From 4ce086f73149d2916633dc93ed9bbc7660124fcd Mon Sep 17 00:00:00 2001 From: Florimond Collette <4939681+florimond-collette@users.noreply.github.com> Date: Thu, 18 May 2023 17:27:57 +0200 Subject: [PATCH] remove code duplication (#3448) * remove code duplication * new interface for remove_trailing_zeros(uint32_t& n, int s = 0) --------- Co-authored-by: Florimond Collette <4939681+florimondcollette@users.noreply.github.com> --- include/fmt/format-inl.h | 24 ++++-------------------- 1 file changed, 4 insertions(+), 20 deletions(-) diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h index 3f605d1f8d4b..d529ed821c2e 100644 --- a/include/fmt/format-inl.h +++ b/include/fmt/format-inl.h @@ -1128,7 +1128,7 @@ bool is_left_endpoint_integer_shorter_interval(int exponent) noexcept { } // Remove trailing zeros from n and return the number of zeros removed (float) -FMT_INLINE int remove_trailing_zeros(uint32_t& n) noexcept { +FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept { FMT_ASSERT(n != 0, ""); // Modular inverse of 5 (mod 2^32): (mod_inv_5 * 5) mod 2^32 = 1. // See https://github.com/fmtlib/fmt/issues/3163 for more details. @@ -1137,7 +1137,6 @@ FMT_INLINE int remove_trailing_zeros(uint32_t& n) noexcept { const uint32_t mod_inv_25 = static_cast(uint64_t(mod_inv_5) * mod_inv_5); - int s = 0; while (true) { auto q = rotr(n * mod_inv_25, 2); if (q > max_value() / 100) break; @@ -1162,25 +1161,10 @@ FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept { // Is n is divisible by 10^8? if ((nm.high() & ((1ull << (90 - 64)) - 1)) == 0 && nm.low() < magic_number) { - // If yes, work with the quotient. + // If yes, work with the quotient... auto n32 = static_cast(nm.high() >> (90 - 64)); - - const uint32_t mod_inv_5 = 0xcccccccd; - const uint32_t mod_inv_25 = mod_inv_5 * mod_inv_5; - - int s = 8; - while (true) { - auto q = rotr(n32 * mod_inv_25, 2); - if (q > max_value() / 100) break; - n32 = q; - s += 2; - } - auto q = rotr(n32 * mod_inv_5, 1); - if (q <= max_value() / 10) { - n32 = q; - s |= 1; - } - + // ... and use the 32 bit variant of the function + int s = remove_trailing_zeros(n32, 8); n = n32; return s; }