From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60886) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YAgEs-00019y-1X for qemu-devel@nongnu.org; Mon, 12 Jan 2015 09:45:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YAgEn-0007vd-Ox for qemu-devel@nongnu.org; Mon, 12 Jan 2015 09:45:05 -0500 Received: from mnementh.archaic.org.uk ([2001:8b0:1d0::1]:54808) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YAgEn-0007v5-HH for qemu-devel@nongnu.org; Mon, 12 Jan 2015 09:45:01 -0500 From: Peter Maydell Date: Mon, 12 Jan 2015 14:38:26 +0000 Message-Id: <1421073508-23909-3-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1421073508-23909-1-git-send-email-peter.maydell@linaro.org> References: <1421073508-23909-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH v2 2/4] softfloat: Revert and reimplement remaining portions of 75d62a5856 and 3430b0be36f List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: patches@linaro.org, "Maciej W. Rozycki" , Anthony Liguori , Paolo Bonzini , =?UTF-8?q?Andreas=20F=C3=A4rber?= , Aurelien Jarno , Richard Henderson Revert the remaining portions of commits 75d62a5856 and 3430b0be36f which are under a SoftFloat-2b license, ie the functions uint64_to_float32() and uint64_to_float64(). (The float64_to_uint64() and float64_to_uint64_round_to_zero() functions were completely rewritten in commits fb3ea83aa and 0a87a3107d so can stay.) Reimplement from scratch the uint64_to_float64() and uint64_to_float32() conversion functions. [This is a mechanical squashing together of two separate "revert" and "reimplement" patches.] Signed-off-by: Peter Maydell --- fpu/softfloat.c | 100 +++++++++++++++++++++++++++++++----------------- include/fpu/softfloat.h | 4 +- 2 files changed, 67 insertions(+), 37 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 6041dbd..ad316e7 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -1302,27 +1302,6 @@ float32 int64_to_float32(int64_t a STATUS_PARAM) } -float32 uint64_to_float32(uint64_t a STATUS_PARAM) -{ - int8 shiftCount; - - if ( a == 0 ) return float32_zero; - shiftCount = countLeadingZeros64( a ) - 40; - if ( 0 <= shiftCount ) { - return packFloat32(0, 0x95 - shiftCount, a<= 0) { + return packFloat32(0, 0x95 - shiftcount, a << shiftcount); + } + /* Otherwise we need to do a round-and-pack. roundAndPackFloat32() + * expects the binary point between bits 30 and 29, hence the + 7. + */ + shiftcount += 7; + if (shiftcount < 0) { + shift64RightJamming(a, -shiftcount, &a); + } else { + a <<= shiftcount; + } + + return roundAndPackFloat32(0, 0x9c - shiftcount, a STATUS_VAR); +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the 64-bit unsigned integer `a' +| to the double-precision floating-point format. The conversion is performed +| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +float64 uint64_to_float64(uint64_t a STATUS_PARAM) +{ + int exp = 0x43C; + int shiftcount; + + if (a == 0) { + return float64_zero; + } + + shiftcount = countLeadingZeros64(a) - 1; + if (shiftcount < 0) { + shift64RightJamming(a, -shiftcount, &a); + } else { + a <<= shiftcount; + } + return roundAndPackFloat64(0, exp - shiftcount, a STATUS_VAR); +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the 64-bit unsigned integer `a' +| to the quadruple-precision floating-point format. The conversion is performed +| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + float128 uint64_to_float128(uint64_t a STATUS_PARAM) { if (a == 0) { diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index 4da5778..b3c710a 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -273,11 +273,11 @@ float64 uint32_to_float64(uint32_t STATUS_PARAM); floatx80 int32_to_floatx80(int32_t STATUS_PARAM); float128 int32_to_float128(int32_t STATUS_PARAM); float32 int64_to_float32(int64_t STATUS_PARAM); -float32 uint64_to_float32(uint64_t STATUS_PARAM); float64 int64_to_float64(int64_t STATUS_PARAM); -float64 uint64_to_float64(uint64_t STATUS_PARAM); floatx80 int64_to_floatx80(int64_t STATUS_PARAM); float128 int64_to_float128(int64_t STATUS_PARAM); +float32 uint64_to_float32(uint64_t STATUS_PARAM); +float64 uint64_to_float64(uint64_t STATUS_PARAM); float128 uint64_to_float128(uint64_t STATUS_PARAM); /* We provide the int16 versions for symmetry of API with float-to-int */ -- 1.9.1