mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

softfloat: fix floatx80 remainder pseudo-denormal check for zero

Browse Source 
The floatx80 remainder implementation ignores the high bit of the
significand when checking whether an operand (numerator) with zero
exponent is zero.  This means it mishandles a pseudo-denormal
representation of 0x1p-16382L by treating it as zero.  Fix this by
checking the whole significand instead.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <alpine.DEB.2.21.2006081655180.23637@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Joseph Myers 2020-06-08 16:55:49 +00:00 committed by Paolo Bonzini
parent 6b8b0136ab
commit 499a2f7b55
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fpu/softfloat.c
View File

@ -5741,7 +5741,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod,
normalizeFloatx80Subnormal( bSig, &bExp, &bSig ); normalizeFloatx80Subnormal( bSig, &bExp, &bSig );
} }
if ( aExp == 0 ) { if ( aExp == 0 ) {
if ( (uint64_t) ( aSig0<<1 ) == 0 ) return a; if ( aSig0 == 0 ) return a;
normalizeFloatx80Subnormal( aSig0, &aExp, &aSig0 ); normalizeFloatx80Subnormal( aSig0, &aExp, &aSig0 );
} }
bSig |= UINT64_C(0x8000000000000000); bSig |= UINT64_C(0x8000000000000000);