Re: [PATCH 05/33] target/mips: Have check_msa_access() return a boolean

[Richard Henderson]

On 10/23/21 2:47 PM, Philippe Mathieu-Daudé wrote:
Have check_msa_access() return a boolean value so we can
return early if MSA is not enabled.
Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
---
  target/mips/tcg/msa_translate.c | 20 +++++++++++++-------
  1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/target/mips/tcg/msa_translate.c b/target/mips/tcg/msa_translate.c
index 3ef912da6b8..9e0a08fe335 100644
--- a/target/mips/tcg/msa_translate.c
+++ b/target/mips/tcg/msa_translate.c
@@ -293,19 +293,19 @@ void msa_translate_init(void)
      }
  }
  
-static inline int check_msa_access(DisasContext *ctx)
+static inline bool check_msa_access(DisasContext *ctx)
  {
      if (unlikely((ctx->hflags & MIPS_HFLAG_FPU) &&
                   !(ctx->hflags & MIPS_HFLAG_F64))) {
          gen_reserved_instruction(ctx);
-        return 0;
+        return false;
      }
  
      if (unlikely(!(ctx->hflags & MIPS_HFLAG_MSA))) {
          generate_exception_end(ctx, EXCP_MSADIS);
-        return 0;
+        return false;
      }

When we return false, we have raised an exception.

@@ -354,7 +354,9 @@ static bool gen_msa_BxZ_V(DisasContext *ctx, int wt, int 
s16, TCGCond cond)
  {
      TCGv_i64 t0;
  
-    check_msa_access(ctx);
+    if (!check_msa_access(ctx)) {
+        return false;
+    }

... which means that here we should return true, meaning that we have recognized the 
instruction and emitted some code for it.  In this case: we have recognized that the 
instruction is valid but not enabled.

Otherwise, we will return to decode_opc and (eventually) emit another 
gen_reserved_instruction.


r~