[PATCH] D11815: Pass subtarget feature "force-align-stack"

[Akira Hatanaka via cfe-commits]

ahatanak added inline comments.

================
Comment at: lib/Driver/Tools.cpp:4232
@@ +4231,3 @@
+                   false))
+    CmdArgs.push_back(Args.MakeArgString("-force-align-stack"));
+
----------------
echristo wrote:
> hfinkel wrote:
> > echristo wrote:
> > > hfinkel wrote:
> > > > The code below for OPT_mstackrealign uses -mstackrealign as the name of the backend option too. Why not do the same for OPT_mstackrealign (use -mstackrealign as the name of the backend option) instead of inventing a new flag name -force-align-stack?
> > > In general we don't do that. But I also don't want this to use a backend option anyhow, why are we doing that here once we have the attribute?
> > It's not a backend option, this is the flag being passed from the driver to clang -cc1.
> > 
> Aha. I must have misread. Then I totally agree :)
I believe the confusing part here is that the CC1 option "-mstackrealign" in the code below indicates stack realignment is allowed, but not necessarily forced (see the definition of StackRealignment in CodeGenOptions.def). This is different from the driver option options::OPT_mstackrealign, which indicates stack alignment should be forced.

Does that answer your question?


http://reviews.llvm.org/D11815