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| author | Bruce Hill <bruce@bruce-hill.com> | 2024-11-25 14:11:06 -0500 |
|---|---|---|
| committer | Bruce Hill <bruce@bruce-hill.com> | 2024-11-25 14:11:06 -0500 |
| commit | 27da373754320ae432539a183f8a7cb2ef32997e (patch) | |
| tree | 5af9e3158deead91faeb67a8c9ea1ac9cd8244a8 | |
| parent | a38161179b7cfc925b4d16bd042f2b1754dca7fd (diff) | |
Micro-optimizations for division and modulus
| -rw-r--r-- | stdlib/integers.h | 40 |
1 files changed, 15 insertions, 25 deletions
diff --git a/stdlib/integers.h b/stdlib/integers.h index 0c4b87fc..12cb90f4 100644 --- a/stdlib/integers.h +++ b/stdlib/integers.h @@ -43,18 +43,12 @@ extern const TypeInfo_t type_name ## $info; \ MACROLIKE c_type type_name ## $divided_by(c_type D, c_type d) { \ c_type q = D/d, r = D%d; \ - if (r < 0) { \ - if (d > 0) q = q-1; \ - else q = q+1; \ - } \ + q -= (r < 0) * (2*(d > 0) - 1); \ return q; \ } \ MACROLIKE c_type type_name ## $modulo(c_type D, c_type d) { \ c_type r = D%d; \ - if (r < 0) { \ - if (d > 0) r = r + d; \ - else r = r - d; \ - } \ + r -= (r < 0) * (2*(d < 0) - 1) * d; \ return r; \ } \ MACROLIKE c_type type_name ## $modulo1(c_type D, c_type d) { \ @@ -180,12 +174,8 @@ MACROLIKE Int_t Int$divided_by(Int_t x, Int_t y) { // Euclidean division, see: https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/divmodnote-letter.pdf const int64_t D = (x.small>>2); const int64_t d = (y.small>>2); - int64_t q = D/d; - int64_t r = D%d; - if (r < 0) { - if (d > 0) q = q-1; - else q = q+1; - } + int64_t q = D/d, r = D%d; + q -= (r < 0) * (2*(d > 0) - 1); if (__builtin_expect(q == (int32_t)q, 1)) return (Int_t){.small=(q<<2)|1}; } @@ -198,10 +188,7 @@ MACROLIKE Int_t Int$modulo(Int_t x, Int_t y) { const int64_t D = (x.small>>2); const int64_t d = (y.small>>2); int64_t r = D%d; - if (r < 0) { - if (d > 0) r = r + d; - else r = r - d; - } + r -= (r < 0) * (2*(d < 0) - 1) * d; return (Int_t){.small=(r<<2)|1}; } return Int$slow_modulo(x, y); @@ -213,10 +200,7 @@ MACROLIKE Int_t Int$modulo1(Int_t x, Int_t y) { const int64_t D = (x.small>>2)-1; const int64_t d = (y.small>>2); int64_t r = D%d; - if (r < 0) { - if (d > 0) r = r + d; - else r = r - d; - } + r -= (r < 0) * (2*(d < 0) - 1) * d; return (Int_t){.small=((r+1)<<2)|1}; } return Int$slow_modulo1(x, y); @@ -289,9 +273,15 @@ MACROLIKE Int_t Int64_to_Int(int64_t i) return Int$from_mpz(result); } -#define Int32_to_Int(i) Int64_to_Int(i) -#define Int16_to_Int(i) Int64_to_Int(i) -#define Int8_to_Int(i) Int64_to_Int(i) +#define Int32_to_Int(i, ...) Int64_to_Int(i) +#define Int16_to_Int(i, ...) Int64_to_Int(i) +#define Int8_to_Int(i, ...) Int64_to_Int(i) +#define Int32_to_Int64(i, ...) (Int64_t)(i) +#define Int16_to_Int64(i, ...) (Int64_t)(i) +#define Int8_to_Int64(i, ...) (Int64_t)(i) +#define Int16_to_Int32(i, ...) (Int32_t)(i) +#define Int8_to_Int32(i, ...) (Int32_t)(i) +#define Int8_to_Int16(i, ...) (Int16_t)(i) MACROLIKE PUREFUNC Int64_t Int_to_Int64(Int_t i, bool truncate) { if (__builtin_expect(i.small & 1, 1)) |