mve.decode b/target/arm/mve.decode
index 410ea746fcf..32de4af3170 100644
--- a/target/arm/mve.decode
+++ b/target/arm/mve.decode
@@ -221,6 +221,8 @@  VMUL             1110 1111 0 . .. ... 0 ... 0 1001 . 1 . 1 ... 0 @2op
 # The VSHLL T2 encoding is not a @2op pattern, but is here because it
 # overlaps what would be size=0b11 VMULH/VRMULH
 {
+  VCVTB_SH       111 0 1110 0 . 11 1111 ... 0 1110 0 0 . 0 ... 1 @1op_nosz
+
   VMAXNMA        111 0 1110 0 . 11 1111 ... 0 1110 1 0 . 0 ... 1 @vmaxnma size=2
 
   VSHLL_BS       111 0 1110 0 . 11 .. 01 ... 0 1110 0 0 . 0 ... 1 @2_shll_esize_b
@@ -235,6 +237,8 @@  VMUL             1110 1111 0 . .. ... 0 ... 0 1001 . 1 . 1 ... 0 @2op
 }
 
 {
+  VCVTB_HS       111 1 1110 0 . 11  1111 ... 0 1110 0 0 . 0 ... 1  @1op_nosz
+
   VMAXNMA        111 1 1110 0 . 11  1111 ... 0 1110 1 0 . 0 ... 1 @vmaxnma size=1
 
   VSHLL_BU       111 1 1110 0 . 11 .. 01 ... 0 1110 0 0 . 0 ... 1 @2_shll_esize_b
@@ -247,6 +251,8 @@  VMUL             1110 1111 0 . .. ... 0 ... 0 1001 . 1 . 1 ... 0 @2op
 }
 
 {
+  VCVTT_SH       111 0 1110 0 . 11  1111 ... 1 1110 0 0 . 0 ... 1 @1op_nosz
+
   VMINNMA        111 0 1110 0 . 11  1111 ... 1 1110 1 0 . 0 ... 1 @vmaxnma size=2
   VSHLL_TS       111 0 1110 0 . 11 .. 01 ... 1 1110 0 0 . 0 ... 1 @2_shll_esize_b
   VSHLL_TS       111 0 1110 0 . 11 .. 01 ... 1 1110 0 0 . 0 ... 1 @2_shll_esize_h
@@ -260,6 +266,8 @@  VMUL             1110 1111 0 . .. ... 0 ... 0 1001 . 1 . 1 ... 0 @2op
 }
 
 {
+  VCVTT_HS       111 1 1110 0 . 11  1111 ... 1 1110 0 0 . 0 ... 1 @1op_nosz
+
   VMINNMA        111 1 1110 0 . 11  1111 ... 1 1110 1 0 . 0 ... 1 @vmaxnma size=1
   VSHLL_TU       111 1 1110 0 . 11 .. 01 ... 1 1110 0 0 . 0 ... 1 @2_shll_esize_b
   VSHLL_TU       111 1 1110 0 . 11 .. 01 ... 1 1110 0 0 . 0 ... 1 @2_shll_esize_h
diff --git a/target/arm/mve_helper.c b/target/arm/mve_helper.c
index 4e0d979e643..7a5143ba6f3 100644
--- a/target/arm/mve_helper.c
+++ b/target/arm/mve_helper.c
@@ -3337,3 +3337,74 @@  DO_VCVT_RMODE(vcvt_rm_sh, 2, uint16_t, helper_vfp_toshh)
 DO_VCVT_RMODE(vcvt_rm_uh, 2, uint16_t, helper_vfp_touhh)
 DO_VCVT_RMODE(vcvt_rm_ss, 4, uint32_t, helper_vfp_tosls)
 DO_VCVT_RMODE(vcvt_rm_us, 4, uint32_t, helper_vfp_touls)
+
+/*
+ * VCVT between halfprec and singleprec. As usual for halfprec
+ * conversions, FZ16 is ignored and AHP is observed.
+ */
+#define DO_VCVT_SH(OP, TOP)                                             \
+    void HELPER(glue(mve_, OP))(CPUARMState *env, void *vd, void *vm)   \
+    {                                                                   \
+        uint16_t *d = vd;                                               \
+        uint32_t *m = vm;                                               \
+        uint16_t r;                                                     \
+        uint16_t mask = mve_element_mask(env);                          \
+        bool ieee = !(env->vfp.xregs[ARM_VFP_FPSCR] & FPCR_AHP);        \
+        unsigned e;                                                     \
+        float_status *fpst;                                             \
+        float_status scratch_fpst;                                      \
+        float_status *base_fpst = &env->vfp.standard_fp_status;         \
+        bool old_fz = get_flush_to_zero(base_fpst);                     \
+        set_flush_to_zero(false, base_fpst);                            \
+        for (e = 0; e < 16 / 4; e++, mask >>= 4) {                      \
+            if ((mask & MAKE_64BIT_MASK(0, 4)) == 0) {                  \
+                continue;                                               \
+            }                                                           \
+            fpst = base_fpst;                                           \
+            if (!(mask & 1)) {                                          \
+                /* We need the result but without updating flags */     \
+                scratch_fpst = *fpst;                                   \
+                fpst = &scratch_fpst;                                   \
+            }                                                           \
+            r = float32_to_float16(m[H4(e)], ieee, fpst);               \
+            mergemask(&d[H2(e * 2 + TOP)], r, mask >> (TOP * 2));       \
+        }                                                               \
+        set_flush_to_zero(old_fz, base_fpst);                           \
+        mve_advance_vpt(env);                                           \
+    }
+
+#define DO_VCVT_HS(OP, TOP)                                             \
+    void HELPER(glue(mve_, OP))(CPUARMState *env, void *vd, void *vm)   \
+    {                                                                   \
+        uint32_t *d = vd;                                               \
+        uint16_t *m = vm;                                               \
+        uint32_t r;                                                     \
+        uint16_t mask = mve_element_mask(env);                          \
+        bool ieee = !(env->vfp.xregs[ARM_VFP_FPSCR] & FPCR_AHP);        \
+        unsigned e;                                                     \
+        float_status *fpst;                                             \
+        float_status scratch_fpst;                                      \
+        float_status *base_fpst = &env->vfp.standard_fp_status;         \
+        bool old_fiz = get_flush_inputs_to_zero(base_fpst);             \
+        set_flush_inputs_to_zero(false, base_fpst);                     \
+        for (e = 0; e < 16 / 4; e++, mask >>= 4) {                      \
+            if ((mask & MAKE_64BIT_MASK(0, 4)) == 0) {                  \
+                continue;                                               \
+            }                                                           \
+            fpst = base_fpst;                                           \
+            if (!(mask & (1 << (TOP * 2)))) {                           \
+                /* We need the result but without updating flags */     \
+                scratch_fpst = *fpst;                                   \
+                fpst = &scratch_fpst;                                   \
+            }                                                           \
+            r = float16_to_float32(m[H2(e * 2 + TOP)], ieee, fpst);     \
+            mergemask(&d[H4(e)], r, mask);                              \
+        }                                                               \
+        set_flush_inputs_to_zero(old_fiz, base_fpst);                   \
+        mve_advance_vpt(env);                                           \
+    }
+
+DO_VCVT_SH(vcvtb_sh, 0)
+DO_VCVT_SH(vcvtt_sh, 1)
+DO_VCVT_HS(vcvtb_hs, 0)
+DO_VCVT_HS(vcvtt_hs, 1)
diff --git a/target/arm/translate-mve.c b/target/arm/translate-mve.c
index e80a55eb62e..194ef99cc74 100644
--- a/target/arm/translate-mve.c
+++ b/target/arm/translate-mve.c
@@ -627,6 +627,20 @@  DO_VCVT_RMODE(VCVTPU, FPROUNDING_POSINF, true)
 DO_VCVT_RMODE(VCVTMS, FPROUNDING_NEGINF, false)
 DO_VCVT_RMODE(VCVTMU, FPROUNDING_NEGINF, true)
 
+#define DO_VCVT_SH(INSN, FN)                                    \
+    static bool trans_##INSN(DisasContext *s, arg_1op *a)       \
+    {                                                           \
+        if (!dc_isar_feature(aa32_mve_fp, s)) {                 \
+            return false;                                       \
+        }                                                       \
+        return do_1op(s, a, gen_helper_mve_##FN);               \
+    }                                                           \
+
+DO_VCVT_SH(VCVTB_SH, vcvtb_sh)
+DO_VCVT_SH(VCVTT_SH, vcvtt_sh)
+DO_VCVT_SH(VCVTB_HS, vcvtb_hs)
+DO_VCVT_SH(VCVTT_HS, vcvtt_hs)
+
 /* Narrowing moves: only size 0 and 1 are valid */
 #define DO_VMOVN(INSN, FN) \
     static bool trans_##INSN(DisasContext *s, arg_1op *a)       \