Merge pull request #253 from fastfloat/update_ci_to_ubuntu24

update CI to ubuntu 24 + safe a shift value to a variable (for elegance)

.github/workflows/ubuntu22-gcc13.yml → .github/workflows/ubuntu24.yml

@@ -1,23 +1,23 @@
-name: Ubuntu 22.04 CI (GCC 13)
+name: Ubuntu 24.04 CI (GCC 13)
 
 on: [push, pull_request]
 
 jobs:
  ubuntu-build:
- runs-on: ubuntu-22.04
+ runs-on: ubuntu-24.04
  steps:
  - uses: actions/checkout@v3
  - name: Use cmake
  run: |
  mkdir build &&
  cd build &&
- CXX=g++-13 CXXFLAGS=-Werror cmake -DFASTFLOAT_TEST=ON .. &&
+ CXXFLAGS=-Werror cmake -DFASTFLOAT_TEST=ON .. &&
  cmake --build . &&
  ctest --output-on-failure
  - name: Use cmake CXX23
  run: |
  mkdir build20 &&
  cd build20 &&
- CXX=g++-13 CXXFLAGS=-Werror cmake -DFASTFLOAT_CONSTEXPR_TESTS=ON -DFASTFLOAT_FIXEDWIDTH_TESTS=ON -DFASTFLOAT_CXX_STANDARD=23 -DFASTFLOAT_TEST=ON .. &&
+ CXXFLAGS=-Werror cmake -DFASTFLOAT_CONSTEXPR_TESTS=ON -DFASTFLOAT_FIXEDWIDTH_TESTS=ON -DFASTFLOAT_CXX_STANDARD=23 -DFASTFLOAT_TEST=ON .. &&
  cmake --build . &&
  ctest --output-on-failure

include/fast_float/decimal_to_binary.h

@@ -127,8 +127,9 @@ adjusted_mantissa compute_float(int64_t q, uint64_t w) noexcept {
  // but in practice, we can win big with the compute_product_approximation if its additional branch
  // is easily predicted. Which is best is data specific.
  int upperbit = int(product.high >> 63);
+ int shift = upperbit + 64 - binary::mantissa_explicit_bits() - 3;
 
- answer.mantissa = product.high >> (upperbit + 64 - binary::mantissa_explicit_bits() - 3);
+ answer.mantissa = product.high >> shift;
 
  answer.power2 = int32_t(detail::power(int32_t(q)) + upperbit - lz - binary::minimum_exponent());
  if (answer.power2 <= 0) { // we have a subnormal?
@@ -164,7 +165,7 @@ adjusted_mantissa compute_float(int64_t q, uint64_t w) noexcept {
  // To be in-between two floats we need that in doing
  // answer.mantissa = product.high >> (upperbit + 64 - binary::mantissa_explicit_bits() - 3);
  // ... we dropped out only zeroes. But if this happened, then we can go back!!!
- if((answer.mantissa << (upperbit + 64 - binary::mantissa_explicit_bits() - 3)) == product.high) {
+ if((answer.mantissa << shift) == product.high) {
  answer.mantissa &= ~uint64_t(1); // flip it so that we do not round up
  }
  }