From 5fa3a975494ee395fef3b28826873520f44b8ce5 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Fri, 9 Mar 2018 01:33:15 -0500
Subject: [PATCH] softfloat: use floatx80_infinity in softfloat

Since f3218a8 ("softfloat: add floatx80 constants")
floatx80_infinity is defined but never used.

This patch updates floatx80 functions to use
this definition.

This allows to define a different default Infinity
value on m68k: the m68k FPU defines infinity with
all bits set to zero in the mantissa.

Backports commit 0f605c889ca3fe9744166ad4149d0dff6dacb696 from qemu
---
 qemu/aarch64.h                  |  1 +
 qemu/aarch64eb.h                |  1 +
 qemu/arm.h                      |  1 +
 qemu/armeb.h                    |  1 +
 qemu/fpu/softfloat-specialize.h | 14 ++++++++++++
 qemu/fpu/softfloat.c            | 39 +++++++++++++++++++++------------
 qemu/header_gen.py              |  1 +
 qemu/include/fpu/softfloat.h    | 13 +++++++++--
 qemu/m68k.h                     |  1 +
 qemu/mips.h                     |  1 +
 qemu/mips64.h                   |  1 +
 qemu/mips64el.h                 |  1 +
 qemu/mipsel.h                   |  1 +
 qemu/powerpc.h                  |  1 +
 qemu/sparc.h                    |  1 +
 qemu/sparc64.h                  |  1 +
 qemu/x86_64.h                   |  1 +
 17 files changed, 64 insertions(+), 16 deletions(-)

diff --git a/qemu/aarch64.h b/qemu/aarch64.h
index 95982fd9..5318722a 100644
--- a/qemu/aarch64.h
+++ b/qemu/aarch64.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_aarch64
 #define floatx80_eq floatx80_eq_aarch64
 #define floatx80_eq_quiet floatx80_eq_quiet_aarch64
+#define floatx80_infinity floatx80_infinity_aarch64
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_aarch64
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_aarch64
 #define floatx80_le floatx80_le_aarch64
diff --git a/qemu/aarch64eb.h b/qemu/aarch64eb.h
index 915896ed..8df32930 100644
--- a/qemu/aarch64eb.h
+++ b/qemu/aarch64eb.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_aarch64eb
 #define floatx80_eq floatx80_eq_aarch64eb
 #define floatx80_eq_quiet floatx80_eq_quiet_aarch64eb
+#define floatx80_infinity floatx80_infinity_aarch64eb
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_aarch64eb
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_aarch64eb
 #define floatx80_le floatx80_le_aarch64eb
diff --git a/qemu/arm.h b/qemu/arm.h
index 573fbf70..2cf2d4bf 100644
--- a/qemu/arm.h
+++ b/qemu/arm.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_arm
 #define floatx80_eq floatx80_eq_arm
 #define floatx80_eq_quiet floatx80_eq_quiet_arm
+#define floatx80_infinity floatx80_infinity_arm
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_arm
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_arm
 #define floatx80_le floatx80_le_arm
diff --git a/qemu/armeb.h b/qemu/armeb.h
index 0e1a4787..74620331 100644
--- a/qemu/armeb.h
+++ b/qemu/armeb.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_armeb
 #define floatx80_eq floatx80_eq_armeb
 #define floatx80_eq_quiet floatx80_eq_quiet_armeb
+#define floatx80_infinity floatx80_infinity_armeb
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_armeb
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_armeb
 #define floatx80_le floatx80_le_armeb
diff --git a/qemu/fpu/softfloat-specialize.h b/qemu/fpu/softfloat-specialize.h
index bc7cc9ad..0ff43734 100644
--- a/qemu/fpu/softfloat-specialize.h
+++ b/qemu/fpu/softfloat-specialize.h
@@ -177,6 +177,20 @@ floatx80 floatx80_default_nan(float_status *status)
     return r;
 }
 
+/*----------------------------------------------------------------------------
+| The pattern for a default generated extended double-precision inf.
+*----------------------------------------------------------------------------*/
+
+#define floatx80_infinity_high 0x7FFF
+#if defined(TARGET_M68K)
+#define floatx80_infinity_low  LIT64(0x0000000000000000)
+#else
+#define floatx80_infinity_low  LIT64(0x8000000000000000)
+#endif
+
+const floatx80 floatx80_infinity
+    = make_floatx80_init(floatx80_infinity_high, floatx80_infinity_low);
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated quadruple-precision NaN.
 *----------------------------------------------------------------------------*/
diff --git a/qemu/fpu/softfloat.c b/qemu/fpu/softfloat.c
index a5ed40b6..e1af21f6 100644
--- a/qemu/fpu/softfloat.c
+++ b/qemu/fpu/softfloat.c
@@ -2615,7 +2615,8 @@ floatx80 roundAndPackFloatx80(int8_t roundingPrecision, flag zSign,
                ) {
                 return packFloatx80( zSign, 0x7FFE, ~ roundMask );
             }
-            return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+            return packFloatx80(zSign, floatx80_infinity_high,
+                                       floatx80_infinity_low);
         }
         if ( zExp <= 0 ) {
             isTiny =
@@ -3150,7 +3151,9 @@ floatx80 float32_to_floatx80(float32 a, float_status *status)
         if (aSig) {
             return commonNaNToFloatx80(float32ToCommonNaN(a, status), status);
         }
-        return packFloatx80( aSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(aSign,
+                            floatx80_infinity_high,
+                            floatx80_infinity_low);
     }
     if ( aExp == 0 ) {
         if ( aSig == 0 ) return packFloatx80( aSign, 0, 0 );
@@ -4002,7 +4005,8 @@ floatx80 float64_to_floatx80(float64 a, float_status *status)
         if (aSig) {
             return commonNaNToFloatx80( float64ToCommonNaN(a, status), status);
         }
-        return packFloatx80( aSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(aSign, floatx80_infinity_high,
+                                   floatx80_infinity_low);
     }
     if ( aExp == 0 ) {
         if ( aSig == 0 ) return packFloatx80( aSign, 0, 0 );
@@ -4513,10 +4517,7 @@ int64_t floatx80_to_int64(floatx80 a, float_status *status)
     if ( shiftCount <= 0 ) {
         if ( shiftCount ) {
             float_raise(float_flag_invalid, status);
-            if (    ! aSign
-                 || (    ( aExp == 0x7FFF )
-                      && ( aSig != LIT64( 0x8000000000000000 ) ) )
-               ) {
+            if (!aSign || floatx80_is_any_nan(a)) {
                 return LIT64( 0x7FFFFFFFFFFFFFFF );
             }
             return (int64_t) LIT64( 0x8000000000000000 );
@@ -4819,7 +4820,9 @@ static floatx80 addFloatx80Sigs(floatx80 a, floatx80 b, flag zSign, float_status
     else if ( expDiff < 0 ) {
         if ( bExp == 0x7FFF ) {
             if ( (uint64_t) ( bSig<<1 ) ) return propagateFloatx80NaN(a, b, status);
-            return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+            return packFloatx80(zSign,
+                                floatx80_infinity_high,
+                                floatx80_infinity_low);
         }
         if ( aExp == 0 ) ++expDiff;
         shift64ExtraRightJamming( aSig, 0, - expDiff, &aSig, &zSig1 );
@@ -4893,7 +4896,8 @@ static floatx80 subFloatx80Sigs(floatx80 a, floatx80 b, flag zSign, float_status
  bExpBigger:
     if ( bExp == 0x7FFF ) {
         if ( (uint64_t) ( bSig<<1 ) ) return propagateFloatx80NaN( a, b, status );
-        return packFloatx80( zSign ^ 1, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(zSign ^ 1, floatx80_infinity_high,
+                            floatx80_infinity_low);
     }
     if ( aExp == 0 ) ++expDiff;
     shift128RightJamming( aSig, 0, - expDiff, &aSig, &zSig1 );
@@ -4998,7 +5002,8 @@ floatx80 floatx80_mul(floatx80 a, floatx80 b, float_status *status)
             return propagateFloatx80NaN( a, b, status );
         }
         if ( ( bExp | bSig ) == 0 ) goto invalid;
-        return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(zSign, floatx80_infinity_high,
+                                   floatx80_infinity_low);
     }
     if ( bExp == 0x7FFF ) {
         if ( (uint64_t) ( bSig<<1 ) ) return propagateFloatx80NaN( a, b, status );
@@ -5007,7 +5012,8 @@ floatx80 floatx80_mul(floatx80 a, floatx80 b, float_status *status)
             float_raise(float_flag_invalid, status);
             return floatx80_default_nan(status);
         }
-        return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(zSign, floatx80_infinity_high,
+                                   floatx80_infinity_low);
     }
     if ( aExp == 0 ) {
         if ( aSig == 0 ) return packFloatx80( zSign, 0, 0 );
@@ -5059,7 +5065,8 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status)
             if ( (uint64_t) ( bSig<<1 ) ) return propagateFloatx80NaN( a, b, status );
             goto invalid;
         }
-        return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(zSign, floatx80_infinity_high,
+                                   floatx80_infinity_low);
     }
     if ( bExp == 0x7FFF ) {
         if ( (uint64_t) ( bSig<<1 ) ) return propagateFloatx80NaN( a, b, status );
@@ -5073,7 +5080,9 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status)
                 return floatx80_default_nan(status);
             }
             float_raise(float_flag_divbyzero, status);
-            return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+            return packFloatx80(zSign,
+                                floatx80_infinity_high,
+                                floatx80_infinity_low);
         }
         normalizeFloatx80Subnormal( bSig, &bExp, &bSig );
     }
@@ -5892,7 +5901,9 @@ floatx80 float128_to_floatx80(float128 a, float_status *status)
         if ( aSig0 | aSig1 ) {
             return commonNaNToFloatx80( float128ToCommonNaN( a, status ), status );
         }
-        return packFloatx80( aSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
+        return packFloatx80(aSign,
+                            floatx80_infinity_high,
+                            floatx80_infinity_low);
     }
     if ( aExp == 0 ) {
         if ( ( aSig0 | aSig1 ) == 0 ) return packFloatx80( aSign, 0, 0 );
diff --git a/qemu/header_gen.py b/qemu/header_gen.py
index e37ac3bd..a96bcf96 100644
--- a/qemu/header_gen.py
+++ b/qemu/header_gen.py
@@ -656,6 +656,7 @@ symbols = (
     'floatx80_div',
     'floatx80_eq',
     'floatx80_eq_quiet',
+    'floatx80_infinity',
     'floatx80_is_quiet_nan',
     'floatx80_is_signaling_nan',
     'floatx80_le',
diff --git a/qemu/include/fpu/softfloat.h b/qemu/include/fpu/softfloat.h
index 7c9e4f64..ddf73c6c 100644
--- a/qemu/include/fpu/softfloat.h
+++ b/qemu/include/fpu/softfloat.h
@@ -579,6 +579,11 @@ float32 floatx80_to_float32(floatx80, float_status *status);
 float64 floatx80_to_float64(floatx80, float_status *status);
 float128 floatx80_to_float128(floatx80, float_status *status);
 
+/*----------------------------------------------------------------------------
+| The pattern for an extended double-precision inf.
+*----------------------------------------------------------------------------*/
+extern const floatx80 floatx80_infinity;
+
 /*----------------------------------------------------------------------------
 | Software IEC/IEEE extended double-precision operations.
 *----------------------------------------------------------------------------*/
@@ -619,7 +624,12 @@ static inline floatx80 floatx80_chs(floatx80 a)
 
 static inline int floatx80_is_infinity(floatx80 a)
 {
-    return (a.high & 0x7fff) == 0x7fff && a.low == 0x8000000000000000LL;
+#if defined(TARGET_M68K)
+    return (a.high & 0x7fff) == floatx80_infinity.high && !(a.low << 1);
+#else
+    return (a.high & 0x7fff) == floatx80_infinity.high &&
+                       a.low == floatx80_infinity.low;
+#endif
 }
 
 static inline int floatx80_is_neg(floatx80 a)
@@ -662,7 +672,6 @@ static inline bool floatx80_invalid_encoding(floatx80 a)
 #define floatx80_ln2 make_floatx80(0x3ffe, 0xb17217f7d1cf79acLL)
 #define floatx80_pi make_floatx80(0x4000, 0xc90fdaa22168c235LL)
 #define floatx80_half make_floatx80(0x3ffe, 0x8000000000000000LL)
-#define floatx80_infinity make_floatx80(0x7fff, 0x8000000000000000LL)
 
 /*----------------------------------------------------------------------------
 | Returns the fraction bits of the extended double-precision floating-point
diff --git a/qemu/m68k.h b/qemu/m68k.h
index 87f5fb50..c249ca29 100644
--- a/qemu/m68k.h
+++ b/qemu/m68k.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_m68k
 #define floatx80_eq floatx80_eq_m68k
 #define floatx80_eq_quiet floatx80_eq_quiet_m68k
+#define floatx80_infinity floatx80_infinity_m68k
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_m68k
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_m68k
 #define floatx80_le floatx80_le_m68k
diff --git a/qemu/mips.h b/qemu/mips.h
index e430b2dd..d96d752b 100644
--- a/qemu/mips.h
+++ b/qemu/mips.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_mips
 #define floatx80_eq floatx80_eq_mips
 #define floatx80_eq_quiet floatx80_eq_quiet_mips
+#define floatx80_infinity floatx80_infinity_mips
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_mips
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_mips
 #define floatx80_le floatx80_le_mips
diff --git a/qemu/mips64.h b/qemu/mips64.h
index fcd0a36f..837344af 100644
--- a/qemu/mips64.h
+++ b/qemu/mips64.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_mips64
 #define floatx80_eq floatx80_eq_mips64
 #define floatx80_eq_quiet floatx80_eq_quiet_mips64
+#define floatx80_infinity floatx80_infinity_mips64
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_mips64
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_mips64
 #define floatx80_le floatx80_le_mips64
diff --git a/qemu/mips64el.h b/qemu/mips64el.h
index d0accfe9..d95ced59 100644
--- a/qemu/mips64el.h
+++ b/qemu/mips64el.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_mips64el
 #define floatx80_eq floatx80_eq_mips64el
 #define floatx80_eq_quiet floatx80_eq_quiet_mips64el
+#define floatx80_infinity floatx80_infinity_mips64el
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_mips64el
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_mips64el
 #define floatx80_le floatx80_le_mips64el
diff --git a/qemu/mipsel.h b/qemu/mipsel.h
index 126c0de6..a59be924 100644
--- a/qemu/mipsel.h
+++ b/qemu/mipsel.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_mipsel
 #define floatx80_eq floatx80_eq_mipsel
 #define floatx80_eq_quiet floatx80_eq_quiet_mipsel
+#define floatx80_infinity floatx80_infinity_mipsel
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_mipsel
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_mipsel
 #define floatx80_le floatx80_le_mipsel
diff --git a/qemu/powerpc.h b/qemu/powerpc.h
index e904581a..95d124a5 100644
--- a/qemu/powerpc.h
+++ b/qemu/powerpc.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_powerpc
 #define floatx80_eq floatx80_eq_powerpc
 #define floatx80_eq_quiet floatx80_eq_quiet_powerpc
+#define floatx80_infinity floatx80_infinity_powerpc
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_powerpc
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_powerpc
 #define floatx80_le floatx80_le_powerpc
diff --git a/qemu/sparc.h b/qemu/sparc.h
index da4a62f4..39b5d139 100644
--- a/qemu/sparc.h
+++ b/qemu/sparc.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_sparc
 #define floatx80_eq floatx80_eq_sparc
 #define floatx80_eq_quiet floatx80_eq_quiet_sparc
+#define floatx80_infinity floatx80_infinity_sparc
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_sparc
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_sparc
 #define floatx80_le floatx80_le_sparc
diff --git a/qemu/sparc64.h b/qemu/sparc64.h
index 4a10acb1..12cfaff3 100644
--- a/qemu/sparc64.h
+++ b/qemu/sparc64.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_sparc64
 #define floatx80_eq floatx80_eq_sparc64
 #define floatx80_eq_quiet floatx80_eq_quiet_sparc64
+#define floatx80_infinity floatx80_infinity_sparc64
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_sparc64
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_sparc64
 #define floatx80_le floatx80_le_sparc64
diff --git a/qemu/x86_64.h b/qemu/x86_64.h
index fd0631c0..077ec293 100644
--- a/qemu/x86_64.h
+++ b/qemu/x86_64.h
@@ -650,6 +650,7 @@
 #define floatx80_div floatx80_div_x86_64
 #define floatx80_eq floatx80_eq_x86_64
 #define floatx80_eq_quiet floatx80_eq_quiet_x86_64
+#define floatx80_infinity floatx80_infinity_x86_64
 #define floatx80_is_quiet_nan floatx80_is_quiet_nan_x86_64
 #define floatx80_is_signaling_nan floatx80_is_signaling_nan_x86_64
 #define floatx80_le floatx80_le_x86_64