[Qemu-devel] [PULL 06/24] target-sparc: Store %asi in TB flags

[Richard Henderson <rth@twiddle.net>]

Knowing the value of %asi at translation time means that we
can handle the common settings without a function call.

The steady state appears to be %asi == ASI_P, so that sparcv9
code can use offset forms of lda/sta.  The %asi register gets
pushed and popped on entry to certain functions, but it rarely
takes on values other than ASI_P or ASI_AIUP.  Therefore we're
unlikely to be expanding the set of TBs created.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-sparc/cpu.h       |  2 ++
 target-sparc/translate.c | 29 ++++++++++++++++++++---------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/target-sparc/cpu.h b/target-sparc/cpu.h
index a7e4723..a3d64a4 100644
--- a/target-sparc/cpu.h
+++ b/target-sparc/cpu.h
@@ -722,6 +722,7 @@ trap_state* cpu_tsptr(CPUSPARCState* env);
 #define TB_FLAG_MMU_MASK     7
 #define TB_FLAG_FPU_ENABLED  (1 << 4)
 #define TB_FLAG_AM_ENABLED   (1 << 5)
+#define TB_FLAG_ASI_SHIFT    24
 
 static inline void cpu_get_tb_cpu_state(CPUSPARCState *env, target_ulong *pc,
                                         target_ulong *cs_base, uint32_t *pflags)
@@ -739,6 +740,7 @@ static inline void cpu_get_tb_cpu_state(CPUSPARCState *env, target_ulong *pc,
         && (env->fprs & FPRS_FEF)) {
         flags |= TB_FLAG_FPU_ENABLED;
     }
+    flags |= env->asi << TB_FLAG_ASI_SHIFT;
 #else
     if ((env->def->features & CPU_FEATURE_FLOAT) && env->psref) {
         flags |= TB_FLAG_FPU_ENABLED;
diff --git a/target-sparc/translate.c b/target-sparc/translate.c
index 90c46df..0b056e5 100644
--- a/target-sparc/translate.c
+++ b/target-sparc/translate.c
@@ -53,7 +53,7 @@ static TCGv cpu_tbr;
 #endif
 static TCGv cpu_cond;
 #ifdef TARGET_SPARC64
-static TCGv_i32 cpu_xcc, cpu_asi, cpu_fprs;
+static TCGv_i32 cpu_xcc, cpu_fprs;
 static TCGv cpu_gsr;
 static TCGv cpu_tick_cmpr, cpu_stick_cmpr, cpu_hstick_cmpr;
 static TCGv cpu_hintp, cpu_htba, cpu_hver, cpu_ssr, cpu_ver;
@@ -81,6 +81,9 @@ typedef struct DisasContext {
     TCGv ttl[5];
     int n_t32;
     int n_ttl;
+#ifdef TARGET_SPARC64
+    int asi;
+#endif
 } DisasContext;
 
 typedef struct {
@@ -1975,19 +1978,19 @@ static inline void gen_ne_fop_QD(DisasContext *dc, int rd, int rs,
 #if !defined(CONFIG_USER_ONLY) || defined(TARGET_SPARC64)
 static TCGv_i32 gen_get_asi(DisasContext *dc, int insn)
 {
-    TCGv_i32 r_asi = tcg_temp_new_i32();
+    int asi;
 
     if (IS_IMM) {
 #ifdef TARGET_SPARC64
-        tcg_gen_mov_i32(r_asi, cpu_asi);
+        asi = dc->asi;
 #else
         gen_exception(dc, TT_ILL_INSN);
-        tcg_gen_movi_i32(r_asi, 0);
+        asi = 0;
 #endif
     } else {
-        tcg_gen_movi_i32(r_asi, GET_FIELD(insn, 19, 26));
+        asi = GET_FIELD(insn, 19, 26);
     }
-    return r_asi;
+    return tcg_const_i32(asi);
 }
 
 static void gen_ld_asi(DisasContext *dc, TCGv dst, TCGv addr,
@@ -2688,7 +2691,7 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                     gen_store_gpr(dc, rd, cpu_dst);
                     break;
                 case 0x3: /* V9 rdasi */
-                    tcg_gen_ext_i32_tl(cpu_dst, cpu_asi);
+                    tcg_gen_movi_tl(cpu_dst, dc->asi);
                     gen_store_gpr(dc, rd, cpu_dst);
                     break;
                 case 0x4: /* V9 rdtick */
@@ -3614,7 +3617,13 @@ static void disas_sparc_insn(DisasContext * dc, unsigned int insn)
                             case 0x3: /* V9 wrasi */
                                 tcg_gen_xor_tl(cpu_tmp0, cpu_src1, cpu_src2);
                                 tcg_gen_andi_tl(cpu_tmp0, cpu_tmp0, 0xff);
-                                tcg_gen_trunc_tl_i32(cpu_asi, cpu_tmp0);
+                                tcg_gen_st32_tl(cpu_tmp0, cpu_env,
+                                                offsetof(CPUSPARCState, asi));
+                                /* End TB to notice changed ASI.  */
+                                save_state(dc);
+                                gen_op_next_insn();
+                                tcg_gen_exit_tb(0);
+                                dc->is_br = 1;
                                 break;
                             case 0x6: /* V9 wrfprs */
                                 tcg_gen_xor_tl(cpu_tmp0, cpu_src1, cpu_src2);
@@ -5195,6 +5204,9 @@ void gen_intermediate_code(CPUSPARCState * env, TranslationBlock * tb)
     dc->fpu_enabled = tb_fpu_enabled(tb->flags);
     dc->address_mask_32bit = tb_am_enabled(tb->flags);
     dc->singlestep = (cs->singlestep_enabled || singlestep);
+#ifdef TARGET_SPARC64
+    dc->asi = (tb->flags >> TB_FLAG_ASI_SHIFT) & 0xff;
+#endif
 
     num_insns = 0;
     max_insns = tb->cflags & CF_COUNT_MASK;
@@ -5304,7 +5316,6 @@ void gen_intermediate_code_init(CPUSPARCState *env)
     static const struct { TCGv_i32 *ptr; int off; const char *name; } r32[] = {
 #ifdef TARGET_SPARC64
         { &cpu_xcc, offsetof(CPUSPARCState, xcc), "xcc" },
-        { &cpu_asi, offsetof(CPUSPARCState, asi), "asi" },
         { &cpu_fprs, offsetof(CPUSPARCState, fprs), "fprs" },
 #else
         { &cpu_wim, offsetof(CPUSPARCState, wim), "wim" },
-- 
2.7.4