add

git-svn-id: http://skia.googlecode.com/svn/trunk@2185 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 109 insertions, 0 deletions

diff --git a/bench/MathBench.cpp b/bench/MathBench.cpp
new file mode 100644
index 0000000000..16eaebe979
--- /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);