There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
  files.
* The linker tells LLVM which symbols are not used from other object files,
  but will be put in the dso symbol table if present.

GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.

LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.

This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
  global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.

llvm-svn: 193800

llvm-svn: 193734

llvm-svn: 193720

llvm-svn: 193710

By vectorizing a series of srl, or, ... instructions we have obfuscated the
intention so much that the backend does not know how to fold this code away.

radar://15336950

llvm-svn: 193573

No test case, because with the current cost model we don't see a difference.
An upcoming ARM memory cost model change will expose and test this bug.

radar://15332579

llvm-svn: 193572

llvm-svn: 193489

This patch implements quick look-up for block in loop by maintaining a hash set for blocks.
It improves the efficiency of loop analysis a lot, the biggest improvement could be 5-6%(458.sjeng).
Below are the compilation time for our benchmark in llc before & after the patch.

Benchmark	llc - trunk		llc - patched	
401.bzip2	0.339081	100.00%	0.329657	102.86%
403.gcc		19.853966	100.00%	19.605466	101.27%
429.mcf		0.049823	100.00%	0.048451	102.83%
433.milc	0.514898	100.00%	0.510217	100.92%
444.namd	1.109328	100.00%	1.103481	100.53%
445.gobmk	4.988028	100.00%	4.929114	101.20%
456.hmmer	0.843871	100.00%	0.825865	102.18%
458.sjeng	0.754238	100.00%	0.714095	105.62%
464.h264ref	2.9668		100.00%	2.90612		102.09%
471.omnetpp	4.556533	100.00%	4.511886	100.99%
bitmnp01	0.038168	100.00%	0.0357		106.91%
idctrn01	0.037745	100.00%	0.037332	101.11%
libquake2	3.78689		100.00%	3.76209		100.66%
libquake_	2.251525	100.00%	2.234104	100.78%
linpack		0.033159	100.00%	0.032788	101.13%
matrix01	0.045319	100.00%	0.043497	104.19%
nbench		0.333161	100.00%	0.329799	101.02%
tblook01	0.017863	100.00%	0.017666	101.12%
ttsprk01	0.054337	100.00%	0.053057	102.41%

Reviewer	: Andrew Trick <atrick@apple.com>, Hal Finkel <hfinkel@anl.gov>
Approver	: Andrew Trick <atrick@apple.com>
Test		: Pass make check-all & llvm test-suite

llvm-svn: 193460

Partial fix for PR17459: wrong code at -O3 on x86_64-linux-gnu
(affecting trunk and 3.3)

When SCEV expands a recurrence outside of a loop it attempts to scale
by the stride of the recurrence. Chained recurrences don't work that
way. We could compute binomial coefficients, but would hve to
guarantee that the chained AddRec's are in a perfectly reduced form.

llvm-svn: 193438

This patch teaches GlobalStatus to analyze a call that uses the global value as
a callee, not as an argument.

With this change internalize call handle the common use of linkonce_odr
functions. This reduces the number of linkonce_odr functions in a LTO build of
clang (checked with the emit-llvm gold plugin option) from 1730 to 60.

llvm-svn: 193436

The loop vectorizer does not currently understand how to vectorize
extractelement instructions. The existing check, which excluded all
vector-valued instructions, did not catch extractelement instructions because
it checked only the return value. As a result, vectorization would proceed,
producing illegal instructions like this:

  %58 = extractelement <2 x i32> %15, i32 0
  %59 = extractelement i32 %58, i32 0

where the second extractelement is illegal because its first operand is not a vector.

llvm-svn: 193434

Patch by: Vincent Lejeune

llvm-svn: 193356

Make sure we mark all loops (scalar and vector) when vectorizing,
so that we don't try to vectorize them anymore. Also, set unroll
to 1, since this is what we check for on early exit.

llvm-svn: 193349

LLVM optimizers may widen accesses to packed structures that overflow the structure itself, but should be in bounds up to the alignment of the object

llvm-svn: 193317

Reviewed by Andy

llvm-svn: 193303

llvm-svn: 193292

llvm-svn: 193268

 Major steps include:
 1). introduces a not-addr-taken bit-field in GlobalVariable
 2). GlobalOpt pass sets "not-address-taken" if it proves a global varirable 
    dosen't have its address taken.
 3). AA use this info for disambiguation. 

llvm-svn: 193251

llvm-svn: 193130

v2:
  - Use CI->cannotDuplicate()

llvm-svn: 193115

llvm-svn: 193109

llvm-svn: 193104

When a linkonce_odr value that is on the dso list is not unnamed_addr
we can still look to see if anything is actually using its address. If
not, it is safe to hide it.

This patch implements that by moving GlobalStatus to Transforms/Utils
and using it in Internalize.

llvm-svn: 193090

Additionally some small comment/stylistic fixes are included as well.

llvm-svn: 193068

A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.

PR17621

llvm-svn: 193064

One optimization simplify-cfg performs is the converting of switches to
lookup tables if the switch has > 4 cases. This is done by:

1. Finding the max/min case value and calculating the switch case range.
2. Create a lookup table basic block.
3. Perform a check in the switch's BB to see if the input value is in
the switch's case range. If the input value satisfies said predicate
branch to the lookup table BB, otherwise branch to the switch's default
destination BB using the default value as the result.

The conditional check consists of subtracting the min case value of the
table from any input iN value and then ensuring that said value is
unsigned less than the size of the lookup table represented as an iN
value.

If the lookup table is a covered lookup table, the size of the table will be N
which is 0 as an iN value. Thus the comparison will be an `icmp ult` of an iN
value against 0 which is always false yielding the incorrect result.

This patch fixes this problem by recognizing if we have a covered lookup table
and if we do, unconditionally jumps to the lookup table BB since the covering
property of the lookup table implies no input values could not be handled by
said BB.

rdar://15268442

llvm-svn: 193045

If the predecessor's being spliced into a landing pad, then we need the PHIs to
come first and the rest of the predecessor's code to come *after* the landing
pad instruction.

llvm-svn: 193035

llvm-svn: 193013

llvm-svn: 192910

llvm-svn: 192907

No functionality change.

llvm-svn: 192906

Switch to sign-extension in r192575 caused 7% perf loss on 482.sphinx3.

llvm-svn: 192882

If a function has no_sanitize_thread attribute,
do not instrument memory accesses in it.

llvm-svn: 192871

radar://15231682

Reapply r192799,
  http://lab.llvm.org:8011/builders/lldb-x86_64-debian-clang/builds/8226
showed that the bot is still broken even with this out.

llvm-svn: 192820

This speculatively reverts commit 192799. It might have broken a linux buildbot.

llvm-svn: 192816

radar://15231682

llvm-svn: 192799

Summary:
Given a global array G[N], which is declared in this CU and has static initializer
avoid instrumenting accesses like G[i], where 'i' is a constant and 0<=i<N.
Also add a bit of stats.

This eliminates ~1% of instrumentations on SPEC2006
and also partially helps when asan is being run together with coverage.

Reviewers: samsonov

Reviewed By: samsonov

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1947

llvm-svn: 192794

llvm-svn: 192717

Remove x86_sse42_crc32_64_8 intrinsic. It has no functional difference from x86_sse42_crc32_32_8 and was not mapped to a clang builtin. I'm not even sure why this form of the instruction is even called out explicitly in the docs. Also add AutoUpgrade support to convert it into the other intrinsic with appropriate trunc and zext.

llvm-svn: 192672

They were leftover from the old profiling support.

Patch by Alastair Murray.

llvm-svn: 192605