Add C and JS APIs for fast math (#3188)

Adds `BinaryenGetFastMath` and `BinaryenSetFastMath` to the C API, respectively `binaryen.getFastMath` and `binaryen.setFastMath` to the JS API.

5 files changed, 30 insertions, 0 deletions

diff --git a/src/binaryen-c.cpp b/src/binaryen-c.cpp
index f4515208f..bbacd517b 100644
--- a/src/binaryen-c.cpp
+++ b/src/binaryen-c.cpp
@@ -3570,6 +3570,10 @@ void BinaryenSetLowMemoryUnused(int on) {
   globalPassOptions.lowMemoryUnused = on != 0;
 }
 
+int BinaryenGetFastMath(void) { return globalPassOptions.fastMath; }
+
+void BinaryenSetFastMath(int value) { globalPassOptions.fastMath = value != 0; }
+
 const char* BinaryenGetPassArgument(const char* key) {
   assert(key);
   const auto& args = globalPassOptions.arguments;
diff --git a/src/binaryen-c.h b/src/binaryen-c.h
index 4ca76657d..10b52dbdd 100644
--- a/src/binaryen-c.h
+++ b/src/binaryen-c.h
@@ -2134,6 +2134,16 @@ BINARYEN_API int BinaryenGetLowMemoryUnused(void);
 // when optimizing. Applies to all modules, globally.
 BINARYEN_API void BinaryenSetLowMemoryUnused(int on);
 
+// Gets whether fast math optimizations are enabled, ignoring for example
+// corner cases of floating-point math like NaN changes.
+// Applies to all modules, globally.
+BINARYEN_API int BinaryenGetFastMath(void);
+
+// Enables or disables fast math optimizations, ignoring for example
+// corner cases of floating-point math like NaN changes.
+// Applies to all modules, globally.
+BINARYEN_API void BinaryenSetFastMath(int value);
+
 // Gets the value of the specified arbitrary pass argument.
 // Applies to all modules, globally.
 BINARYEN_API const char* BinaryenGetPassArgument(const char* name);
diff --git a/src/js/binaryen.js-post.js b/src/js/binaryen.js-post.js
index 529474098..3cce22411 100644
--- a/src/js/binaryen.js-post.js
+++ b/src/js/binaryen.js-post.js
@@ -3046,6 +3046,18 @@ Module['setLowMemoryUnused'] = function(on) {
   Module['_BinaryenSetLowMemoryUnused'](on);
 };
 
+// Gets whether fast math optimizations are enabled, ignoring for example
+// corner cases of floating-point math like NaN changes.
+Module['getFastMath'] = function() {
+  return Boolean(Module['_BinaryenGetFastMath']());
+};
+
+// Enables or disables fast math optimizations, ignoring for example
+// corner cases of floating-point math like NaN changes.
+Module['setFastMath'] = function(value) {
+  Module['_BinaryenSetFastMath'](value);
+};
+
 // Gets the value of the specified arbitrary pass argument.
 Module['getPassArgument'] = function(key) {
   return preserveStack(() => {
diff --git a/test/binaryen.js/fast-math.js b/test/binaryen.js/fast-math.js
new file mode 100644
index 000000000..48b575b41
--- /dev/null
+++ b/test/binaryen.js/fast-math.js
@@ -0,0 +1,3 @@
+console.log("// fastMath=" + binaryen.getFastMath());
+binaryen.setFastMath(true);
+assert(binaryen.getFastMath() == true);
diff --git a/test/binaryen.js/fast-math.js.txt b/test/binaryen.js/fast-math.js.txt
new file mode 100644
index 000000000..0a0d43cb6
--- /dev/null
+++ b/test/binaryen.js/fast-math.js.txt
@@ -0,0 +1 @@
+// fastMath=false