[flang] [clang] [flang] Enable alias tags pass by default (PR #73111)

[Mats Petersson via cfe-commits]

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@@ -242,10 +242,24 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
                    clang::driver::options::OPT_fno_loop_versioning, false))
     opts.LoopVersioning = 1;
 
-  opts.AliasAnalysis =
-      args.hasFlag(clang::driver::options::OPT_falias_analysis,
-                   clang::driver::options::OPT_fno_alias_analysis,
-                   /*default=*/false);
+  bool aliasAnalysis = false;
+  bool noAliasAnalysis = false;
+  if (auto *arg =
+          args.getLastArg(clang::driver::options::OPT_falias_analysis,
+                          clang::driver::options::OPT_fno_alias_analysis)) {
+    if (arg->getOption().matches(clang::driver::options::OPT_falias_analysis))
+      aliasAnalysis = true;
+    else
+      noAliasAnalysis = true;
+  }
+  opts.AliasAnalysis = 0;
+  if (opts.OptimizationLevel > 0) {
+    if (!noAliasAnalysis)
+      opts.AliasAnalysis = 1;
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Leporacanthicus wrote:

Is there a reason that AliasAnalysis is an integer, rather than a boolean?

https://github.com/llvm/llvm-project/pull/73111