diff mbox series

[03/10] target/tricore: Correctly handle FPU RM from PSW

Message ID 20230826160242.312052-4-kbastian@mail.uni-paderborn.de (mailing list archive)
State New, archived
Headers show
Series TriCore 1.6.2 insn and bugfixes | expand

Commit Message

Bastian Koppelmann Aug. 26, 2023, 4:02 p.m. UTC 
when we reconstructed PSW using psw_read(), we were trying to clear the
cached USB bits out of env->PSW. The mask was wrong and we would clear
PSW.RM as well.

when we write the PSW using psw_write() we update the rounding modes in
env->fp_status for softfloat. The order of bits used by TriCore is not
the one used by softfloat.

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
---
 target/tricore/helper.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Comments

Richard Henderson Aug. 27, 2023, 4:37 a.m. UTC | #1 
On 8/26/23 09:02, Bastian Koppelmann wrote:
> when we reconstructed PSW using psw_read(), we were trying to clear the
> cached USB bits out of env->PSW. The mask was wrong and we would clear
> PSW.RM as well.
> 
> when we write the PSW using psw_write() we update the rounding modes in
> env->fp_status for softfloat. The order of bits used by TriCore is not
> the one used by softfloat.
> 
> Signed-off-by: Bastian Koppelmann<kbastian@mail.uni-paderborn.de>
> ---
>   target/tricore/helper.c | 18 ++++++++++++++++--
>   1 file changed, 16 insertions(+), 2 deletions(-)

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


r~
diff mbox series

Patch

diff --git a/target/tricore/helper.c b/target/tricore/helper.c
index 6d076ac36f..e615c3d6d4 100644
--- a/target/tricore/helper.c
+++ b/target/tricore/helper.c
@@ -120,7 +120,21 @@  void tricore_cpu_list(void)
 
 void fpu_set_state(CPUTriCoreState *env)
 {
-    set_float_rounding_mode(env->PSW & MASK_PSW_FPU_RM, &env->fp_status);
+    switch (extract32(env->PSW, 24, 2)) {
+    case 0:
+        set_float_rounding_mode(float_round_nearest_even, &env->fp_status);
+        break;
+    case 1:
+        set_float_rounding_mode(float_round_up, &env->fp_status);
+        break;
+    case 2:
+        set_float_rounding_mode(float_round_down, &env->fp_status);
+        break;
+    case 3:
+        set_float_rounding_mode(float_round_to_zero, &env->fp_status);
+        break;
+    }
+
     set_flush_inputs_to_zero(1, &env->fp_status);
     set_flush_to_zero(1, &env->fp_status);
     set_default_nan_mode(1, &env->fp_status);
@@ -129,7 +143,7 @@  void fpu_set_state(CPUTriCoreState *env)
 uint32_t psw_read(CPUTriCoreState *env)
 {
     /* clear all USB bits */
-    env->PSW &= 0x6ffffff;
+    env->PSW &= 0x7ffffff;
     /* now set them from the cache */
     env->PSW |= ((env->PSW_USB_C != 0) << 31);
     env->PSW |= ((env->PSW_USB_V   & (1 << 31))  >> 1);