make use of Boost.SIMD opt-in

Author: jjallaire

R/build.R

@@ -6,8 +6,8 @@
 #
 #  PKG_CXXFLAGS += $(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" -e "RcppParallel::CxxFlags()")
 #
-CxxFlags <- function(simd = TRUE) {
-   cat(tbbCxxFlags(simd = simd))
+CxxFlags <- function() {
+   cat(tbbCxxFlags())
 }
 
 
@@ -40,18 +40,14 @@ inlineCxxPlugin <- function() {
    )
 }
 
-tbbCxxFlags <- function(simd = TRUE) {
+tbbCxxFlags <- function() {
 
    flags <- c()
 
    # opt-in to TBB on Windows
    if (Sys.info()['sysname'] == "Windows")
       flags <- paste(flags, "-DRCPP_PARALLEL_USE_TBB=1")
 
-   # reflect requested use of boost::simd
-   if (!simd)
-      flags <- paste(flags, "-DRCPP_PARALLEL_USE_SIMD=0")
-   
    flags
 }
 

examples/boost-simd-abssum.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 using namespace Rcpp;

examples/boost-simd-accumulate.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 using namespace Rcpp;

examples/boost-simd-capabilities.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 using namespace Rcpp;

examples/boost-simd-dot.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 using namespace Rcpp;

examples/boost-simd-hello-world.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 using namespace Rcpp;

examples/boost-simd-transform.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 using namespace Rcpp;

examples/rcpp-simd-transform.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 

examples/simd-operations.Rmd

@@ -28,6 +28,7 @@ using `Boost.SIMD`.
 
 ```{r, engine='Rcpp'}
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 #include <Rcpp.h>
 
@@ -72,49 +73,21 @@ These functions operate like their `std::` counterparts, but expect a functor wi
 
 To build an R package that uses Boost.SIMD you need to make some modifications to the standard RcppParallel configuration:
 
-1. Make sure you call the `CxxFlags` and `LdFlags` functions in `Makevars`
-2. Add the **BH** package as a LinkingTo dependency
-3. Add C++11 as a SystemRequirement
+1. Add the **BH** package as a LinkingTo dependency
+2. Add C++11 as a SystemRequirement
 
-Here's the complete recipe for using RcppParallel with Boost.SIMD in an R package:
-
-**DESCRIPTION**
-
-```yaml
-Imports: RcppParallel
-LinkingTo: RcppParallel, BH
-SystemRequirements: GNU make, C++11
-```
-
-**NAMESPACE**
-
-```R
-importFrom(RcppParallel, RcppParallelLibs)
-```
-
-**src/Makevars**
-
-```make
-PKG_CXXFLAGS += $(shell ${R_HOME}/bin/Rscript -e "RcppParallel::CxxFlags()")
-PKG_LIBS += $(shell ${R_HOME}/bin/Rscript -e "RcppParallel::LdFlags()")
-```
-
-**src/Makevars.win**
-
-```make
-PKG_CXXFLAGS += $(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" \ -e "RcppParallel::CxxFlags()")
-PKG_LIBS += $(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" -e "RcppParallel::LdFlags()")
-```
 
 ### Platform Compatibility
 
 Note that Boost.SIMD requires a C++11 conformant compiler. This means that packages making use of SIMD features may not compile on platforms with older compilers including Windows and RedHat/CentOS Linux. You can however create a package that takes advantage of Boost.SIMD where available and falls back to a non-SIMD implementation elsewhere.
 
-You can test for the availability of Boost.SIMD on a given platform using the `RCPP_PARALLEL_USE_SIMD` preprocessor variable. If the current compiler doesn't support C++11 (as determined by `__cplusplus <= 199711L`) the variable will be undefined. This allows you to write code like this:
+You can test for the availability of Boost.SIMD on a given platform using the `RCPP_PARALLEL_USE_SIMD` preprocessor variable. If the current compiler doesn't support C++11 (as determined by `__cplusplus <= 199711L`) the variable will be undefined (even if you defined it explicitly). This allows you to write code like this:
 
 ```cpp
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 
+
 #if RCPP_PARALLEL_USE_SIMD
 
 #include <boost/simd/sdk/simd/pack.hpp>
@@ -146,28 +119,6 @@ The two `transformDataImpl` functions have the same name, but only one will be c
 
 Note that if you conditionally compile all uses of Boost.SIMD within your package then you can actually drop the `C++11` from `SystemRequirements` (it's no longer required as a result of your fallback implementation).
 
-## Disabling SIMD
-
-If you don't want to use Boost.SIMD at all you can explicitly disable it as follows:
-
-1. For `sourceCpp` you can define `RCPP_PARALLEL_USE_SIMD`:
-
-    ```cpp
-    #define RCPP_PARALLEL_USE_SIMD 0
-    ```
-
-2. For R packages you can pass `simd = FALSE` to the CxxFlags function:
-
-    ```make
-    PKG_CXXFLAGS += $(shell ${R_HOME}/bin/Rscript -e "RcppParallel::CxxFlags(simd = FALSE)")
-    ```
-   
-
-   
-
-
-
-
 
 
    

gallery/simd-variance.cpp

@@ -1,4 +1,5 @@
 // [[Rcpp::depends(RcppParallel)]]
+#define RCPP_PARALLEL_USE_SIMD 1
 #include <RcppParallel.h>
 using namespace RcppParallel;