struct_benchmark_test.lua

struct_benchmark_test.lua

local ffi = require("ffi")

local tests = {
	aligned_float = [[
		struct __attribute__(( aligned(16) )) NAME {
			__attribute__(( packed ))
			float x, y, z;
		};
	]],
	aligned_double = [[
		struct __attribute__(( aligned(16) )) NAME {
			__attribute__(( packed ))
			float x, y, z;
		};
	]],
	float = [[
		struct NAME {
			float x, y, z;
		};
	]],
	double = [[
		struct NAME {
			double x, y, z;
		};
	]]	,
}

for name, declaration in pairs(tests) do
	name = "gtest_" .. name .. "_ct"
	declaration = declaration:gsub("NAME", name)
	ffi.cdef(declaration)
	local ctor

	local meta = {
		__add = function(v1, v2) return ctor(v1.x + v2.x, v1.y + v2.y, v1.z + v2.z) end,
		__sub = function(v1, v2) return ctor(v1.x - v2.x, v1.y - v2.y, v1.z - v2.z) end,
		__mul = function(v1, v2) return ctor(v1.x * v2.x, v1.y * v2.y, v1.z * v2.z) end,
		__div = function(v1, v2) return ctor(v1.x / v2.x, v1.y / v2.y, v1.z / v2.z) end,
	}

	ctor = ffi.metatype("struct " .. name, meta)
	local vec3 = ctor

	do
		io.write(name, " multiplication: ")
		local t = os.clock()
		local v = vec3(math.random(), math.random(), math.random())
		pairs({}) -- trace barrier
		for i = 1, 100000000 do
			v = v * v
		end
		pairs({}) -- trace barrier
		t = os.clock() - t
		io.write(t, " seconds\n")
	end

	do
		io.write(name, " addition: ")
		local t = os.clock()
		local v = vec3(math.random(), math.random(), math.random())
		pairs({}) -- trace barrier
		for i = 1, 100000000 do
			v = v + v
		end
		pairs({}) -- trace barrier
		t = os.clock() - t
		io.write(t, " seconds\n")
	end
end