Pass float_status structure pointer to the pickNaN so that
machine-specific settings are available to NaN selection code.
Add use_first_nan property to float_status and use it in Xtensa-specific
pickNaN.
Cc: Peter Maydell <peter.mayd...@linaro.org>
Cc: "Alex Bennée" <alex.ben...@linaro.org>
Signed-off-by: Max Filippov <jcmvb...@gmail.com>
---
fpu/softfloat-specialize.inc.c | 30 ++++++++++++++++++++++++------
fpu/softfloat.c | 2 +-
include/fpu/softfloat-helpers.h | 5 +++++
include/fpu/softfloat-types.h | 1 +
4 files changed, 31 insertions(+), 7 deletions(-)
diff --git a/fpu/softfloat-specialize.inc.c b/fpu/softfloat-specialize.inc.c
index b26bc039b0b6..e17327b405c5 100644
--- a/fpu/softfloat-specialize.inc.c
+++ b/fpu/softfloat-specialize.inc.c
@@ -368,7 +368,7 @@ static float32 commonNaNToFloat32(commonNaNT a,
float_status *status)
*----------------------------------------------------------------------------*/
static int pickNaN(FloatClass a_cls, FloatClass b_cls,
- bool aIsLargerSignificand)
+ bool aIsLargerSignificand, float_status *status)
{
#if defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA)
/* ARM mandated NaN propagation rules (see FPProcessNaNs()), take
@@ -401,7 +401,7 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls,
} else {
return 1;
}
-#elif defined(TARGET_PPC) || defined(TARGET_XTENSA) || defined(TARGET_M68K)
+#elif defined(TARGET_PPC) || defined(TARGET_M68K)
/* PowerPC propagation rules:
* 1. A if it sNaN or qNaN
* 2. B if it sNaN or qNaN
@@ -426,6 +426,24 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls,
} else {
return 1;
}
+#elif defined(TARGET_XTENSA)
+ /*
+ * Xtensa has two NaN propagation modes.
+ * Which one is active is controlled by float_status::use_first_nan.
+ */
+ if (status->use_first_nan) {
+ if (is_nan(a_cls)) {
+ return 0;
+ } else {
+ return 1;
+ }
+ } else {
+ if (is_nan(b_cls)) {
+ return 1;
+ } else {
+ return 0;
+ }
+ }
#else
/* This implements x87 NaN propagation rules:
* SNaN + QNaN => return the QNaN
@@ -613,7 +631,7 @@ static float32 propagateFloat32NaN(float32 a, float32 b,
float_status *status)
aIsLargerSignificand = (av < bv) ? 1 : 0;
}
- if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
+ if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return float32_silence_nan(b, status);
}
@@ -751,7 +769,7 @@ static float64 propagateFloat64NaN(float64 a, float64 b,
float_status *status)
aIsLargerSignificand = (av < bv) ? 1 : 0;
}
- if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
+ if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return float64_silence_nan(b, status);
}
@@ -915,7 +933,7 @@ floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b,
float_status *status)
aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
}
- if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
+ if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return floatx80_silence_nan(b, status);
}
@@ -1063,7 +1081,7 @@ static float128 propagateFloat128NaN(float128 a, float128
b,
aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
}
- if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
+ if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return float128_silence_nan(b, status);
}
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 5e9746c2876f..a89056a1816e 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -881,7 +881,7 @@ static FloatParts pick_nan(FloatParts a, FloatParts b,
float_status *s)
} else {
if (pickNaN(a.cls, b.cls,
a.frac > b.frac ||
- (a.frac == b.frac && a.sign < b.sign))) {
+ (a.frac == b.frac && a.sign < b.sign), s)) {
a = b;
}
if (is_snan(a.cls)) {
diff --git a/include/fpu/softfloat-helpers.h b/include/fpu/softfloat-helpers.h
index e842f83a1285..2f0674fbddec 100644
--- a/include/fpu/softfloat-helpers.h
+++ b/include/fpu/softfloat-helpers.h
@@ -95,6 +95,11 @@ static inline void set_snan_bit_is_one(bool val,
float_status *status)
status->snan_bit_is_one = val;
}
+static inline void set_use_first_nan(bool val, float_status *status)
+{
+ status->use_first_nan = val;
+}
+
static inline void set_no_signaling_nans(bool val, float_status *status)
{
status->no_signaling_nans = val;
diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h
index 10bd208e559f..aaee6e4cdd23 100644
--- a/include/fpu/softfloat-types.h
+++ b/include/fpu/softfloat-types.h
@@ -167,6 +167,7 @@ typedef struct float_status {
bool default_nan_mode;
/* not always used -- see snan_bit_is_one() in softfloat-specialize.h */
bool snan_bit_is_one;
+ bool use_first_nan;
bool no_signaling_nans;
} float_status;
--
2.20.1
