turn on precise i32 multiplication by default

1 files changed, 3 insertions, 7 deletions

diff --git a/src/settings.js b/src/settings.js
index 1023ee11..df9da926 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -92,13 +92,9 @@ var PRECISE_I64_MATH = 1; // If enabled, i64 addition etc. is emulated - which i
                           // that we can't know at compile time that 64-bit math is needed. For example, if you
                           // print 64-bit values with printf, but never add them, we can't know at compile time
                           // and you need to set this to 2.
-var PRECISE_I32_MUL = 0; // If enabled, i64 math is done in i32 multiplication. This is necessary if the values
-                         // exceed the JS double-integer limit of ~52 bits. This option can normally be disabled
-                         // because generally i32 multiplication works ok without it, and enabling it has a big
-                         // impact on performance.
-                         // Note that you can hand-optimize your code to avoid the need for this: If you do
-                         // multiplications that actually need 64-bit precision inside 64-bit values, things
-                         // will work properly. (Unless the LLVM optimizer turns them into 32-bit values?)
+var PRECISE_I32_MUL = 1; // If enabled, i32 multiplication is done with full precision, which means it is
+                         // correct even if the value exceeds the JS double-integer limit of ~52 bits (otherwise,
+                         // rounding will occur above that range).
 
 var CLOSURE_ANNOTATIONS = 0; // If set, the generated code will be annotated for the closure
                              // compiler. This potentially lets closure optimize the code better.