Patchwork [20/33] target-alpha: All ISA checks to use TB->FLAGS.

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Submitter Richard Henderson
Date April 28, 2011, 8:51 p.m.
Message ID <1304023875-25040-21-git-send-email-rth@twiddle.net>
Download mbox | patch
Permalink /patch/93315/
State New
Headers show

Comments

Richard Henderson - April 28, 2011, 8:51 p.m.
We had two different methods in use, both of which referenced ENV,
and neither of which indicated to the generic code when different
compilation modes are not compatible.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-alpha/cpu.h       |   32 ++++-
 target-alpha/translate.c |  396 ++++++++++++++++++++++++----------------------
 2 files changed, 239 insertions(+), 189 deletions(-)

Patch

diff --git a/target-alpha/cpu.h b/target-alpha/cpu.h
index 88281bb..c1ccf01 100644
--- a/target-alpha/cpu.h
+++ b/target-alpha/cpu.h
@@ -419,12 +419,40 @@  uint64_t cpu_alpha_load_fpcr (CPUState *env);
 void cpu_alpha_store_fpcr (CPUState *env, uint64_t val);
 extern void swap_shadow_regs(CPUState *env);
 
+/* Bits in TB->FLAGS that control how translation is processed.  */
+enum {
+    TB_FLAGS_PAL_MODE = 1,
+    TB_FLAGS_FEN = 2,
+    TB_FLAGS_USER_MODE = 8,
+
+    TB_FLAGS_AMASK_SHIFT = 4,
+    TB_FLAGS_AMASK_BWX = AMASK_BWX << TB_FLAGS_AMASK_SHIFT,
+    TB_FLAGS_AMASK_FIX = AMASK_FIX << TB_FLAGS_AMASK_SHIFT,
+    TB_FLAGS_AMASK_CIX = AMASK_CIX << TB_FLAGS_AMASK_SHIFT,
+    TB_FLAGS_AMASK_MVI = AMASK_MVI << TB_FLAGS_AMASK_SHIFT,
+    TB_FLAGS_AMASK_TRAP = AMASK_TRAP << TB_FLAGS_AMASK_SHIFT,
+    TB_FLAGS_AMASK_PREFETCH = AMASK_PREFETCH << TB_FLAGS_AMASK_SHIFT,
+};
+
 static inline void cpu_get_tb_cpu_state(CPUState *env, target_ulong *pc,
-                                        target_ulong *cs_base, int *flags)
+                                        target_ulong *cs_base, int *pflags)
 {
+    int flags = 0;
+
     *pc = env->pc;
     *cs_base = 0;
-    *flags = env->ps;
+
+    if (env->pal_mode) {
+        flags = TB_FLAGS_PAL_MODE;
+    } else {
+        flags = env->ps & PS_USER_MODE;
+    }
+    if (env->fen) {
+        flags |= TB_FLAGS_FEN;
+    }
+    flags |= env->amask << TB_FLAGS_AMASK_SHIFT;
+
+    *pflags = flags;
 }
 
 #if defined(CONFIG_USER_ONLY)
diff --git a/target-alpha/translate.c b/target-alpha/translate.c
index 42a80e6..28ccf6b 100644
--- a/target-alpha/translate.c
+++ b/target-alpha/translate.c
@@ -47,10 +47,6 @@  struct DisasContext {
     CPUAlphaState *env;
     uint64_t pc;
     int mem_idx;
-#if !defined (CONFIG_USER_ONLY)
-    int pal_mode;
-#endif
-    uint32_t amask;
 
     /* Current rounding mode for this TB.  */
     int tb_rm;
@@ -1653,20 +1649,22 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
         break;
     case 0x0A:
         /* LDBU */
-        if (!(ctx->amask & AMASK_BWX))
-            goto invalid_opc;
-        gen_load_mem(ctx, &tcg_gen_qemu_ld8u, ra, rb, disp16, 0, 0);
-        break;
+        if (ctx->tb->flags & TB_FLAGS_AMASK_BWX) {
+            gen_load_mem(ctx, &tcg_gen_qemu_ld8u, ra, rb, disp16, 0, 0);
+            break;
+        }
+        goto invalid_opc;
     case 0x0B:
         /* LDQ_U */
         gen_load_mem(ctx, &tcg_gen_qemu_ld64, ra, rb, disp16, 0, 1);
         break;
     case 0x0C:
         /* LDWU */
-        if (!(ctx->amask & AMASK_BWX))
-            goto invalid_opc;
-        gen_load_mem(ctx, &tcg_gen_qemu_ld16u, ra, rb, disp16, 0, 0);
-        break;
+        if (ctx->tb->flags & TB_FLAGS_AMASK_BWX) {
+            gen_load_mem(ctx, &tcg_gen_qemu_ld16u, ra, rb, disp16, 0, 0);
+            break;
+        }
+        goto invalid_opc;
     case 0x0D:
         /* STW */
         gen_store_mem(ctx, &tcg_gen_qemu_st16, ra, rb, disp16, 0, 0);
@@ -2070,20 +2068,12 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
         case 0x61:
             /* AMASK */
             if (likely(rc != 31)) {
-                if (islit)
-                    tcg_gen_movi_i64(cpu_ir[rc], lit);
-                else
-                    tcg_gen_mov_i64(cpu_ir[rc], cpu_ir[rb]);
-                switch (ctx->env->implver) {
-                case IMPLVER_2106x:
-                    /* EV4, EV45, LCA, LCA45 & EV5 */
-                    break;
-                case IMPLVER_21164:
-                case IMPLVER_21264:
-                case IMPLVER_21364:
-                    tcg_gen_andi_i64(cpu_ir[rc], cpu_ir[rc],
-                                     ~(uint64_t)ctx->amask);
-                    break;
+                uint64_t amask = ctx->tb->flags >> TB_FLAGS_AMASK_SHIFT;
+
+                if (islit) {
+                    tcg_gen_movi_i64(cpu_ir[rc], lit & ~amask);
+                } else {
+                    tcg_gen_andi_i64(cpu_ir[rc], cpu_ir[rb], ~amask);
                 }
             }
             break;
@@ -2297,8 +2287,9 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
         switch (fpfn) { /* fn11 & 0x3F */
         case 0x04:
             /* ITOFS */
-            if (!(ctx->amask & AMASK_FIX))
+            if ((ctx->tb->flags & TB_FLAGS_AMASK_FIX) == 0) {
                 goto invalid_opc;
+            }
             if (likely(rc != 31)) {
                 if (ra != 31) {
                     TCGv_i32 tmp = tcg_temp_new_i32();
@@ -2311,20 +2302,23 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
             break;
         case 0x0A:
             /* SQRTF */
-            if (!(ctx->amask & AMASK_FIX))
-                goto invalid_opc;
-            gen_fsqrtf(rb, rc);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_FIX) {
+                gen_fsqrtf(rb, rc);
+                break;
+            }
+            goto invalid_opc;
         case 0x0B:
             /* SQRTS */
-            if (!(ctx->amask & AMASK_FIX))
-                goto invalid_opc;
-            gen_fsqrts(ctx, rb, rc, fn11);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_FIX) {
+                gen_fsqrts(ctx, rb, rc, fn11);
+                break;
+            }
+            goto invalid_opc;
         case 0x14:
             /* ITOFF */
-            if (!(ctx->amask & AMASK_FIX))
+            if ((ctx->tb->flags & TB_FLAGS_AMASK_FIX) == 0) {
                 goto invalid_opc;
+            }
             if (likely(rc != 31)) {
                 if (ra != 31) {
                     TCGv_i32 tmp = tcg_temp_new_i32();
@@ -2337,8 +2331,9 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
             break;
         case 0x24:
             /* ITOFT */
-            if (!(ctx->amask & AMASK_FIX))
+            if ((ctx->tb->flags & TB_FLAGS_AMASK_FIX) == 0) {
                 goto invalid_opc;
+            }
             if (likely(rc != 31)) {
                 if (ra != 31)
                     tcg_gen_mov_i64(cpu_fir[rc], cpu_ir[ra]);
@@ -2348,16 +2343,18 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
             break;
         case 0x2A:
             /* SQRTG */
-            if (!(ctx->amask & AMASK_FIX))
-                goto invalid_opc;
-            gen_fsqrtg(rb, rc);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_FIX) {
+                gen_fsqrtg(rb, rc);
+                break;
+            }
+            goto invalid_opc;
         case 0x02B:
             /* SQRTT */
-            if (!(ctx->amask & AMASK_FIX))
-                goto invalid_opc;
-            gen_fsqrtt(ctx, rb, rc, fn11);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_FIX) {
+                gen_fsqrtt(ctx, rb, rc, fn11);
+                break;
+            }
+            goto invalid_opc;
         default:
             goto invalid_opc;
         }
@@ -2658,14 +2655,13 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
         break;
     case 0x19:
         /* HW_MFPR (PALcode) */
-#if defined (CONFIG_USER_ONLY)
-        goto invalid_opc;
-#else
-        if (!ctx->pal_mode)
-            goto invalid_opc;
-        gen_mfpr(ra, insn & 0xffff);
-        break;
+#ifndef CONFIG_USER_ONLY
+        if (ctx->tb->flags & TB_FLAGS_PAL_MODE) {
+            gen_mfpr(ra, insn & 0xffff);
+            break;
+        }
 #endif
+        goto invalid_opc;
     case 0x1A:
         /* JMP, JSR, RET, JSR_COROUTINE.  These only differ by the branch
            prediction stack action, which of course we don't implement.  */
@@ -2681,13 +2677,15 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
         break;
     case 0x1B:
         /* HW_LD (PALcode) */
-#if defined (CONFIG_USER_ONLY)
-        goto invalid_opc;
-#else
-        if (!ctx->pal_mode)
-            goto invalid_opc;
-        if (ra != 31) {
-            TCGv addr = tcg_temp_new();
+#ifndef CONFIG_USER_ONLY
+        if (ctx->tb->flags & TB_FLAGS_PAL_MODE) {
+            TCGv addr;
+
+            if (ra == 31) {
+                break;
+            }
+
+            addr = tcg_temp_new();
             if (rb != 31)
                 tcg_gen_addi_i64(addr, cpu_ir[rb], disp12);
             else
@@ -2754,15 +2752,17 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
                 break;
             }
             tcg_temp_free(addr);
+            break;
         }
-        break;
 #endif
+        goto invalid_opc;
     case 0x1C:
         switch (fn7) {
         case 0x00:
             /* SEXTB */
-            if (!(ctx->amask & AMASK_BWX))
+            if ((ctx->tb->flags & TB_FLAGS_AMASK_BWX) == 0) {
                 goto invalid_opc;
+            }
             if (likely(rc != 31)) {
                 if (islit)
                     tcg_gen_movi_i64(cpu_ir[rc], (int64_t)((int8_t)lit));
@@ -2772,138 +2772,164 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
             break;
         case 0x01:
             /* SEXTW */
-            if (!(ctx->amask & AMASK_BWX))
-                goto invalid_opc;
-            if (likely(rc != 31)) {
-                if (islit)
-                    tcg_gen_movi_i64(cpu_ir[rc], (int64_t)((int16_t)lit));
-                else
-                    tcg_gen_ext16s_i64(cpu_ir[rc], cpu_ir[rb]);
+            if (ctx->tb->flags & TB_FLAGS_AMASK_BWX) {
+                if (likely(rc != 31)) {
+                    if (islit) {
+                        tcg_gen_movi_i64(cpu_ir[rc], (int64_t)((int16_t)lit));
+                    } else {
+                        tcg_gen_ext16s_i64(cpu_ir[rc], cpu_ir[rb]);
+                    }
+                }
+                break;
             }
-            break;
+            goto invalid_opc;
         case 0x30:
             /* CTPOP */
-            if (!(ctx->amask & AMASK_CIX))
-                goto invalid_opc;
-            if (likely(rc != 31)) {
-                if (islit)
-                    tcg_gen_movi_i64(cpu_ir[rc], ctpop64(lit));
-                else
-                    gen_helper_ctpop(cpu_ir[rc], cpu_ir[rb]);
+            if (ctx->tb->flags & TB_FLAGS_AMASK_CIX) {
+                if (likely(rc != 31)) {
+                    if (islit) {
+                        tcg_gen_movi_i64(cpu_ir[rc], ctpop64(lit));
+                    } else {
+                        gen_helper_ctpop(cpu_ir[rc], cpu_ir[rb]);
+                    }
+                }
+                break;
             }
-            break;
+            goto invalid_opc;
         case 0x31:
             /* PERR */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_perr(ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_perr(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x32:
             /* CTLZ */
-            if (!(ctx->amask & AMASK_CIX))
-                goto invalid_opc;
-            if (likely(rc != 31)) {
-                if (islit)
-                    tcg_gen_movi_i64(cpu_ir[rc], clz64(lit));
-                else
-                    gen_helper_ctlz(cpu_ir[rc], cpu_ir[rb]);
+            if (ctx->tb->flags & TB_FLAGS_AMASK_CIX) {
+                if (likely(rc != 31)) {
+                    if (islit) {
+                        tcg_gen_movi_i64(cpu_ir[rc], clz64(lit));
+                    } else {
+                        gen_helper_ctlz(cpu_ir[rc], cpu_ir[rb]);
+                    }
+                }
+                break;
             }
-            break;
+            goto invalid_opc;
         case 0x33:
             /* CTTZ */
-            if (!(ctx->amask & AMASK_CIX))
-                goto invalid_opc;
-            if (likely(rc != 31)) {
-                if (islit)
-                    tcg_gen_movi_i64(cpu_ir[rc], ctz64(lit));
-                else
-                    gen_helper_cttz(cpu_ir[rc], cpu_ir[rb]);
+            if (ctx->tb->flags & TB_FLAGS_AMASK_CIX) {
+                if (likely(rc != 31)) {
+                    if (islit) {
+                        tcg_gen_movi_i64(cpu_ir[rc], ctz64(lit));
+                    } else {
+                        gen_helper_cttz(cpu_ir[rc], cpu_ir[rb]);
+                    }
+                }
+                break;
             }
-            break;
+            goto invalid_opc;
         case 0x34:
             /* UNPKBW */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            if (real_islit || ra != 31)
-                goto invalid_opc;
-            gen_unpkbw (rb, rc);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                if (real_islit || ra != 31) {
+                    goto invalid_opc;
+                }
+                gen_unpkbw(rb, rc);
+                break;
+            }
+            goto invalid_opc;
         case 0x35:
             /* UNPKBL */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            if (real_islit || ra != 31)
-                goto invalid_opc;
-            gen_unpkbl (rb, rc);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                if (real_islit || ra != 31) {
+                    goto invalid_opc;
+                }
+                gen_unpkbl(rb, rc);
+                break;
+            }
+            goto invalid_opc;
         case 0x36:
             /* PKWB */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            if (real_islit || ra != 31)
-                goto invalid_opc;
-            gen_pkwb (rb, rc);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                if (real_islit || ra != 31) {
+                    goto invalid_opc;
+                }
+                gen_pkwb(rb, rc);
+                break;
+            }
+            goto invalid_opc;
         case 0x37:
             /* PKLB */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            if (real_islit || ra != 31)
-                goto invalid_opc;
-            gen_pklb (rb, rc);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                if (real_islit || ra != 31) {
+                    goto invalid_opc;
+                }
+                gen_pklb(rb, rc);
+                break;
+            }
+            goto invalid_opc;
         case 0x38:
             /* MINSB8 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_minsb8 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_minsb8(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x39:
             /* MINSW4 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_minsw4 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_minsw4(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x3A:
             /* MINUB8 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_minub8 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_minub8(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x3B:
             /* MINUW4 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_minuw4 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_minuw4(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x3C:
             /* MAXUB8 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_maxub8 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_maxub8(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x3D:
             /* MAXUW4 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_maxuw4 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_maxuw4(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x3E:
             /* MAXSB8 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_maxsb8 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_maxsb8(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x3F:
             /* MAXSW4 */
-            if (!(ctx->amask & AMASK_MVI))
-                goto invalid_opc;
-            gen_maxsw4 (ra, rb, rc, islit, lit);
-            break;
+            if (ctx->tb->flags & TB_FLAGS_AMASK_MVI) {
+                gen_maxsw4(ra, rb, rc, islit, lit);
+                break;
+            }
+            goto invalid_opc;
         case 0x70:
             /* FTOIT */
-            if (!(ctx->amask & AMASK_FIX))
+            if ((ctx->tb->flags & TB_FLAGS_AMASK_FIX) == 0) {
                 goto invalid_opc;
+            }
             if (likely(rc != 31)) {
                 if (ra != 31)
                     tcg_gen_mov_i64(cpu_ir[rc], cpu_fir[ra]);
@@ -2913,8 +2939,9 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
             break;
         case 0x78:
             /* FTOIS */
-            if (!(ctx->amask & AMASK_FIX))
+            if ((ctx->tb->flags & TB_FLAGS_AMASK_FIX) == 0) {
                 goto invalid_opc;
+            }
             if (rc != 31) {
                 TCGv_i32 tmp1 = tcg_temp_new_i32();
                 if (ra != 31)
@@ -2934,42 +2961,36 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
         break;
     case 0x1D:
         /* HW_MTPR (PALcode) */
-#if defined (CONFIG_USER_ONLY)
-        goto invalid_opc;
-#else
-        if (!ctx->pal_mode)
-            goto invalid_opc;
-        gen_mtpr(rb, insn & 0xffff);
-        break;
+#ifndef CONFIG_USER_ONLY
+        if (ctx->tb->flags & TB_FLAGS_PAL_MODE) {
+            gen_mtpr(rb, insn & 0xffff);
+            break;
+        }
 #endif
+        goto invalid_opc;
     case 0x1E:
         /* HW_RET (PALcode) */
-#if defined (CONFIG_USER_ONLY)
-        goto invalid_opc;
-#else
-        if (!ctx->pal_mode)
-            goto invalid_opc;
-        if (rb == 31) {
-            /* Pre-EV6 CPUs interpreted this as HW_REI, loading the return
-               address from EXC_ADDR.  This turns out to be useful for our
-               emulation PALcode, so continue to accept it.  */
-            TCGv tmp = tcg_temp_new();
-            tcg_gen_ld_i64(tmp, cpu_env, offsetof(CPUState, exc_addr));
-            gen_helper_hw_ret(tmp);
-            tcg_temp_free(tmp);
-        } else {
-            gen_helper_hw_ret(cpu_ir[rb]);
+#ifndef CONFIG_USER_ONLY
+        if (ctx->tb->flags & TB_FLAGS_PAL_MODE) {
+            if (rb == 31) {
+                /* Pre-EV6 CPUs interpreted this as HW_REI, loading the return
+                   address from EXC_ADDR.  This turns out to be useful for our
+                   emulation PALcode, so continue to accept it.  */
+                TCGv tmp = tcg_temp_new();
+                tcg_gen_ld_i64(tmp, cpu_env, offsetof(CPUState, exc_addr));
+                gen_helper_hw_ret(tmp);
+                tcg_temp_free(tmp);
+            } else {
+                gen_helper_hw_ret(cpu_ir[rb]);
+            }
+            return EXIT_PC_UPDATED;
         }
-        return EXIT_PC_UPDATED;
 #endif
+        goto invalid_opc;
     case 0x1F:
         /* HW_ST (PALcode) */
-#if defined (CONFIG_USER_ONLY)
-        goto invalid_opc;
-#else
-        if (!ctx->pal_mode)
-            goto invalid_opc;
-        else {
+#ifndef CONFIG_USER_ONLY
+        if (ctx->tb->flags & TB_FLAGS_PAL_MODE) {
             TCGv addr, val;
             addr = tcg_temp_new();
             if (rb != 31)
@@ -3039,9 +3060,10 @@  static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
             if (ra == 31)
                 tcg_temp_free(val);
             tcg_temp_free(addr);
+            break;
         }
-        break;
 #endif
+        goto invalid_opc;
     case 0x20:
         /* LDF */
         gen_load_mem(ctx, &gen_qemu_ldf, ra, rb, disp16, 1, 0);
@@ -3192,8 +3214,8 @@  static inline void gen_intermediate_code_internal(CPUState *env,
     ctx.tb = tb;
     ctx.env = env;
     ctx.pc = pc_start;
-    ctx.amask = env->amask;
-    ctx.mem_idx = cpu_mmu_index(env);
+    ctx.mem_idx = (tb->flags & TB_FLAGS_USER_MODE
+                   ? MMU_USER_IDX : MMU_KERNEL_IDX);
 
     /* ??? Every TB begins with unset rounding mode, to be initialized on
        the first fp insn of the TB.  Alternately we could define a proper