6090 Commits

Author SHA1 Message Date
Chad Rosier
1523db7c64 Reapply r221924: "[GVN] Perform Scalar PRE on gep indices that feed loads before
doing Load PRE"

This commit updates the failing test in
Analysis/TypeBasedAliasAnalysis/gvn-nonlocal-type-mismatch.ll

The failing test is sensitive to the order in which we process loads.  This
version turns on the RPO traversal instead of the while DT traversal in GVN.
The new test code is functionally same just the order of loads that are
eliminated is swapped.

This new version also fixes an issue where GVN splits a critical edge and
potentially invalidate the RPO/DT iterator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222039 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-14 21:09:13 +00:00
Chad Rosier
5c76b3d03e [Reassociate] Canonicalize the operands of all binary operators.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222008 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-14 17:09:19 +00:00
Chad Rosier
1298a29c64 [Reassociate] Canonicalize operands of vector binary operators.
Prior to this commit fmul and fadd binary operators were being canonicalized for
both scalar and vector versions.  We now canonicalize add, mul, and, or, and xor
vector instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222006 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-14 17:08:15 +00:00
Chad Rosier
7e61b1fb62 [Reassociate] Canonicalize constants to RHS operand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222005 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-14 17:05:59 +00:00
Chad Rosier
1945dcff86 [Reassociate] Improve rank debug information. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221999 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-14 15:01:38 +00:00
Chad Rosier
7984fde2dc Revert "[GVN] Perform Scalar PRE on gep indices that feed loads before doing Load PRE."
This reverts commit r221924.  It appears the commit was a bit premature and is causing
bot failures that need further investigation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221939 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 22:54:59 +00:00
Chad Rosier
a9cc4e7e35 [GVN] Perform Scalar PRE on gep indices that feed loads before doing Load PRE.
Phabricator Revision: http://reviews.llvm.org/D6103
Patch by "Balaram Makam" <bmakam@codeaurora.org>!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221924 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 21:17:58 +00:00
Chad Rosier
ddf4026dd8 [Reassociate] Update comment. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221894 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 15:40:20 +00:00
Jingyue Wu
83c8e732dd Disable indvar widening if arithmetics on the wider type are more expensive
Summary:
Reapply r221772. The old patch breaks the bot because the @indvar_32_bit test
was run whether NVPTX was enabled or not.

IndVarSimplify should not widen an indvar if arithmetics on the wider
indvar are more expensive than those on the narrower indvar. For
instance, although NVPTX64 treats i64 as a legal type, an ADD on i64 is
twice as expensive as that on i32, because the hardware needs to
simulate a 64-bit integer using two 32-bit integers.

Split from D6188, and based on D6195 which adds NVPTXTargetTransformInfo.

Fixes PR21148.

Test Plan:
Added @indvar_32_bit that verifies we do not widen an indvar if the arithmetics
on the wider type are more expensive. This test is run only when NVPTX is
enabled.

Reviewers: jholewinski, eliben, meheff, atrick

Reviewed By: atrick

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D6196



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221799 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:09:15 +00:00
Jingyue Wu
ee709fe497 Reverts r221772 which fails tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221773 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 07:19:25 +00:00
Jingyue Wu
69adc159ee Disable indvar widening if arithmetics on the wider type are more expensive
Summary:
IndVarSimplify should not widen an indvar if arithmetics on the wider
indvar are more expensive than those on the narrower indvar. For
instance, although NVPTX64 treats i64 as a legal type, an ADD on i64 is
twice as expensive as that on i32, because the hardware needs to
simulate a 64-bit integer using two 32-bit integers.

Split from D6188, and based on D6195 which adds NVPTXTargetTransformInfo.

Fixes PR21148.

Test Plan:
Added @indvar_32_bit that verifies we do not widen an indvar if the arithmetics
on the wider type are more expensive.

Reviewers: jholewinski, eliben, meheff, atrick

Reviewed By: atrick

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D6196

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221772 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 06:58:45 +00:00
Chad Rosier
7ad8db4cbb [Reassociate] Canonicalize negative constants out of expressions.
Add support for FDiv, which was regressed by the previous commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221738 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:36:42 +00:00
Chad Rosier
2244d9a5d2 [Reassociate] Canonicalize negative constants out of expressions.
This is a reapplication of r221171, but we only perform the transformation
on expressions which include a multiplication.  We do not transform rem/div
operations as this doesn't appear to be safe in all cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221721 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 22:58:35 +00:00
Duncan P. N. Exon Smith
5bf8ade9d0 Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221711 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:30:22 +00:00
Chad Rosier
bcdc4769f4 [Reassociate] Better preserve NSW/NUW flags.
Part of PR12985.

Phabricator Revision: http://reviews.llvm.org/D6172

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221555 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-07 22:12:57 +00:00
David Majnemer
3f2ffe0423 SCCP: overdefined calls cannot become constant
We would attempt to fold away a call instruction which had been marked
overdefined.  However, it's not valid to transition to constant from
overdefined.

This fixes PR21512.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221513 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-07 08:54:19 +00:00
Chad Rosier
e15b20eb13 [Reassociate] Don't reassociate when mixing regular and fast-math FP
instructions.  Inlining might cause such cases and it's not valid to
reassociate floating-point instructions without the unsafe algebra flag.

Patch by Mehdi Amini <mehdi_amini@apple.com>!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221462 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-06 16:46:37 +00:00
Reid Kleckner
11e6e005b7 Revert "[Reassociate] Canonicalize negative constants out of expressions."
This reverts commit r221171.

It performs this invalid transformation:
-  %div.i = urem i64 -1, %add
-  %sub.i = sub i64 -2, %div.i
+  %div.i = urem i64 1, %add
+  %sub.i1 = add i64 %div.i, -2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221317 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-04 23:42:45 +00:00
Reid Kleckner
9d18e626cc Revert "Transforms: reapply SVN r219899"
This reverts commit r220811 and r220839. It made an incorrect change to
musttail handling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221226 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-04 02:02:14 +00:00
Hal Finkel
cd9acde7f3 Use AA in LoadCombine
LoadCombine can be smarter about aborting when a writing instruction is
encountered, instead of aborting upon encountering any writing instruction, use
an AliasSetTracker, and only abort when encountering some write that might
alias with the loads that could potentially be combined.

This was originally motivated by comments made (and a test case provided) by
David Majnemer in response to PR21448. It turned out that LoadCombine was not
responsible for that PR, but LoadCombine should also be improved so that
unrelated stores (and @llvm.assume) don't interrupt load combining.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221203 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-03 23:19:16 +00:00
Hal Finkel
f16d6b1ff1 EarlyCSE should ignore calls to @llvm.assume
EarlyCSE uses a simple generation scheme for handling memory-based
dependencies, and calls to @llvm.assume (which are marked as writing to memory
to ensure the preservation of control dependencies) disturb that scheme
unnecessarily. Skipping calls to @llvm.assume is legal, and the alternative
(adding AA calls in EarlyCSE) is likely undesirable (we have GVN for that).

Fixes PR21448.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221175 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-03 20:21:32 +00:00
Chad Rosier
3f4e9cb609 [Reassociate] Canonicalize negative constants out of expressions.
This gives CSE/GVN more options to eliminate duplicate expressions.
This is a follow up patch to http://reviews.llvm.org/D4904.

http://reviews.llvm.org/D5363

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221171 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-03 19:11:30 +00:00
Duncan P. N. Exon Smith
5e84760dde IR: MDNode => Value: Instruction::getAllMetadataOtherThanDebugLoc()
Change `Instruction::getAllMetadataOtherThanDebugLoc()` from a vector of
`MDNode` to one of `Value`.  Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221167 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-03 18:13:57 +00:00
Diego Novillo
2b6bd7aaf5 Use ErrorOr for the ::create factory on instrumented and sample profilers.
Summary:
As discussed in
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20141027/242445.html,
the creation of reader and writer instances is better done using
ErrorOr. There are no functional changes, but several callers needed to
be adjusted.

Reviewers: bogner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6076

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221120 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-03 00:51:45 +00:00
Elena Demikhovsky
01d89eee39 Use Alias Analysis to hoist 2 loads from diamond to the common predecessor basic block.
Alias Analysis allows to detect real barriers for load hoisting.

Review in http://reviews.llvm.org/D5991



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221091 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-02 08:03:05 +00:00
Diego Novillo
496bd0b8a5 Fix Twine corruption problem with diagnostics.
This fixes the autobuilders I broke with a recent patch. Thanks echristo
and dblaikie for beating me with a clue stick.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220918 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-30 18:48:41 +00:00
Diego Novillo
e75c2b3e54 Add profile writing capabilities for sampling profiles.
Summary:
This patch finishes up support for handling sampling profiles in both
text and binary formats. The new binary format uses uleb128 encoding to
represent numeric values. This makes profiles files about 25% smaller.

The profile writer class can write profiles in the existing text and the
new binary format. In subsequent patches, I will add the capability to
read (and perhaps write) profiles in the gcov format used by GCC.

Additionally, I will be adding support in llvm-profdata to manipulate
sampling profiles.

There was a bit of refactoring needed to separate some code that was in
the reader files, but is actually common to both the reader and writer.

The new test checks that reading the same profile encoded as text or
raw, produces the same results.

Reviewers: bogner, dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6000

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220915 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-30 18:00:06 +00:00
Yi Jiang
a5ca5d9f82 Do not simplifyLatch for loops where hoisting increments couldresult in extra live range interferance
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220872 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-29 20:19:47 +00:00
Saleem Abdulrasool
586cf3d88d Transforms: reapply SVN r219899
This restores the commit from SVN r219899 with an additional change to ensure
that the CodeGen is correct for the case that was identified as being incorrect
(originally PR7272).

In the case that during inlining we need to synthesize a value on the stack
(i.e. for passing a value byval), then any function involving that alloca must
be stripped of its tailness as the restriction that it does not access the
parent's stack no longer holds.  Unfortunately, a single alloca can cause a
rippling effect through out the inlining as the value may be aliased or may be
mutated through an escaped external call.  As such, we simply track if an alloca
has been introduced in the frame during inlining, and strip any tail calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-28 18:27:37 +00:00
NAKAMURA Takumi
81ae170379 Reformat partially, where I touched for whitespace changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220773 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-28 11:54:52 +00:00
NAKAMURA Takumi
2ffeb9f523 LoopRerollPass.cpp: Use range-based loop. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220772 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-28 11:54:05 +00:00
NAKAMURA Takumi
0f06462959 Untabify and whitespace cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220771 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-28 11:53:30 +00:00
Andrew Trick
916ba45c62 LSR: Minor cleanup after Daniel's patch.
Combine the Inserted an Done sets into a Visited set.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220623 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-25 19:59:30 +00:00
Andrew Trick
abb11dd303 Fix LSR compile time.
This is a simple fix that brings the compilation time from 5min to 5s
on a specific real-world example. It's a large chain of computation in
a crypto routine (always a problem for SCEV). A unit test is not
feasible and there would be no way to check it. The fix is just basic
good practice for dealing with SCEVs, there's no risk of regression.

Patch by Daniel Reynaud!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220622 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-25 19:42:07 +00:00
Jingyue Wu
71fe4f0197 [SeparateConstOffsetFromGEP] Fixed a bug related to unsigned modulo
The dividend in "signed % unsigned" is treated as unsigned instead of signed,
causing unexpected behavior such as -64 % (uint64_t)24 == 0.

Added a regression test in split-gep.ll

Patched by Hao Liu.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220618 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-25 18:34:03 +00:00
Jingyue Wu
5c50ab84b3 [SeparateConstOffsetFromGEP] Fixed a bug in rebuilding OR expressions
The two operands of the new OR expression should be NextInChain and TheOther
instead of the two original operands.

Added a regression test in split-gep.ll.

Hao Liu reported this bug, and provded the test case and an initial patch.
Thanks! 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220615 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-25 17:36:21 +00:00
Timur Iskhodzhanov
da45b2bdbd Make getDISubprogram(const Function *F) available in LLVM
Reviewed at http://reviews.llvm.org/D5950

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220536 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-23 23:46:28 +00:00
Diego Novillo
0b70f777bb Shorten auto iterators for function basic blocks.
Use consistent naming for basic block instances.

No functional changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220404 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 18:39:50 +00:00
Diego Novillo
e64e141886 Use auto iteration in lib/Transforms/Scalar/SampleProfile.cpp. No functional changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220394 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 16:51:50 +00:00
Diego Novillo
79ca2c234d Change error to warning when a profile cannot be found.
When the profile for a function cannot be applied, we use to emit an
error. This seems extreme. The compiler can continue, it's just that the
optimization opportunities won't include profile information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220386 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 13:36:35 +00:00
Diego Novillo
418d0cf1c1 Support using sample profiles with partial debug info.
Summary:
When using a profile, we used to require the use -gmlt so that we could
get access to the line locations. This is used to match line numbers in
the input profile to the line numbers in the function's IR.

But this is actually not necessary. The driver can provide source
location tracking without the emission of debug information. In these
cases, the annotation 'llvm.dbg.cu' is missing from the IR, but the
actual line location annotations are still present.

This patch adds a new way of looking for the start of the current
function. Instead of looking through the compile units in llvm.dbg.cu,
we can walk up the scope for the first instruction in the function with
a debug loc. If that describes the function, we use it. Otherwise, we
keep looking until we find one.

If no such instruction is found, we then give up and produce an error.

Reviewers: echristo, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5887

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220382 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 12:59:00 +00:00
Hans Wennborg
ec4e924836 Revert "Teach the load analysis to allow finding available values which require" (r220277)
This seems to have caused PR21330.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220349 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 23:49:52 +00:00
Chandler Carruth
9156c5e3ba Teach the load analysis to allow finding available values which require
inttoptr or ptrtoint cast provided there is datalayout available.
Eventually, the datalayout can just be required but in practice it will
always be there today.

To go with the ability to expose available values requiring a ptrtoint
or inttoptr cast, helpers are added to perform one of these three casts.

These smarts are necessary to finish canonicalizing loads and stores to
the operational type requirements without regressing fundamental
combines.

I've added some test cases. These should actually improve as the load
combining and store combining improves, but they may fundamentally be
highlighting some missing combines for select in addition to exercising
the specific added logic to load analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220277 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 09:00:40 +00:00
Philip Reames
9be9473394 Introduce enum values for previously defined metadata types. (NFC)
Our metadata scheme lazily assigns IDs to string metadata, but we have a mechanism to preassign them as well.  Using a preassigned ID is helpful since we get compile time type checking, and avoid some (minimal) string construction and comparison.  This change adds enum value for three existing metadata types:
+    MD_nontemporal = 9, // "nontemporal"
+    MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
+    MD_nonnull = 11 // "nonnull"

I went through an updated various uses as well.  I made no attempt to get all uses; I focused on the ones which were easily grepable and easily to translate.  For example, there were several items in LoopInfo.cpp I chose not to update.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220248 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 00:13:20 +00:00
Chandler Carruth
080dfb5bda Fix a somewhat subtle pair of issues with JumpThreading I introduced in
r220178. First, the creation routine doesn't insert prior to the
terminator of the basic block provided, but really at the end of the
basic block. Instead, get the terminator and insert before that. The
next issue was that we need to ensure multiple PHI node entries for
a single predecessor re-use the same cast instruction rather than
creating new ones.

All of the logic here was without tests previously. I've reduced and
added a test case from the test suite that crashed without both of these
fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220186 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 05:34:36 +00:00
Chandler Carruth
35c4e071be Teach the load analysis driving core instcombine logic and other bits of
logic to look through pointer casts, making them trivially stronger in
the face of loads and stores with intervening pointer casts.

I've included a few test cases that demonstrate the kind of folding
instcombine can do without pointer casts and then variations which
obfuscate the logic through bitcasts. Without this patch, the variations
all fail to optimize fully.

This is more important now than it has been in the past as I've started
moving the load canonicialization to more closely follow the value type
requirements rather than the pointer type requirements and thus this
needs to be prepared for more pointer casts. When I made the same change
to stores several test cases regressed without logic along these lines
so I wanted to systematically improve matters first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 00:24:14 +00:00
Chandler Carruth
908d4514f6 Fix a long-standing miscompile in the load analysis that was uncovered
by my refactoring of this code.

The method isSafeToLoadUnconditionally assumes that the load will
proceed with the preferred type alignment. Given that, it has to ensure
that the alloca or global is at least that aligned. It has always done
this historically when a datalayout is present, but has never checked it
when the datalayout is absent. When I refactored the code in r220156,
I exposed this path when datalayout was present and that turned the
latent bug into a patent bug.

This fixes the issue by just removing the special case which allows
folding things without datalayout. This isn't worth the complexity of
trying to tease apart when it is or isn't safe without actually knowing
the preferred alignment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220161 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-19 08:17:50 +00:00
Chandler Carruth
2402e6315d [SROA] Change how SROA does vector-based promotion of allocas to handle
cases where the alloca type, the load types, and the store types used
all disagree.

Previously, the only way that vector-based promotion occured was if the
alloca type was a vector type. This was one of the *very* few remaining
uses of the alloca's type to guide SROA/mem2reg left in LLVM. It turns
out it was a bad idea.

The alloca type can change very easily based on the mixture of types
loaded and stored to that alloca. We shouldn't be relying on it as
a signal for very much. Instead, the source of truth should be loads and
stores. We should canonicalize the loads and stores as much as possible
and then rely on them exclusively in SROA.

When looking and loads and stores, we may find many different candidate
vector types. This change will let SROA try all of them to find a vector
type which is a viable way to promote the entire alloca to a vector
register.

With this change, it becomes possible to do better canonicalization and
optimization of loads and stores without breaking SROA in random ways,
and that should allow fixing a core source of performance loss in hot
numerical loops such as those in Eigen.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220116 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-18 00:44:02 +00:00
Rafael Espindola
ec51f45338 Revert "TRE: make TRE a bit more aggressive"
This reverts commit r219899.

This also updates byval-tail-call.ll to make it clear what was breaking.
Adding r219899 again will cause the load/store to disappear.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220093 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 21:25:48 +00:00
Hal Finkel
9d85eff56a [DSE] Remove no-data-layout-only type-based overlap checking
DSE's overlap checking contained special logic, used only when no DataLayout
was available, which inferred a complete overwrite when the pointee types were
equal. This logic seems fine for regular loads/stores, but does not work for
memcpy and friends. Instead of fixing this, I'm just removing it.
Philosophically, transformations should not contain enhanced behavior used only
when data layout is lacking (data layout should be strictly additive), and
maintaining these rarely-tested code paths seems not worthwhile at this stage.

Credit to Aliaksei Zasenka for the bug report and the diagnosis. The test case
(slightly reduced from that provided by Aliaksei) replaces the original
contents of test/Transforms/DeadStoreElimination/no-targetdata.ll -- a few
other tests have been updated to have a data layout.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220035 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 11:56:00 +00:00