Merge pull request #22455 from JuliaLang/yyc/codegen/dce-ptls

Add a dead code elimination pass before lowering ptls

Author: yuyichao

src/jitlayers.cpp

@@ -148,6 +148,7 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level)
 #if JL_LLVM_VERSION < 50000
     PM->add(createLowerExcHandlersPass());
     PM->add(createLateLowerGCFramePass());
+    PM->add(createDeadCodeEliminationPass());
     PM->add(createLowerPTLSPass(imaging_mode));
 #endif
 
@@ -240,6 +241,7 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level)
     PM->add(createLowerExcHandlersPass());
     PM->add(createGCInvariantVerifierPass(false));
     PM->add(createLateLowerGCFramePass());
+    PM->add(createDeadCodeEliminationPass());
     PM->add(createLowerPTLSPass(imaging_mode));
 #endif
 }

test/choosetests.jl

@@ -35,7 +35,7 @@ function choosetests(choices = [])
         "enums", "cmdlineargs", "i18n", "workspace", "libdl", "int",
         "checked", "intset", "floatfuncs", "compile", "distributed", "inline",
         "boundscheck", "error", "ambiguous", "cartesian", "asmvariant", "osutils",
-        "channels", "iostream", "specificity"
+        "channels", "iostream", "specificity", "codegen"
     ]
     profile_skipped = false
     if startswith(string(Sys.ARCH), "arm")

test/codegen.jl

@@ -0,0 +1,14 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+# tests for codegen and optimizations
+
+const opt_level = Base.JLOptions().opt_level
+
+# `_dump_function` might be more efficient but it doesn't really matter here...
+get_llvm(f::ANY, t::ANY, strip_ir_metadata=true, dump_module=false) =
+    sprint(code_llvm, f, t, strip_ir_metadata, dump_module)
+
+if opt_level > 0
+    # Make sure getptls call is removed at IR level with optimization on
+    @test !contains(get_llvm(identity, Tuple{String}), " call ")
+end