[PATCH 05/21] target/loongarch: Explicitly set 2-NaN propagation rule

Peter Maydell posted 21 patches 4 weeks, 1 day ago
[PATCH 05/21] target/loongarch: Explicitly set 2-NaN propagation rule
Posted by Peter Maydell 4 weeks, 1 day ago
Set the 2-NaN propagation rule explicitly in the float_status word we
use.

(There are a couple of places in fpu_helper.c where we create a
dummy float_status word with "float_status *s = { };", but these
are only used for calling float*_is_quiet_nan() so it doesn't
matter that we don't set a 2-NaN propagation rule there.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/loongarch/tcg/fpu_helper.c | 1 +
 fpu/softfloat-specialize.c.inc    | 6 +++---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/target/loongarch/tcg/fpu_helper.c b/target/loongarch/tcg/fpu_helper.c
index f6753c5875b..21bc3b04a96 100644
--- a/target/loongarch/tcg/fpu_helper.c
+++ b/target/loongarch/tcg/fpu_helper.c
@@ -31,6 +31,7 @@ void restore_fp_status(CPULoongArchState *env)
     set_float_rounding_mode(ieee_rm[(env->fcsr0 >> FCSR0_RM) & 0x3],
                             &env->fp_status);
     set_flush_to_zero(0, &env->fp_status);
+    set_float_2nan_prop_rule(float_2nan_prop_s_ab, &env->fp_status);
 }
 
 int ieee_ex_to_loongarch(int xcpt)
diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index c60b999aa3d..bbc3b70fa9d 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -402,10 +402,10 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls,
         /* target didn't set the rule: fall back to old ifdef choices */
 #if defined(TARGET_AVR) || defined(TARGET_HEXAGON) \
     || defined(TARGET_RISCV) || defined(TARGET_SH4) \
-    || defined(TARGET_TRICORE) || defined(TARGET_ARM) || defined(TARGET_MIPS)
+    || defined(TARGET_TRICORE) || defined(TARGET_ARM) || defined(TARGET_MIPS) \
+    || defined(TARGET_LOONGARCH64)
         g_assert_not_reached();
-#elif defined(TARGET_HPPA) || \
-    defined(TARGET_LOONGARCH64) || defined(TARGET_S390X)
+#elif defined(TARGET_HPPA) || defined(TARGET_S390X)
         rule = float_2nan_prop_s_ab;
 #elif defined(TARGET_PPC) || defined(TARGET_M68K)
         /*
-- 
2.34.1
Re: [PATCH 05/21] target/loongarch: Explicitly set 2-NaN propagation rule
Posted by Richard Henderson 3 weeks, 5 days ago
On 10/25/24 15:12, Peter Maydell wrote:
> Set the 2-NaN propagation rule explicitly in the float_status word we
> use.
> 
> (There are a couple of places in fpu_helper.c where we create a
> dummy float_status word with "float_status *s = { };", but these
> are only used for calling float*_is_quiet_nan() so it doesn't
> matter that we don't set a 2-NaN propagation rule there.)
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/loongarch/tcg/fpu_helper.c | 1 +
>   fpu/softfloat-specialize.c.inc    | 6 +++---
>   2 files changed, 4 insertions(+), 3 deletions(-)

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

r~