[Qemu-devel] [PATCH v2 2/3] softfloat: change default nan definitions to variables

[Paolo Bonzini <pbonzini@redhat.com>]

Most definitions in softfloat.h are really target-independent, but the
file is not because it includes definitions of the default NaN values.
Change those to variables to allow including softfloat.h from files that
are not compiled per-target.  By making them const, the compiler is
allowed to optimize them into softfloat functions that use them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 fpu/softfloat-specialize.h |   72 ++++++++++++++++++++++++++++++++++++++++++++
 fpu/softfloat.h            |   60 +++++-------------------------------
 2 files changed, 81 insertions(+), 51 deletions(-)

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index c7d35a1..c165205 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -35,6 +35,78 @@ these four paragraphs for those parts of this code that are retained.
 
 =============================================================================*/
 
+#if defined(TARGET_MIPS) || defined(TARGET_SH4) || defined(TARGET_UNICORE32)
+#define SNAN_BIT_IS_ONE		1
+#else
+#define SNAN_BIT_IS_ONE		0
+#endif
+
+/*----------------------------------------------------------------------------
+| The pattern for a default generated half-precision NaN.
+*----------------------------------------------------------------------------*/
+#if defined(TARGET_ARM)
+const float16 float16_default_nan = const_float16(0x7E00);
+#elif SNAN_BIT_IS_ONE
+const float16 float16_default_nan = const_float16(0x7DFF);
+#else
+const float16 float16_default_nan = const_float16(0xFE00);
+#endif
+
+/*----------------------------------------------------------------------------
+| The pattern for a default generated single-precision NaN.
+*----------------------------------------------------------------------------*/
+#if defined(TARGET_SPARC)
+const float32 float32_default_nan = const_float32(0x7FFFFFFF);
+#elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA)
+const float32 float32_default_nan = const_float32(0x7FC00000);
+#elif SNAN_BIT_IS_ONE
+const float32 float32_default_nan = const_float32(0x7FBFFFFF);
+#else
+const float32 float32_default_nan = const_float32(0xFFC00000);
+#endif
+
+/*----------------------------------------------------------------------------
+| The pattern for a default generated double-precision NaN.
+*----------------------------------------------------------------------------*/
+#if defined(TARGET_SPARC)
+const float64 float64_default_nan = const_float64(LIT64( 0x7FFFFFFFFFFFFFFF ));
+#elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA)
+const float64 float64_default_nan = const_float64(LIT64( 0x7FF8000000000000 ));
+#elif SNAN_BIT_IS_ONE
+const float64 float64_default_nan = const_float64(LIT64( 0x7FF7FFFFFFFFFFFF ));
+#else
+const float64 float64_default_nan = const_float64(LIT64( 0xFFF8000000000000 ));
+#endif
+
+/*----------------------------------------------------------------------------
+| The pattern for a default generated extended double-precision NaN.
+*----------------------------------------------------------------------------*/
+#if SNAN_BIT_IS_ONE
+#define floatx80_default_nan_high 0x7FFF
+#define floatx80_default_nan_low  LIT64( 0xBFFFFFFFFFFFFFFF )
+#else
+#define floatx80_default_nan_high 0xFFFF
+#define floatx80_default_nan_low  LIT64( 0xC000000000000000 )
+#endif
+
+const floatx80 floatx80_default_nan = make_floatx80(floatx80_default_nan_high,
+                                                    floatx80_default_nan_low);
+
+/*----------------------------------------------------------------------------
+| The pattern for a default generated quadruple-precision NaN.  The `high' and
+| `low' values hold the most- and least-significant bits, respectively.
+*----------------------------------------------------------------------------*/
+#if SNAN_BIT_IS_ONE
+#define float128_default_nan_high LIT64( 0x7FFF7FFFFFFFFFFF )
+#define float128_default_nan_low  LIT64( 0xFFFFFFFFFFFFFFFF )
+#else
+#define float128_default_nan_high LIT64( 0xFFFF800000000000 )
+#define float128_default_nan_low  LIT64( 0x0000000000000000 )
+#endif
+
+const float128 float128_default_nan = make_float128(float128_default_nan_high,
+                                                    float128_default_nan_low);
+
 /*----------------------------------------------------------------------------
 | Raises the exceptions specified by `flags'.  Floating-point traps can be
 | defined here if desired.  It is currently not possible for such a trap
diff --git a/fpu/softfloat.h b/fpu/softfloat.h
index bde2500..3bb7d8f 100644
--- a/fpu/softfloat.h
+++ b/fpu/softfloat.h
@@ -43,7 +43,7 @@ these four paragraphs for those parts of this code that are retained.
 #endif
 
 #include <inttypes.h>
-#include "config.h"
+#include "config-host.h"
 
 /*----------------------------------------------------------------------------
 | Each of the following `typedef's defines the most convenient type that holds
@@ -68,12 +68,6 @@ typedef int64_t int64;
 #define LIT64( a ) a##LL
 #define INLINE static inline
 
-#if defined(TARGET_MIPS) || defined(TARGET_SH4) || defined(TARGET_UNICORE32)
-#define SNAN_BIT_IS_ONE		1
-#else
-#define SNAN_BIT_IS_ONE		0
-#endif
-
 #define STATUS_PARAM , float_status *status
 #define STATUS(field) status->field
 #define STATUS_VAR , status
@@ -142,6 +136,7 @@ typedef struct {
     uint64_t low, high;
 #endif
 } float128;
+#define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ })
 
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE floating-point underflow tininess-detection mode.
@@ -248,13 +243,7 @@ float16 float16_maybe_silence_nan( float16 );
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/
-#if defined(TARGET_ARM)
-#define float16_default_nan make_float16(0x7E00)
-#elif SNAN_BIT_IS_ONE
-#define float16_default_nan make_float16(0x7DFF)
-#else
-#define float16_default_nan make_float16(0xFE00)
-#endif
+extern const float16 float16_default_nan;
 
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE single-precision conversion routines.
@@ -357,15 +346,7 @@ INLINE float32 float32_set_sign(float32 a, int sign)
 /*----------------------------------------------------------------------------
 | The pattern for a default generated single-precision NaN.
 *----------------------------------------------------------------------------*/
-#if defined(TARGET_SPARC)
-#define float32_default_nan make_float32(0x7FFFFFFF)
-#elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA)
-#define float32_default_nan make_float32(0x7FC00000)
-#elif SNAN_BIT_IS_ONE
-#define float32_default_nan make_float32(0x7FBFFFFF)
-#else
-#define float32_default_nan make_float32(0xFFC00000)
-#endif
+extern const float32 float32_default_nan;
 
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE double-precision conversion routines.
@@ -470,15 +451,7 @@ INLINE float64 float64_set_sign(float64 a, int sign)
 /*----------------------------------------------------------------------------
 | The pattern for a default generated double-precision NaN.
 *----------------------------------------------------------------------------*/
-#if defined(TARGET_SPARC)
-#define float64_default_nan make_float64(LIT64( 0x7FFFFFFFFFFFFFFF ))
-#elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA)
-#define float64_default_nan make_float64(LIT64( 0x7FF8000000000000 ))
-#elif SNAN_BIT_IS_ONE
-#define float64_default_nan make_float64(LIT64( 0x7FF7FFFFFFFFFFFF ))
-#else
-#define float64_default_nan make_float64(LIT64( 0xFFF8000000000000 ))
-#endif
+extern const float64 float64_default_nan;
 
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE extended double-precision conversion routines.
@@ -561,17 +534,9 @@ INLINE int floatx80_is_any_nan(floatx80 a)
 #define floatx80_infinity make_floatx80(0x7fff, 0x8000000000000000LL)
 
 /*----------------------------------------------------------------------------
-| The pattern for a default generated extended double-precision NaN.  The
-| `high' and `low' values hold the most- and least-significant bits,
-| respectively.
+| The pattern for a default generated extended double-precision NaN.
 *----------------------------------------------------------------------------*/
-#if SNAN_BIT_IS_ONE
-#define floatx80_default_nan_high 0x7FFF
-#define floatx80_default_nan_low  LIT64( 0xBFFFFFFFFFFFFFFF )
-#else
-#define floatx80_default_nan_high 0xFFFF
-#define floatx80_default_nan_low  LIT64( 0xC000000000000000 )
-#endif
+extern const floatx80 floatx80_default_nan;
 
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE quadruple-precision conversion routines.
@@ -648,15 +613,8 @@ INLINE int float128_is_any_nan(float128 a)
 }
 
 /*----------------------------------------------------------------------------
-| The pattern for a default generated quadruple-precision NaN.  The `high' and
-| `low' values hold the most- and least-significant bits, respectively.
+| The pattern for a default generated quadruple-precision NaN.
 *----------------------------------------------------------------------------*/
-#if SNAN_BIT_IS_ONE
-#define float128_default_nan_high LIT64( 0x7FFF7FFFFFFFFFFF )
-#define float128_default_nan_low  LIT64( 0xFFFFFFFFFFFFFFFF )
-#else
-#define float128_default_nan_high LIT64( 0xFFFF800000000000 )
-#define float128_default_nan_low  LIT64( 0x0000000000000000 )
-#endif
+extern const float128 float128_default_nan;
 
 #endif /* !SOFTFLOAT_H */
-- 
1.7.4.4