[Qemu-devel] [PATCH v2 08/10] target-xtensa: implement FP0 conversions

[Max Filippov <jcmvbkbc@gmail.com>]

These are FP to integer and integer to FP conversion opcodes.
See ISA, 4.3.10 for more details.

Note that utrunc.s implementation follows ISS behaviour, not ISA.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
Changes v1->v2:
- replace float32_mul/div in FP-to-integer convertors with float32_scalbn
- reimplement comparison with zero in FP-to-integer convertors

 target-xtensa/helper.h    |    4 +++
 target-xtensa/op_helper.c |   37 ++++++++++++++++++++++++++++++++++
 target-xtensa/translate.c |   48 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 0 deletions(-)

diff --git a/target-xtensa/helper.h b/target-xtensa/helper.h
index 4e6e417..9557347 100644
--- a/target-xtensa/helper.h
+++ b/target-xtensa/helper.h
@@ -44,5 +44,9 @@ DEF_HELPER_3(sub_s, f32, env, f32, f32)
 DEF_HELPER_3(mul_s, f32, env, f32, f32)
 DEF_HELPER_4(madd_s, f32, env, f32, f32, f32)
 DEF_HELPER_4(msub_s, f32, env, f32, f32, f32)
+DEF_HELPER_FLAGS_3(ftoi, TCG_CALL_CONST | TCG_CALL_PURE, i32, f32, i32, i32)
+DEF_HELPER_FLAGS_3(ftoui, TCG_CALL_CONST | TCG_CALL_PURE, i32, f32, i32, i32)
+DEF_HELPER_3(itof, f32, env, i32, i32)
+DEF_HELPER_3(uitof, f32, env, i32, i32)
 
 #include "def-helper.h"
diff --git a/target-xtensa/op_helper.c b/target-xtensa/op_helper.c
index ba935a8..5cf9c02 100644
--- a/target-xtensa/op_helper.c
+++ b/target-xtensa/op_helper.c
@@ -821,3 +821,40 @@ float32 HELPER(msub_s)(CPUXtensaState *env, float32 a, float32 b, float32 c)
     return float32_muladd(b, c, a, float_muladd_negate_product,
             &env->fp_status);
 }
+
+uint32_t HELPER(ftoi)(float32 v, uint32_t rounding_mode, uint32_t scale)
+{
+    float_status fp_status = {0};
+
+    set_float_rounding_mode(rounding_mode, &fp_status);
+    return float32_to_int32(
+            float32_scalbn(v, scale, &fp_status), &fp_status);
+}
+
+uint32_t HELPER(ftoui)(float32 v, uint32_t rounding_mode, uint32_t scale)
+{
+    float_status fp_status = {0};
+    float32 res;
+
+    set_float_rounding_mode(rounding_mode, &fp_status);
+
+    res = float32_scalbn(v, scale, &fp_status);
+
+    if (float32_is_neg(v) && !float32_is_any_nan(v)) {
+        return float32_to_int32(res, &fp_status);
+    } else {
+        return float32_to_uint32(res, &fp_status);
+    }
+}
+
+float32 HELPER(itof)(CPUXtensaState *env, uint32_t v, uint32_t scale)
+{
+    return float32_scalbn(int32_to_float32(v, &env->fp_status),
+            (int32_t)scale, &env->fp_status);
+}
+
+float32 HELPER(uitof)(CPUXtensaState *env, uint32_t v, uint32_t scale)
+{
+    return float32_scalbn(uint32_to_float32(v, &env->fp_status),
+            (int32_t)scale, &env->fp_status);
+}
diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index a2ce286..fabde4f 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -1915,6 +1915,54 @@ static void disas_xtensa_insn(DisasContext *dc)
                         cpu_FR[RRR_R], cpu_FR[RRR_S], cpu_FR[RRR_T]);
                 break;
 
+            case 8: /*ROUND.Sf*/
+            case 9: /*TRUNC.Sf*/
+            case 10: /*FLOOR.Sf*/
+            case 11: /*CEIL.Sf*/
+            case 14: /*UTRUNC.Sf*/
+                gen_window_check1(dc, RRR_R);
+                {
+                    static const unsigned rounding_mode_const[] = {
+                        float_round_nearest_even,
+                        float_round_to_zero,
+                        float_round_down,
+                        float_round_up,
+                        [6] = float_round_to_zero,
+                    };
+                    TCGv_i32 rounding_mode = tcg_const_i32(
+                            rounding_mode_const[OP2 & 7]);
+                    TCGv_i32 scale = tcg_const_i32(RRR_T);
+
+                    if (OP2 == 14) {
+                        gen_helper_ftoui(cpu_R[RRR_R], cpu_FR[RRR_S],
+                                rounding_mode, scale);
+                    } else {
+                        gen_helper_ftoi(cpu_R[RRR_R], cpu_FR[RRR_S],
+                                rounding_mode, scale);
+                    }
+
+                    tcg_temp_free(rounding_mode);
+                    tcg_temp_free(scale);
+                }
+                break;
+
+            case 12: /*FLOAT.Sf*/
+            case 13: /*UFLOAT.Sf*/
+                gen_window_check1(dc, RRR_S);
+                {
+                    TCGv_i32 scale = tcg_const_i32(-RRR_T);
+
+                    if (OP2 == 13) {
+                        gen_helper_uitof(cpu_FR[RRR_R], cpu_env,
+                                cpu_R[RRR_S], scale);
+                    } else {
+                        gen_helper_itof(cpu_FR[RRR_R], cpu_env,
+                                cpu_R[RRR_S], scale);
+                    }
+                    tcg_temp_free(scale);
+                }
+                break;
+
             case 15: /*FP1OP*/
                 switch (RRR_T) {
                 case 0: /*MOV.Sf*/
-- 
1.7.7.6