fixup! change place of pass in pipeline

Author: madhur13490

clang/include/clang/Driver/Options.td

@@ -4268,10 +4268,10 @@ def floop_interchange : Flag<["-"], "floop-interchange">, Group<f_Group>,
   HelpText<"Enable the loop interchange pass">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
 def fno_loop_interchange: Flag<["-"], "fno-loop-interchange">, Group<f_Group>,
   HelpText<"Disable the loop interchange pass">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
-def fexperimental_loop_fusion : Flag<["-"], "fexperimental-loop-fusion">, Group<f_Group>,
-  HelpText<"Enable the experimental loop fusion pass">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
-def fno_experimental_loop_fusion: Flag<["-"], "fno-experimental-loop-fusion">, Group<f_Group>,
-  HelpText<"Disable the experimental loop fusion pass">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
+defm experimental_loop_fusion
+    : OptInCC1FFlag<"experimental-loop-fusion", "Enable", "Disable",
+                    "Enable the loop fusion pass",
+                    [ClangOption, CC1Option, FlangOption, FC1Option]>;
 def funroll_loops : Flag<["-"], "funroll-loops">, Group<f_Group>,
   HelpText<"Turn on loop unroller">, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
 def fno_unroll_loops : Flag<["-"], "fno-unroll-loops">, Group<f_Group>,

clang/lib/Frontend/CompilerInvocation.cpp

@@ -1673,8 +1673,6 @@ void CompilerInvocationBase::GenerateCodeGenArgs(const CodeGenOptions &Opts,
 
   if (Opts.FuseLoops)
     GenerateArg(Consumer, OPT_fexperimental_loop_fusion);
-  else
-    GenerateArg(Consumer, OPT_fno_experimental_loop_fusion);
 
   if (!Opts.BinutilsVersion.empty())
     GenerateArg(Consumer, OPT_fbinutils_version_EQ, Opts.BinutilsVersion);

clang/test/CodeGen/loop-fusion.c

@@ -0,0 +1,8 @@
+// Check if LoopFusion pass is triggered.
+//
+// RUN: %clang -c -fexperimental-loop-fusion -mllvm -print-pipeline-passes -O3 %s 2>&1 | FileCheck --check-prefixes=LOOP-FUSION-ON %s
+// RUN: %clang -c -mllvm -print-pipeline-passes -O3 %s 2>&1 | FileCheck --check-prefixes=LOOP-FUSION-OFF %s
+
+// LOOP-FUSION-ON: loop-fusion
+// LOOP-FUSION-OFF-NOT: loop-fusion
+void foo(void) {}

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -1554,14 +1554,14 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
   if (PTO.LoopInterchange)
     LPM.addPass(LoopInterchangePass());
 
+  OptimizePM.addPass(createFunctionToLoopPassAdaptor(
+      std::move(LPM), /*UseMemorySSA=*/false, /*UseBlockFrequencyInfo=*/false));
+
   // FIXME: This may not be the right place in the pipeline.
   // We need to have the data to support the right place.
   if (PTO.LoopFusion)
     OptimizePM.addPass(LoopFusePass());
 
-  OptimizePM.addPass(createFunctionToLoopPassAdaptor(
-      std::move(LPM), /*UseMemorySSA=*/false, /*UseBlockFrequencyInfo=*/false));
-
   // Distribute loops to allow partial vectorization.  I.e. isolate dependences
   // into separate loop that would otherwise inhibit vectorization.  This is
   // currently only performed for loops marked with the metadata