142 Commits

Author SHA1 Message Date
Nadav Rotem
df96d1dffb Refactor some code to use the IRBuilder.
llvm-svn: 173467
2013-01-25 18:34:09 +00:00
Nadav Rotem
52f5279653 Add support for reverse pointer induction variables. These are loops that contain pointers that count backwards.
For example, this is the hot loop in BZIP:

  do {
    m = *--p;
    *p = ( ... );
  } while (--n);

llvm-svn: 173219
2013-01-23 01:35:00 +00:00
Nadav Rotem
6e8c348e91 Fix a comment. Induction vars dont need to start at zero.
llvm-svn: 173061
2013-01-21 17:59:18 +00:00
Benjamin Kramer
3acd79adc5 LoopVectorize: Fix a C++11 incompatibility.
llvm-svn: 172990
2013-01-20 20:29:52 +00:00
Nadav Rotem
7c9244fdca Fix a build error.
llvm-svn: 172971
2013-01-20 09:39:17 +00:00
Nadav Rotem
9ec02f071a LoopVectorizer: Implement a new heuristics for selecting the unroll factor.
We ignore the cpu frontend and focus on pipeline utilization. We do this because we
don't have a good way to estimate the loop body size at the IR level.

llvm-svn: 172964
2013-01-20 05:24:29 +00:00
Benjamin Kramer
28c812f680 LoopVectorizer: Emit memory checks into their own basic block.
This separates the check for "too few elements to run the vector loop" from the
"memory overlap" check, giving a lot nicer code and allowing to skip the memory
checks when we're not going to execute the vector code anyways. We still leave
the decision of whether to emit the memory checks as branches or setccs, but it
seems to be doing a good job. If ugly code pops up we may want to emit them as
separate blocks too. Small speedup on MultiSource/Benchmarks/MallocBench/espresso.

Most of this is legwork to allow multiple bypass blocks while updating PHIs,
dominators and loop info.

llvm-svn: 172902
2013-01-19 13:57:58 +00:00
Nadav Rotem
3fc70ae776 LoopVectorizer cost model. Honor the user command line flag that selects the vectorization factor even if the target machine does not have any vector registers.
llvm-svn: 172544
2013-01-15 18:25:16 +00:00
Nadav Rotem
c6cce40085 Fix PR14547. Handle induction variables of small sizes smaller than i32 (i8 and i16).
llvm-svn: 172348
2013-01-13 07:56:29 +00:00
Nadav Rotem
008741a0e0 ARM Cost Model: We need to detect the max bitwidth of types in the loop in order to select the max vectorization factor.
We don't have a detailed analysis on which values are vectorized and which stay scalars in the vectorized loop so we use
another method. We look at reduction variables, loads and stores, which are the only ways to get information in and out
of loop iterations. If the data types are extended and truncated then the cost model will catch the cost of the vector
zext/sext/trunc operations.

llvm-svn: 172178
2013-01-11 07:11:59 +00:00
Nadav Rotem
d5f59a81d9 LoopVectorizer: Fix a bug in the vectorization of BinaryOperators. The BinaryOperator can be folded to an Undef, and we don't want to set NSW flags to undef vals.
PR14878

llvm-svn: 172079
2013-01-10 17:34:39 +00:00
Nadav Rotem
436dc952aa ARM Cost model: Use the size of vector registers and widest vectorizable instruction to determine the max vectorization factor.
llvm-svn: 172010
2013-01-09 22:29:00 +00:00
Nadav Rotem
9c27f36e59 Cost Model: Move the 'max unroll factor' variable to the TTI and add initial Cost Model support on ARM.
llvm-svn: 171928
2013-01-09 01:15:42 +00:00
Nadav Rotem
df0bfd2e95 Code cleanup: refactor the switch statements in the generation of reduction variables into an IR builder call.
llvm-svn: 171871
2013-01-08 17:37:45 +00:00
Nadav Rotem
5bb578a21c Rename the enum members to match the LLVM coding style.
llvm-svn: 171868
2013-01-08 17:23:17 +00:00
Nadav Rotem
4aa065a2a3 LoopVectorizer: Add support for floating point reductions
llvm-svn: 171812
2013-01-07 23:13:00 +00:00
Nadav Rotem
5906222eab LoopVectorizer: When we vectorizer and widen loops we process many elements at once. This is a good thing, except for
small loops. On small loops post-loop that handles scalars (and runs slower) can take more time to execute than the
rest of the loop. This patch disables widening of loops with a small static trip count.

llvm-svn: 171798
2013-01-07 21:54:51 +00:00
Chandler Carruth
c894d24706 Simplify LoopVectorize to require target transform info and rely on it
being present. Make a member of one of the helper classes a reference as
part of this.

Reformatting goodness brought to you by clang-format.

llvm-svn: 171726
2013-01-07 11:12:29 +00:00
Chandler Carruth
cbf30d85b9 Merge the unused header file for LoopVectorizer into the source file.
This makes the loop vectorizer match the pattern followed by roughly all
other passses. =]

Notably, this header file was braken in several regards: it contained
a using namespace directive, global #define's that aren't globaly
appropriate, and global constants defined directly in the header file.

As a side benefit, lots of the types in this file become internal, which
will cause the optimizer to chew on this pass more effectively.

llvm-svn: 171723
2013-01-07 10:44:06 +00:00
Chandler Carruth
7723d75e9e Fix the enumerator names for ShuffleKind to match tho coding standards,
and make its comments doxygen comments.

llvm-svn: 171688
2013-01-07 03:20:02 +00:00
Chandler Carruth
3c0f5d4efb Move TargetTransformInfo to live under the Analysis library. This no
longer would violate any dependency layering and it is in fact an
analysis. =]

llvm-svn: 171686
2013-01-07 03:08:10 +00:00
Chandler Carruth
7e058addc4 Switch the loop vectorizer from VTTI to just use TTI directly.
llvm-svn: 171620
2013-01-05 10:16:02 +00:00
Nadav Rotem
836b9a9fda iLoopVectorize: Non commutative operators can be used as reduction variables as long as the reduction chain is used in the LHS.
PR14803.

llvm-svn: 171583
2013-01-05 01:15:47 +00:00
Paul Redmond
6ce33a6ae9 Do not vectorize loops with subtraction reductions
Since subtraction does not commute the loop vectorizer incorrectly vectorizes
reductions such as x = A[i] - x.

Disabling for now.

llvm-svn: 171537
2013-01-04 22:10:16 +00:00
Nadav Rotem
3349017273 Fix a warning
llvm-svn: 171525
2013-01-04 21:08:44 +00:00
Nadav Rotem
cb3562a88e LoopVectorizer:
1. Add code to estimate register pressure.
2. Add code to select the unroll factor based on register pressure.
3. Add bits to TargetTransformInfo to provide the number of registers.

llvm-svn: 171469
2013-01-04 17:48:25 +00:00
Nadav Rotem
29dd0667aa LoopVectorizer: Add support for loop-unrolling during vectorization for increasing the ILP. At the moment this feature is disabled by default and this commit should not cause any functional changes.
llvm-svn: 171436
2013-01-03 00:52:27 +00:00
Nadav Rotem
a7cac72b7d Avoid vectorization when the function has the "noimplicitflot" attribute.
llvm-svn: 171429
2013-01-02 23:54:43 +00:00
Chandler Carruth
4c1f3c24db Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Benjamin Kramer
ddae3440aa Add IRBuilder::CreateVectorSplat and use it to simplify code.
llvm-svn: 171349
2013-01-01 19:55:16 +00:00
Bill Wendling
e0920e4122 Remove the Function::getFnAttributes method in favor of using the AttributeSet
directly.

This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.

llvm-svn: 171253
2012-12-30 10:32:01 +00:00
Nadav Rotem
0e391907a5 LoopVectorizer: Fix a bug in the code that updates the loop exiting block.
LCSSA PHIs may have undef values. The vectorizer updates values that are used by outside users such as PHIs.
The bug happened because undefs are not loop values. This patch handles these PHIs.

PR14725

llvm-svn: 171251
2012-12-30 07:47:00 +00:00
Nadav Rotem
4cad811734 If all of the write objects are identified then we can vectorize the loop even if the read objects are unidentified.
PR14719.

llvm-svn: 171124
2012-12-26 23:30:53 +00:00
Nadav Rotem
90712b89cc LoopVectorizer: Optimize the vectorization of consecutive memory access when the iteration step is -1
llvm-svn: 171114
2012-12-26 19:08:17 +00:00
Hal Finkel
f9b3cb9121 LoopVectorize: Enable vectorization of the fmuladd intrinsic
llvm-svn: 171076
2012-12-25 23:21:29 +00:00
Nadav Rotem
ace51e510e LoopVectorizer: When checking for vectorizable types, also check
the StoreInst operands.

PR14705.

llvm-svn: 171023
2012-12-24 09:14:18 +00:00
Nadav Rotem
309d628c4f LoopVectorizer: Fix an endless loop in the code that looks for reductions.
The bug was in the code that detects PHIs in if-then-else block sequence.

PR14701.

llvm-svn: 171008
2012-12-24 01:22:06 +00:00
Benjamin Kramer
1add5cc571 LoopVectorize: Fix accidentaly inverted condition.
llvm-svn: 171001
2012-12-23 13:21:41 +00:00
Benjamin Kramer
d0a5bcaf53 LoopVectorize: For scalars and void types there is no need to compute vector insert/extract costs.
Fixes an assert during the build of oggenc in the test suite.

llvm-svn: 171000
2012-12-23 13:19:18 +00:00
Nadav Rotem
e237376e62 Loop Vectorizer: Update the cost model of scatter/gather operations and make
them more expensive.

llvm-svn: 170995
2012-12-23 07:23:55 +00:00
Bill Wendling
a16e5519db Change 'AttrVal' to 'AttrKind' to better reflect that it's a kind of attribute instead of the value of the attribute.
llvm-svn: 170972
2012-12-22 00:37:52 +00:00
Roman Divacky
a299a2efa5 Remove duplicate includes.
llvm-svn: 170902
2012-12-21 17:06:44 +00:00
Nadav Rotem
ad3bbdd5b0 Enable if-conversion.
llvm-svn: 170841
2012-12-21 04:47:54 +00:00
Nadav Rotem
80fefbe978 Fix a bug in the code that checks if we can vectorize loops while using dynamic
memory bound checks.  Before the fix we were able to vectorize this loop from
the Livermore Loops benchmark:

for ( k=1 ; k<n ; k++ )
  x[k] = x[k-1] + y[k];

llvm-svn: 170811
2012-12-21 00:07:35 +00:00
Nadav Rotem
ccffd4527d LoopVectorize: Fix a bug in the scalarization of instructions.
Before if-conversion we could check if a value is loop invariant
if it was declared inside the basic block. Now that loops have
multiple blocks this check is incorrect.

This fixes External/SPEC/CINT95/099_go/099_go

llvm-svn: 170756
2012-12-20 20:24:40 +00:00
Nadav Rotem
759544a715 Loop Vectorizer: turn-off if-conversion.
llvm-svn: 170708
2012-12-20 17:42:53 +00:00
Nadav Rotem
f79dac509d Loop Vectorizer: Enable if-conversion.
llvm-svn: 170632
2012-12-20 02:00:02 +00:00
Bill Wendling
56d9c4b832 Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.
llvm-svn: 170502
2012-12-19 07:18:57 +00:00
Benjamin Kramer
820b613d80 LoopVectorize: Emit reductions as log2(vectorsize) shuffles + vector ops instead of scalar operations.
For example on x86 with SSE4.2 a <8 x i8> add reduction becomes
	movdqa	%xmm0, %xmm1
	movhlps	%xmm1, %xmm1            ## xmm1 = xmm1[1,1]
	paddw	%xmm0, %xmm1
	pshufd	$1, %xmm1, %xmm0        ## xmm0 = xmm1[1,0,0,0]
	paddw	%xmm1, %xmm0
	phaddw	%xmm0, %xmm0
	pextrb	$0, %xmm0, %edx

instead of
	pextrb	$2, %xmm0, %esi
	pextrb	$0, %xmm0, %edx
	addb	%sil, %dl
	pextrb	$4, %xmm0, %esi
	addb	%dl, %sil
	pextrb	$6, %xmm0, %edx
	addb	%sil, %dl
	pextrb	$8, %xmm0, %esi
	addb	%dl, %sil
	pextrb	$10, %xmm0, %edi
	pextrb	$14, %xmm0, %edx
	addb	%sil, %dil
	pextrb	$12, %xmm0, %esi
	addb	%dil, %sil
	addb	%sil, %dl

llvm-svn: 170439
2012-12-18 18:40:20 +00:00
Nadav Rotem
9e2542c0cb Enable the Loop Vectorizer by default for O2 and O3. Disable if-conversion by default. I plan to revert this patch later today.
llvm-svn: 170157
2012-12-13 23:11:54 +00:00