[PATCH v3 9/9] target/mips: Remove unreachable 32-bit code on 64-bit Loongson Ext

Philippe Mathieu-Daudé posted 9 patches 4 weeks ago
[PATCH v3 9/9] target/mips: Remove unreachable 32-bit code on 64-bit Loongson Ext
Posted by Philippe Mathieu-Daudé 4 weeks ago
Loongson fixed-point multiplies and divisions opcodes are
specific to 64-bit cores (Loongson-2 and Loongson-3 families).
Simplify by removing the 32-bit checks.

Reported-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 target/mips/tcg/loong_translate.c | 41 ++-----------------------------
 1 file changed, 2 insertions(+), 39 deletions(-)

diff --git a/target/mips/tcg/loong_translate.c b/target/mips/tcg/loong_translate.c
index c02e60bb15b..a005c279a3e 100644
--- a/target/mips/tcg/loong_translate.c
+++ b/target/mips/tcg/loong_translate.c
@@ -31,13 +31,6 @@ static bool gen_lext_DIV_G(DisasContext *s, int rd, int rs, int rt,
     TCGv t0, t1;
     TCGLabel *l1, *l2, *l3;
 
-    if (is_double) {
-        if (TARGET_LONG_BITS != 64) {
-            return false;
-        }
-        check_mips_64(s);
-    }
-
     if (rd == 0) {
         /* Treat as NOP. */
         return true;
@@ -61,8 +54,7 @@ static bool gen_lext_DIV_G(DisasContext *s, int rd, int rs, int rt,
     tcg_gen_br(l3);
     gen_set_label(l1);
 
-    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double && TARGET_LONG_BITS == 64
-                                        ? LLONG_MIN : INT_MIN, l2);
+    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double ? LLONG_MIN : INT_MIN, l2);
     tcg_gen_brcondi_tl(TCG_COND_NE, t1, -1LL, l2);
     tcg_gen_mov_tl(cpu_gpr[rd], t0);
 
@@ -93,13 +85,6 @@ static bool gen_lext_DIVU_G(DisasContext *s, int rd, int rs, int rt,
     TCGv t0, t1;
     TCGLabel *l1, *l2;
 
-    if (is_double) {
-        if (TARGET_LONG_BITS != 64) {
-            return false;
-        }
-        check_mips_64(s);
-    }
-
     if (rd == 0) {
         /* Treat as NOP. */
         return true;
@@ -147,13 +132,6 @@ static bool gen_lext_MOD_G(DisasContext *s, int rd, int rs, int rt,
     TCGv t0, t1;
     TCGLabel *l1, *l2, *l3;
 
-    if (is_double) {
-        if (TARGET_LONG_BITS != 64) {
-            return false;
-        }
-        check_mips_64(s);
-    }
-
     if (rd == 0) {
         /* Treat as NOP. */
         return true;
@@ -173,8 +151,7 @@ static bool gen_lext_MOD_G(DisasContext *s, int rd, int rs, int rt,
         tcg_gen_ext32u_tl(t1, t1);
     }
     tcg_gen_brcondi_tl(TCG_COND_EQ, t1, 0, l1);
-    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double && TARGET_LONG_BITS == 64
-                                        ? LLONG_MIN : INT_MIN, l2);
+    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double ? LLONG_MIN : INT_MIN, l2);
     tcg_gen_brcondi_tl(TCG_COND_NE, t1, -1LL, l2);
     gen_set_label(l1);
     tcg_gen_movi_tl(cpu_gpr[rd], 0);
@@ -205,13 +182,6 @@ static bool gen_lext_MODU_G(DisasContext *s, int rd, int rs, int rt,
     TCGv t0, t1;
     TCGLabel *l1, *l2;
 
-    if (is_double) {
-        if (TARGET_LONG_BITS != 64) {
-            return false;
-        }
-        check_mips_64(s);
-    }
-
     if (rd == 0) {
         /* Treat as NOP. */
         return true;
@@ -257,13 +227,6 @@ static bool gen_lext_MULT_G(DisasContext *s, int rd, int rs, int rt,
 {
     TCGv t0, t1;
 
-    if (is_double) {
-        if (TARGET_LONG_BITS != 64) {
-            return false;
-        }
-        check_mips_64(s);
-    }
-
     if (rd == 0) {
         /* Treat as NOP. */
         return true;
-- 
2.45.2


Re: [PATCH v3 9/9] target/mips: Remove unreachable 32-bit code on 64-bit Loongson Ext
Posted by Pierrick Bouvier 3 weeks, 2 days ago
On 10/26/24 10:53, Philippe Mathieu-Daudé wrote:
> Loongson fixed-point multiplies and divisions opcodes are
> specific to 64-bit cores (Loongson-2 and Loongson-3 families).
> Simplify by removing the 32-bit checks.
> 
> Reported-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   target/mips/tcg/loong_translate.c | 41 ++-----------------------------
>   1 file changed, 2 insertions(+), 39 deletions(-)
> 
> diff --git a/target/mips/tcg/loong_translate.c b/target/mips/tcg/loong_translate.c
> index c02e60bb15b..a005c279a3e 100644
> --- a/target/mips/tcg/loong_translate.c
> +++ b/target/mips/tcg/loong_translate.c
> @@ -31,13 +31,6 @@ static bool gen_lext_DIV_G(DisasContext *s, int rd, int rs, int rt,
>       TCGv t0, t1;
>       TCGLabel *l1, *l2, *l3;
>   
> -    if (is_double) {
> -        if (TARGET_LONG_BITS != 64) {
> -            return false;
> -        }
> -        check_mips_64(s);
> -    }
> -
>       if (rd == 0) {
>           /* Treat as NOP. */
>           return true;
> @@ -61,8 +54,7 @@ static bool gen_lext_DIV_G(DisasContext *s, int rd, int rs, int rt,
>       tcg_gen_br(l3);
>       gen_set_label(l1);
>   
> -    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double && TARGET_LONG_BITS == 64
> -                                        ? LLONG_MIN : INT_MIN, l2);
> +    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double ? LLONG_MIN : INT_MIN, l2);
>       tcg_gen_brcondi_tl(TCG_COND_NE, t1, -1LL, l2);
>       tcg_gen_mov_tl(cpu_gpr[rd], t0);
>   
> @@ -93,13 +85,6 @@ static bool gen_lext_DIVU_G(DisasContext *s, int rd, int rs, int rt,
>       TCGv t0, t1;
>       TCGLabel *l1, *l2;
>   
> -    if (is_double) {
> -        if (TARGET_LONG_BITS != 64) {
> -            return false;
> -        }
> -        check_mips_64(s);
> -    }
> -
>       if (rd == 0) {
>           /* Treat as NOP. */
>           return true;
> @@ -147,13 +132,6 @@ static bool gen_lext_MOD_G(DisasContext *s, int rd, int rs, int rt,
>       TCGv t0, t1;
>       TCGLabel *l1, *l2, *l3;
>   
> -    if (is_double) {
> -        if (TARGET_LONG_BITS != 64) {
> -            return false;
> -        }
> -        check_mips_64(s);
> -    }
> -
>       if (rd == 0) {
>           /* Treat as NOP. */
>           return true;
> @@ -173,8 +151,7 @@ static bool gen_lext_MOD_G(DisasContext *s, int rd, int rs, int rt,
>           tcg_gen_ext32u_tl(t1, t1);
>       }
>       tcg_gen_brcondi_tl(TCG_COND_EQ, t1, 0, l1);
> -    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double && TARGET_LONG_BITS == 64
> -                                        ? LLONG_MIN : INT_MIN, l2);
> +    tcg_gen_brcondi_tl(TCG_COND_NE, t0, is_double ? LLONG_MIN : INT_MIN, l2);
>       tcg_gen_brcondi_tl(TCG_COND_NE, t1, -1LL, l2);
>       gen_set_label(l1);
>       tcg_gen_movi_tl(cpu_gpr[rd], 0);
> @@ -205,13 +182,6 @@ static bool gen_lext_MODU_G(DisasContext *s, int rd, int rs, int rt,
>       TCGv t0, t1;
>       TCGLabel *l1, *l2;
>   
> -    if (is_double) {
> -        if (TARGET_LONG_BITS != 64) {
> -            return false;
> -        }
> -        check_mips_64(s);
> -    }
> -
>       if (rd == 0) {
>           /* Treat as NOP. */
>           return true;
> @@ -257,13 +227,6 @@ static bool gen_lext_MULT_G(DisasContext *s, int rd, int rs, int rt,
>   {
>       TCGv t0, t1;
>   
> -    if (is_double) {
> -        if (TARGET_LONG_BITS != 64) {
> -            return false;
> -        }
> -        check_mips_64(s);
> -    }
> -
>       if (rd == 0) {
>           /* Treat as NOP. */
>           return true;

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>