aboutsummaryrefslogtreecommitdiffstats
path: root/lib/builtins/fp_add_impl.inc
diff options
context:
space:
mode:
authorDimitry Andric <dim@FreeBSD.org>2019-08-20 20:51:06 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-08-20 20:51:06 +0000
commit8f3cadc28cb2bb9e8f9d69eeaaea1f57f2f7b2ab (patch)
tree05a2b6ec297fe6283d9557c791445d1daf88dcd0 /lib/builtins/fp_add_impl.inc
parent63714eb5809e39666dec2454c354195e76f916ba (diff)
downloadsrc-8f3cadc28cb2bb9e8f9d69eeaaea1f57f2f7b2ab.tar.gz
src-8f3cadc28cb2bb9e8f9d69eeaaea1f57f2f7b2ab.zip
Vendor import of stripped compiler-rt trunk r366426 (just before the release_90vendor/compiler-rt/compiler-rt-trunk-r366426
Notes
Notes: svn path=/vendor/compiler-rt/dist/; revision=351282 svn path=/vendor/compiler-rt/compiler-rt-trunk-r366426/; revision=351283; tag=vendor/compiler-rt/compiler-rt-trunk-r366426
Diffstat (limited to 'lib/builtins/fp_add_impl.inc')
-rw-r--r--lib/builtins/fp_add_impl.inc259
1 files changed, 136 insertions, 123 deletions
diff --git a/lib/builtins/fp_add_impl.inc b/lib/builtins/fp_add_impl.inc
index b47be1b648e6..da8639341703 100644
--- a/lib/builtins/fp_add_impl.inc
+++ b/lib/builtins/fp_add_impl.inc
@@ -1,9 +1,8 @@
//===----- lib/fp_add_impl.inc - floaing point addition -----------*- C -*-===//
//
-// 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
//
//===----------------------------------------------------------------------===//
//
@@ -15,130 +14,144 @@
#include "fp_lib.h"
static __inline fp_t __addXf3__(fp_t a, fp_t b) {
- rep_t aRep = toRep(a);
- rep_t bRep = toRep(b);
- const rep_t aAbs = aRep & absMask;
- const rep_t bAbs = bRep & absMask;
-
- // Detect if a or b is zero, infinity, or NaN.
- if (aAbs - REP_C(1) >= infRep - REP_C(1) ||
- bAbs - REP_C(1) >= infRep - REP_C(1)) {
- // NaN + anything = qNaN
- if (aAbs > infRep) return fromRep(toRep(a) | quietBit);
- // anything + NaN = qNaN
- if (bAbs > infRep) return fromRep(toRep(b) | quietBit);
-
- if (aAbs == infRep) {
- // +/-infinity + -/+infinity = qNaN
- if ((toRep(a) ^ toRep(b)) == signBit) return fromRep(qnanRep);
- // +/-infinity + anything remaining = +/- infinity
- else return a;
- }
-
- // anything remaining + +/-infinity = +/-infinity
- if (bAbs == infRep) return b;
-
- // zero + anything = anything
- if (!aAbs) {
- // but we need to get the sign right for zero + zero
- if (!bAbs) return fromRep(toRep(a) & toRep(b));
- else return b;
- }
-
- // anything + zero = anything
- if (!bAbs) return a;
+ rep_t aRep = toRep(a);
+ rep_t bRep = toRep(b);
+ const rep_t aAbs = aRep & absMask;
+ const rep_t bAbs = bRep & absMask;
+
+ // Detect if a or b is zero, infinity, or NaN.
+ if (aAbs - REP_C(1) >= infRep - REP_C(1) ||
+ bAbs - REP_C(1) >= infRep - REP_C(1)) {
+ // NaN + anything = qNaN
+ if (aAbs > infRep)
+ return fromRep(toRep(a) | quietBit);
+ // anything + NaN = qNaN
+ if (bAbs > infRep)
+ return fromRep(toRep(b) | quietBit);
+
+ if (aAbs == infRep) {
+ // +/-infinity + -/+infinity = qNaN
+ if ((toRep(a) ^ toRep(b)) == signBit)
+ return fromRep(qnanRep);
+ // +/-infinity + anything remaining = +/- infinity
+ else
+ return a;
}
- // Swap a and b if necessary so that a has the larger absolute value.
- if (bAbs > aAbs) {
- const rep_t temp = aRep;
- aRep = bRep;
- bRep = temp;
+ // anything remaining + +/-infinity = +/-infinity
+ if (bAbs == infRep)
+ return b;
+
+ // zero + anything = anything
+ if (!aAbs) {
+ // We need to get the sign right for zero + zero.
+ if (!bAbs)
+ return fromRep(toRep(a) & toRep(b));
+ else
+ return b;
}
- // Extract the exponent and significand from the (possibly swapped) a and b.
- int aExponent = aRep >> significandBits & maxExponent;
- int bExponent = bRep >> significandBits & maxExponent;
- rep_t aSignificand = aRep & significandMask;
- rep_t bSignificand = bRep & significandMask;
-
- // Normalize any denormals, and adjust the exponent accordingly.
- if (aExponent == 0) aExponent = normalize(&aSignificand);
- if (bExponent == 0) bExponent = normalize(&bSignificand);
-
- // The sign of the result is the sign of the larger operand, a. If they
- // have opposite signs, we are performing a subtraction; otherwise addition.
- const rep_t resultSign = aRep & signBit;
- const bool subtraction = (aRep ^ bRep) & signBit;
-
- // Shift the significands to give us round, guard and sticky, and or in the
- // implicit significand bit. (If we fell through from the denormal path it
- // was already set by normalize( ), but setting it twice won't hurt
- // anything.)
- aSignificand = (aSignificand | implicitBit) << 3;
- bSignificand = (bSignificand | implicitBit) << 3;
-
- // Shift the significand of b by the difference in exponents, with a sticky
- // bottom bit to get rounding correct.
- const unsigned int align = aExponent - bExponent;
- if (align) {
- if (align < typeWidth) {
- const bool sticky = bSignificand << (typeWidth - align);
- bSignificand = bSignificand >> align | sticky;
- } else {
- bSignificand = 1; // sticky; b is known to be non-zero.
- }
- }
- if (subtraction) {
- aSignificand -= bSignificand;
- // If a == -b, return +zero.
- if (aSignificand == 0) return fromRep(0);
-
- // If partial cancellation occured, we need to left-shift the result
- // and adjust the exponent:
- if (aSignificand < implicitBit << 3) {
- const int shift = rep_clz(aSignificand) - rep_clz(implicitBit << 3);
- aSignificand <<= shift;
- aExponent -= shift;
- }
+ // anything + zero = anything
+ if (!bAbs)
+ return a;
+ }
+
+ // Swap a and b if necessary so that a has the larger absolute value.
+ if (bAbs > aAbs) {
+ const rep_t temp = aRep;
+ aRep = bRep;
+ bRep = temp;
+ }
+
+ // Extract the exponent and significand from the (possibly swapped) a and b.
+ int aExponent = aRep >> significandBits & maxExponent;
+ int bExponent = bRep >> significandBits & maxExponent;
+ rep_t aSignificand = aRep & significandMask;
+ rep_t bSignificand = bRep & significandMask;
+
+ // Normalize any denormals, and adjust the exponent accordingly.
+ if (aExponent == 0)
+ aExponent = normalize(&aSignificand);
+ if (bExponent == 0)
+ bExponent = normalize(&bSignificand);
+
+ // The sign of the result is the sign of the larger operand, a. If they
+ // have opposite signs, we are performing a subtraction. Otherwise, we
+ // perform addition.
+ const rep_t resultSign = aRep & signBit;
+ const bool subtraction = (aRep ^ bRep) & signBit;
+
+ // Shift the significands to give us round, guard and sticky, and set the
+ // implicit significand bit. If we fell through from the denormal path it
+ // was already set by normalize( ), but setting it twice won't hurt
+ // anything.
+ aSignificand = (aSignificand | implicitBit) << 3;
+ bSignificand = (bSignificand | implicitBit) << 3;
+
+ // Shift the significand of b by the difference in exponents, with a sticky
+ // bottom bit to get rounding correct.
+ const unsigned int align = aExponent - bExponent;
+ if (align) {
+ if (align < typeWidth) {
+ const bool sticky = bSignificand << (typeWidth - align);
+ bSignificand = bSignificand >> align | sticky;
+ } else {
+ bSignificand = 1; // Set the sticky bit. b is known to be non-zero.
}
- else /* addition */ {
- aSignificand += bSignificand;
-
- // If the addition carried up, we need to right-shift the result and
- // adjust the exponent:
- if (aSignificand & implicitBit << 4) {
- const bool sticky = aSignificand & 1;
- aSignificand = aSignificand >> 1 | sticky;
- aExponent += 1;
- }
+ }
+ if (subtraction) {
+ aSignificand -= bSignificand;
+ // If a == -b, return +zero.
+ if (aSignificand == 0)
+ return fromRep(0);
+
+ // If partial cancellation occured, we need to left-shift the result
+ // and adjust the exponent.
+ if (aSignificand < implicitBit << 3) {
+ const int shift = rep_clz(aSignificand) - rep_clz(implicitBit << 3);
+ aSignificand <<= shift;
+ aExponent -= shift;
}
-
- // If we have overflowed the type, return +/- infinity:
- if (aExponent >= maxExponent) return fromRep(infRep | resultSign);
-
- if (aExponent <= 0) {
- // Result is denormal before rounding; the exponent is zero and we
- // need to shift the significand.
- const int shift = 1 - aExponent;
- const bool sticky = aSignificand << (typeWidth - shift);
- aSignificand = aSignificand >> shift | sticky;
- aExponent = 0;
+ } else /* addition */ {
+ aSignificand += bSignificand;
+
+ // If the addition carried up, we need to right-shift the result and
+ // adjust the exponent.
+ if (aSignificand & implicitBit << 4) {
+ const bool sticky = aSignificand & 1;
+ aSignificand = aSignificand >> 1 | sticky;
+ aExponent += 1;
}
-
- // Low three bits are round, guard, and sticky.
- const int roundGuardSticky = aSignificand & 0x7;
-
- // Shift the significand into place, and mask off the implicit bit.
- rep_t result = aSignificand >> 3 & significandMask;
-
- // Insert the exponent and sign.
- result |= (rep_t)aExponent << significandBits;
- result |= resultSign;
-
- // Final rounding. The result may overflow to infinity, but that is the
- // correct result in that case.
- if (roundGuardSticky > 0x4) result++;
- if (roundGuardSticky == 0x4) result += result & 1;
- return fromRep(result);
+ }
+
+ // If we have overflowed the type, return +/- infinity.
+ if (aExponent >= maxExponent)
+ return fromRep(infRep | resultSign);
+
+ if (aExponent <= 0) {
+ // The result is denormal before rounding. The exponent is zero and we
+ // need to shift the significand.
+ const int shift = 1 - aExponent;
+ const bool sticky = aSignificand << (typeWidth - shift);
+ aSignificand = aSignificand >> shift | sticky;
+ aExponent = 0;
+ }
+
+ // Low three bits are round, guard, and sticky.
+ const int roundGuardSticky = aSignificand & 0x7;
+
+ // Shift the significand into place, and mask off the implicit bit.
+ rep_t result = aSignificand >> 3 & significandMask;
+
+ // Insert the exponent and sign.
+ result |= (rep_t)aExponent << significandBits;
+ result |= resultSign;
+
+ // Perform the final rounding. The result may overflow to infinity, but
+ // that is the correct result in that case.
+ if (roundGuardSticky > 0x4)
+ result++;
+ if (roundGuardSticky == 0x4)
+ result += result & 1;
+ return fromRep(result);
}