[Qemu-devel] [PATCH v4 06/21] target-mips: split decode_opc_special* into *_r6 and *_legacy

[Leon Alrae]

For better code readability and to avoid 'if' statements for all R6 and preR6
instructions whose opcodes are the same - decode_opc_special* functions are
split into functions with _r6 and _legacy suffixes.

*_r6 functions will contain instructions which were introduced in R6.
*_legacy functions will contain instructions which were removed in R6.

Signed-off-by: Leon Alrae <address@hidden>
Reviewed-by: Aurelien Jarno <address@hidden>
---
v2:
* imm contains shifted value
---
 target-mips/translate.c | 228 +++++++++++++++++++++++++++++++++---------------
 1 file changed, 160 insertions(+), 68 deletions(-)

diff --git a/target-mips/translate.c b/target-mips/translate.c
index 5b8f762..0c64aeb 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -14482,6 +14482,70 @@ static void gen_mipsdsp_accinsn(DisasContext *ctx, 
uint32_t op1, uint32_t op2,
 
 /* End MIPSDSP functions. */
 
+static void decode_opc_special_r6(CPUMIPSState *env, DisasContext *ctx)
+{
+    int rs, rt, rd;
+    uint32_t op1;
+
+    rs = (ctx->opcode >> 21) & 0x1f;
+    rt = (ctx->opcode >> 16) & 0x1f;
+    rd = (ctx->opcode >> 11) & 0x1f;
+
+    op1 = MASK_SPECIAL(ctx->opcode);
+    switch (op1) {
+    case OPC_SELEQZ:
+    case OPC_SELNEZ:
+        gen_cond_move(ctx, op1, rd, rs, rt);
+        break;
+    default:            /* Invalid */
+        MIPS_INVAL("special_r6");
+        generate_exception(ctx, EXCP_RI);
+        break;
+    }
+}
+
+static void decode_opc_special_legacy(CPUMIPSState *env, DisasContext *ctx)
+{
+    int rs, rt, rd;
+    uint32_t op1;
+
+    rs = (ctx->opcode >> 21) & 0x1f;
+    rt = (ctx->opcode >> 16) & 0x1f;
+    rd = (ctx->opcode >> 11) & 0x1f;
+
+    op1 = MASK_SPECIAL(ctx->opcode);
+    switch (op1) {
+    case OPC_MOVN:         /* Conditional move */
+    case OPC_MOVZ:
+        check_insn(ctx, ISA_MIPS4 | ISA_MIPS32 |
+                   INSN_LOONGSON2E | INSN_LOONGSON2F);
+        gen_cond_move(ctx, op1, rd, rs, rt);
+        break;
+    case OPC_MFHI:          /* Move from HI/LO */
+    case OPC_MFLO:
+        gen_HILO(ctx, op1, rs & 3, rd);
+        break;
+    case OPC_MTHI:
+    case OPC_MTLO:          /* Move to HI/LO */
+        gen_HILO(ctx, op1, rd & 3, rs);
+        break;
+    case OPC_MOVCI:
+        check_insn(ctx, ISA_MIPS4 | ISA_MIPS32);
+        if (env->CP0_Config1 & (1 << CP0C1_FP)) {
+            check_cp1_enabled(ctx);
+            gen_movci(ctx, rd, rs, (ctx->opcode >> 18) & 0x7,
+                      (ctx->opcode >> 16) & 1);
+        } else {
+            generate_exception_err(ctx, EXCP_CpU, 1);
+        }
+        break;
+    default:            /* Invalid */
+        MIPS_INVAL("special_legacy");
+        generate_exception(ctx, EXCP_RI);
+        break;
+    }
+}
+
 static void decode_opc_special(CPUMIPSState *env, DisasContext *ctx)
 {
     int rs, rt, rd, sa;
@@ -14514,18 +14578,6 @@ static void decode_opc_special(CPUMIPSState *env, 
DisasContext *ctx)
             break;
         }
         break;
-    case OPC_MOVN:         /* Conditional move */
-    case OPC_MOVZ:
-        check_insn_opc_removed(ctx, ISA_MIPS32R6);
-        check_insn(ctx, ISA_MIPS4 | ISA_MIPS32 |
-                   INSN_LOONGSON2E | INSN_LOONGSON2F);
-        gen_cond_move(ctx, op1, rd, rs, rt);
-        break;
-    case OPC_SELEQZ:
-    case OPC_SELNEZ:
-        check_insn(ctx, ISA_MIPS32R6);
-        gen_cond_move(ctx, op1, rd, rs, rt);
-        break;
     case OPC_ADD ... OPC_SUBU:
         gen_arith(ctx, op1, rd, rs, rt);
         break;
@@ -14580,16 +14632,6 @@ static void decode_opc_special(CPUMIPSState *env, 
DisasContext *ctx)
     case OPC_TNE:
         gen_trap(ctx, op1, rs, rt, -1);
         break;
-    case OPC_MFHI:          /* Move from HI/LO */
-    case OPC_MFLO:
-        check_insn_opc_removed(ctx, ISA_MIPS32R6);
-        gen_HILO(ctx, op1, rs & 3, rd);
-        break;
-    case OPC_MTHI:
-    case OPC_MTLO:          /* Move to HI/LO */
-        check_insn_opc_removed(ctx, ISA_MIPS32R6);
-        gen_HILO(ctx, op1, rd & 3, rs);
-        break;
     case OPC_PMON:          /* Pmon entry point, also R4010 selsl */
 #ifdef MIPS_STRICT_STANDARD
         MIPS_INVAL("PMON / selsl");
@@ -14619,18 +14661,6 @@ static void decode_opc_special(CPUMIPSState *env, 
DisasContext *ctx)
         /* Treat as NOP. */
         break;
 
-    case OPC_MOVCI:
-        check_insn_opc_removed(ctx, ISA_MIPS32R6);
-        check_insn(ctx, ISA_MIPS4 | ISA_MIPS32);
-        if (ctx->CP0_Config1 & (1 << CP0C1_FP)) {
-            check_cp1_enabled(ctx);
-            gen_movci(ctx, rd, rs, (ctx->opcode >> 18) & 0x7,
-                      (ctx->opcode >> 16) & 1);
-        } else {
-            generate_exception_err(ctx, EXCP_CpU, 1);
-        }
-        break;
-
 #if defined(TARGET_MIPS64)
         /* MIPS64 specific opcodes */
     case OPC_DSLL:
@@ -14712,14 +14742,29 @@ static void decode_opc_special(CPUMIPSState *env, 
DisasContext *ctx)
         gen_muldiv(ctx, op1, 0, rs, rt);
         break;
 #endif
+    default:
+        if (ctx->insn_flags & ISA_MIPS32R6) {
+            decode_opc_special_r6(env, ctx);
+        } else {
+            decode_opc_special_legacy(env, ctx);
+        }
+    }
+}
+
+static void decode_opc_special2_r6(CPUMIPSState *env, DisasContext *ctx)
+{
+    uint32_t op1;
+
+    op1 = MASK_SPECIAL2(ctx->opcode);
+    switch (op1) {
     default:            /* Invalid */
-        MIPS_INVAL("special");
+        MIPS_INVAL("special2_r6");
         generate_exception(ctx, EXCP_RI);
         break;
     }
 }
 
-static void decode_opc_special2(CPUMIPSState *env, DisasContext *ctx)
+static void decode_opc_special2_legacy(CPUMIPSState *env, DisasContext *ctx)
 {
     int rs, rt, rd;
     uint32_t op1;
@@ -14732,14 +14777,30 @@ static void decode_opc_special2(CPUMIPSState *env, 
DisasContext *ctx)
     switch (op1) {
     case OPC_MADD ... OPC_MADDU: /* Multiply and add/sub */
     case OPC_MSUB ... OPC_MSUBU:
-        check_insn_opc_removed(ctx, ISA_MIPS32R6);
         check_insn(ctx, ISA_MIPS32);
         gen_muldiv(ctx, op1, rd & 3, rs, rt);
         break;
     case OPC_MUL:
-        check_insn_opc_removed(ctx, ISA_MIPS32R6);
         gen_arith(ctx, op1, rd, rs, rt);
         break;
+    default:            /* Invalid */
+        MIPS_INVAL("special2_legacy");
+        generate_exception(ctx, EXCP_RI);
+        break;
+    }
+}
+
+static void decode_opc_special2(CPUMIPSState *env, DisasContext *ctx)
+{
+    int rs, rt, rd;
+    uint32_t op1;
+
+    rs = (ctx->opcode >> 21) & 0x1f;
+    rt = (ctx->opcode >> 16) & 0x1f;
+    rd = (ctx->opcode >> 11) & 0x1f;
+
+    op1 = MASK_SPECIAL2(ctx->opcode);
+    switch (op1) {
     case OPC_CLO:
     case OPC_CLZ:
         check_insn(ctx, ISA_MIPS32);
@@ -14783,30 +14844,78 @@ static void decode_opc_special2(CPUMIPSState *env, 
DisasContext *ctx)
         gen_loongson_integer(ctx, op1, rd, rs, rt);
         break;
 #endif
+    default:
+        if (ctx->insn_flags & ISA_MIPS32R6) {
+            decode_opc_special2_r6(env, ctx);
+        } else {
+            decode_opc_special2_legacy(env, ctx);
+        }
+    }
+}
+
+static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
+{
+    int rs, rt;
+    uint32_t op1;
+    int16_t imm;
+
+    rs = (ctx->opcode >> 21) & 0x1f;
+    rt = (ctx->opcode >> 16) & 0x1f;
+    imm = (int16_t)ctx->opcode >> 7;
+
+    op1 = MASK_SPECIAL3(ctx->opcode);
+    switch (op1) {
+    case R6_OPC_SC:
+        gen_st_cond(ctx, op1, rt, rs, imm);
+        break;
+    case R6_OPC_LL:
+        gen_ld(ctx, op1, rt, rs, imm);
+        break;
     default:            /* Invalid */
-        MIPS_INVAL("special2");
+        MIPS_INVAL("special3_r6");
         generate_exception(ctx, EXCP_RI);
         break;
     }
 }
+
+static void decode_opc_special3_legacy(CPUMIPSState *env, DisasContext *ctx)
+{
+    uint32_t op1;
+#if defined(TARGET_MIPS64)
+    int rd = (ctx->opcode >> 11) & 0x1f;
+    int rs = (ctx->opcode >> 21) & 0x1f;
+    int rt = (ctx->opcode >> 16) & 0x1f;
+#endif
+
+    op1 = MASK_SPECIAL3(ctx->opcode);
+    switch (op1) {
+#if defined(TARGET_MIPS64)
+    case OPC_DDIV_G_2E ... OPC_DDIVU_G_2E:
+    case OPC_DMULT_G_2E ... OPC_DMULTU_G_2E:
+    case OPC_DMOD_G_2E ... OPC_DMODU_G_2E:
+        check_insn(ctx, INSN_LOONGSON2E);
+        gen_loongson_integer(ctx, op1, rd, rs, rt);
+        break;
+#endif
+    default:            /* Invalid */
+        MIPS_INVAL("special3_legacy");
+        generate_exception(ctx, EXCP_RI);
+        break;
+    }
+}
+
 static void decode_opc_special3(CPUMIPSState *env, DisasContext *ctx)
 {
     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;
 
     op1 = MASK_SPECIAL3(ctx->opcode);
     switch (op1) {
-    case R6_OPC_LL:
-        check_insn(ctx, ISA_MIPS32R6);
-        gen_ld(ctx, op1, rt, rs, imm >> 7);
-        break;
     case OPC_EXT:
     case OPC_INS:
         check_insn(ctx, ISA_MIPS32R2);
@@ -15111,19 +15220,6 @@ static void decode_opc_special3(CPUMIPSState *env, 
DisasContext *ctx)
             break;
         }
         break;
-    case R6_OPC_SC: /* OPC_DMOD_G_2E */
-        if (ctx->insn_flags & ISA_MIPS32R6) {
-            gen_st_cond(ctx, op1, rt, rs, imm >> 7);
-        } else {
-#if defined(TARGET_MIPS64)
-            check_insn(ctx, INSN_LOONGSON2E);
-            gen_loongson_integer(ctx, op1, rd, rs, rt);
-#else
-            /* Invalid in MIPS32 */
-            generate_exception(ctx, EXCP_RI);
-#endif
-        }
-        break;
 #if defined(TARGET_MIPS64)
     case OPC_DEXTM ... OPC_DEXT:
     case OPC_DINSM ... OPC_DINS:
@@ -15137,12 +15233,6 @@ static void decode_opc_special3(CPUMIPSState *env, 
DisasContext *ctx)
         op2 = MASK_DBSHFL(ctx->opcode);
         gen_bshfl(ctx, op2, rt, rd);
         break;
-    case OPC_DDIV_G_2E ... OPC_DDIVU_G_2E:
-    case OPC_DMULT_G_2E ... OPC_DMULTU_G_2E:
-    case OPC_DMODU_G_2E:
-        check_insn(ctx, INSN_LOONGSON2E);
-        gen_loongson_integer(ctx, op1, rd, rs, rt);
-        break;
     case OPC_ABSQ_S_QH_DSP:
         op2 = MASK_ABSQ_S_QH(ctx->opcode);
         switch (op2) {
@@ -15374,10 +15464,12 @@ static void decode_opc_special3(CPUMIPSState *env, 
DisasContext *ctx)
         gen_mipsdsp_shift(ctx, op1, rd, rs, rt);
         break;
 #endif
-    default:            /* Invalid */
-        MIPS_INVAL("special3");
-        generate_exception(ctx, EXCP_RI);
-        break;
+    default:
+        if (ctx->insn_flags & ISA_MIPS32R6) {
+            decode_opc_special3_r6(env, ctx);
+        } else {
+            decode_opc_special3_legacy(env, ctx);
+        }
     }
 }
 
-- 
2.1.0