Patchwork [v2,02/10] softfloat: add NO_SIGNALING_NANS

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Submitter Max Filippov
Date Sept. 9, 2012, 4:04 p.m.
Message ID <1347206679-428-3-git-send-email-jcmvbkbc@gmail.com>
Download mbox | patch
Permalink /patch/182626/
State New
Headers show

Comments

Max Filippov - Sept. 9, 2012, 4:04 p.m.
Architectures that don't have signaling NaNs can define
NO_SIGNALING_NANS, it will make float*_is_quiet_nan return 1 for any NaN
and float*_is_signaling_nan always return 0.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 fpu/softfloat-specialize.h |   64 ++++++++++++++++++++++++++++++++++++++++++++
 fpu/softfloat.h            |    5 +++
 2 files changed, 69 insertions(+), 0 deletions(-)
Peter Maydell - Sept. 9, 2012, 4:18 p.m.
On 9 September 2012 17:04, Max Filippov <jcmvbkbc@gmail.com> wrote:
> Architectures that don't have signaling NaNs can define
> NO_SIGNALING_NANS, it will make float*_is_quiet_nan return 1 for any NaN
> and float*_is_signaling_nan always return 0.
>
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> ---
>  fpu/softfloat-specialize.h |   64 ++++++++++++++++++++++++++++++++++++++++++++
>  fpu/softfloat.h            |    5 +++
>  2 files changed, 69 insertions(+), 0 deletions(-)
>
> diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
> index 4902450..2b203b9 100644
> --- a/fpu/softfloat-specialize.h
> +++ b/fpu/softfloat-specialize.h
> @@ -41,6 +41,10 @@ these four paragraphs for those parts of this code that are retained.
>  #define SNAN_BIT_IS_ONE                0
>  #endif
>
> +#if defined(TARGET_XTENSA)
> +#define NO_SIGNALING_NANS 1
> +#endif

This could use a comment, I think.
/* Define for architectures which deviate from IEEE in not supporting
 * signaling NaNs (so all NaNs are treated as quiet).
 */

-- PMM

Patch

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 4902450..2b203b9 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -41,6 +41,10 @@  these four paragraphs for those parts of this code that are retained.
 #define SNAN_BIT_IS_ONE		0
 #endif
 
+#if defined(TARGET_XTENSA)
+#define NO_SIGNALING_NANS 1
+#endif
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/
@@ -127,6 +131,17 @@  typedef struct {
     uint64_t high, low;
 } commonNaNT;
 
+#ifdef NO_SIGNALING_NANS
+int float16_is_quiet_nan(float16 a_)
+{
+    return float16_is_any_nan(a_);
+}
+
+int float16_is_signaling_nan(float16 a_)
+{
+    return 0;
+}
+#else
 /*----------------------------------------------------------------------------
 | Returns 1 if the half-precision floating-point value `a' is a quiet
 | NaN; otherwise returns 0.
@@ -156,6 +171,7 @@  int float16_is_signaling_nan(float16 a_)
     return (((a >> 9) & 0x3F) == 0x3E) && (a & 0x1FF);
 #endif
 }
+#endif
 
 /*----------------------------------------------------------------------------
 | Returns a quiet NaN if the half-precision floating point value `a' is a
@@ -217,6 +233,17 @@  static float16 commonNaNToFloat16(commonNaNT a STATUS_PARAM)
     }
 }
 
+#ifdef NO_SIGNALING_NANS
+int float32_is_quiet_nan(float32 a_)
+{
+    return float32_is_any_nan(a_);
+}
+
+int float32_is_signaling_nan(float32 a_)
+{
+    return 0;
+}
+#else
 /*----------------------------------------------------------------------------
 | Returns 1 if the single-precision floating-point value `a' is a quiet
 | NaN; otherwise returns 0.
@@ -246,6 +273,7 @@  int float32_is_signaling_nan( float32 a_ )
     return ( ( ( a>>22 ) & 0x1FF ) == 0x1FE ) && ( a & 0x003FFFFF );
 #endif
 }
+#endif
 
 /*----------------------------------------------------------------------------
 | Returns a quiet NaN if the single-precision floating point value `a' is a
@@ -586,6 +614,17 @@  static float32 propagateFloat32MulAddNaN(float32 a, float32 b,
     }
 }
 
+#ifdef NO_SIGNALING_NANS
+int float64_is_quiet_nan(float64 a_)
+{
+    return float64_is_any_nan(a_);
+}
+
+int float64_is_signaling_nan(float64 a_)
+{
+    return 0;
+}
+#else
 /*----------------------------------------------------------------------------
 | Returns 1 if the double-precision floating-point value `a' is a quiet
 | NaN; otherwise returns 0.
@@ -619,6 +658,7 @@  int float64_is_signaling_nan( float64 a_ )
         && ( a & LIT64( 0x0007FFFFFFFFFFFF ) );
 #endif
 }
+#endif
 
 /*----------------------------------------------------------------------------
 | Returns a quiet NaN if the double-precision floating point value `a' is a
@@ -773,6 +813,17 @@  static float64 propagateFloat64MulAddNaN(float64 a, float64 b,
     }
 }
 
+#ifdef NO_SIGNALING_NANS
+int floatx80_is_quiet_nan(floatx80 a_)
+{
+    return floatx80_is_any_nan(a_);
+}
+
+int floatx80_is_signaling_nan(floatx80 a_)
+{
+    return 0;
+}
+#else
 /*----------------------------------------------------------------------------
 | Returns 1 if the extended double-precision floating-point value `a' is a
 | quiet NaN; otherwise returns 0. This slightly differs from the same
@@ -816,6 +867,7 @@  int floatx80_is_signaling_nan( floatx80 a )
         && ( a.low == aLow );
 #endif
 }
+#endif
 
 /*----------------------------------------------------------------------------
 | Returns a quiet NaN if the extended double-precision floating point value
@@ -929,6 +981,17 @@  static floatx80 propagateFloatx80NaN( floatx80 a, floatx80 b STATUS_PARAM)
     }
 }
 
+#ifdef NO_SIGNALING_NANS
+int float128_is_quiet_nan(float128 a_)
+{
+    return float128_is_any_nan(a_);
+}
+
+int float128_is_signaling_nan(float128 a_)
+{
+    return 0;
+}
+#else
 /*----------------------------------------------------------------------------
 | Returns 1 if the quadruple-precision floating-point value `a' is a quiet
 | NaN; otherwise returns 0.
@@ -964,6 +1027,7 @@  int float128_is_signaling_nan( float128 a )
         && ( a.low || ( a.high & LIT64( 0x00007FFFFFFFFFFF ) ) );
 #endif
 }
+#endif
 
 /*----------------------------------------------------------------------------
 | Returns a quiet NaN if the quadruple-precision floating point value `a' is
diff --git a/fpu/softfloat.h b/fpu/softfloat.h
index 2860ca0..d8999b3 100644
--- a/fpu/softfloat.h
+++ b/fpu/softfloat.h
@@ -251,6 +251,11 @@  int float16_is_quiet_nan( float16 );
 int float16_is_signaling_nan( float16 );
 float16 float16_maybe_silence_nan( float16 );
 
+INLINE int float16_is_any_nan(float16 a)
+{
+    return ((float16_val(a) & ~0x8000) > 0x7c00);
+}
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/