target/nios2: Split PC out of env->regs[]

It is cleaner to have a separate name for this variable.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-17-richard.henderson@linaro.org>

4 files changed, 45 insertions, 51 deletions

diff --git a/target/nios2/cpu.c b/target/nios2/cpu.c
index 9774a3b..dc15512 100644
--- a/target/nios2/cpu.c
+++ b/target/nios2/cpu.c
@@ -31,7 +31,7 @@ static void nios2_cpu_set_pc(CPUState *cs, vaddr value)
     Nios2CPU *cpu = NIOS2_CPU(cs);
     CPUNios2State *env = &cpu->env;
 
-    env->regs[R_PC] = value;
+    env->pc = value;
 }
 
 static bool nios2_cpu_has_work(CPUState *cs)
@@ -49,7 +49,7 @@ static void nios2_cpu_reset(DeviceState *dev)
     ncc->parent_reset(dev);
 
     memset(env->regs, 0, sizeof(uint32_t) * NUM_CORE_REGS);
-    env->regs[R_PC] = cpu->reset_addr;
+    env->pc = cpu->reset_addr;
 
 #if defined(CONFIG_USER_ONLY)
     /* Start in user mode with interrupts enabled. */
@@ -156,7 +156,7 @@ static int nios2_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
     if (n < 32) {          /* GP regs */
         return gdb_get_reg32(mem_buf, env->regs[n]);
     } else if (n == 32) {    /* PC */
-        return gdb_get_reg32(mem_buf, env->regs[R_PC]);
+        return gdb_get_reg32(mem_buf, env->pc);
     } else if (n < 49) {     /* Status regs */
         return gdb_get_reg32(mem_buf, env->regs[n - 1]);
     }
@@ -178,7 +178,7 @@ static int nios2_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
     if (n < 32) {            /* GP regs */
         env->regs[n] = ldl_p(mem_buf);
     } else if (n == 32) {    /* PC */
-        env->regs[R_PC] = ldl_p(mem_buf);
+        env->pc = ldl_p(mem_buf);
     } else if (n < 49) {     /* Status regs */
         env->regs[n - 1] = ldl_p(mem_buf);
     }
diff --git a/target/nios2/cpu.h b/target/nios2/cpu.h
index 09dc38a..7c48b34 100644
--- a/target/nios2/cpu.h
+++ b/target/nios2/cpu.h
@@ -59,8 +59,8 @@ struct Nios2CPUClass {
 #define NUM_GP_REGS 32
 #define NUM_CR_REGS 32
 
-/* GP regs + CR regs + PC */
-#define NUM_CORE_REGS (NUM_GP_REGS + NUM_CR_REGS + 1)
+/* GP regs + CR regs */
+#define NUM_CORE_REGS (NUM_GP_REGS + NUM_CR_REGS)
 
 /* General purpose register aliases */
 #define R_ZERO   0
@@ -130,9 +130,6 @@ struct Nios2CPUClass {
 #define CR_MPUBASE   (CR_BASE + 14)
 #define CR_MPUACC    (CR_BASE + 15)
 
-/* Other registers */
-#define R_PC         64
-
 /* Exceptions */
 #define EXCP_BREAK    0x1000
 #define EXCP_RESET    0
@@ -158,6 +155,7 @@ struct Nios2CPUClass {
 
 struct CPUArchState {
     uint32_t regs[NUM_CORE_REGS];
+    uint32_t pc;
 
 #if !defined(CONFIG_USER_ONLY)
     Nios2MMU mmu;
@@ -237,7 +235,7 @@ typedef Nios2CPU ArchCPU;
 static inline void cpu_get_tb_cpu_state(CPUNios2State *env, target_ulong *pc,
                                         target_ulong *cs_base, uint32_t *flags)
 {
-    *pc = env->regs[R_PC];
+    *pc = env->pc;
     *cs_base = 0;
     *flags = (env->regs[CR_STATUS] & (CR_STATUS_EH | CR_STATUS_U));
 }
diff --git a/target/nios2/helper.c b/target/nios2/helper.c
index 04a8831..34b3e18 100644
--- a/target/nios2/helper.c
+++ b/target/nios2/helper.c
@@ -38,7 +38,7 @@ void nios2_cpu_do_interrupt(CPUState *cs)
     case EXCP_IRQ:
         assert(env->regs[CR_STATUS] & CR_STATUS_PIE);
 
-        qemu_log_mask(CPU_LOG_INT, "interrupt at pc=%x\n", env->regs[R_PC]);
+        qemu_log_mask(CPU_LOG_INT, "interrupt at pc=%x\n", env->pc);
 
         env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
         env->regs[CR_STATUS] |= CR_STATUS_IH;
@@ -47,14 +47,13 @@ void nios2_cpu_do_interrupt(CPUState *cs)
         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 
-        env->regs[R_EA] = env->regs[R_PC] + 4;
-        env->regs[R_PC] = cpu->exception_addr;
+        env->regs[R_EA] = env->pc + 4;
+        env->pc = cpu->exception_addr;
         break;
 
     case EXCP_TLBD:
         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
-            qemu_log_mask(CPU_LOG_INT, "TLB MISS (fast) at pc=%x\n",
-                          env->regs[R_PC]);
+            qemu_log_mask(CPU_LOG_INT, "TLB MISS (fast) at pc=%x\n", env->pc);
 
             /* Fast TLB miss */
             /* Variation from the spec. Table 3-35 of the cpu reference shows
@@ -70,11 +69,10 @@ void nios2_cpu_do_interrupt(CPUState *cs)
             env->regs[CR_TLBMISC] &= ~CR_TLBMISC_DBL;
             env->regs[CR_TLBMISC] |= CR_TLBMISC_WR;
 
-            env->regs[R_EA] = env->regs[R_PC] + 4;
-            env->regs[R_PC] = cpu->fast_tlb_miss_addr;
+            env->regs[R_EA] = env->pc + 4;
+            env->pc = cpu->fast_tlb_miss_addr;
         } else {
-            qemu_log_mask(CPU_LOG_INT, "TLB MISS (double) at pc=%x\n",
-                          env->regs[R_PC]);
+            qemu_log_mask(CPU_LOG_INT, "TLB MISS (double) at pc=%x\n", env->pc);
 
             /* Double TLB miss */
             env->regs[CR_STATUS] |= CR_STATUS_EH;
@@ -85,14 +83,14 @@ void nios2_cpu_do_interrupt(CPUState *cs)
 
             env->regs[CR_TLBMISC] |= CR_TLBMISC_DBL;
 
-            env->regs[R_PC] = cpu->exception_addr;
+            env->pc = cpu->exception_addr;
         }
         break;
 
     case EXCP_TLBR:
     case EXCP_TLBW:
     case EXCP_TLBX:
-        qemu_log_mask(CPU_LOG_INT, "TLB PERM at pc=%x\n", env->regs[R_PC]);
+        qemu_log_mask(CPU_LOG_INT, "TLB PERM at pc=%x\n", env->pc);
 
         env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
         env->regs[CR_STATUS] |= CR_STATUS_EH;
@@ -105,19 +103,18 @@ void nios2_cpu_do_interrupt(CPUState *cs)
             env->regs[CR_TLBMISC] |= CR_TLBMISC_WR;
         }
 
-        env->regs[R_EA] = env->regs[R_PC] + 4;
-        env->regs[R_PC] = cpu->exception_addr;
+        env->regs[R_EA] = env->pc + 4;
+        env->pc = cpu->exception_addr;
         break;
 
     case EXCP_SUPERA:
     case EXCP_SUPERI:
     case EXCP_SUPERD:
-        qemu_log_mask(CPU_LOG_INT, "SUPERVISOR exception at pc=%x\n",
-                      env->regs[R_PC]);
+        qemu_log_mask(CPU_LOG_INT, "SUPERVISOR exception at pc=%x\n", env->pc);
 
         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
             env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
-            env->regs[R_EA] = env->regs[R_PC] + 4;
+            env->regs[R_EA] = env->pc + 4;
         }
 
         env->regs[CR_STATUS] |= CR_STATUS_EH;
@@ -126,17 +123,16 @@ void nios2_cpu_do_interrupt(CPUState *cs)
         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 
-        env->regs[R_PC] = cpu->exception_addr;
+        env->pc = cpu->exception_addr;
         break;
 
     case EXCP_ILLEGAL:
     case EXCP_TRAP:
-        qemu_log_mask(CPU_LOG_INT, "TRAP exception at pc=%x\n",
-                      env->regs[R_PC]);
+        qemu_log_mask(CPU_LOG_INT, "TRAP exception at pc=%x\n", env->pc);
 
         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
             env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
-            env->regs[R_EA] = env->regs[R_PC] + 4;
+            env->regs[R_EA] = env->pc + 4;
         }
 
         env->regs[CR_STATUS] |= CR_STATUS_EH;
@@ -145,24 +141,23 @@ void nios2_cpu_do_interrupt(CPUState *cs)
         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 
-        env->regs[R_PC] = cpu->exception_addr;
+        env->pc = cpu->exception_addr;
         break;
 
     case EXCP_BREAK:
-        qemu_log_mask(CPU_LOG_INT, "BREAK exception at pc=%x\n",
-                      env->regs[R_PC]);
+        qemu_log_mask(CPU_LOG_INT, "BREAK exception at pc=%x\n", env->pc);
         /* The semihosting instruction is "break 1".  */
         if (semihosting_enabled() &&
-            cpu_ldl_code(env, env->regs[R_PC]) == 0x003da07a)  {
+            cpu_ldl_code(env, env->pc) == 0x003da07a)  {
             qemu_log_mask(CPU_LOG_INT, "Entering semihosting\n");
-            env->regs[R_PC] += 4;
+            env->pc += 4;
             do_nios2_semihosting(env);
             break;
         }
 
         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
             env->regs[CR_BSTATUS] = env->regs[CR_STATUS];
-            env->regs[R_BA] = env->regs[R_PC] + 4;
+            env->regs[R_BA] = env->pc + 4;
         }
 
         env->regs[CR_STATUS] |= CR_STATUS_EH;
@@ -171,7 +166,7 @@ void nios2_cpu_do_interrupt(CPUState *cs)
         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 
-        env->regs[R_PC] = cpu->exception_addr;
+        env->pc = cpu->exception_addr;
         break;
 
     default:
diff --git a/target/nios2/translate.c b/target/nios2/translate.c
index d61e349..226bd9e 100644
--- a/target/nios2/translate.c
+++ b/target/nios2/translate.c
@@ -104,6 +104,7 @@ typedef struct DisasContext {
 } DisasContext;
 
 static TCGv cpu_R[NUM_CORE_REGS];
+static TCGv cpu_pc;
 
 typedef struct Nios2Instruction {
     void     (*handler)(DisasContext *dc, uint32_t code, uint32_t flags);
@@ -144,7 +145,7 @@ static void t_gen_helper_raise_exception(DisasContext *dc,
 {
     TCGv_i32 tmp = tcg_const_i32(index);
 
-    tcg_gen_movi_tl(cpu_R[R_PC], dc->pc);
+    tcg_gen_movi_tl(cpu_pc, dc->pc);
     gen_helper_raise_exception(cpu_env, tmp);
     tcg_temp_free_i32(tmp);
     dc->base.is_jmp = DISAS_NORETURN;
@@ -156,10 +157,10 @@ static void gen_goto_tb(DisasContext *dc, int n, uint32_t dest)
 
     if (translator_use_goto_tb(&dc->base, dest)) {
         tcg_gen_goto_tb(n);
-        tcg_gen_movi_tl(cpu_R[R_PC], dest);
+        tcg_gen_movi_tl(cpu_pc, dest);
         tcg_gen_exit_tb(tb, n);
     } else {
-        tcg_gen_movi_tl(cpu_R[R_PC], dest);
+        tcg_gen_movi_tl(cpu_pc, dest);
         tcg_gen_exit_tb(NULL, 0);
     }
 }
@@ -391,7 +392,7 @@ static void eret(DisasContext *dc, uint32_t code, uint32_t flags)
     }
 
     tcg_gen_mov_tl(cpu_R[CR_STATUS], cpu_R[CR_ESTATUS]);
-    tcg_gen_mov_tl(cpu_R[R_PC], cpu_R[R_EA]);
+    tcg_gen_mov_tl(cpu_pc, cpu_R[R_EA]);
 
     dc->base.is_jmp = DISAS_JUMP;
 }
@@ -399,7 +400,7 @@ static void eret(DisasContext *dc, uint32_t code, uint32_t flags)
 /* PC <- ra */
 static void ret(DisasContext *dc, uint32_t code, uint32_t flags)
 {
-    tcg_gen_mov_tl(cpu_R[R_PC], cpu_R[R_RA]);
+    tcg_gen_mov_tl(cpu_pc, cpu_R[R_RA]);
 
     dc->base.is_jmp = DISAS_JUMP;
 }
@@ -407,7 +408,7 @@ static void ret(DisasContext *dc, uint32_t code, uint32_t flags)
 /* PC <- ba */
 static void bret(DisasContext *dc, uint32_t code, uint32_t flags)
 {
-    tcg_gen_mov_tl(cpu_R[R_PC], cpu_R[R_BA]);
+    tcg_gen_mov_tl(cpu_pc, cpu_R[R_BA]);
 
     dc->base.is_jmp = DISAS_JUMP;
 }
@@ -417,7 +418,7 @@ static void jmp(DisasContext *dc, uint32_t code, uint32_t flags)
 {
     R_TYPE(instr, code);
 
-    tcg_gen_mov_tl(cpu_R[R_PC], load_gpr(dc, instr.a));
+    tcg_gen_mov_tl(cpu_pc, load_gpr(dc, instr.a));
 
     dc->base.is_jmp = DISAS_JUMP;
 }
@@ -440,7 +441,7 @@ static void callr(DisasContext *dc, uint32_t code, uint32_t flags)
 {
     R_TYPE(instr, code);
 
-    tcg_gen_mov_tl(cpu_R[R_PC], load_gpr(dc, instr.a));
+    tcg_gen_mov_tl(cpu_pc, load_gpr(dc, instr.a));
     tcg_gen_movi_tl(cpu_R[R_RA], dc->base.pc_next);
 
     dc->base.is_jmp = DISAS_JUMP;
@@ -742,7 +743,7 @@ illegal_op:
     t_gen_helper_raise_exception(dc, EXCP_ILLEGAL);
 }
 
-static const char * const regnames[] = {
+static const char * const regnames[NUM_CORE_REGS] = {
     "zero",       "at",         "r2",         "r3",
     "r4",         "r5",         "r6",         "r7",
     "r8",         "r9",         "r10",        "r11",
@@ -759,7 +760,6 @@ static const char * const regnames[] = {
     "reserved6",  "reserved7",  "reserved8",  "reserved9",
     "reserved10", "reserved11", "reserved12", "reserved13",
     "reserved14", "reserved15", "reserved16", "reserved17",
-    "rpc"
 };
 
 #include "exec/gen-icount.h"
@@ -827,7 +827,7 @@ static void nios2_tr_tb_stop(DisasContextBase *dcbase, CPUState *cs)
     case DISAS_TOO_MANY:
     case DISAS_UPDATE:
         /* Save the current PC back into the CPU register */
-        tcg_gen_movi_tl(cpu_R[R_PC], dc->base.pc_next);
+        tcg_gen_movi_tl(cpu_pc, dc->base.pc_next);
         tcg_gen_exit_tb(NULL, 0);
         break;
 
@@ -877,8 +877,7 @@ void nios2_cpu_dump_state(CPUState *cs, FILE *f, int flags)
         return;
     }
 
-    qemu_fprintf(f, "IN: PC=%x %s\n",
-                 env->regs[R_PC], lookup_symbol(env->regs[R_PC]));
+    qemu_fprintf(f, "IN: PC=%x %s\n", env->pc, lookup_symbol(env->pc));
 
     for (i = 0; i < NUM_CORE_REGS; i++) {
         qemu_fprintf(f, "%9s=%8.8x ", regnames[i], env->regs[i]);
@@ -904,10 +903,12 @@ void nios2_tcg_init(void)
                                       offsetof(CPUNios2State, regs[i]),
                                       regnames[i]);
     }
+    cpu_pc = tcg_global_mem_new(cpu_env,
+                                offsetof(CPUNios2State, pc), "pc");
 }
 
 void restore_state_to_opc(CPUNios2State *env, TranslationBlock *tb,
                           target_ulong *data)
 {
-    env->regs[R_PC] = data[0];
+    env->pc = data[0];
 }