[PATCH] D14148: [GlobalOpt] Demote globals to locals more aggressively

[Duncan P. N. Exon Smith via llvm-commits]

> On 2015-Oct-28, at 08:59, David Majnemer <david.majnemer at gmail.com> wrote:
> 
> majnemer added inline comments.
> 
> ================
> Comment at: lib/Transforms/IPO/GlobalOpt.cpp:1747
> @@ +1746,3 @@
> +
> +// main() is known not to be recursive and to only be called once.
> +static bool isFunctionMain(const Function *F) {
> ----------------
> This is not true if the program is not a C++ program.  `main` can be recursively called in C.  Also, the name `main` may be reused for a function other than the entry point if it is not a hosted program which would be important to LTO something like the Linux kernel.
> 
> At the very least, we should check the functions prototype.

Note that this "main" shortcut isn't new; that check has been around
for quite some time.

> ================
> Comment at: lib/Transforms/IPO/GlobalOpt.cpp:1786
> @@ +1785,3 @@
> +    // FIXME: Deal with constantexpr bitcasts?
> +    Instruction *I = dyn_cast<Instruction>(U);
> +    if (!I)
> ----------------
> `auto *I`
> 
> ================
> Comment at: lib/Transforms/IPO/GlobalOpt.cpp:1803
> @@ +1802,3 @@
> +      for (auto *UU : I->users()) {
> +        LoadInst *LI = dyn_cast<LoadInst>(UU);
> +        if (!LI)
> ----------------
> `auto *LI`
> 
> 
> Repository:
>  rL LLVM
> 
> http://reviews.llvm.org/D14148
> 
> 
>