aboutsummaryrefslogtreecommitdiff
path: root/fpu/softfloat.c
diff options
context:
space:
mode:
Diffstat (limited to 'fpu/softfloat.c')
-rw-r--r--fpu/softfloat.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 3d5169d..4d58744 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -2057,6 +2057,53 @@ float32 float32_sqrt( float32 a STATUS_PARAM )
}
/*----------------------------------------------------------------------------
+| Returns the binary log of the single-precision floating-point value `a'.
+| The operation is performed according to the IEC/IEEE Standard for Binary
+| Floating-Point Arithmetic.
+*----------------------------------------------------------------------------*/
+float32 float32_log2( float32 a STATUS_PARAM )
+{
+ flag aSign, zSign;
+ int16 aExp;
+ bits32 aSig, zSig, i;
+
+ aSig = extractFloat32Frac( a );
+ aExp = extractFloat32Exp( a );
+ aSign = extractFloat32Sign( a );
+
+ if ( aExp == 0 ) {
+ if ( aSig == 0 ) return packFloat32( 1, 0xFF, 0 );
+ normalizeFloat32Subnormal( aSig, &aExp, &aSig );
+ }
+ if ( aSign ) {
+ float_raise( float_flag_invalid STATUS_VAR);
+ return float32_default_nan;
+ }
+ if ( aExp == 0xFF ) {
+ if ( aSig ) return propagateFloat32NaN( a, float32_zero STATUS_VAR );
+ return a;
+ }
+
+ aExp -= 0x7F;
+ aSig |= 0x00800000;
+ zSign = aExp < 0;
+ zSig = aExp << 23;
+
+ for (i = 1 << 22; i > 0; i >>= 1) {
+ aSig = ( (bits64)aSig * aSig ) >> 23;
+ if ( aSig & 0x01000000 ) {
+ aSig >>= 1;
+ zSig |= i;
+ }
+ }
+
+ if ( zSign )
+ zSig = -zSig;
+
+ return normalizeRoundAndPackFloat32( zSign, 0x85, zSig STATUS_VAR );
+}
+
+/*----------------------------------------------------------------------------
| Returns 1 if the single-precision floating-point value `a' is equal to
| the corresponding value `b', and 0 otherwise. The comparison is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
@@ -3006,6 +3053,52 @@ float64 float64_sqrt( float64 a STATUS_PARAM )
}
/*----------------------------------------------------------------------------
+| Returns the binary log of the double-precision floating-point value `a'.
+| The operation is performed according to the IEC/IEEE Standard for Binary
+| Floating-Point Arithmetic.
+*----------------------------------------------------------------------------*/
+float64 float64_log2( float64 a STATUS_PARAM )
+{
+ flag aSign, zSign;
+ int16 aExp;
+ bits64 aSig, aSig0, aSig1, zSig, i;
+
+ aSig = extractFloat64Frac( a );
+ aExp = extractFloat64Exp( a );
+ aSign = extractFloat64Sign( a );
+
+ if ( aExp == 0 ) {
+ if ( aSig == 0 ) return packFloat64( 1, 0x7FF, 0 );
+ normalizeFloat64Subnormal( aSig, &aExp, &aSig );
+ }
+ if ( aSign ) {
+ float_raise( float_flag_invalid STATUS_VAR);
+ return float64_default_nan;
+ }
+ if ( aExp == 0x7FF ) {
+ if ( aSig ) return propagateFloat64NaN( a, float64_zero STATUS_VAR );
+ return a;
+ }
+
+ aExp -= 0x3FF;
+ aSig |= LIT64( 0x0010000000000000 );
+ zSign = aExp < 0;
+ zSig = (bits64)aExp << 52;
+ for (i = 1LL << 51; i > 0; i >>= 1) {
+ mul64To128( aSig, aSig, &aSig0, &aSig1 );
+ aSig = ( aSig0 << 12 ) | ( aSig1 >> 52 );
+ if ( aSig & LIT64( 0x0020000000000000 ) ) {
+ aSig >>= 1;
+ zSig |= i;
+ }
+ }
+
+ if ( zSign )
+ zSig = -zSig;
+ return normalizeRoundAndPackFloat64( zSign, 0x408, zSig STATUS_VAR );
+}
+
+/*----------------------------------------------------------------------------
| Returns 1 if the double-precision floating-point value `a' is equal to the
| corresponding value `b', and 0 otherwise. The comparison is performed
| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.