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author | Jordan Rupprecht <rupprecht@google.com> | 2019-05-14 21:58:59 +0000 |
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committer | Jordan Rupprecht <rupprecht@google.com> | 2019-05-14 21:58:59 +0000 |
commit | b6bc976d7be8ee56d3be4b6dbd2f3ab0a4021c86 (patch) | |
tree | f5ed5db8cb5d237a073ea00c4d4cd63153a16a6c /lib/builtins/fp_extend_impl.inc | |
parent | 05342ccc9cff16425c0a831fddd510879544a0bf (diff) | |
parent | 098ca93185735ec3687106d0967a70fc99a85059 (diff) | |
download | compiler-rt-google/stable.tar.gz |
Creating branches/google/stable and tags/google/stable/2019-05-14 from r360103google/stable
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/branches/google/stable@360714 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/builtins/fp_extend_impl.inc')
-rw-r--r-- | lib/builtins/fp_extend_impl.inc | 121 |
1 files changed, 60 insertions, 61 deletions
diff --git a/lib/builtins/fp_extend_impl.inc b/lib/builtins/fp_extend_impl.inc index b785cc768..4fa3ed8d9 100644 --- a/lib/builtins/fp_extend_impl.inc +++ b/lib/builtins/fp_extend_impl.inc @@ -1,9 +1,8 @@ //=-lib/fp_extend_impl.inc - low precision -> high precision conversion -*-- -// // -// The LLVM Compiler Infrastructure -// -// This file is dual licensed under the MIT and the University of Illinois Open -// Source Licenses. See LICENSE.TXT for details. +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // @@ -39,70 +38,70 @@ #include "fp_extend.h" static __inline dst_t __extendXfYf2__(src_t a) { - // Various constants whose values follow from the type parameters. - // Any reasonable optimizer will fold and propagate all of these. - const int srcBits = sizeof(src_t)*CHAR_BIT; - const int srcExpBits = srcBits - srcSigBits - 1; - const int srcInfExp = (1 << srcExpBits) - 1; - const int srcExpBias = srcInfExp >> 1; + // Various constants whose values follow from the type parameters. + // Any reasonable optimizer will fold and propagate all of these. + const int srcBits = sizeof(src_t) * CHAR_BIT; + const int srcExpBits = srcBits - srcSigBits - 1; + const int srcInfExp = (1 << srcExpBits) - 1; + const int srcExpBias = srcInfExp >> 1; - const src_rep_t srcMinNormal = SRC_REP_C(1) << srcSigBits; - const src_rep_t srcInfinity = (src_rep_t)srcInfExp << srcSigBits; - const src_rep_t srcSignMask = SRC_REP_C(1) << (srcSigBits + srcExpBits); - const src_rep_t srcAbsMask = srcSignMask - 1; - const src_rep_t srcQNaN = SRC_REP_C(1) << (srcSigBits - 1); - const src_rep_t srcNaNCode = srcQNaN - 1; + const src_rep_t srcMinNormal = SRC_REP_C(1) << srcSigBits; + const src_rep_t srcInfinity = (src_rep_t)srcInfExp << srcSigBits; + const src_rep_t srcSignMask = SRC_REP_C(1) << (srcSigBits + srcExpBits); + const src_rep_t srcAbsMask = srcSignMask - 1; + const src_rep_t srcQNaN = SRC_REP_C(1) << (srcSigBits - 1); + const src_rep_t srcNaNCode = srcQNaN - 1; - const int dstBits = sizeof(dst_t)*CHAR_BIT; - const int dstExpBits = dstBits - dstSigBits - 1; - const int dstInfExp = (1 << dstExpBits) - 1; - const int dstExpBias = dstInfExp >> 1; + const int dstBits = sizeof(dst_t) * CHAR_BIT; + const int dstExpBits = dstBits - dstSigBits - 1; + const int dstInfExp = (1 << dstExpBits) - 1; + const int dstExpBias = dstInfExp >> 1; - const dst_rep_t dstMinNormal = DST_REP_C(1) << dstSigBits; + const dst_rep_t dstMinNormal = DST_REP_C(1) << dstSigBits; - // Break a into a sign and representation of the absolute value - const src_rep_t aRep = srcToRep(a); - const src_rep_t aAbs = aRep & srcAbsMask; - const src_rep_t sign = aRep & srcSignMask; - dst_rep_t absResult; + // Break a into a sign and representation of the absolute value + const src_rep_t aRep = srcToRep(a); + const src_rep_t aAbs = aRep & srcAbsMask; + const src_rep_t sign = aRep & srcSignMask; + dst_rep_t absResult; - // If sizeof(src_rep_t) < sizeof(int), the subtraction result is promoted - // to (signed) int. To avoid that, explicitly cast to src_rep_t. - if ((src_rep_t)(aAbs - srcMinNormal) < srcInfinity - srcMinNormal) { - // a is a normal number. - // Extend to the destination type by shifting the significand and - // exponent into the proper position and rebiasing the exponent. - absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits); - absResult += (dst_rep_t)(dstExpBias - srcExpBias) << dstSigBits; - } + // If sizeof(src_rep_t) < sizeof(int), the subtraction result is promoted + // to (signed) int. To avoid that, explicitly cast to src_rep_t. + if ((src_rep_t)(aAbs - srcMinNormal) < srcInfinity - srcMinNormal) { + // a is a normal number. + // Extend to the destination type by shifting the significand and + // exponent into the proper position and rebiasing the exponent. + absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits); + absResult += (dst_rep_t)(dstExpBias - srcExpBias) << dstSigBits; + } - else if (aAbs >= srcInfinity) { - // a is NaN or infinity. - // Conjure the result by beginning with infinity, then setting the qNaN - // bit (if needed) and right-aligning the rest of the trailing NaN - // payload field. - absResult = (dst_rep_t)dstInfExp << dstSigBits; - absResult |= (dst_rep_t)(aAbs & srcQNaN) << (dstSigBits - srcSigBits); - absResult |= (dst_rep_t)(aAbs & srcNaNCode) << (dstSigBits - srcSigBits); - } + else if (aAbs >= srcInfinity) { + // a is NaN or infinity. + // Conjure the result by beginning with infinity, then setting the qNaN + // bit (if needed) and right-aligning the rest of the trailing NaN + // payload field. + absResult = (dst_rep_t)dstInfExp << dstSigBits; + absResult |= (dst_rep_t)(aAbs & srcQNaN) << (dstSigBits - srcSigBits); + absResult |= (dst_rep_t)(aAbs & srcNaNCode) << (dstSigBits - srcSigBits); + } - else if (aAbs) { - // a is denormal. - // renormalize the significand and clear the leading bit, then insert - // the correct adjusted exponent in the destination type. - const int scale = src_rep_t_clz(aAbs) - src_rep_t_clz(srcMinNormal); - absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits + scale); - absResult ^= dstMinNormal; - const int resultExponent = dstExpBias - srcExpBias - scale + 1; - absResult |= (dst_rep_t)resultExponent << dstSigBits; - } + else if (aAbs) { + // a is denormal. + // renormalize the significand and clear the leading bit, then insert + // the correct adjusted exponent in the destination type. + const int scale = src_rep_t_clz(aAbs) - src_rep_t_clz(srcMinNormal); + absResult = (dst_rep_t)aAbs << (dstSigBits - srcSigBits + scale); + absResult ^= dstMinNormal; + const int resultExponent = dstExpBias - srcExpBias - scale + 1; + absResult |= (dst_rep_t)resultExponent << dstSigBits; + } - else { - // a is zero. - absResult = 0; - } + else { + // a is zero. + absResult = 0; + } - // Apply the signbit to (dst_t)abs(a). - const dst_rep_t result = absResult | (dst_rep_t)sign << (dstBits - srcBits); - return dstFromRep(result); + // Apply the signbit to (dst_t)abs(a). + const dst_rep_t result = absResult | (dst_rep_t)sign << (dstBits - srcBits); + return dstFromRep(result); } |