Eli, thanks for responding, unfortunately, this did not resolve my issue. It's a locally allocated array in the C code, but I'm not seeing any alloca in the IR just geps from the variable, which is never setup. On Wed, Aug 15, 2012 at 11:33 AM, Eli Friedman <eli.friedman at gmail.com>wrote:> On Wed, Aug 15, 2012 at 11:26 AM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > I have a const array allocated inside a function and the IR is showing > this > > has a global function (ie. there is no allocation for the space inside > the > > function). > > > > For example: > > > > const int32 local_array[256] = {constValue, constValue, ..... } > > > > Is there any particular reason this may be occuring? > > It's an optimization; IIRC, you can turn it off with > -fno-merge-all-constants. > > -Eli >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20120815/67d69c82/attachment.html>
On Wed, Aug 15, 2012 at 11:40 AM, Ryan Taylor <ryta1203 at gmail.com> wrote:> Eli, thanks for responding, unfortunately, this did not resolve my issue. > It's a locally allocated array in the C code, but I'm not seeing any alloca > in the IR just geps from the variable, which is never setup.That's strange; I just checked, and -fno-merge-all-constants definitely does have an effect for a simple testcase like the following (just using clang -emit-llvm at -O0): void f() { const int x[5] = {1,2,3,4}; } What does your testcase look like? -Eli
#define r10(p,q,r,s) 0x##s##r##q##p
#undef r
#define r r10
const word it_tab[4][256] = { r(const, const, const, const),
r(.......), r(.......) ....... };
All of this is done inside the function I want the alloc in. The variable
is not declared/defined/used anywhere else.
On Wed, Aug 15, 2012 at 12:00 PM, Eli Friedman <eli.friedman at
gmail.com>wrote:
> On Wed, Aug 15, 2012 at 11:40 AM, Ryan Taylor <ryta1203 at gmail.com>
wrote:
> > Eli, thanks for responding, unfortunately, this did not resolve my
issue.
> > It's a locally allocated array in the C code, but I'm not
seeing any
> alloca
> > in the IR just geps from the variable, which is never setup.
>
> That's strange; I just checked, and -fno-merge-all-constants
> definitely does have an effect for a simple testcase like the
> following (just using clang -emit-llvm at -O0):
>
> void f() { const int x[5] = {1,2,3,4}; }
>
> What does your testcase look like?
>
> -Eli
>
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