Add support for RDRAND in IvyBridge.

The standard library now provides a variety of rdrand() functions
that call out to RDRAND, when available.

Issue #263.

tests/rdrand-1.ispc

@@ -0,0 +1,21 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+#if !defined(ISPC_TARGET_AVX11) && !defined(ISPC_TARGET_AVX2)
+    RET[programIndex] = 1;
+#else
+
+    uniform float r = -1;
+    uniform int count = 0;
+    while (!rdrand(&r)) {
+        ++count;
+    }
+    RET[programIndex] = (r >= 0 && r < 1);
+
+#endif
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 1;
+}

tests/rdrand-2.ispc

@@ -0,0 +1,19 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+#if !defined(ISPC_TARGET_AVX11) && !defined(ISPC_TARGET_AVX2)
+    RET[programIndex] = 1;
+#else
+
+    float r = -1;
+    while (!rdrand(&r))
+        ;
+    RET[programIndex] = (r >= 0 && r < 1);
+
+#endif
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 1;
+}

tests/rdrand-3.ispc

@@ -0,0 +1,25 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+#if !defined(ISPC_TARGET_AVX11) && !defined(ISPC_TARGET_AVX2)
+    RET[programIndex] = 1;
+#else
+
+    int lessHalf = 0, moreHalf = 0;
+    for (uniform int i = 0; i < 1024*1024; ++i) {
+        float r = -1;
+        while (!rdrand(&r))
+            ;
+        if (r < 0.5) ++lessHalf;
+        else ++moreHalf;
+    }
+
+    float r = (double)lessHalf / (double)(lessHalf + moreHalf);
+    RET[programIndex] = (r >= .49 && r < .51);
+#endif
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 1;
+}

tests/rdrand-4.ispc

@@ -0,0 +1,33 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+#if !defined(ISPC_TARGET_AVX11) && !defined(ISPC_TARGET_AVX2)
+    RET[programIndex] = 0;
+#else
+
+    uniform int set[64] = { 0 };
+    uniform int count = 1024*1024;
+    for (uniform int i = 0; i < count; ++i) {
+        uniform int64 r;
+        while (!rdrand(&r))
+            ;
+        for (uniform int b = 0; b < 64; ++b) 
+            if (((unsigned int64)r >> b) & 1)
+                ++set[b];
+    }
+
+    RET[programIndex] = 0;
+    for (uniform int b = 0; b < 64; ++b)  {
+        float r = (double)set[b] / (double)(count);
+        if (!(r >= .49 && r < .51)) {
+            print("% % - %\n", b, r, set[b]);
+            ++RET[programIndex];
+        }
+    }
+#endif
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 0;
+}

tests/rdrand-5.ispc

@@ -0,0 +1,33 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+#if !defined(ISPC_TARGET_AVX11) && !defined(ISPC_TARGET_AVX2)
+    RET[programIndex] = 0;
+#else
+
+    int set[32] = { 0 };
+    uniform int count = 1024*1024;
+    for (uniform int i = 0; i < count; ++i) {
+        int32 r;
+        while (!rdrand(&r))
+            ;
+        for (uniform int b = 0; b < 32; ++b) 
+            if (((unsigned int32)r >> b) & 1)
+                ++set[b];
+    }
+
+    RET[programIndex] = 0;
+    for (uniform int b = 0; b < 32; ++b)  {
+        float r = (double)set[b] / (double)(count);
+        if (!(r >= .49 && r < .51)) {
+            print("% % - %\n", b, r, set[b]);
+            ++RET[programIndex];
+        }
+    }
+#endif
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 0;
+}

tests/rdrand-6.ispc

@@ -0,0 +1,35 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+#if !defined(ISPC_TARGET_AVX11) && !defined(ISPC_TARGET_AVX2)
+    RET[programIndex] = 0;
+#else
+
+    int set[32] = { 0 };
+    uniform int count = 1024*1024;
+    for (uniform int i = 0; i < count; ++i) {
+        uniform int32 rr[programCount];
+        int * ptr = rr + programIndex;
+        while (!rdrand(ptr))
+            ;
+        int32 r = rr[programIndex];
+        for (uniform int b = 0; b < 32; ++b) 
+            if (((unsigned int32)r >> b) & 1)
+                ++set[b];
+    }
+
+    RET[programIndex] = 0;
+    for (uniform int b = 0; b < 32; ++b)  {
+        float r = (double)set[b] / (double)(count);
+        if (!(r >= .49 && r < .51)) {
+            print("% % - %\n", b, r, set[b]);
+            ++RET[programIndex];
+        }
+    }
+#endif
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 0;
+}