Move range_reduce_log to a header. Drive-by fix listing libOpenCL.so.1 as well.

Author: mcourteaux

src/FastMathFunctions.cpp

@@ -9,9 +9,6 @@
 namespace Halide {
 namespace Internal {
 
-// Implemented in IROperator.cpp
-void range_reduce_log(const Expr &input, Expr *reduced, Expr *exponent);
-
 namespace {
 
 Expr constant(Type t, double value) {
@@ -295,7 +292,7 @@ Expr fast_log(const Expr &x, ApproximationPrecision prec) {
 
     Expr log2 = constant(type, std::log(2.0));
     Expr reduced, exponent;
-    range_reduce_log(x, &reduced, &exponent);
+    Internal::range_reduce_log(x, &reduced, &exponent);
 
     Expr x1 = reduced - 1.0f;
     const Internal::Approximation *approx = Internal::best_log_approximation(prec, type);

src/IROperator.cpp

@@ -743,7 +743,6 @@ void match_types_bitwise(Expr &x, Expr &y, const char *op_name) {
 // Fast math ops based on those from Syrah (http://github.com/boulos/syrah). Thanks, Solomon!
 
 // Factor a float into 2^exponent * reduced, where reduced is between 0.75 and 1.5
-// (This function is not in an anonymous namespace, because it's reused in FastMathFunctions.cpp)
 void range_reduce_log(const Expr &input, Expr *reduced, Expr *exponent) {
     Type type = input.type();
     Type int_type = Int(32, type.lanes());

src/IROperator.h

@@ -207,6 +207,9 @@ Expr halide_exp(const Expr &a);
 Expr halide_erf(const Expr &a);
 // @}
 
+/** Factor a float into 2^exponent * reduced, where reduced is between 0.75 and 1.5 */
+void range_reduce_log(const Expr &input, Expr *reduced, Expr *exponent);
+
 /** Raise an expression to an integer power by repeatedly multiplying
  * it by itself. */
 Expr raise_to_integer_power(Expr a, int64_t b);

src/runtime/opencl.cpp

@@ -38,6 +38,7 @@ extern "C" WEAK void *halide_opencl_get_symbol(void *user_context, const char *n
         "opencl.dll",
 #else
         "libOpenCL.so",
+        "libOpenCL.so.1",
         "/System/Library/Frameworks/OpenCL.framework/OpenCL",
 #endif
     };