motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-04 00:03:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

target/arm: Implement FPST_STD_F16 fpstatus

Browse source 
Architecturally, Neon FP16 operations use the "standard FPSCR" like
all other Neon operations.  However, this is defined in the Arm ARM
pseudocode as "a fixed value, except that FZ16 (and AHP) follow the
FPSCR bits". In QEMU, the softfloat float_status doesn't include
separate flush-to-zero for FP16 operations, so we must keep separate
fp_status for "Neon non-FP16" and "Neon fp16" operations, in the
same way we do already for the non-Neon "fp_status" vs "fp_status_f16".

Add the extra float_status field to the CPU state structure,
ensure it is correctly initialized and updated on FPSCR writes,
and make fpstatus_ptr(FPST_STD_F16) return a pointer to it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200806104453.30393-4-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2020-08-06 11:44:52 +01:00
parent a84d1d1316
commit aaae563bc7
4 changed files with 18 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

3
target/arm/cpu.c
View file

@ -391,12 +391,15 @@ static void arm_cpu_reset(DeviceState *dev)
set_flush_to_zero(1, &env->vfp.standard_fp_status);
set_flush_inputs_to_zero(1, &env->vfp.standard_fp_status);
set_default_nan_mode(1, &env->vfp.standard_fp_status);
set_default_nan_mode(1, &env->vfp.standard_fp_status_f16);
set_float_detect_tininess(float_tininess_before_rounding,
&env->vfp.fp_status);
set_float_detect_tininess(float_tininess_before_rounding,
&env->vfp.standard_fp_status);
set_float_detect_tininess(float_tininess_before_rounding,
&env->vfp.fp_status_f16);
set_float_detect_tininess(float_tininess_before_rounding,
&env->vfp.standard_fp_status_f16);
#ifndef CONFIG_USER_ONLY
if (kvm_enabled()) {
kvm_arm_reset_vcpu(cpu);