[Qemu-devel] [PATCH v4 12/21] target-mips: add ALIGN, DALIGN, BITSWAP and DBITSWAP instructions

[Leon Alrae <leon.alrae@imgtec.com>]

From: Yongbok Kim <yongbok.kim@imgtec.com>

Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
---
v3:
* bitswap: use gen_load_gpr instead of optimizing very unlikely case and
  making it less readable
v2:
* have separate bitswap and dbitswap helpers and use common function
* use TCG_CALL_NO_RWG_SE flag for bitswap and dbitswap helpers
* remove useless shift in ALIGN and DALIGN
* improve ALIGN implementation by merging rt and rs into 64-bit register
* add missing zero register case
---
 disas/mips.c            |   4 ++
 target-mips/helper.h    |   5 ++
 target-mips/op_helper.c |  23 ++++++++++
 target-mips/translate.c | 120 +++++++++++++++++++++++++++++++++++++++++++-----
 4 files changed, 140 insertions(+), 12 deletions(-)

diff --git a/disas/mips.c b/disas/mips.c
index 8ee8758..61313f4 100644
--- a/disas/mips.c
+++ b/disas/mips.c
@@ -1246,6 +1246,10 @@ const struct mips_opcode mips_builtin_opcodes[] =
 {"cache",   "k,o(b)",   0x7c000025, 0xfc00007f, RD_b,                 0, I32R6},
 {"seleqz",  "d,v,t",    0x00000035, 0xfc0007ff, WR_d|RD_s|RD_t,       0, I32R6},
 {"selnez",  "d,v,t",    0x00000037, 0xfc0007ff, WR_d|RD_s|RD_t,       0, I32R6},
+{"align",   "d,v,t",    0x7c000220, 0xfc00073f, WR_d|RD_s|RD_t,       0, I32R6},
+{"dalign",  "d,v,t",    0x7c000224, 0xfc00063f, WR_d|RD_s|RD_t,       0, I64R6},
+{"bitswap", "d,w",      0x7c000020, 0xffe007ff, WR_d|RD_t,            0, I32R6},
+{"dbitswap","d,w",      0x7c000024, 0xffe007ff, WR_d|RD_t,            0, I64R6},
 {"pref",    "k,o(b)",   0xcc000000, 0xfc000000, RD_b,           	0,		I4|I32|G3	},
 {"prefx",   "h,t(b)",	0x4c00000f, 0xfc0007ff, RD_b|RD_t,		0,		I4|I33	},
 {"nop",     "",         0x00000000, 0xffffffff, 0,              	INSN2_ALIAS,	I1      }, /* sll */
diff --git a/target-mips/helper.h b/target-mips/helper.h
index 74ef094..5511dfc 100644
--- a/target-mips/helper.h
+++ b/target-mips/helper.h
@@ -39,6 +39,11 @@ DEF_HELPER_3(macchiu, tl, env, tl, tl)
 DEF_HELPER_3(msachi, tl, env, tl, tl)
 DEF_HELPER_3(msachiu, tl, env, tl, tl)
 
+DEF_HELPER_FLAGS_1(bitswap, TCG_CALL_NO_RWG_SE, tl, tl)
+#ifdef TARGET_MIPS64
+DEF_HELPER_FLAGS_1(dbitswap, TCG_CALL_NO_RWG_SE, tl, tl)
+#endif
+
 #ifndef CONFIG_USER_ONLY
 /* CP0 helpers */
 DEF_HELPER_1(mfc0_mvpcontrol, tl, env)
diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index df97b35..c9841e2 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -266,6 +266,29 @@ target_ulong helper_mulshiu(CPUMIPSState *env, target_ulong arg1,
                        (uint64_t)(uint32_t)arg2);
 }
 
+static inline target_ulong bitswap(target_ulong v)
+{
+    v = ((v >> 1) & (target_ulong)0x5555555555555555) |
+              ((v & (target_ulong)0x5555555555555555) << 1);
+    v = ((v >> 2) & (target_ulong)0x3333333333333333) |
+              ((v & (target_ulong)0x3333333333333333) << 2);
+    v = ((v >> 4) & (target_ulong)0x0F0F0F0F0F0F0F0F) |
+              ((v & (target_ulong)0x0F0F0F0F0F0F0F0F) << 4);
+    return v;
+}
+
+#ifdef TARGET_MIPS64
+target_ulong helper_dbitswap(target_ulong rt)
+{
+    return bitswap(rt);
+}
+#endif
+
+target_ulong helper_bitswap(target_ulong rt)
+{
+    return (int32_t)bitswap(rt);
+}
+
 #ifndef CONFIG_USER_ONLY
 
 static inline hwaddr do_translate_address(CPUMIPSState *env,
diff --git a/target-mips/translate.c b/target-mips/translate.c
index 7420485..0052e24 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -392,17 +392,23 @@ enum {
 #define MASK_BSHFL(op)     MASK_SPECIAL3(op) | (op & (0x1F << 6))
 
 enum {
-    OPC_WSBH     = (0x02 << 6) | OPC_BSHFL,
-    OPC_SEB      = (0x10 << 6) | OPC_BSHFL,
-    OPC_SEH      = (0x18 << 6) | OPC_BSHFL,
+    OPC_WSBH      = (0x02 << 6) | OPC_BSHFL,
+    OPC_SEB       = (0x10 << 6) | OPC_BSHFL,
+    OPC_SEH       = (0x18 << 6) | OPC_BSHFL,
+    OPC_ALIGN     = (0x08 << 6) | OPC_BSHFL, /* 010.bp */
+    OPC_ALIGN_END = (0x0B << 6) | OPC_BSHFL, /* 010.00 to 010.11 */
+    OPC_BITSWAP   = (0x00 << 6) | OPC_BSHFL  /* 00000 */
 };
 
 /* DBSHFL opcodes */
 #define MASK_DBSHFL(op)    MASK_SPECIAL3(op) | (op & (0x1F << 6))
 
 enum {
-    OPC_DSBH     = (0x02 << 6) | OPC_DBSHFL,
-    OPC_DSHD     = (0x05 << 6) | OPC_DBSHFL,
+    OPC_DSBH       = (0x02 << 6) | OPC_DBSHFL,
+    OPC_DSHD       = (0x05 << 6) | OPC_DBSHFL,
+    OPC_DALIGN     = (0x08 << 6) | OPC_DBSHFL, /* 01.bp */
+    OPC_DALIGN_END = (0x0F << 6) | OPC_DBSHFL, /* 01.000 to 01.111 */
+    OPC_DBITSWAP   = (0x00 << 6) | OPC_DBSHFL, /* 00000 */
 };
 
 /* MIPS DSP REGIMM opcodes */
@@ -15162,12 +15168,14 @@ static void decode_opc_special2_legacy(CPUMIPSState *env, DisasContext *ctx)
 
 static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
 {
-    int rs, rt;
-    uint32_t op1;
+    int rs, rt, rd, sa;
+    uint32_t op1, op2;
     int16_t imm;
 
     rs = (ctx->opcode >> 21) & 0x1f;
     rt = (ctx->opcode >> 16) & 0x1f;
+    rd = (ctx->opcode >> 11) & 0x1f;
+    sa = (ctx->opcode >> 6) & 0x1f;
     imm = (int16_t)ctx->opcode >> 7;
 
     op1 = MASK_SPECIAL3(ctx->opcode);
@@ -15188,6 +15196,43 @@ static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
     case R6_OPC_LL:
         gen_ld(ctx, op1, rt, rs, imm);
         break;
+    case OPC_BSHFL:
+        {
+            if (rd == 0) {
+                /* Treat as NOP. */
+                break;
+            }
+            TCGv t0 = tcg_temp_new();
+            gen_load_gpr(t0, rt);
+
+            op2 = MASK_BSHFL(ctx->opcode);
+            switch (op2) {
+            case OPC_ALIGN ... OPC_ALIGN_END:
+                sa &= 3;
+                if (sa == 0) {
+                    tcg_gen_mov_tl(cpu_gpr[rd], t0);
+                } else {
+                    TCGv t1 = tcg_temp_new();
+                    TCGv_i64 t2 = tcg_temp_new_i64();
+                    gen_load_gpr(t1, rs);
+                    tcg_gen_concat_tl_i64(t2, t1, t0);
+                    tcg_gen_shri_i64(t2, t2, 8 * (4 - sa));
+#if defined(TARGET_MIPS64)
+                    tcg_gen_ext32s_i64(cpu_gpr[rd], t2);
+#else
+                    tcg_gen_trunc_i64_i32(cpu_gpr[rd], t2);
+#endif
+                    tcg_temp_free_i64(t2);
+                    tcg_temp_free(t1);
+                }
+                break;
+            case OPC_BITSWAP:
+                gen_helper_bitswap(cpu_gpr[rd], t0);
+                break;
+            }
+            tcg_temp_free(t0);
+        }
+        break;
 #if defined(TARGET_MIPS64)
     case R6_OPC_SCD:
         gen_st_cond(ctx, op1, rt, rs, imm);
@@ -15195,6 +15240,38 @@ static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
     case R6_OPC_LLD:
         gen_ld(ctx, op1, rt, rs, imm);
         break;
+    case OPC_DBSHFL:
+        check_mips_64(ctx);
+        {
+            if (rd == 0) {
+                /* Treat as NOP. */
+                break;
+            }
+            TCGv t0 = tcg_temp_new();
+            gen_load_gpr(t0, rt);
+
+            op2 = MASK_DBSHFL(ctx->opcode);
+            switch (op2) {
+            case OPC_DALIGN ... OPC_DALIGN_END:
+                sa &= 7;
+                if (sa == 0) {
+                    tcg_gen_mov_tl(cpu_gpr[rd], t0);
+                } else {
+                    TCGv t1 = tcg_temp_new();
+                    gen_load_gpr(t1, rs);
+                    tcg_gen_shli_tl(t0, t0, 8 * sa);
+                    tcg_gen_shri_tl(t1, t1, 8 * (8 - sa));
+                    tcg_gen_or_tl(cpu_gpr[rd], t1, t0);
+                    tcg_temp_free(t1);
+                }
+                break;
+            case OPC_DBITSWAP:
+                gen_helper_dbitswap(cpu_gpr[rd], t0);
+                break;
+            }
+            tcg_temp_free(t0);
+        }
+        break;
 #endif
     default:            /* Invalid */
         MIPS_INVAL("special3_r6");
@@ -15743,9 +15820,18 @@ static void decode_opc_special3(CPUMIPSState *env, DisasContext *ctx)
         gen_bitops(ctx, op1, rt, rs, sa, rd);
         break;
     case OPC_BSHFL:
-        check_insn(ctx, ISA_MIPS32R2);
         op2 = MASK_BSHFL(ctx->opcode);
-        gen_bshfl(ctx, op2, rt, rd);
+        switch (op2) {
+        case OPC_ALIGN ... OPC_ALIGN_END:
+        case OPC_BITSWAP:
+            check_insn(ctx, ISA_MIPS32R6);
+            decode_opc_special3_r6(env, ctx);
+            break;
+        default:
+            check_insn(ctx, ISA_MIPS32R2);
+            gen_bshfl(ctx, op2, rt, rd);
+            break;
+        }
         break;
 #if defined(TARGET_MIPS64)
     case OPC_DEXTM ... OPC_DEXT:
@@ -15755,10 +15841,20 @@ static void decode_opc_special3(CPUMIPSState *env, DisasContext *ctx)
         gen_bitops(ctx, op1, rt, rs, sa, rd);
         break;
     case OPC_DBSHFL:
-        check_insn(ctx, ISA_MIPS64R2);
-        check_mips_64(ctx);
         op2 = MASK_DBSHFL(ctx->opcode);
-        gen_bshfl(ctx, op2, rt, rd);
+        switch (op2) {
+        case OPC_DALIGN ... OPC_DALIGN_END:
+        case OPC_DBITSWAP:
+            check_insn(ctx, ISA_MIPS32R6);
+            decode_opc_special3_r6(env, ctx);
+            break;
+        default:
+            check_insn(ctx, ISA_MIPS64R2);
+            check_mips_64(ctx);
+            op2 = MASK_DBSHFL(ctx->opcode);
+            gen_bshfl(ctx, op2, rt, rd);
+            break;
+        }
         break;
 #endif
     case OPC_RDHWR:
-- 
2.1.0