tcg: define tcg_init_ctx and make tcg_ctx a pointer

Groundwork for supporting multiple TCG contexts.

The core of this patch is this change to tcg/tcg.h:

> -extern TCGContext tcg_ctx;
> +extern TCGContext tcg_init_ctx;
> +extern TCGContext *tcg_ctx;

Note that for now we set *tcg_ctx to whatever TCGContext is passed
to tcg_context_init -- in this case &tcg_init_ctx.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

3 files changed, 46 insertions, 43 deletions

diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 8c7668de60..ba603281d3 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -48,7 +48,7 @@ extern TCGv_i32 TCGV_HIGH_link_error(TCGv_i64);
 
 static inline TCGOp *tcg_emit_op(TCGOpcode opc)
 {
-    TCGContext *ctx = &tcg_ctx;
+    TCGContext *ctx = tcg_ctx;
     int oi = ctx->gen_next_op_idx;
     int ni = oi + 1;
     int pi = oi - 1;
@@ -121,7 +121,7 @@ void tcg_gen_op6(TCGOpcode opc, TCGArg a1, TCGArg a2, TCGArg a3,
 
 void tcg_gen_mb(TCGBar mb_type)
 {
-    if (tcg_ctx.tb_cflags & CF_PARALLEL) {
+    if (tcg_ctx->tb_cflags & CF_PARALLEL) {
         tcg_gen_op1(INDEX_op_mb, mb_type);
     }
 }
@@ -2552,8 +2552,8 @@ void tcg_gen_goto_tb(unsigned idx)
     tcg_debug_assert(idx <= 1);
 #ifdef CONFIG_DEBUG_TCG
     /* Verify that we havn't seen this numbered exit before.  */
-    tcg_debug_assert((tcg_ctx.goto_tb_issue_mask & (1 << idx)) == 0);
-    tcg_ctx.goto_tb_issue_mask |= 1 << idx;
+    tcg_debug_assert((tcg_ctx->goto_tb_issue_mask & (1 << idx)) == 0);
+    tcg_ctx->goto_tb_issue_mask |= 1 << idx;
 #endif
     tcg_gen_op1i(INDEX_op_goto_tb, idx);
 }
@@ -2562,7 +2562,7 @@ void tcg_gen_lookup_and_goto_ptr(void)
 {
     if (TCG_TARGET_HAS_goto_ptr && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
         TCGv_ptr ptr = tcg_temp_new_ptr();
-        gen_helper_lookup_tb_ptr(ptr, tcg_ctx.tcg_env);
+        gen_helper_lookup_tb_ptr(ptr, tcg_ctx->tcg_env);
         tcg_gen_op1i(INDEX_op_goto_ptr, tcgv_ptr_arg(ptr));
         tcg_temp_free_ptr(ptr);
     } else {
@@ -2648,7 +2648,7 @@ void tcg_gen_qemu_ld_i32(TCGv_i32 val, TCGv addr, TCGArg idx, TCGMemOp memop)
 {
     tcg_gen_req_mo(TCG_MO_LD_LD | TCG_MO_ST_LD);
     memop = tcg_canonicalize_memop(memop, 0, 0);
-    trace_guest_mem_before_tcg(tcg_ctx.cpu, tcg_ctx.tcg_env,
+    trace_guest_mem_before_tcg(tcg_ctx->cpu, tcg_ctx->tcg_env,
                                addr, trace_mem_get_info(memop, 0));
     gen_ldst_i32(INDEX_op_qemu_ld_i32, val, addr, memop, idx);
 }
@@ -2657,7 +2657,7 @@ void tcg_gen_qemu_st_i32(TCGv_i32 val, TCGv addr, TCGArg idx, TCGMemOp memop)
 {
     tcg_gen_req_mo(TCG_MO_LD_ST | TCG_MO_ST_ST);
     memop = tcg_canonicalize_memop(memop, 0, 1);
-    trace_guest_mem_before_tcg(tcg_ctx.cpu, tcg_ctx.tcg_env,
+    trace_guest_mem_before_tcg(tcg_ctx->cpu, tcg_ctx->tcg_env,
                                addr, trace_mem_get_info(memop, 1));
     gen_ldst_i32(INDEX_op_qemu_st_i32, val, addr, memop, idx);
 }
@@ -2676,7 +2676,7 @@ void tcg_gen_qemu_ld_i64(TCGv_i64 val, TCGv addr, TCGArg idx, TCGMemOp memop)
     }
 
     memop = tcg_canonicalize_memop(memop, 1, 0);
-    trace_guest_mem_before_tcg(tcg_ctx.cpu, tcg_ctx.tcg_env,
+    trace_guest_mem_before_tcg(tcg_ctx->cpu, tcg_ctx->tcg_env,
                                addr, trace_mem_get_info(memop, 0));
     gen_ldst_i64(INDEX_op_qemu_ld_i64, val, addr, memop, idx);
 }
@@ -2690,7 +2690,7 @@ void tcg_gen_qemu_st_i64(TCGv_i64 val, TCGv addr, TCGArg idx, TCGMemOp memop)
     }
 
     memop = tcg_canonicalize_memop(memop, 1, 1);
-    trace_guest_mem_before_tcg(tcg_ctx.cpu, tcg_ctx.tcg_env,
+    trace_guest_mem_before_tcg(tcg_ctx->cpu, tcg_ctx->tcg_env,
                                addr, trace_mem_get_info(memop, 1));
     gen_ldst_i64(INDEX_op_qemu_st_i64, val, addr, memop, idx);
 }
@@ -2780,7 +2780,7 @@ void tcg_gen_atomic_cmpxchg_i32(TCGv_i32 retv, TCGv addr, TCGv_i32 cmpv,
 {
     memop = tcg_canonicalize_memop(memop, 0, 0);
 
-    if (!(tcg_ctx.tb_cflags & CF_PARALLEL)) {
+    if (!(tcg_ctx->tb_cflags & CF_PARALLEL)) {
         TCGv_i32 t1 = tcg_temp_new_i32();
         TCGv_i32 t2 = tcg_temp_new_i32();
 
@@ -2806,11 +2806,11 @@ void tcg_gen_atomic_cmpxchg_i32(TCGv_i32 retv, TCGv addr, TCGv_i32 cmpv,
 #ifdef CONFIG_SOFTMMU
         {
             TCGv_i32 oi = tcg_const_i32(make_memop_idx(memop & ~MO_SIGN, idx));
-            gen(retv, tcg_ctx.tcg_env, addr, cmpv, newv, oi);
+            gen(retv, tcg_ctx->tcg_env, addr, cmpv, newv, oi);
             tcg_temp_free_i32(oi);
         }
 #else
-        gen(retv, tcg_ctx.tcg_env, addr, cmpv, newv);
+        gen(retv, tcg_ctx->tcg_env, addr, cmpv, newv);
 #endif
 
         if (memop & MO_SIGN) {
@@ -2824,7 +2824,7 @@ void tcg_gen_atomic_cmpxchg_i64(TCGv_i64 retv, TCGv addr, TCGv_i64 cmpv,
 {
     memop = tcg_canonicalize_memop(memop, 1, 0);
 
-    if (!(tcg_ctx.tb_cflags & CF_PARALLEL)) {
+    if (!(tcg_ctx->tb_cflags & CF_PARALLEL)) {
         TCGv_i64 t1 = tcg_temp_new_i64();
         TCGv_i64 t2 = tcg_temp_new_i64();
 
@@ -2851,14 +2851,14 @@ void tcg_gen_atomic_cmpxchg_i64(TCGv_i64 retv, TCGv addr, TCGv_i64 cmpv,
 #ifdef CONFIG_SOFTMMU
         {
             TCGv_i32 oi = tcg_const_i32(make_memop_idx(memop, idx));
-            gen(retv, tcg_ctx.tcg_env, addr, cmpv, newv, oi);
+            gen(retv, tcg_ctx->tcg_env, addr, cmpv, newv, oi);
             tcg_temp_free_i32(oi);
         }
 #else
-        gen(retv, tcg_ctx.tcg_env, addr, cmpv, newv);
+        gen(retv, tcg_ctx->tcg_env, addr, cmpv, newv);
 #endif
 #else
-        gen_helper_exit_atomic(tcg_ctx.tcg_env);
+        gen_helper_exit_atomic(tcg_ctx->tcg_env);
         /* Produce a result, so that we have a well-formed opcode stream
            with respect to uses of the result in the (dead) code following.  */
         tcg_gen_movi_i64(retv, 0);
@@ -2914,11 +2914,11 @@ static void do_atomic_op_i32(TCGv_i32 ret, TCGv addr, TCGv_i32 val,
 #ifdef CONFIG_SOFTMMU
     {
         TCGv_i32 oi = tcg_const_i32(make_memop_idx(memop & ~MO_SIGN, idx));
-        gen(ret, tcg_ctx.tcg_env, addr, val, oi);
+        gen(ret, tcg_ctx->tcg_env, addr, val, oi);
         tcg_temp_free_i32(oi);
     }
 #else
-    gen(ret, tcg_ctx.tcg_env, addr, val);
+    gen(ret, tcg_ctx->tcg_env, addr, val);
 #endif
 
     if (memop & MO_SIGN) {
@@ -2959,14 +2959,14 @@ static void do_atomic_op_i64(TCGv_i64 ret, TCGv addr, TCGv_i64 val,
 #ifdef CONFIG_SOFTMMU
         {
             TCGv_i32 oi = tcg_const_i32(make_memop_idx(memop & ~MO_SIGN, idx));
-            gen(ret, tcg_ctx.tcg_env, addr, val, oi);
+            gen(ret, tcg_ctx->tcg_env, addr, val, oi);
             tcg_temp_free_i32(oi);
         }
 #else
-        gen(ret, tcg_ctx.tcg_env, addr, val);
+        gen(ret, tcg_ctx->tcg_env, addr, val);
 #endif
 #else
-        gen_helper_exit_atomic(tcg_ctx.tcg_env);
+        gen_helper_exit_atomic(tcg_ctx->tcg_env);
         /* Produce a result, so that we have a well-formed opcode stream
            with respect to uses of the result in the (dead) code following.  */
         tcg_gen_movi_i64(ret, 0);
@@ -3001,7 +3001,7 @@ static void * const table_##NAME[16] = {                                \
 void tcg_gen_atomic_##NAME##_i32                                        \
     (TCGv_i32 ret, TCGv addr, TCGv_i32 val, TCGArg idx, TCGMemOp memop) \
 {                                                                       \
-    if (tcg_ctx.tb_cflags & CF_PARALLEL) {                              \
+    if (tcg_ctx->tb_cflags & CF_PARALLEL) {                             \
         do_atomic_op_i32(ret, addr, val, idx, memop, table_##NAME);     \
     } else {                                                            \
         do_nonatomic_op_i32(ret, addr, val, idx, memop, NEW,            \
@@ -3011,7 +3011,7 @@ void tcg_gen_atomic_##NAME##_i32                                        \
 void tcg_gen_atomic_##NAME##_i64                                        \
     (TCGv_i64 ret, TCGv addr, TCGv_i64 val, TCGArg idx, TCGMemOp memop) \
 {                                                                       \
-    if (tcg_ctx.tb_cflags & CF_PARALLEL) {                              \
+    if (tcg_ctx->tb_cflags & CF_PARALLEL) {                             \
         do_atomic_op_i64(ret, addr, val, idx, memop, table_##NAME);     \
     } else {                                                            \
         do_nonatomic_op_i64(ret, addr, val, idx, memop, NEW,            \
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 3a73912827..62f418ac8a 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -243,7 +243,7 @@ static void tcg_out_label(TCGContext *s, TCGLabel *l, tcg_insn_unit *ptr)
 
 TCGLabel *gen_new_label(void)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     TCGLabel *l = tcg_malloc(sizeof(TCGLabel));
 
     *l = (TCGLabel){
@@ -382,6 +382,8 @@ void tcg_context_init(TCGContext *s)
     for (; i < ARRAY_SIZE(tcg_target_reg_alloc_order); ++i) {
         indirect_reg_alloc_order[i] = tcg_target_reg_alloc_order[i];
     }
+
+    tcg_ctx = s;
 }
 
 /*
@@ -522,7 +524,7 @@ void tcg_set_frame(TCGContext *s, TCGReg reg, intptr_t start, intptr_t size)
 
 TCGv_i32 tcg_global_reg_new_i32(TCGReg reg, const char *name)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     TCGTemp *t;
 
     if (tcg_regset_test_reg(s->reserved_regs, reg)) {
@@ -534,7 +536,7 @@ TCGv_i32 tcg_global_reg_new_i32(TCGReg reg, const char *name)
 
 TCGv_i64 tcg_global_reg_new_i64(TCGReg reg, const char *name)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     TCGTemp *t;
 
     if (tcg_regset_test_reg(s->reserved_regs, reg)) {
@@ -547,7 +549,7 @@ TCGv_i64 tcg_global_reg_new_i64(TCGReg reg, const char *name)
 TCGTemp *tcg_global_mem_new_internal(TCGType type, TCGv_ptr base,
                                      intptr_t offset, const char *name)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     TCGTemp *base_ts = tcgv_ptr_temp(base);
     TCGTemp *ts = tcg_global_alloc(s);
     int indirect_reg = 0, bigendian = 0;
@@ -602,7 +604,7 @@ TCGTemp *tcg_global_mem_new_internal(TCGType type, TCGv_ptr base,
 
 static TCGTemp *tcg_temp_new_internal(TCGType type, int temp_local)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     TCGTemp *ts;
     int idx, k;
 
@@ -659,7 +661,7 @@ TCGv_i64 tcg_temp_new_internal_i64(int temp_local)
 
 static void tcg_temp_free_internal(TCGTemp *ts)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     int k, idx;
 
 #if defined(CONFIG_DEBUG_TCG)
@@ -723,13 +725,13 @@ TCGv_i64 tcg_const_local_i64(int64_t val)
 #if defined(CONFIG_DEBUG_TCG)
 void tcg_clear_temp_count(void)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     s->temps_in_use = 0;
 }
 
 int tcg_check_temp_count(void)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     if (s->temps_in_use) {
         /* Clear the count so that we don't give another
          * warning immediately next time around.
@@ -969,7 +971,7 @@ bool tcg_op_supported(TCGOpcode op)
    and endian swap in tcg_reg_alloc_call(). */
 void tcg_gen_callN(void *func, TCGTemp *ret, int nargs, TCGTemp **args)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     int i, real_args, nb_rets, pi;
     unsigned sizemask, flags;
     TCGHelperInfo *info;
@@ -2908,7 +2910,7 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
 #ifdef CONFIG_PROFILER
 void tcg_dump_info(FILE *f, fprintf_function cpu_fprintf)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     int64_t tb_count = s->tb_count;
     int64_t tb_div_count = tb_count ? tb_count : 1;
     int64_t tot = s->interm_time + s->code_time;
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 76324c9ad6..17fd146557 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -688,12 +688,13 @@ struct TCGContext {
     target_ulong gen_insn_data[TCG_MAX_INSNS][TARGET_INSN_START_WORDS];
 };
 
-extern TCGContext tcg_ctx;
+extern TCGContext tcg_init_ctx;
+extern TCGContext *tcg_ctx;
 
 static inline size_t temp_idx(TCGTemp *ts)
 {
-    ptrdiff_t n = ts - tcg_ctx.temps;
-    tcg_debug_assert(n >= 0 && n < tcg_ctx.nb_temps);
+    ptrdiff_t n = ts - tcg_ctx->temps;
+    tcg_debug_assert(n >= 0 && n < tcg_ctx->nb_temps);
     return n;
 }
 
@@ -713,7 +714,7 @@ static inline TCGTemp *arg_temp(TCGArg a)
 static inline TCGTemp *tcgv_i32_temp(TCGv_i32 v)
 {
     uintptr_t o = (uintptr_t)v;
-    TCGTemp *t = (void *)&tcg_ctx + o;
+    TCGTemp *t = (void *)tcg_ctx + o;
     tcg_debug_assert(offsetof(TCGContext, temps[temp_idx(t)]) == o);
     return t;
 }
@@ -746,7 +747,7 @@ static inline TCGArg tcgv_ptr_arg(TCGv_ptr v)
 static inline TCGv_i32 temp_tcgv_i32(TCGTemp *t)
 {
     (void)temp_idx(t); /* trigger embedded assert */
-    return (TCGv_i32)((void *)t - (void *)&tcg_ctx);
+    return (TCGv_i32)((void *)t - (void *)tcg_ctx);
 }
 
 static inline TCGv_i64 temp_tcgv_i64(TCGTemp *t)
@@ -773,13 +774,13 @@ static inline TCGv_i32 TCGV_HIGH(TCGv_i64 t)
 
 static inline void tcg_set_insn_param(int op_idx, int arg, TCGArg v)
 {
-    tcg_ctx.gen_op_buf[op_idx].args[arg] = v;
+    tcg_ctx->gen_op_buf[op_idx].args[arg] = v;
 }
 
 /* The number of opcodes emitted so far.  */
 static inline int tcg_op_buf_count(void)
 {
-    return tcg_ctx.gen_next_op_idx;
+    return tcg_ctx->gen_next_op_idx;
 }
 
 /* Test for whether to terminate the TB for using too many opcodes.  */
@@ -798,7 +799,7 @@ TranslationBlock *tcg_tb_alloc(TCGContext *s);
 /* Called with tb_lock held.  */
 static inline void *tcg_malloc(int size)
 {
-    TCGContext *s = &tcg_ctx;
+    TCGContext *s = tcg_ctx;
     uint8_t *ptr, *ptr_end;
 
     /* ??? This is a weak placeholder for minimum malloc alignment.  */
@@ -807,7 +808,7 @@ static inline void *tcg_malloc(int size)
     ptr = s->pool_cur;
     ptr_end = ptr + size;
     if (unlikely(ptr_end > s->pool_end)) {
-        return tcg_malloc_internal(&tcg_ctx, size);
+        return tcg_malloc_internal(tcg_ctx, size);
     } else {
         s->pool_cur = ptr_end;
         return ptr;
@@ -1147,7 +1148,7 @@ static inline unsigned get_mmuidx(TCGMemOpIdx oi)
 uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr);
 #else
 # define tcg_qemu_tb_exec(env, tb_ptr) \
-    ((uintptr_t (*)(void *, void *))tcg_ctx.code_gen_prologue)(env, tb_ptr)
+    ((uintptr_t (*)(void *, void *))tcg_ctx->code_gen_prologue)(env, tb_ptr)
 #endif
 
 void tcg_register_jit(void *buf, size_t buf_size);