From 647dcf9cf512629e1f7f3e63a65a7f3572c50bd9 Mon Sep 17 00:00:00 2001
From: Quinton Miller <nicetas.c@gmail.com>
Date: Sun, 25 Aug 2024 17:19:57 +0800
Subject: [PATCH] Optimize arithmetic between `BigFloat` and integers

---
 src/big/big_float.cr | 65 ++++++++++++++++++++++++++++++++++++++++++++
 src/big/lib_gmp.cr   |  3 ++
 src/big/number.cr    | 22 ---------------
 3 files changed, 68 insertions(+), 22 deletions(-)

diff --git a/src/big/big_float.cr b/src/big/big_float.cr
index cadc91282fc1..2c567f21eec9 100644
--- a/src/big/big_float.cr
+++ b/src/big/big_float.cr
@@ -115,18 +115,60 @@ struct BigFloat < Float
     BigFloat.new { |mpf| LibGMP.mpf_neg(mpf, self) }
   end
 
+  def +(other : Int::Primitive) : BigFloat
+    Int.primitive_ui_check(other) do |ui, neg_ui, big_i|
+      {
+        ui:     BigFloat.new { |mpf| LibGMP.mpf_add_ui(mpf, self, {{ ui }}) },
+        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_sub_ui(mpf, self, {{ neg_ui }}) },
+        big_i:  self + {{ big_i }},
+      }
+    end
+  end
+
   def +(other : Number) : BigFloat
     BigFloat.new { |mpf| LibGMP.mpf_add(mpf, self, other.to_big_f) }
   end
 
+  def -(other : Int::Primitive) : BigFloat
+    Int.primitive_ui_check(other) do |ui, neg_ui, big_i|
+      {
+        ui:     BigFloat.new { |mpf| LibGMP.mpf_sub_ui(mpf, self, {{ ui }}) },
+        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_add_ui(mpf, self, {{ neg_ui }}) },
+        big_i:  self - {{ big_i }},
+      }
+    end
+  end
+
   def -(other : Number) : BigFloat
     BigFloat.new { |mpf| LibGMP.mpf_sub(mpf, self, other.to_big_f) }
   end
 
+  def *(other : Int::Primitive) : BigFloat
+    Int.primitive_ui_check(other) do |ui, neg_ui, big_i|
+      {
+        ui:     BigFloat.new { |mpf| LibGMP.mpf_mul_ui(mpf, self, {{ ui }}) },
+        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_mul_ui(mpf, self, {{ neg_ui }}); LibGMP.mpf_neg(mpf, mpf) },
+        big_i:  self + {{ big_i }},
+      }
+    end
+  end
+
   def *(other : Number) : BigFloat
     BigFloat.new { |mpf| LibGMP.mpf_mul(mpf, self, other.to_big_f) }
   end
 
+  def /(other : Int::Primitive) : BigFloat
+    # Division by 0 in BigFloat is not allowed, there is no BigFloat::Infinity
+    raise DivisionByZeroError.new if other == 0
+    Int.primitive_ui_check(other) do |ui, neg_ui, _|
+      {
+        ui:     BigFloat.new { |mpf| LibGMP.mpf_div_ui(mpf, self, {{ ui }}) },
+        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_div_ui(mpf, self, {{ neg_ui }}); LibGMP.mpf_neg(mpf, mpf) },
+        big_i:  BigFloat.new { |mpf| LibGMP.mpf_div(mpf, self, BigFloat.new(other)) },
+      }
+    end
+  end
+
   def /(other : BigFloat) : BigFloat
     # Division by 0 in BigFloat is not allowed, there is no BigFloat::Infinity
     raise DivisionByZeroError.new if other == 0
@@ -448,6 +490,29 @@ struct Int
   def <=>(other : BigFloat)
     -(other <=> self)
   end
+
+  def -(other : BigFloat) : BigFloat
+    Int.primitive_ui_check(self) do |ui, neg_ui, _|
+      {
+        ui:     BigFloat.new { |mpf| LibGMP.mpf_neg(mpf, other); LibGMP.mpf_add_ui(mpf, mpf, {{ ui }}) },
+        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_neg(mpf, other); LibGMP.mpf_sub_ui(mpf, mpf, {{ neg_ui }}) },
+        big_i:  BigFloat.new { |mpf| LibGMP.mpf_sub(mpf, BigFloat.new(self), other) },
+      }
+    end
+  end
+
+  def /(other : BigFloat) : BigFloat
+    # Division by 0 in BigFloat is not allowed, there is no BigFloat::Infinity
+    raise DivisionByZeroError.new if other == 0
+
+    Int.primitive_ui_check(self) do |ui, neg_ui, _|
+      {
+        ui:     BigFloat.new { |mpf| LibGMP.mpf_ui_div(mpf, {{ ui }}, other) },
+        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_ui_div(mpf, {{ neg_ui }}, other); LibGMP.mpf_neg(mpf, mpf) },
+        big_i:  BigFloat.new { |mpf| LibGMP.mpf_div(mpf, BigFloat.new(self), other) },
+      }
+    end
+  end
 end
 
 struct Float
diff --git a/src/big/lib_gmp.cr b/src/big/lib_gmp.cr
index 00834598d9d2..5ae18b5a4606 100644
--- a/src/big/lib_gmp.cr
+++ b/src/big/lib_gmp.cr
@@ -233,8 +233,11 @@ lib LibGMP
 
   # # Arithmetic
   fun mpf_add = __gmpf_add(rop : MPF*, op1 : MPF*, op2 : MPF*)
+  fun mpf_add_ui = __gmpf_add_ui(rop : MPF*, op1 : MPF*, op2 : UI)
   fun mpf_sub = __gmpf_sub(rop : MPF*, op1 : MPF*, op2 : MPF*)
+  fun mpf_sub_ui = __gmpf_sub_ui(rop : MPF*, op1 : MPF*, op2 : UI)
   fun mpf_mul = __gmpf_mul(rop : MPF*, op1 : MPF*, op2 : MPF*)
+  fun mpf_mul_ui = __gmpf_mul_ui(rop : MPF*, op1 : MPF*, op2 : UI)
   fun mpf_div = __gmpf_div(rop : MPF*, op1 : MPF*, op2 : MPF*)
   fun mpf_div_ui = __gmpf_div_ui(rop : MPF*, op1 : MPF*, op2 : UI)
   fun mpf_ui_div = __gmpf_ui_div(rop : MPF*, op1 : UI, op2 : MPF*)
diff --git a/src/big/number.cr b/src/big/number.cr
index 1251e8113db3..8761a2aa8b6c 100644
--- a/src/big/number.cr
+++ b/src/big/number.cr
@@ -8,18 +8,6 @@ struct BigFloat
     self.class.new(self / other)
   end
 
-  def /(other : Int::Primitive) : BigFloat
-    # Division by 0 in BigFloat is not allowed, there is no BigFloat::Infinity
-    raise DivisionByZeroError.new if other == 0
-    Int.primitive_ui_check(other) do |ui, neg_ui, _|
-      {
-        ui:     BigFloat.new { |mpf| LibGMP.mpf_div_ui(mpf, self, {{ ui }}) },
-        neg_ui: BigFloat.new { |mpf| LibGMP.mpf_div_ui(mpf, self, {{ neg_ui }}); LibGMP.mpf_neg(mpf, mpf) },
-        big_i:  BigFloat.new { |mpf| LibGMP.mpf_div(mpf, self, BigFloat.new(other)) },
-      }
-    end
-  end
-
   Number.expand_div [Float32, Float64], BigFloat
 end
 
@@ -91,70 +79,60 @@ end
 
 struct Int8
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct Int16
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct Int32
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct Int64
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct Int128
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct UInt8
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct UInt16
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct UInt32
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct UInt64
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end
 
 struct UInt128
   Number.expand_div [BigInt], BigFloat
-  Number.expand_div [BigFloat], BigFloat
   Number.expand_div [BigDecimal], BigDecimal
   Number.expand_div [BigRational], BigRational
 end