-time-ir-parsing flag

This breaks the layering of the Support library. We can't add an
implementation side to IRReader because it refers directly to entities
only accessible as part of the IR, AsmParser, and BitcodeReader
libraries. It can only be used in a context where all of those libraries
will be available.

We'll need to find some other way to get this functionality, and
hopefully solve the long-standing layering problem of IRReader.h...

llvm-svn: 177695

For mips a branch an 18-bit signed offset (the 16-bit 
offset field shifted left 2 bits) is added to the 
address of the instruction following the branch 
(not the branch itself), in the branch delay slot, 
to form a PC-relative effective target address. 

Previously, the code generator did not perform the 
shift of the immediate branch offset which resulted 
in wrong instruction opcode. This patch fixes the issue.

Contributor: Vladimir Medic
llvm-svn: 177687

This patch uses the generated instruction info tables to 
identify memory/load store instructions.
After successful matching and based on the operand type 
and size, it generates additional instructions to the output.

Contributor: Vladimir Medic
llvm-svn: 177685

As Jakob pointed out in his review of r177423, having a shared ZERO
register between the 32- and 64-bit register classes causes this
odd G8RC_NOX0_and_GPRC_NOR0 class to be created. As recommended,
this adds a ZERO8 register which differentiates the 32- and 64-bit
zeros.

No functionality change intended.

llvm-svn: 177683

To use this in conjunction with exuberant ctags to generate a single
combined tags file, run tblgen first and then
  $ ctags --append [...]

Since some identifiers have corresponding definitions in C++ code,
it can be useful (if using vim) to also use cscope, and
  :set cscopetagorder=1
so that
  :tag X
will preferentially select the tablegen symbol, while
  :cscope find g X
will always find the C++ symbol.

Patch by Kevin Schoedel!

(a couple small formatting changes courtesy of clang-format)

llvm-svn: 177682

How did this ever work?

Basically, if you have a function that's inlined into the caller, it may not
have any 'call' instructions, but any 'resume' instructions it may have should
still be forwarded to the outer (caller's) landing pad. This requires that all
of the 'landingpad' instructions in the callee have their clauses merged with
the caller's outer 'landingpad' instruction (hence the bit of ugly code in the
`forwardResume' method).

Testcase in a follow commit to the test-suite repository.

<rdar://problem/13360379> & PR15555

llvm-svn: 177680

Thanks to Jakob for isolating the underlying problem from the
test case in r177423. The original commit had introduced
asymmetric copy operations, but these turned out to be a work-around
to the real problem (the use of == instead of hasSubClassEq in PPCCTRLoops).

llvm-svn: 177679

Refactor the filename/directory information in DISubprogram to refer directly to the pair rather than the DIFile.

llvm-svn: 177677

llvm-svn: 177675

llvm-svn: 177674

<rdar://problem/13477190> On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR for the system temporary directory.

The DARWIN_USER_TEMP_DIR and DARWIN_USER_CACHE_DIR configuration
settings are more idiomatic for Darwin than the TMPDIR environment
variable.

llvm-svn: 177669

The .set directive in the Mips the assembler can be 
used to set the value of a symbol to an expression. 
This changes the symbol's value and type to conform 
to the expression's.

Syntax: .set symbol, expression

This patch implements the parsing of the above syntax 
and enables the parser to use defined symbols when 
parsing operands.

Contributor: Vladimir Medic
llvm-svn: 177667

This implements SJLJ lowering on PPC, making the Clang functions
__builtin_{setjmp/longjmp} functional on PPC platforms. The implementation
strategy is similar to that on X86, with the exception that a branch-and-link
variant is used to get the right jump address. Credit goes to Bill Schmidt for
suggesting the use of the unconditional bcl form (instead of the regular bl
instruction) to limit return-address-cache pollution.

Benchmarking the speed at -O3 of:

static jmp_buf env_sigill;

void foo() {
                __builtin_longjmp(env_sigill,1);
}

main() {
	...

        for (int i = 0; i < c; ++i) {
                if (__builtin_setjmp(env_sigill)) {
                        goto done;
                } else {
                        foo();
                }

done:;
        }

	...
}

vs. the same code using the libc setjmp/longjmp functions on a P7 shows that
this builtin implementation is ~4x faster with Altivec enabled and ~7.25x
faster with Altivec disabled. This comparison is somewhat unfair because the
libc version must also save/restore the VSX registers which we don't yet
support.

llvm-svn: 177666

llvm-svn: 177664

llvm-svn: 177661

Although there is only one Altivec VRSAVE register, it is a member of
a register class, and we need the ability to spill it. Because this
register is normally callee-preserved and handled by special code this
has never before been necessary. However, this capability will be required by
a forthcoming commit adding SjLj support.

llvm-svn: 177654

The old code used to lower FRAMEADDR tried to replicate the logic in the real
frame-lowering code that determines whether or not the frame pointer (r31) will
be used. When it seemed as through the frame pointer would not be used, the
stack pointer (r1) was used instead. Unfortunately, because the stack size is
not yet known, this does not work. Instead, this change introduces new
always-reserved pseudo-registers (FP and FP8) that are replaced during prologue
insertion with the real frame-pointer register (either r1 or r31).

It is important that this intrinsic always return a valid frame address because
it is used by Clang to store the frame address as part of code generation for
__builtin_setjmp.

llvm-svn: 177653

NEON is not IEEE 754 compliant, so we should avoid lowering single-precision
floating point operations with NEON unless unsafe-math is turned on. The
equivalent VFP instructions are IEEE 754 compliant, but in some cores they're
much slower, so some archs/OSs might still request it to be on by default,
such as Swift and Darwin.

llvm-svn: 177651

The landingpad instruction needs to be the first non-PHI instruction in the
unwind destination block.

llvm-svn: 177650

header.

This method is called in the hot path for *many* passes, SROA is what
caught my interest. A common pattern is that which branch of the switch
should be taken is known in the callsite and so it is a very good
candidate for inlining and simplification. Moving it into the header
allows the optimizer to fold a lot of boring, repeatitive code in
callers of this routine.

I'm seeing pretty significant speedups in parts of SROA and I suspect
other passes will see similar speedups if they end up working with type
sizes frequently. I've not seen any significant growth of the binaries
as a consequence, but let me know if you see anything suspicious here.

llvm-svn: 177632

The key part of this is ensuring that name prefixes remain in a Twine
form until we get to a point where we can nuke them under NDEBUG. This
is tricky using the old APIs as they played fast and loose with Twine,
which is prone to serious error. The inserter is much cleaner as it is
actually in the call stack leading to the setName call, and so has
a good opportunity to prepend the prefix.

This matters more than you might imagine because most runs over an
alloca find a single partition, and rewrite 3 or 4 instructions
referring to it. As a consequence doing this lazily and exclusively with
Twine allows the optimizer to delete more of it and shaves another 2% to
3% off of the release build's SROA run time for PR15412. I also think
the APIs are cleaner, and the use of Twine is more reliable, so
I consider it a win-win despite the churn required to reach this state.

llvm-svn: 177631

llvm-svn: 177630

The 'Modified' variable should have been removed from SimplifyLibCalls
in r177619, but was missed.  This commit removes it.

llvm-svn: 177622

llvm-svn: 177620

The simplify-libcalls pass implemented a doInitialization hook to infer
function prototype attributes for well-known functions.  Given that the
simplify-libcalls pass is going away *and* that the functionattrs pass
is already in place to deduce function attributes, I am moving this logic
to the functionattrs pass.  This approach was discussed during patch
review:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121126/157465.html.

llvm-svn: 177619

llvm-svn: 177614

llvm-svn: 177611

This removes the DICompileUnit special case from DIScope.

llvm-svn: 177610

They are generally faster (at least not slower) than post-inc, post-dec.

llvm-svn: 177608

llvm-svn: 177607

Native Windows Python will do line ending translation by default, which
we don't want in bash scripts.  If we're not native Windows Python, then
'b' is ignored.

llvm-svn: 177602

llvm-svn: 177600

It's not yet clear if these instructions need a more careful model.

llvm-svn: 177599

This is used for all the expensive system instructions.

llvm-svn: 177598

When computing the demanded bits of Load SDNodes, make sure that we are looking at the loaded-value operand and not the ptr result (in case of pre-inc loads).
rdar://13348420

llvm-svn: 177596

llvm-svn: 177595

llvm-svn: 177592

llvm-svn: 177591

llvm-svn: 177590

- After moving logic recognizing vector shift with scalar amount from
  DAG combining into DAG lowering, we declare to customize all vector
  shifts even vector shift on AVX is legal. As a result, the cost model
  needs special tuning to identify these legal cases.

llvm-svn: 177586