diff options
| author | Will Newton <will.newton@linaro.org> | 2014-01-31 14:47:35 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2014-01-31 14:47:35 +0000 |
| commit | 43630e585300465b72ecf328822c8611724307de (patch) | |
| tree | dcec72fd1e962c01ec659c148d7379cbb46ee5b6 | |
| parent | 2ce7062501c715aae0ad37c3923a3710dd8914df (diff) | |
| download | qemu-43630e585300465b72ecf328822c8611724307de.zip | |
target-arm: Add set_neon_rmode helper
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.newton@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| -rw-r--r-- | target-arm/helper.c | 17 | ||||
| -rw-r--r-- | target-arm/helper.h | 1 |
2 files changed, 18 insertions, 0 deletions
diff --git a/target-arm/helper.c b/target-arm/helper.c index b1541b9c40..ca5b0000ad 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 70872dffc6..71b8411120 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) |