Only warn about missed transformations when debug output is enabled. (#521)

Author: maleadt

src/optim.jl

@@ -43,7 +43,9 @@ function buildNewPMPipeline!(mpm, @nospecialize(job::CompilerJob), opt_level=2)
             #      and actually causes issues with some back-end compilers (like Metal).
             buildVectorPipeline(fpm, job, opt_level)
         end
-        add!(fpm, WarnMissedTransformationsPass())
+        if isdebug(:optim)
+            add!(fpm, WarnMissedTransformationsPass())
+        end
     end
     buildIntrinsicLoweringPipeline(mpm, job, opt_level)
     buildCleanupPipeline(mpm, job, opt_level)

src/utils.jl

@@ -17,6 +17,9 @@ should_verify() = ccall(:jl_is_debugbuild, Cint, ()) == 1 ||
                   Base.JLOptions().debug_level >= 2 ||
                   parse(Bool, get(ENV, "CI", "false"))
 
+isdebug(group, mod=GPUCompiler) =
+    Base.CoreLogging.current_logger_for_env(Base.CoreLogging.Debug, group, mod) !== nothing
+
 
 ## lazy module loading