diff options
| author | Paul Burton <paul.burton@imgtec.com> | 2016-04-21 14:04:54 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2016-05-13 14:02:23 +0200 |
| commit | db57f29d50683afd75c7f8b9908af7669837c3a9 (patch) | |
| tree | 0811a8ef970725d4fe6d22c27d3987fcaf455fa5 /arch/mips/math-emu/sp_maddf.c | |
| parent | 5c18c936b52ae80db5737849e11f436e79b84b2d (diff) | |
MIPS: math-emu: Fix m{add,sub}.s shifts
The code in _sp_maddf (formerly ieee754sp_madd) appears to have been
copied verbatim from ieee754sp_add, and although it's adding the
unpacked "r" & "z" floats it kept using macros that operate on "x" &
"y". This led to the addition being carried out incorrectly on some
mismash of the product, accumulator & multiplicand fields. Typically
this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing
since ze & re hadn't been operated upon.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/math-emu/sp_maddf.c')
| -rw-r--r-- | arch/mips/math-emu/sp_maddf.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/mips/math-emu/sp_maddf.c b/arch/mips/math-emu/sp_maddf.c index 86e1d0b25446..a8cd8b4f235e 100644 --- a/arch/mips/math-emu/sp_maddf.c +++ b/arch/mips/math-emu/sp_maddf.c @@ -214,16 +214,18 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x, if (ze > re) { /* - * Have to shift y fraction right to align. + * Have to shift r fraction right to align. */ s = ze - re; - SPXSRSYn(s); + rm = XSPSRS(rm, s); + re += s; } else if (re > ze) { /* - * Have to shift x fraction right to align. + * Have to shift z fraction right to align. */ s = re - ze; - SPXSRSYn(s); + zm = XSPSRS(zm, s); + ze += s; } assert(ze == re); assert(ze <= SP_EMAX); @@ -236,7 +238,8 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x, zm = zm + rm; if (zm >> (SP_FBITS + 1 + 3)) { /* carry out */ - SPXSRSX1(); + zm = XSPSRS1(zm); + ze++; } } else { if (zm >= rm) { |