accel/tcg: Renumber TLB_DISCARD_WRITE

Move to fill a hole in the set of bits.
Reduce the total number of tlb bits by 1.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/exec/cpu-all.h

@@ -325,10 +325,10 @@ CPUArchState *cpu_copy(CPUArchState *env);
 #define TLB_NOTDIRTY        (1 << (TARGET_PAGE_BITS_MIN - 2))
 /* Set if TLB entry is an IO callback.  */
 #define TLB_MMIO            (1 << (TARGET_PAGE_BITS_MIN - 3))
+/* Set if TLB entry writes ignored.  */
+#define TLB_DISCARD_WRITE   (1 << (TARGET_PAGE_BITS_MIN - 4))
 /* Set if the slow path must be used; more flags in CPUTLBEntryFull. */
 #define TLB_FORCE_SLOW      (1 << (TARGET_PAGE_BITS_MIN - 5))
-/* Set if TLB entry writes ignored.  */
-#define TLB_DISCARD_WRITE   (1 << (TARGET_PAGE_BITS_MIN - 6))
 
 /*
  * Use this mask to check interception with an alignment mask

tcg/tcg-op-ldst.c

@@ -39,7 +39,7 @@ static void check_max_alignment(unsigned a_bits)
      * The requested alignment cannot overlap the TLB flags.
      * FIXME: Must keep the count up-to-date with "exec/cpu-all.h".
      */
-    tcg_debug_assert(a_bits + 6 <= tcg_ctx->page_bits);
+    tcg_debug_assert(a_bits + 5 <= tcg_ctx->page_bits);
 #endif
 }