From: Aleksandar Markovic <[email protected]> If accumulator value is zero, just return the value of previously calculated product. This brings logic in MADDf/MSUBF implementation closer to the logic in ADD/SUB case.
Signed-off-by: Miodrag Dinic <[email protected]> Signed-off-by: Goran Ferenc <[email protected]> Signed-off-by: Aleksandar Markovic <[email protected]> --- arch/mips/math-emu/dp_maddf.c | 5 ++++- arch/mips/math-emu/sp_maddf.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/mips/math-emu/dp_maddf.c b/arch/mips/math-emu/dp_maddf.c index 4a2d03c..caa62f2 100644 --- a/arch/mips/math-emu/dp_maddf.c +++ b/arch/mips/math-emu/dp_maddf.c @@ -54,7 +54,7 @@ static union ieee754dp _dp_maddf(union ieee754dp z, union ieee754dp x, return ieee754dp_nanxcpt(z); case IEEE754_CLASS_DNORM: DPDNORMZ; - /* QNAN is handled separately below */ + /* QNAN and ZERO cases are handled separately below */ } switch (CLPAIR(xc, yc)) { @@ -210,6 +210,9 @@ static union ieee754dp _dp_maddf(union ieee754dp z, union ieee754dp x, } assert(rm & (DP_HIDDEN_BIT << 3)); + if (zc == IEEE754_CLASS_ZERO) + return ieee754dp_format(rs, re, rm); + /* And now the addition */ assert(zm & DP_HIDDEN_BIT); diff --git a/arch/mips/math-emu/sp_maddf.c b/arch/mips/math-emu/sp_maddf.c index a8cd8b4..c91d5e5 100644 --- a/arch/mips/math-emu/sp_maddf.c +++ b/arch/mips/math-emu/sp_maddf.c @@ -54,7 +54,7 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x, return ieee754sp_nanxcpt(z); case IEEE754_CLASS_DNORM: SPDNORMZ; - /* QNAN is handled separately below */ + /* QNAN and ZERO cases are handled separately below */ } switch (CLPAIR(xc, yc)) { @@ -203,6 +203,9 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x, } assert(rm & (SP_HIDDEN_BIT << 3)); + if (zc == IEEE754_CLASS_ZERO) + return ieee754sp_format(rs, re, rm); + /* And now the addition */ assert(zm & SP_HIDDEN_BIT); -- 2.7.4
