Re: [PATCH v2 16/50] target/i386: Tidy REX_B, REX_X definition

[Paolo Bonzini]

On 14/05/21 17:13, Richard Henderson wrote:
Change the storage from int to uint8_t since the value is in {0,8}.
For x86_64 add 0 in the macros to (1) promote the type back to int,
and (2) make the macro an rvalue.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>

Might be easier in the end to put all rex bits in the same uint8_t, but 
that can be done later.

Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>

Paolo

---
  target/i386/tcg/translate.c | 17 +++++++----------
  1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 79a37fb1a7..9bb37215d8 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -41,14 +41,6 @@
  #define PREFIX_VEX    0x20
  #define PREFIX_REX    0x40
  
-#ifdef TARGET_X86_64
-#define REX_X(s) ((s)->rex_x)
-#define REX_B(s) ((s)->rex_b)
-#else
-#define REX_X(s) 0
-#define REX_B(s) 0
-#endif
-
  #ifdef TARGET_X86_64
  # define ctztl  ctz64
  # define clztl  clz64
@@ -100,7 +92,8 @@ typedef struct DisasContext {
  #endif
  
  #ifdef TARGET_X86_64
-    int rex_x, rex_b;
+    uint8_t rex_x;
+    uint8_t rex_b;
  #endif
      int vex_l;  /* vex vector length */
      int vex_v;  /* vex vvvv register, without 1's complement.  */
@@ -173,8 +166,12 @@ typedef struct DisasContext {
  
  #ifdef TARGET_X86_64
  #define REX_PREFIX(S)  (((S)->prefix & PREFIX_REX) != 0)
+#define REX_X(S)       ((S)->rex_x + 0)
+#define REX_B(S)       ((S)->rex_b + 0)
  #else
  #define REX_PREFIX(S)  false
+#define REX_X(S)       0
+#define REX_B(S)       0
  #endif
  
  static void gen_eob(DisasContext *s);
@@ -4617,7 +4614,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState 
*cpu)
              rex_w = (b >> 3) & 1;
              rex_r = (b & 0x4) << 1;
              s->rex_x = (b & 0x2) << 2;
-            REX_B(s) = (b & 0x1) << 3;
+            s->rex_b = (b & 0x1) << 3;
              goto next_byte;
          }
          break;