Re: [PATCH 3/5] target/mips: Make check_cp0_enabled() return a boolean

[Richard Henderson]

On 4/20/21 12:34 PM, Philippe Mathieu-Daudé wrote:

To avoid callers to emit dead code if check_cp0_enabled()
raise an exception, let it return a boolean value, whether
CP0 is enabled or not.

Suggested-by: Richard Henderson
Signed-off-by: Philippe Mathieu-Daudé
---
  target/mips/translate.h | 7 ++-
  target/mips/translate.c | 4 +++-
  2 files changed, 9 insertions(+), 2 deletions(-)


Reviewed-by: Richard Henderson 

r~

[PATCH 3/5] target/mips: Make check_cp0_enabled() return a boolean

[Philippe Mathieu-Daudé]

To avoid callers to emit dead code if check_cp0_enabled()
raise an exception, let it return a boolean value, whether
CP0 is enabled or not.

Suggested-by: Richard Henderson 
Signed-off-by: Philippe Mathieu-Daudé 
---
 target/mips/translate.h | 7 ++-
 target/mips/translate.c | 4 +++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/target/mips/translate.h b/target/mips/translate.h
index 2b3c7a69ec6..61442590340 100644
--- a/target/mips/translate.h
+++ b/target/mips/translate.h
@@ -120,7 +120,12 @@ void gen_reserved_instruction(DisasContext *ctx);
 
 void check_insn(DisasContext *ctx, uint64_t flags);
 void check_mips_64(DisasContext *ctx);
-void check_cp0_enabled(DisasContext *ctx);
+/**
+ * check_cp0_enabled:
+ * Return %true if CP0 is enabled, otherwise return %false
+ * and emit a 'coprocessor unusable' exception.
+ */
+bool check_cp0_enabled(DisasContext *ctx);
 void check_cp1_enabled(DisasContext *ctx);
 void check_cp1_64bitmode(DisasContext *ctx);
 void check_cp1_registers(DisasContext *ctx, int regs);
diff --git a/target/mips/translate.c b/target/mips/translate.c
index 03fb67f6f22..be5382b41f2 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -1572,11 +1572,13 @@ void gen_move_high32(TCGv ret, TCGv_i64 arg)
 #endif
 }
 
-void check_cp0_enabled(DisasContext *ctx)
+bool check_cp0_enabled(DisasContext *ctx)
 {
 if (unlikely(!(ctx->hflags & MIPS_HFLAG_CP0))) {
 generate_exception_end(ctx, EXCP_CpU);
+return false;
 }
+return true;
 }
 
 void check_cp1_enabled(DisasContext *ctx)
-- 
2.26.3