This helper sets the rounding mode in the standard_fp_status word to
allow NEON instructions to modify the rounding mode whilst using the
standard FPSCR values for everything else.
Signed-off-by: Will Newton <will.new...@linaro.org>
Reviewed-by: Peter Maydell <peter.mayd...@linaro.org>
---
target-arm/helper.c | 17 +++++++++++++++++
target-arm/helper.h | 1 +
2 files changed, 18 insertions(+)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index b1541b9..ca5b000 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -4048,6 +4048,23 @@ uint32_t HELPER(set_rmode)(uint32_t rmode, CPUARMState
*env)
return prev_rmode;
}
+/* Set the current fp rounding mode in the standard fp status and return
+ * the old one. This is for NEON instructions that need to change the
+ * rounding mode but wish to use the standard FPSCR values for everything
+ * else. Always set the rounding mode back to the correct value after
+ * modifying it.
+ * The argument is a softfloat float_round_ value.
+ */
+uint32_t HELPER(set_neon_rmode)(uint32_t rmode, CPUARMState *env)
+{
+ float_status *fp_status = &env->vfp.standard_fp_status;
+
+ uint32_t prev_rmode = get_float_rounding_mode(fp_status);
+ set_float_rounding_mode(rmode, fp_status);
+
+ return prev_rmode;
+}
+
/* Half precision conversions. */
static float32 do_fcvt_f16_to_f32(uint32_t a, CPUARMState *env, float_status
*s)
{
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 70872df..71b8411 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -149,6 +149,7 @@ DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr)
DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr)
DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, env)
+DEF_HELPER_FLAGS_2(set_neon_rmode, TCG_CALL_NO_RWG, i32, i32, env)
DEF_HELPER_2(vfp_fcvt_f16_to_f32, f32, i32, env)
DEF_HELPER_2(vfp_fcvt_f32_to_f16, i32, f32, env)
--
1.8.1.4
