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[69.14.184.20]) by smtp.gmail.com with ESMTPSA id p20sm1575524ioj.63.2019.05.24.19.20.29 (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 24 May 2019 19:20:30 -0700 (PDT) From: John Arbuckle To: richard.henderson@linaro.org, qemu-devel@nongnu.org, qemu-ppc@nongnu.orgd, david@gibson.dropbear.id.au, mark.cave-ayland@ilande.co.uk Date: Fri, 24 May 2019 22:20:07 -0400 Message-Id: <20190525022008.24788-2-programmingkidx@gmail.com> X-Mailer: git-send-email 2.14.3 (Apple Git-98) In-Reply-To: <20190525022008.24788-1-programmingkidx@gmail.com> References: <20190525022008.24788-1-programmingkidx@gmail.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::143 Subject: [Qemu-devel] [PATCH 1/2] Implement Floating Point flag Fraction Rounded X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: John Arbuckle Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: John Arbuckle Reviewed-by: Richard Henderson --- fpu/softfloat.c | 15 ++++++++++++--- include/fpu/softfloat-types.h | 1 + 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 2ba36ec370..ac34f6a2de 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -702,7 +702,7 @@ static FloatParts round_canonical(FloatParts p, float_status *s, const uint64_t roundeven_mask = parm->roundeven_mask; const int exp_max = parm->exp_max; const int frac_shift = parm->frac_shift; - uint64_t frac, inc; + uint64_t frac, inc, rounded; int exp, flags = 0; bool overflow_norm; @@ -744,7 +744,12 @@ static FloatParts round_canonical(FloatParts p, float_status *s, if (likely(exp > 0)) { if (frac & round_mask) { flags |= float_flag_inexact; - frac += inc; + rounded = frac + inc; + if ((rounded ^ frac) & frac_lsb) { + flags |= float_flag_rounded; + } + frac = rounded; + if (frac & DECOMPOSED_OVERFLOW_BIT) { frac >>= 1; exp++; @@ -793,7 +798,11 @@ static FloatParts round_canonical(FloatParts p, float_status *s, break; } flags |= float_flag_inexact; - frac += inc; + rounded = frac + inc; + if ((rounded ^ frac) & frac_lsb) { + flags |= float_flag_rounded; + } + frac = rounded; } exp = (frac & DECOMPOSED_IMPLICIT_BIT ? 1 : 0); diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h index 2aae6a89b1..bee576e0fd 100644 --- a/include/fpu/softfloat-types.h +++ b/include/fpu/softfloat-types.h @@ -147,6 +147,7 @@ enum { enum { float_flag_invalid = 1, + float_flag_rounded = 2, float_flag_divbyzero = 4, float_flag_overflow = 8, float_flag_underflow = 16,