Commit Graph

6 Commits

Author SHA1 Message Date
Rafael Espindola 63c378d343 Go back to sometimes assuming intristics are local.
This fixes pr36674.

While it is valid for shouldAssumeDSOLocal to return false anytime,
always returning false for intrinsics is not optimal on i386 and also
hits a bug in the backend.

To use a plt, the caller must first setup ebx to handle the case of
that file being linked into a PIE executable or shared library. In
those cases the generated PLT uses ebx.

Currently we can produce "calll expf@plt" without setting ebx. We
could fix that by correctly setting ebx, but this would produce worse
code for the case where the runtime library is statically linked. It
would also required other tools to handle R_386_PLT32.

llvm-svn: 327198
2018-03-10 02:42:14 +00:00
Rafael Espindola c7e51805ff Bring back r323297.
It was reverted because it broke the grub build. The reason the grub
build broke is because grub does its own relocation processing and was
not handing R_386_PLT32. Since grub has no dynamic linker, the fix is
trivial: handle R_386_PLT32 exactly like R_386_PC32.

On the report it was noted that they are using
-fno-integrated-assembler. The upstream GAS (starting with
451875b4f976a527395e9303224c7881b65e12ed) will already be producing a
R_386_PLT32 anyway, so they have to update their code one way or the
other

Original message:

Don't assume a null GV is local for ELF and MachO.

This is already a simplification, and should help with avoiding a plt
reference when calling an intrinsic with -fno-plt.

With this change we return false for null GVs, so the caller only
needs to check the new metadata to decide if it should use foo@plt or
*foo@got.

llvm-svn: 325514
2018-02-19 16:02:38 +00:00
Reid Kleckner 697d1bc236 Revert "Don't assume a null GV is local for ELF and MachO."
This reverts r323297.

It breaks building grub.

llvm-svn: 324301
2018-02-06 00:47:14 +00:00
Rafael Espindola 432a587cf0 Don't assume a null GV is local for ELF and MachO.
This is already a simplification, and should help with avoiding a plt
reference when calling an intrinsic with -fno-plt.

With this change we return false for null GVs, so the caller only
needs to check the new metadata to decide if it should use foo@plt or
*foo@got.

llvm-svn: 323297
2018-01-24 02:11:18 +00:00
Sanjay Patel 37e28e40cb [SelectionDAG] lower math intrinsics to finite version of libcalls when possible (PR35672)
Ingredients in this patch:
1. Add HANDLE_LIBCALL defs for finite mathlib functions that correspond to LLVM intrinsics.
2. Plumbing to send TargetLibraryInfo down to SelectionDAGLegalize.
3. Relaxed math and library checking in SelectionDAGLegalize::ConvertNodeToLibcall() to choose finite libcalls.

There was a bug about determining the availability of the finite calls that should be fixed with:
rL322010

Not in this patch:
This doesn't resolve the question/bug of clang creating the intrinsic IR in the first place.
There's likely follow-up work needed to support the long double variants better.
There's room for improvement to reduce the code duplication.
Create finite calls that don't originate from a corresponding intrinsic or DAG node?

Differential Revision: https://reviews.llvm.org/D41338

llvm-svn: 322087
2018-01-09 15:41:00 +00:00
Sanjay Patel 9da049fa8a [x86] add tests for finite libcall lowering (PR35672); NFC
llvm-svn: 320955
2017-12-18 00:38:45 +00:00