target/arm: Implement MVE VCADD

Implement the MVE VCADD insn.  Note that here the size bit is the
opposite sense to the other 2-operand fp insns.

We don't check for the sz == 1 && Qd == Qm UNPREDICTABLE case,
because that would mean we can't use the DO_2OP_FP macro in
translate-mve.c.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/helper-mve.h

@@ -428,6 +428,12 @@ DEF_HELPER_FLAGS_4(mve_vmaxnms, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
 DEF_HELPER_FLAGS_4(mve_vminnmh, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
 DEF_HELPER_FLAGS_4(mve_vminnms, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
 
+DEF_HELPER_FLAGS_4(mve_vfcadd90h, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
+DEF_HELPER_FLAGS_4(mve_vfcadd90s, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
+
+DEF_HELPER_FLAGS_4(mve_vfcadd270h, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
+DEF_HELPER_FLAGS_4(mve_vfcadd270s, TCG_CALL_NO_WG, void, env, ptr, ptr, ptr)
+
 DEF_HELPER_FLAGS_4(mve_vadd_scalarb, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(mve_vadd_scalarh, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(mve_vadd_scalarw, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)

target/arm/mve.decode

@@ -29,6 +29,8 @@
 # 2 operand fp insns have size in bit 20: 1 for 16 bit, 0 for 32 bit,
 # like Neon FP insns.
 %2op_fp_size 20:1 !function=neon_3same_fp_size
+# VCADD is an exception, where bit 20 is 0 for 16 bit and 1 for 32 bit
+%2op_fp_size_rev 20:1 !function=plus_1
 
 # 1imm format immediate
 %imm_28_16_0 28:1 16:3 0:4
@@ -125,6 +127,9 @@
 @2op_fp .... .... .... .... .... .... .... .... &2op \
         qd=%qd qn=%qn qm=%qm size=%2op_fp_size
 
+@2op_fp_size_rev .... .... .... .... .... .... .... .... &2op \
+                 qd=%qd qn=%qn qm=%qm size=%2op_fp_size_rev
+
 # Vector loads and stores
 
 # Widening loads and narrowing stores:
@@ -631,3 +636,6 @@ VABD_fp           1111 1111 0 . 1 . ... 0 ... 0 1101 . 1 . 0 ... 0 @2op_fp
 
 VMAXNM            1111 1111 0 . 0 . ... 0 ... 0 1111 . 1 . 1 ... 0 @2op_fp
 VMINNM            1111 1111 0 . 1 . ... 0 ... 0 1111 . 1 . 1 ... 0 @2op_fp
+
+VCADD90_fp        1111 1100 1 . 0 . ... 0 ... 0 1000 . 1 . 0 ... 0 @2op_fp_size_rev
+VCADD270_fp       1111 1101 1 . 0 . ... 0 ... 0 1000 . 1 . 0 ... 0 @2op_fp_size_rev

target/arm/mve_helper.c

@@ -2854,3 +2854,43 @@ static inline float32 float32_abd(float32 a, float32 b, float_status *s)
 DO_2OP_FP_ALL(vfabd, abd)
 DO_2OP_FP_ALL(vmaxnm, maxnum)
 DO_2OP_FP_ALL(vminnm, minnum)
+
+#define DO_VCADD_FP(OP, ESIZE, TYPE, FN0, FN1)                          \
+    void HELPER(glue(mve_, OP))(CPUARMState *env,                       \
+                                void *vd, void *vn, void *vm)           \
+    {                                                                   \
+        TYPE *d = vd, *n = vn, *m = vm;                                 \
+        TYPE r[16 / ESIZE];                                             \
+        uint16_t tm, mask = mve_element_mask(env);                      \
+        unsigned e;                                                     \
+        float_status *fpst;                                             \
+        float_status scratch_fpst;                                      \
+        /* Calculate all results first to avoid overwriting inputs */   \
+        for (e = 0, tm = mask; e < 16 / ESIZE; e++, tm >>= ESIZE) {     \
+            if ((tm & MAKE_64BIT_MASK(0, ESIZE)) == 0) {                \
+                r[e] = 0;                                               \
+                continue;                                               \
+            }                                                           \
+            fpst = (ESIZE == 2) ? &env->vfp.standard_fp_status_f16 :    \
+                &env->vfp.standard_fp_status;                           \
+            if (!(tm & 1)) {                                            \
+                /* We need the result but without updating flags */     \
+                scratch_fpst = *fpst;                                   \
+                fpst = &scratch_fpst;                                   \
+            }                                                           \
+            if (!(e & 1)) {                                             \
+                r[e] = FN0(n[H##ESIZE(e)], m[H##ESIZE(e + 1)], fpst);   \
+            } else {                                                    \
+                r[e] = FN1(n[H##ESIZE(e)], m[H##ESIZE(e - 1)], fpst);   \
+            }                                                           \
+        }                                                               \
+        for (e = 0; e < 16 / ESIZE; e++, mask >>= ESIZE) {              \
+            mergemask(&d[H##ESIZE(e)], r[e], mask);                     \
+        }                                                               \
+        mve_advance_vpt(env);                                           \
+    }
+
+DO_VCADD_FP(vfcadd90h, 2, float16, float16_sub, float16_add)
+DO_VCADD_FP(vfcadd90s, 4, float32, float32_sub, float32_add)
+DO_VCADD_FP(vfcadd270h, 2, float16, float16_add, float16_sub)
+DO_VCADD_FP(vfcadd270s, 4, float32, float32_add, float32_sub)

target/arm/translate-mve.c

@@ -852,6 +852,8 @@ DO_2OP_FP(VMUL_fp, vfmul)
 DO_2OP_FP(VABD_fp, vfabd)
 DO_2OP_FP(VMAXNM, vmaxnm)
 DO_2OP_FP(VMINNM, vminnm)
+DO_2OP_FP(VCADD90_fp, vfcadd90)
+DO_2OP_FP(VCADD270_fp, vfcadd270)
 
 static bool do_2op_scalar(DisasContext *s, arg_2scalar *a,
                           MVEGenTwoOpScalarFn fn)