[libc-commits] [libc] [libc][NFC] Remove dead code (PR #81005)
Guillaume Chatelet via libc-commits
libc-commits at lists.llvm.org
Wed Feb 7 07:59:57 PST 2024
https://github.com/gchatelet created https://github.com/llvm/llvm-project/pull/81005
None
>From b2ce92d3daed15bafe5ac6e18250e77396d95e5d Mon Sep 17 00:00:00 2001
From: Guillaume Chatelet <gchatelet at google.com>
Date: Wed, 7 Feb 2024 15:59:30 +0000
Subject: [PATCH] [libc][NFC] Remove dead code
---
libc/src/__support/FPUtil/CMakeLists.txt | 10 --
libc/src/__support/FPUtil/XFloat.h | 180 -----------------------
2 files changed, 190 deletions(-)
delete mode 100644 libc/src/__support/FPUtil/XFloat.h
diff --git a/libc/src/__support/FPUtil/CMakeLists.txt b/libc/src/__support/FPUtil/CMakeLists.txt
index 47c102a47426c9..3307d33434f0b3 100644
--- a/libc/src/__support/FPUtil/CMakeLists.txt
+++ b/libc/src/__support/FPUtil/CMakeLists.txt
@@ -143,16 +143,6 @@ add_header_library(
libc.src.__support.uint128
)
-add_header_library(
- xfloat
- HDRS
- XFloat.h
- DEPENDS
- .fp_bits
- .normal_float
- libc.src.__support.uint
-)
-
add_header_library(
sqrt
HDRS
diff --git a/libc/src/__support/FPUtil/XFloat.h b/libc/src/__support/FPUtil/XFloat.h
deleted file mode 100644
index fe334f8a33011d..00000000000000
--- a/libc/src/__support/FPUtil/XFloat.h
+++ /dev/null
@@ -1,180 +0,0 @@
-//===-- Utility class to manipulate wide floats. ----------------*- C++ -*-===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-#include "FPBits.h"
-#include "NormalFloat.h"
-#include "src/__support/UInt.h"
-
-#include <stdint.h>
-
-namespace LIBC_NAMESPACE {
-namespace fputil {
-
-// Store and manipulate positive double precision numbers at |Precision| bits.
-template <size_t Precision> class XFloat {
- static constexpr uint64_t OneMask = (uint64_t(1) << 63);
- UInt<Precision> man;
- static constexpr uint64_t WORDCOUNT = Precision / 64;
- int exp;
-
- size_t bit_width(uint64_t x) {
- if (x == 0)
- return 0;
- size_t shift = 0;
- while ((OneMask & x) == 0) {
- ++shift;
- x <<= 1;
- }
- return 64 - shift;
- }
-
-public:
- XFloat() : exp(0) {
- for (int i = 0; i < WORDCOUNT; ++i)
- man[i] = 0;
- }
-
- XFloat(const XFloat &other) : exp(other.exp) {
- for (int i = 0; i < WORDCOUNT; ++i)
- man[i] = other.man[i];
- }
-
- explicit XFloat(double x) {
- auto xn = NormalFloat<double>(x);
- exp = xn.exponent;
- man[WORDCOUNT - 1] = xn.mantissa << 11;
- for (int i = 0; i < WORDCOUNT - 1; ++i)
- man[i] = 0;
- }
-
- XFloat(int e, const UInt<Precision> &bits) : exp(e) {
- for (size_t i = 0; i < WORDCOUNT; ++i)
- man[i] = bits[i];
- }
-
- // Multiply this number with x and store the result in this number.
- void mul(double x) {
- auto xn = NormalFloat<double>(x);
- exp += xn.exponent;
- uint64_t carry = man.mul(xn.mantissa << 11);
- size_t carry_width = bit_width(carry);
- carry_width = (carry_width == 64 ? 64 : 63);
- man.shift_right(carry_width);
- man[WORDCOUNT - 1] = man[WORDCOUNT - 1] + (carry << (64 - carry_width));
- exp += carry_width == 64 ? 1 : 0;
- normalize();
- }
-
- void drop_int() {
- if (exp < 0)
- return;
- if (exp > int(Precision - 1)) {
- for (size_t i = 0; i < WORDCOUNT; ++i)
- man[i] = 0;
- return;
- }
-
- man.shift_left(exp + 1);
- man.shift_right(exp + 1);
-
- normalize();
- }
-
- double mul(const XFloat<Precision> &other) {
- constexpr size_t row_words = 2 * WORDCOUNT + 1;
- constexpr size_t row_precision = row_words * 64;
- constexpr size_t result_bits = 2 * Precision;
- UInt<row_precision> rows[WORDCOUNT];
-
- for (size_t r = 0; r < WORDCOUNT; ++r) {
- for (size_t i = 0; i < row_words; ++i) {
- if (i < WORDCOUNT)
- rows[r][i] = man[i];
- else
- rows[r][i] = 0;
- }
- rows[r].mul(other.man[r]);
- rows[r].shift_left(r * 64);
- }
-
- for (size_t r = 1; r < WORDCOUNT; ++r) {
- rows[0].add(rows[r]);
- }
- int result_exp = exp + other.exp;
- uint64_t carry = rows[0][row_words - 1];
- if (carry) {
- size_t carry_width = bit_width(carry);
- rows[0].shift_right(carry_width);
- rows[0][row_words - 2] =
- rows[0][row_words - 2] + (carry << (64 - carry_width));
- result_exp += carry_width;
- }
-
- if (rows[0][row_words - 2] & OneMask) {
- ++result_exp;
- } else {
- rows[0].shift_left(1);
- }
-
- UInt<result_bits> result_man;
- for (size_t i = 0; i < result_bits / 64; ++i)
- result_man[i] = rows[0][i];
- XFloat<result_bits> result(result_exp, result_man);
- result.normalize();
- return double(result);
- }
-
- explicit operator double() {
- normalize();
-
- constexpr uint64_t one = uint64_t(1) << 10;
- constexpr uint64_t excess_mask = (one << 1) - 1;
- uint64_t excess = man[WORDCOUNT - 1] & excess_mask;
- uint64_t new_man = man[WORDCOUNT - 1] >> 11;
- if (excess > one) {
- // We have to round up.
- ++new_man;
- } else if (excess == one) {
- bool greater_than_one = false;
- for (size_t i = 0; i < WORDCOUNT - 1; ++i) {
- greater_than_one = (man[i] != 0);
- if (greater_than_one)
- break;
- }
- if (greater_than_one || (new_man & 1) != 0) {
- ++new_man;
- }
- }
-
- if (new_man == (uint64_t(1) << 53))
- ++exp;
-
- // We use NormalFloat as it can produce subnormal numbers or underflow to 0
- // if necessary.
- NormalFloat<double> d(exp, new_man, 0);
- return double(d);
- }
-
- // Normalizes this number.
- void normalize() {
- uint64_t man_bits = 0;
- for (size_t i = 0; i < WORDCOUNT; ++i)
- man_bits |= man[i];
-
- if (man_bits == 0)
- return;
-
- while ((man[WORDCOUNT - 1] & OneMask) == 0) {
- man.shift_left(1);
- --exp;
- }
- }
-};
-
-} // namespace fputil
-} // namespace LIBC_NAMESPACE
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