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authorGravatar Abseil Team <absl-team@google.com>2018-05-14 13:41:38 -0700
committerGravatar jueminyang <jueminyang@google.com>2018-05-15 11:00:30 -0400
commit04dd99d8c1813ded74cd2a9c90ecb7eaa2d68ab1 (patch)
treebcbac48462be4c3d39c1dcf933b55ea98f3928e8 /absl/strings/numbers.cc
parentadd89fd0e4bfd7d874bb55b67f4e13bf8beca762 (diff)
- abe587c2360b21f085b7d65a77d840015bc04cf6 Factor an internal interface into its own header, as it w... by Greg Falcon <gfalcon@google.com>
- 2201f1644336e64280dbd20207d8fbc3bfea2bf4 Internal change. by Abseil Team <absl-team@google.com> - 94e6b5b20d2cc754c99a18c575a4f1f3cd1f28d4 Rename no_throw_ctor to nothrow_ctor to match the standar... by Abseil Team <absl-team@google.com> - 86aa34d2129c4914c5133b7b619480aae786288e Update header files in debugging target by Tom Manshreck <shreck@google.com> - ed234519ced458724a7267b8fdf184eaae1c97c7 Remove CMAKE_CXX_WARNING_VLA from our c++ flags in the cm... by Jon Cohen <cohenjon@google.com> GitOrigin-RevId: abe587c2360b21f085b7d65a77d840015bc04cf6 Change-Id: I92f9301c69419d3830c358b88984967185aa33f6
Diffstat (limited to 'absl/strings/numbers.cc')
-rw-r--r--absl/strings/numbers.cc17
1 files changed, 3 insertions, 14 deletions
diff --git a/absl/strings/numbers.cc b/absl/strings/numbers.cc
index b4140b3..68ef799 100644
--- a/absl/strings/numbers.cc
+++ b/absl/strings/numbers.cc
@@ -32,6 +32,7 @@
#include "absl/base/internal/raw_logging.h"
#include "absl/strings/ascii.h"
+#include "absl/strings/internal/bits.h"
#include "absl/strings/internal/memutil.h"
#include "absl/strings/str_cat.h"
@@ -302,18 +303,6 @@ char* numbers_internal::FastIntToBuffer(int64_t i, char* buffer) {
return numbers_internal::FastIntToBuffer(u, buffer);
}
-// Returns the number of leading 0 bits in a 64-bit value.
-// TODO(jorg): Replace with builtin_clzll if available.
-// Are we shipping util/bits in absl?
-static inline int CountLeadingZeros64(uint64_t n) {
- int zeroes = 60;
- if (n >> 32) zeroes -= 32, n >>= 32;
- if (n >> 16) zeroes -= 16, n >>= 16;
- if (n >> 8) zeroes -= 8, n >>= 8;
- if (n >> 4) zeroes -= 4, n >>= 4;
- return "\4\3\2\2\1\1\1\1\0\0\0\0\0\0\0\0"[n] + zeroes;
-}
-
// Given a 128-bit number expressed as a pair of uint64_t, high half first,
// return that number multiplied by the given 32-bit value. If the result is
// too large to fit in a 128-bit number, divide it by 2 until it fits.
@@ -351,7 +340,7 @@ static std::pair<uint64_t, uint64_t> Mul32(std::pair<uint64_t, uint64_t> num,
uint64_t bits128_up = (bits96_127 >> 32) + (bits64_127 < bits64_95);
if (bits128_up == 0) return {bits64_127, bits0_63};
- int shift = 64 - CountLeadingZeros64(bits128_up);
+ int shift = 64 - strings_internal::CountLeadingZeros64(bits128_up);
uint64_t lo = (bits0_63 >> shift) + (bits64_127 << (64 - shift));
uint64_t hi = (bits64_127 >> shift) + (bits128_up << (64 - shift));
return {hi, lo};
@@ -382,7 +371,7 @@ static std::pair<uint64_t, uint64_t> PowFive(uint64_t num, int expfive) {
5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5,
5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5};
result = Mul32(result, powers_of_five[expfive & 15]);
- int shift = CountLeadingZeros64(result.first);
+ int shift = strings_internal::CountLeadingZeros64(result.first);
if (shift != 0) {
result.first = (result.first << shift) + (result.second >> (64 - shift));
result.second = (result.second << shift);