[PATCH for-10.0 08/25] target/mips: Set FloatInfZeroNaNRule explicitly

Peter Maydell posted 25 patches 4 weeks ago
[PATCH for-10.0 08/25] target/mips: Set FloatInfZeroNaNRule explicitly
Posted by Peter Maydell 4 weeks ago
Set the FloatInfZeroNaNRule explicitly for the MIPS target,
so we can remove the ifdef from pickNaNMulAdd().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/mips/fpu_helper.h       |  9 +++++++++
 target/mips/msa.c              |  4 ++++
 fpu/softfloat-specialize.c.inc | 16 +---------------
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/target/mips/fpu_helper.h b/target/mips/fpu_helper.h
index 7c3c7897b45..be66f2f813a 100644
--- a/target/mips/fpu_helper.h
+++ b/target/mips/fpu_helper.h
@@ -28,6 +28,7 @@ static inline void restore_flush_mode(CPUMIPSState *env)
 static inline void restore_snan_bit_mode(CPUMIPSState *env)
 {
     bool nan2008 = env->active_fpu.fcr31 & (1 << FCR31_NAN2008);
+    FloatInfZeroNaNRule izn_rule;
 
     /*
      * With nan2008, SNaNs are silenced in the usual way.
@@ -35,6 +36,14 @@ static inline void restore_snan_bit_mode(CPUMIPSState *env)
      */
     set_snan_bit_is_one(!nan2008, &env->active_fpu.fp_status);
     set_default_nan_mode(!nan2008, &env->active_fpu.fp_status);
+    /*
+     * For MIPS systems that conform to IEEE754-1985, the (inf,zero,nan)
+     * case sets InvalidOp and returns the default NaN.
+     * For MIPS systems that conform to IEEE754-2008, the (inf,zero,nan)
+     * case sets InvalidOp and returns the input value 'c'.
+     */
+    izn_rule = nan2008 ? float_infzeronan_dnan_never : float_infzeronan_dnan_always;
+    set_float_infzeronan_rule(izn_rule, &env->active_fpu.fp_status);
 }
 
 static inline void restore_fp_status(CPUMIPSState *env)
diff --git a/target/mips/msa.c b/target/mips/msa.c
index 9dffc428f5c..cc152db27f9 100644
--- a/target/mips/msa.c
+++ b/target/mips/msa.c
@@ -74,4 +74,8 @@ void msa_reset(CPUMIPSState *env)
 
     /* set proper signanling bit meaning ("1" means "quiet") */
     set_snan_bit_is_one(0, &env->active_tc.msa_fp_status);
+
+    /* Inf * 0 + NaN returns the input NaN */
+    set_float_infzeronan_rule(float_infzeronan_dnan_never,
+                              &env->active_tc.msa_fp_status);
 }
diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index 2023b2bd632..db9a466e05b 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -489,21 +489,7 @@ static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls, FloatClass c_cls,
         /*
          * Temporarily fall back to ifdef ladder
          */
-#if defined(TARGET_MIPS)
-        if (snan_bit_is_one(status)) {
-            /*
-             * For MIPS systems that conform to IEEE754-1985, the (inf,zero,nan)
-             * case sets InvalidOp and returns the default NaN
-             */
-            rule = float_infzeronan_dnan_always;
-        } else {
-            /*
-             * For MIPS systems that conform to IEEE754-2008, the (inf,zero,nan)
-             * case sets InvalidOp and returns the input value 'c'
-             */
-            rule = float_infzeronan_dnan_never;
-        }
-#elif defined(TARGET_SPARC) || \
+#if defined(TARGET_SPARC) || \
     defined(TARGET_XTENSA) || defined(TARGET_HPPA) || \
     defined(TARGET_I386) || defined(TARGET_LOONGARCH)
         /*
-- 
2.34.1
Re: [PATCH for-10.0 08/25] target/mips: Set FloatInfZeroNaNRule explicitly
Posted by Richard Henderson 3 weeks, 6 days ago
On 11/28/24 04:42, Peter Maydell wrote:
> Set the FloatInfZeroNaNRule explicitly for the MIPS target,
> so we can remove the ifdef from pickNaNMulAdd().
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/mips/fpu_helper.h       |  9 +++++++++
>   target/mips/msa.c              |  4 ++++
>   fpu/softfloat-specialize.c.inc | 16 +---------------
>   3 files changed, 14 insertions(+), 15 deletions(-)

Lovely.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~