typo fixes + view generated low level code

This commit is contained in:
Laban Kimotho 2014-01-24 10:59:53 +02:00
parent bb7d69154d
commit 400b00aa87

View File

@ -427,7 +427,7 @@ end
keyword_args(name2="ness") #=> ["name2"=>"ness","k1"=>4]
keyword_args(k1="mine") #=> ["k1"=>"mine","name2"=>"hello"]
keyword_args() #=> ["name2"=>"hello","k2"=>4]
keyword_args() #=> ["name2"=>"hello","k1"=>4]
# You can combine all kinds of arguments in the same function
function all_the_args(normal_arg, optional_positional_arg=2; keyword_arg="foo")
@ -560,7 +560,7 @@ type Panther <: Cat # Panther is also a subtype of Cat
Panther() = new("green")
# Panthers will only have this constructor, and no default constructor.
end
# Using inner constructors, like Panter does, gives you control
# Using inner constructors, like Panther does, gives you control
# over how values of the type can be created.
# When possible, you should use outer constructors rather than inner ones.
@ -657,6 +657,81 @@ fight(Lion("RAR"),Lion("brown","rarrr")) #=> prints The victorious cat says rarr
fight(l::Lion,l2::Lion) = println("The lions come to a tie")
fight(Lion("RAR"),Lion("brown","rarrr")) #=> prints The lions come to a tie
# Under the hood
# You can take a look at the llvm intermediate code and the assembly code generated.
square_area(l) = l * l # square_area (generic function with 1 method)
square_area(5) #25
code_native(square_area, (Int32,)) # What happens when we feed square_area an integer?
# .section __TEXT,__text,regular,pure_instructions
# Filename: none
# Source line: 1 # Prologue
# push RBP
# mov RBP, RSP
# Source line: 1
# movsxd RAX, EDI # Fetch l from memory?
# imul RAX, RAX # 32bit square of l and store the result in RAX
# pop RBP # Restore old base pointer
# ret # Result will still be in RAX
code_native(square_area, (Float32,))
# .section __TEXT,__text,regular,pure_instructions
# Filename: none
# Source line: 1
# push RBP
# mov RBP, RSP
# Source line: 1
# vmulss XMM0, XMM0, XMM0 # Scalar single precision multiplication (AVX) (in this case square the number)
# pop RBP
# ret
code_native(square_area, (Float64,))
# .section __TEXT,__text,regular,pure_instructions
# Filename: none
# Source line: 1
# push RBP
# mov RBP, RSP
# Source line: 1
# vmulsd XMM0, XMM0, XMM0 # Scalar double precision multiplacation (AVX)
# pop RBP
# ret
#
# Note that julia will use floating point instructions if any of the arguements are floats.
# Let's calculate the area of a circle
circle_area(r) = pi * r * r # circle_area (generic function with 1 method)
circle_area(5) # 78.53981633974483
code_native(circle_area, (Int32,))
# .section __TEXT,__text,regular,pure_instructions
# Filename: none
# Source line: 1
# push RBP
# mov RBP, RSP
# Source line: 1
# vcvtsi2sd XMM0, XMM0, EDI # Load integer (r) from memory
# movabs RAX, 4593140240 # Load pi
# vmulsd XMM1, XMM0, QWORD PTR [RAX] # pi * r
# vmulsd XMM0, XMM0, XMM1 # (pi * r) * r
# pop RBP
# ret
#
code_native(circle_area, (Float64,))
# .section __TEXT,__text,regular,pure_instructions
# Filename: none
# Source line: 1
# push RBP
# mov RBP, RSP
# movabs RAX, 4593140496
# Source line: 1
# vmulsd XMM1, XMM0, QWORD PTR [RAX]
# vmulsd XMM0, XMM1, XMM0
# pop RBP
# ret
#
```
## Further Reading