This eliminates a set of runtime shifts.  It turns out that we
require TARGET_PAGE_MASK more often than TARGET_PAGE_SIZE, so
redefine TARGET_PAGE_SIZE based on TARGET_PAGE_MASK instead of
the other way around.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/exec/cpu-all.h | 8 ++++++--
 exec-vary.c            | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index ba6d3306bf..08b3a5ab06 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -213,6 +213,7 @@ static inline void stl_phys_notdirty(AddressSpace *as, hwaddr addr, uint32_t val
 typedef struct {
     bool decided;
     int bits;
+    target_long mask;
 } TargetPageBits;
 # if defined(CONFIG_ATTRIBUTE_ALIAS) || !defined(IN_EXEC_VARY)
 extern const TargetPageBits target_page;
@@ -221,15 +222,18 @@ extern TargetPageBits target_page;
 # endif
 # ifdef CONFIG_DEBUG_TCG
 #  define TARGET_PAGE_BITS (assert(target_page.decided), target_page.bits)
+#  define TARGET_PAGE_MASK (assert(target_page.decided), target_page.mask)
 # else
 #  define TARGET_PAGE_BITS target_page.bits
+#  define TARGET_PAGE_MASK target_page.mask
 # endif
+# define TARGET_PAGE_SIZE  (-(int)TARGET_PAGE_MASK)
 #else
 #define TARGET_PAGE_BITS_MIN TARGET_PAGE_BITS
+#define TARGET_PAGE_SIZE   (1 << TARGET_PAGE_BITS)
+#define TARGET_PAGE_MASK   ((target_long)-1 << TARGET_PAGE_BITS)
 #endif
 
-#define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS)
-#define TARGET_PAGE_MASK ((target_long)-1 << TARGET_PAGE_BITS)
 #define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE)
 
 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
diff --git a/exec-vary.c b/exec-vary.c
index e0befd502a..0594f61fef 100644
--- a/exec-vary.c
+++ b/exec-vary.c
@@ -97,5 +97,6 @@ void finalize_target_page_bits(void)
         init_target_page.bits = TARGET_PAGE_BITS_MIN;
     }
     init_target_page.decided = true;
+    init_target_page.mask = (target_long)-1 << init_target_page.bits;
 #endif
 }
-- 
2.17.1