From 34f2ab1f3c389e7d802128706008db2d8445fc3f Mon Sep 17 00:00:00 2001
From: Takashi Kokubun <takashikkbn@gmail.com>
Date: Thu, 2 Mar 2023 23:21:28 -0800
Subject: [PATCH] Optimize Integer#/

---
 lib/ruby_vm/mjit/insn_compiler.rb | 31 ++++++++++++++++++++++++++-----
 mjit_c.rb                         |  4 ++++
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/lib/ruby_vm/mjit/insn_compiler.rb b/lib/ruby_vm/mjit/insn_compiler.rb
index 625f01b13c..e68c68e3a9 100644
--- a/lib/ruby_vm/mjit/insn_compiler.rb
+++ b/lib/ruby_vm/mjit/insn_compiler.rb
@@ -1694,8 +1694,9 @@ module RubyVM::MJIT
       asm.mov(:rax, Qfalse)
       asm.mov(:rcx, Qtrue)
       asm.cmovz(:rax, :rcx)
-      asm.mov(ctx.stack_push, :rax)
 
+      stack_ret = ctx.stack_push
+      asm.mov(stack_ret, :rax)
       true
     end
 
@@ -1738,13 +1739,11 @@ module RubyVM::MJIT
     def jit_rb_int_mul(jit, ctx, asm, argc)
       return false if argc != 1
       return false unless two_fixnums_on_stack?(jit)
-      asm.comment('rb_int_mul')
 
       side_exit = side_exit(jit, ctx)
       guard_two_fixnums(jit, ctx, asm, side_exit)
 
-      jit_prepare_routine_call(jit, ctx, asm)
-
+      asm.comment('rb_int_mul')
       y_opnd = ctx.stack_pop
       x_opnd = ctx.stack_pop
       asm.mov(C_ARGS[0], x_opnd)
@@ -1753,7 +1752,29 @@ module RubyVM::MJIT
 
       ret_opnd = ctx.stack_push
       asm.mov(ret_opnd, C_RET)
+      true
+    end
 
+    def jit_rb_int_div(jit, ctx, asm, argc)
+      return false if argc != 1
+      return false unless two_fixnums_on_stack?(jit)
+
+      side_exit = side_exit(jit, ctx)
+      guard_two_fixnums(jit, ctx, asm, side_exit)
+
+      asm.comment('rb_int_div')
+      y_opnd = ctx.stack_pop
+      x_opnd = ctx.stack_pop
+      asm.mov(:rax, y_opnd)
+      asm.cmp(:rax, C.to_value(0))
+      asm.je(side_exit)
+
+      asm.mov(C_ARGS[0], x_opnd)
+      asm.mov(C_ARGS[1], :rax)
+      asm.call(C.rb_fix_div_fix)
+
+      ret_opnd = ctx.stack_push
+      asm.mov(ret_opnd, C_RET)
       true
     end
 
@@ -1774,7 +1795,6 @@ module RubyVM::MJIT
 
       ret_opnd = ctx.stack_push
       asm.mov(ret_opnd, C_RET)
-
       true
     end
 
@@ -1789,6 +1809,7 @@ module RubyVM::MJIT
       register_cfunc_method(Integer, :==, :jit_rb_int_equal)
       register_cfunc_method(Integer, :===, :jit_rb_int_equal)
       register_cfunc_method(Integer, :*, :jit_rb_int_mul)
+      register_cfunc_method(Integer, :/, :jit_rb_int_div)
 
       register_cfunc_method(Array, :<<, :jit_rb_ary_push)
     end
diff --git a/mjit_c.rb b/mjit_c.rb
index d1c01d4069..aab9515257 100644
--- a/mjit_c.rb
+++ b/mjit_c.rb
@@ -289,6 +289,10 @@ module RubyVM::MJIT # :nodoc: all
       Primitive.cexpr! 'SIZET2NUM((size_t)rb_fix_mul_fix)'
     end
 
+    def rb_fix_div_fix
+      Primitive.cexpr! 'SIZET2NUM((size_t)rb_fix_div_fix)'
+    end
+
     def rb_ary_push
       Primitive.cexpr! 'SIZET2NUM((size_t)rb_ary_push)'
     end