[Qemu-devel] [MIPS] Clear softfpu exception state for round, trunc, ceil and floor

[Qemu-devel] [MIPS] Clear softfpu exception state for round, trunc, ceil and floor

[Chris Dearman]

MIPS FPU instructions should start with a clean softfpu status. This
is done for the arithmetic operations and cvt instructions, but not
for round, trunc, ceil and floor.

Chris

-- 
Chris Dearman               Desk: +1 408 530 5092  Cell: +1 408 398 5531
MIPS Technologies Inc            955 East Arques Ave, Sunnyvale CA 94085

[Qemu-devel] [PATCH] [MIPS] Clear softfpu exception state for round, trunc, ceil and floor

[Chris Dearman]

Signed-off-by: Chris Dearman <chris@mips.com>
---
 target-mips/op_helper.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index 41abd57..e044db4 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -2294,6 +2294,7 @@ uint64_t helper_float_roundl_d(uint64_t fdt0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_nearest_even, &env->active_fpu.fp_status);
     dt2 = float64_to_int64(fdt0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2307,6 +2308,7 @@ uint64_t helper_float_roundl_s(uint32_t fst0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_nearest_even, &env->active_fpu.fp_status);
     dt2 = float32_to_int64(fst0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2320,6 +2322,7 @@ uint32_t helper_float_roundw_d(uint64_t fdt0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_nearest_even, &env->active_fpu.fp_status);
     wt2 = float64_to_int32(fdt0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2333,6 +2336,7 @@ uint32_t helper_float_roundw_s(uint32_t fst0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_nearest_even, &env->active_fpu.fp_status);
     wt2 = float32_to_int32(fst0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2346,6 +2350,7 @@ uint64_t helper_float_truncl_d(uint64_t fdt0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     dt2 = float64_to_int64_round_to_zero(fdt0, &env->active_fpu.fp_status);
     update_fcr31();
     if (GET_FP_CAUSE(env->active_fpu.fcr31) & (FP_OVERFLOW | FP_INVALID))
@@ -2357,6 +2362,7 @@ uint64_t helper_float_truncl_s(uint32_t fst0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     dt2 = float32_to_int64_round_to_zero(fst0, &env->active_fpu.fp_status);
     update_fcr31();
     if (GET_FP_CAUSE(env->active_fpu.fcr31) & (FP_OVERFLOW | FP_INVALID))
@@ -2368,6 +2374,7 @@ uint32_t helper_float_truncw_d(uint64_t fdt0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     wt2 = float64_to_int32_round_to_zero(fdt0, &env->active_fpu.fp_status);
     update_fcr31();
     if (GET_FP_CAUSE(env->active_fpu.fcr31) & (FP_OVERFLOW | FP_INVALID))
@@ -2379,6 +2386,7 @@ uint32_t helper_float_truncw_s(uint32_t fst0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     wt2 = float32_to_int32_round_to_zero(fst0, &env->active_fpu.fp_status);
     update_fcr31();
     if (GET_FP_CAUSE(env->active_fpu.fcr31) & (FP_OVERFLOW | FP_INVALID))
@@ -2390,6 +2398,7 @@ uint64_t helper_float_ceill_d(uint64_t fdt0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_up, &env->active_fpu.fp_status);
     dt2 = float64_to_int64(fdt0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2403,6 +2412,7 @@ uint64_t helper_float_ceill_s(uint32_t fst0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_up, &env->active_fpu.fp_status);
     dt2 = float32_to_int64(fst0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2416,6 +2426,7 @@ uint32_t helper_float_ceilw_d(uint64_t fdt0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_up, &env->active_fpu.fp_status);
     wt2 = float64_to_int32(fdt0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2429,6 +2440,7 @@ uint32_t helper_float_ceilw_s(uint32_t fst0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_up, &env->active_fpu.fp_status);
     wt2 = float32_to_int32(fst0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2442,6 +2454,7 @@ uint64_t helper_float_floorl_d(uint64_t fdt0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_down, &env->active_fpu.fp_status);
     dt2 = float64_to_int64(fdt0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2455,6 +2468,7 @@ uint64_t helper_float_floorl_s(uint32_t fst0)
 {
     uint64_t dt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_down, &env->active_fpu.fp_status);
     dt2 = float32_to_int64(fst0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2468,6 +2482,7 @@ uint32_t helper_float_floorw_d(uint64_t fdt0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_down, &env->active_fpu.fp_status);
     wt2 = float64_to_int32(fdt0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;
@@ -2481,6 +2496,7 @@ uint32_t helper_float_floorw_s(uint32_t fst0)
 {
     uint32_t wt2;
 
+    set_float_exception_flags(0, &env->active_fpu.fp_status);
     set_float_rounding_mode(float_round_down, &env->active_fpu.fp_status);
     wt2 = float32_to_int32(fst0, &env->active_fpu.fp_status);
     RESTORE_ROUNDING_MODE;

Re: [Qemu-devel] [MIPS] Clear softfpu exception state for round, trunc, ceil and floor

[Aurelien Jarno]

On Tue, Feb 08, 2011 at 07:03:21PM -0800, Chris Dearman wrote:
> MIPS FPU instructions should start with a clean softfpu status. This
> is done for the arithmetic operations and cvt instructions, but not
> for round, trunc, ceil and floor.
> 

Good catch, I have applied the patch.

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net