This is a preliminary patch for fast instruction selection on
PowerPC.  Code generation can differ between DAG isel and fast isel.
Existing tests that specify -O0 were written to expect DAG isel.  Make
this explicit by adding -fast-isel=false to the tests.

In some cases specifying -fast-isel=false produces different code even
when there isn't a fast instruction selector specified.  This is
because TM.Options.EnableFastISel = 1 at -O0 whether or not a FastISel
object exists.  Thus disabling fast isel can actually produce less
conservative code.  Because of this, some of the expected code
generation in the -O0 tests needs to be adjusted.

In particular, handling of function arguments is less conservative
with -fast-isel=false (see isOnlyUsedInEntryBlock() in
SelectionDAGBuilder.cpp).  This results in fewer stack accesses and,
in some cases, reduced stack size as uselessly loaded values are no
longer stored back to spill locations in the stack.

No functional change with this patch; test case adjustments only.

llvm-svn: 183939

The test case for this is way too complex to be useful as a lit test,
and I was unable to reduce it.

https://bugs.freedesktop.org/show_bug.cgi?id=65438

llvm-svn: 183937

llvm-svn: 183934

This pass was assuming that if hasAddressTaken() returns false for a
function, the function's only uses are call sites.  That's not true
because there can be references by BlockAddresses too.

Fix the pass to handle this case.  Fix
BlockAddress::replaceUsesOfWithOnConstant() to allow a function's type
to be changed by RAUW'ing the function with a bitcast of the recreated
function.

Patch by Mark Seaborn.

llvm-svn: 183933

llvm-svn: 183928

Backends shouldn't retain any global state. No functionality change.

llvm-svn: 183927

This is in preparation for switching the clang driver over to using LLVM's
Option library.  Richard Smith introduced most of these changes to the clang
driver in r167638.

Reviewers: espindola on IRC

Differential Revision: http://llvm-reviews.chandlerc.com/D970

llvm-svn: 183925

llvm-svn: 183921

llvm-svn: 183920

Now PathV1.h is not needed in GraphWriter.h.

llvm-svn: 183919

llvm-svn: 183915

llvm-svn: 183914

llvm-svn: 183913

llvm-svn: 183912

llvm-svn: 183909

llvm-svn: 183908

llvm-svn: 183907

Execute's Data parameter is now optional, so we won't allocate memory
for it on Windows and we'll close the process handle.

The Unix code should probably do something similar to avoid accumulation
of zombie children that haven't been waited on.

Tested on Linux and Windows.

llvm-svn: 183906

llvm-svn: 183904

operator<< so that functions are printed as just their name instead of as their
entire definition, which is excessively verbose in this context.

llvm-svn: 183871

llvm-svn: 183868

llvm-svn: 183866

llvm-svn: 183865

It was only used to implement ExecuteAndWait and ExecuteNoWait. Expose just
those two functions and make Execute and Wait implementations details.

llvm-svn: 183864

Now that the PRED_BAD has been removed, this is failing the Clang
-Werror build due to -Wcovered-switch-default.

llvm-svn: 183863

This is a temporary stepping stone for moving them out of Program.

llvm-svn: 183860

I'm taking David Blaikie's suggestion to use an
Optional<PPC::Predicate> return value instead.  That's the right
solution for this problem.  Thanks for pointing out that possibility!

llvm-svn: 183858

Introducing PRED_BAD caused some unexpected warnings that are now
suppressed.

llvm-svn: 183854

These records are mandatory for executables and are used by the loader.

Reviewers: rafael

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D939

llvm-svn: 183852

Should fix the dragonegg build bots.

llvm-svn: 183845

This is a preparatory patch for fast-isel support.  The instruction
selector will need to access some functions in PPCGenCallingConv.inc,
which in turn requires several helper functions to be defined.  These
are currently defined near the only use of PCCGenCallingConv.inc,
inside PPCISelLowering.cpp.  This patch moves the declaration of the
functions into the associated header file to provide the needed
visibility.

No functional change intended.

llvm-svn: 183844

llvm-svn: 183843

No functionality change.

llvm-svn: 183842

Allows returning a PPC::Predicate from a function with a no-predicate
value possible.  Preparatory patch for fast-isel on PPC64 ELF.  No
behavioral change intended.

llvm-svn: 183841

llvm-svn: 183840

llvm-svn: 183839

llvm-svn: 183838

llvm-svn: 183836

llvm-svn: 183835

[MC/DWARF] Support .debug_frame / .debug_line code alignment factors

I've been comparing the object file output of LLVM's integrated
assembler against the external assembler on PowerPC, and one
area where differences still remain are in DWARF sections.

In particular, the GNU assembler generates .debug_frame and
.debug_line sections using a code alignment factor of 4, since
all PowerPC instructions have size 4 and must be aligned to a
multiple of 4.  However, current MC code hard-codes a code
alignment factor of 1.

This patch changes this by adding a "minimum instruction alignment"
data element to MCAsmInfo and using this as code alignment factor.

This requires passing a MCContext into MCDwarfLineAddr::Encode
and MCDwarfLineAddr::EncodeAdvanceLoc.  Note that one caller,
MCDwarfLineAddr::Write, didn't actually have that information
available.  However, it turns out that this routine is in fact
never used in the whole code base, so the patch simply removes
it.  If it turns out to be needed again at a later time, it
could be re-added with an updated interface.

llvm-svn: 183834