xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

sh: Subnormal double to float conversion

Browse Source 
This patch adds support for the SH4 to convert a subnormal double
into a float by catching the FPE and implementing the FCNVDS
instruction in software.

Signed-off-by: Carl Shaw <carl.shaw@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Carl Shaw
2008-09-05 16:36:19 +09:00
committed by Paul Mundt
parent f040ddaf4c
commit b6ad1e8c3f
2 changed files with 53 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
arch/sh/kernel/cpu/sh4/softfloat.c
View File

@@ -85,6 +85,7 @@ float64 float64_div(float64 a, float64 b);
float32 float32_div(float32 a, float32 b);
float32 float32_mul(float32 a, float32 b);
float64 float64_mul(float64 a, float64 b);
float32 float64_to_float32(float64 a);
inline void add128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
bits64 * z1Ptr);
inline void sub128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
@@ -890,3 +891,31 @@ float64 float64_mul(float64 a, float64 b)
}
return roundAndPackFloat64(zSign, zExp, zSig0);
}
/*
* -------------------------------------------------------------------------------
* Returns the result of converting the double-precision floating-point value
* `a' to the single-precision floating-point format. The conversion is
* performed according to the IEC/IEEE Standard for Binary Floating-point
* Arithmetic.
* -------------------------------------------------------------------------------
* */
float32 float64_to_float32(float64 a)
{
flag aSign;
int16 aExp;
bits64 aSig;
bits32 zSig;
aSig = extractFloat64Frac( a );
aExp = extractFloat64Exp( a );
aSign = extractFloat64Sign( a );
shift64RightJamming( aSig, 22, &aSig );
zSig = aSig;
if ( aExp || zSig ) {
zSig |= 0x40000000;
aExp -= 0x381;
}
return roundAndPackFloat32(aSign, aExp, zSig);
}