add
git-svn-id: http://skia.googlecode.com/svn/trunk@2185 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/MathBench.cpp b/bench/MathBench.cpp
new file mode 100644
index 0000000..16eaebe
--- /dev/null
+++ b/bench/MathBench.cpp
@@ -0,0 +1,109 @@
+#include "SkBenchmark.h"
+#include "SkMatrix.h"
+#include "SkRandom.h"
+#include "SkString.h"
+
+class MathBench : public SkBenchmark {
+ enum {
+ kBuffer = 100,
+ kLoop = 10000
+ };
+ SkString fName;
+ float fSrc[kBuffer], fDst[kBuffer];
+public:
+ MathBench(void* param, const char name[]) : INHERITED(param) {
+ fName.printf("math_%s", name);
+
+ SkRandom rand;
+ for (int i = 0; i < kBuffer; ++i) {
+ fSrc[i] = rand.nextSScalar1();
+ }
+ }
+
+ virtual void performTest(float dst[], const float src[], int count) = 0;
+
+protected:
+ virtual int mulLoopCount() const { return 1; }
+
+ virtual const char* onGetName() {
+ return fName.c_str();
+ }
+
+ virtual void onDraw(SkCanvas* canvas) {
+ int n = kLoop * this->mulLoopCount();
+ for (int i = 0; i < n; i++) {
+ this->performTest(fDst, fSrc, kBuffer);
+ }
+ }
+
+private:
+ typedef SkBenchmark INHERITED;
+};
+
+int gMathBench_NonStaticGlobal;
+
+#define always_do(pred) \
+ do { \
+ if (pred) { \
+ ++gMathBench_NonStaticGlobal; \
+ } \
+ } while (0)
+
+class NoOpMathBench : public MathBench {
+public:
+ NoOpMathBench(void* param) : INHERITED(param, "slowIsqrt") {}
+protected:
+ virtual void performTest(float dst[], const float src[], int count) {
+ for (int i = 0; i < count; ++i) {
+ dst[i] = src[i] + 1;
+ }
+ }
+private:
+ typedef MathBench INHERITED;
+};
+
+class SlowISqrtMathBench : public MathBench {
+public:
+ SlowISqrtMathBench(void* param) : INHERITED(param, "slowIsqrt") {}
+protected:
+ virtual void performTest(float dst[], const float src[], int count) {
+ for (int i = 0; i < count; ++i) {
+ dst[i] = 1.0f / sk_float_sqrt(src[i]);
+ }
+ }
+private:
+ typedef MathBench INHERITED;
+};
+
+static inline float SkFastInvSqrt(float x) {
+ float xhalf = 0.5f*x;
+ int i = *(int*)&x;
+ i = 0x5f3759df - (i>>1);
+ x = *(float*)&i;
+ x = x*(1.5f-xhalf*x*x);
+// x = x*(1.5f-xhalf*x*x); // this line takes err from 10^-3 to 10^-6
+ return x;
+}
+
+class FastISqrtMathBench : public MathBench {
+public:
+ FastISqrtMathBench(void* param) : INHERITED(param, "fastIsqrt") {}
+protected:
+ virtual void performTest(float dst[], const float src[], int count) {
+ for (int i = 0; i < count; ++i) {
+ dst[i] = SkFastInvSqrt(src[i]);
+ }
+ }
+private:
+ typedef MathBench INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+static SkBenchmark* M0(void* p) { return new NoOpMathBench(p); }
+static SkBenchmark* M1(void* p) { return new SlowISqrtMathBench(p); }
+static SkBenchmark* M2(void* p) { return new FastISqrtMathBench(p); }
+
+static BenchRegistry gReg0(M0);
+static BenchRegistry gReg1(M1);
+static BenchRegistry gReg2(M2);