[PATCH v3 08/21] target/xtensa: don't access BR regfile directly

[Max Filippov]

BR registers used in FPU comparison opcodes are available as opcode
arguments for translators. Use them. This simplifies comparison helpers
interface and makes them usable in FLIX bundles.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target/xtensa/fpu_helper.c | 42 +++++++++++++++++---------------------
 target/xtensa/helper.h     | 14 ++++++-------
 target/xtensa/translate.c  | 20 ++++++++++++++----
 3 files changed, 42 insertions(+), 34 deletions(-)

diff --git a/target/xtensa/fpu_helper.c b/target/xtensa/fpu_helper.c
index 57a284924045..fae6836d3223 100644
--- a/target/xtensa/fpu_helper.c
+++ b/target/xtensa/fpu_helper.c
@@ -118,49 +118,45 @@ float32 HELPER(uitof_s)(CPUXtensaState *env, uint32_t v, 
uint32_t scale)
                           (int32_t)scale, &env->fp_status);
 }
 
-static inline void set_br(CPUXtensaState *env, bool v, uint32_t br)
+uint32_t HELPER(un_s)(CPUXtensaState *env, float32 a, float32 b)
 {
-    if (v) {
-        env->sregs[BR] |= br;
-    } else {
-        env->sregs[BR] &= ~br;
-    }
-}
-
-void HELPER(un_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
-{
-    set_br(env, float32_unordered_quiet(a, b, &env->fp_status), br);
+    return float32_unordered_quiet(a, b, &env->fp_status);
 }
 
-void HELPER(oeq_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
+uint32_t HELPER(oeq_s)(CPUXtensaState *env, float32 a, float32 b)
 {
-    set_br(env, float32_eq_quiet(a, b, &env->fp_status), br);
+    return float32_eq_quiet(a, b, &env->fp_status);
 }
 
-void HELPER(ueq_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
+uint32_t HELPER(ueq_s)(CPUXtensaState *env, float32 a, float32 b)
 {
     FloatRelation v = float32_compare_quiet(a, b, &env->fp_status);
-    set_br(env, v == float_relation_equal || v == float_relation_unordered, 
br);
+
+    return v == float_relation_equal ||
+           v == float_relation_unordered;
 }
 
-void HELPER(olt_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
+uint32_t HELPER(olt_s)(CPUXtensaState *env, float32 a, float32 b)
 {
-    set_br(env, float32_lt_quiet(a, b, &env->fp_status), br);
+    return float32_lt_quiet(a, b, &env->fp_status);
 }
 
-void HELPER(ult_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
+uint32_t HELPER(ult_s)(CPUXtensaState *env, float32 a, float32 b)
 {
     FloatRelation v = float32_compare_quiet(a, b, &env->fp_status);
-    set_br(env, v == float_relation_less || v == float_relation_unordered, br);
+
+    return v == float_relation_less ||
+           v == float_relation_unordered;
 }
 
-void HELPER(ole_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
+uint32_t HELPER(ole_s)(CPUXtensaState *env, float32 a, float32 b)
 {
-    set_br(env, float32_le_quiet(a, b, &env->fp_status), br);
+    return float32_le_quiet(a, b, &env->fp_status);
 }
 
-void HELPER(ule_s)(CPUXtensaState *env, uint32_t br, float32 a, float32 b)
+uint32_t HELPER(ule_s)(CPUXtensaState *env, float32 a, float32 b)
 {
     FloatRelation v = float32_compare_quiet(a, b, &env->fp_status);
-    set_br(env, v != float_relation_greater, br);
+
+    return v != float_relation_greater;
 }
diff --git a/target/xtensa/helper.h b/target/xtensa/helper.h
index a692254fe10a..bbada1c0b864 100644
--- a/target/xtensa/helper.h
+++ b/target/xtensa/helper.h
@@ -59,13 +59,13 @@ DEF_HELPER_FLAGS_3(ftoui_s, TCG_CALL_NO_RWG_SE, i32, f32, 
i32, i32)
 DEF_HELPER_3(itof_s, f32, env, i32, i32)
 DEF_HELPER_3(uitof_s, f32, env, i32, i32)
 
-DEF_HELPER_4(un_s, void, env, i32, f32, f32)
-DEF_HELPER_4(oeq_s, void, env, i32, f32, f32)
-DEF_HELPER_4(ueq_s, void, env, i32, f32, f32)
-DEF_HELPER_4(olt_s, void, env, i32, f32, f32)
-DEF_HELPER_4(ult_s, void, env, i32, f32, f32)
-DEF_HELPER_4(ole_s, void, env, i32, f32, f32)
-DEF_HELPER_4(ule_s, void, env, i32, f32, f32)
+DEF_HELPER_3(un_s,  i32, env, f32, f32)
+DEF_HELPER_3(oeq_s, i32, env, f32, f32)
+DEF_HELPER_3(ueq_s, i32, env, f32, f32)
+DEF_HELPER_3(olt_s, i32, env, f32, f32)
+DEF_HELPER_3(ult_s, i32, env, f32, f32)
+DEF_HELPER_3(ole_s, i32, env, f32, f32)
+DEF_HELPER_3(ule_s, i32, env, f32, f32)
 
 DEF_HELPER_2(rer, i32, env, i32)
 DEF_HELPER_3(wer, void, env, i32, i32)
diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index f859cd3f0818..85bd63dffc9f 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -6319,7 +6319,7 @@ enum {
 static void translate_compare_s(DisasContext *dc, const OpcodeArg arg[],
                                 const uint32_t par[])
 {
-    static void (* const helper[])(TCGv_env env, TCGv_i32 bit,
+    static void (* const helper[])(TCGv_i32 res, TCGv_env env,
                                    TCGv_i32 s, TCGv_i32 t) = {
         [COMPARE_UN] = gen_helper_un_s,
         [COMPARE_OEQ] = gen_helper_oeq_s,
@@ -6329,10 +6329,22 @@ static void translate_compare_s(DisasContext *dc, const 
OpcodeArg arg[],
         [COMPARE_OLE] = gen_helper_ole_s,
         [COMPARE_ULE] = gen_helper_ule_s,
     };
-    TCGv_i32 bit = tcg_const_i32(1 << arg[0].imm);
+    TCGv_i32 zero = tcg_const_i32(0);
+    TCGv_i32 res = tcg_temp_new_i32();
+    TCGv_i32 set_br = tcg_temp_new_i32();
+    TCGv_i32 clr_br = tcg_temp_new_i32();
 
-    helper[par[0]](cpu_env, bit, arg[1].in, arg[2].in);
-    tcg_temp_free(bit);
+    tcg_gen_ori_i32(set_br, arg[0].in, 1 << arg[0].imm);
+    tcg_gen_andi_i32(clr_br, arg[0].in, ~(1 << arg[0].imm));
+
+    helper[par[0]](res, cpu_env, arg[1].in, arg[2].in);
+    tcg_gen_movcond_i32(TCG_COND_NE,
+                        arg[0].out, res, zero,
+                        set_br, clr_br);
+    tcg_temp_free(zero);
+    tcg_temp_free(res);
+    tcg_temp_free(set_br);
+    tcg_temp_free(clr_br);
 }
 
 static void translate_float_s(DisasContext *dc, const OpcodeArg arg[],
-- 
2.20.1