[IR] Remove unbounded as possible value for vscale_range minimum

The default for min is changed to 1. The behaviour of -mvscale-{min,max}
in Clang is also changed such that 16 is the max vscale when targeting
SVE and no max is specified.

Reviewed By: sdesmalen, paulwalker-arm

Differential Revision: https://reviews.llvm.org/D113294

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index c104a6f..f760eb2 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -4123,6 +4123,13 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
         {std::string(Split.first), std::string(Split.second)});
   }
 
+  // Error if -mvscale-min is unbounded.
+  if (Arg *A = Args.getLastArg(options::OPT_mvscale_min_EQ)) {
+    unsigned VScaleMin;
+    if (StringRef(A->getValue()).getAsInteger(10, VScaleMin) || VScaleMin == 0)
+      Diags.Report(diag::err_cc1_unbounded_vscale_min);
+  }
+
   return Diags.getNumErrors() == NumErrorsBefore;
 }