The shl instruction is used to represent multiplication by a constant
power of two as well as bitwise left shifts. Some InstCombine
transformations would turn an shl instruction into a bit mask operation,
making it difficult for later analysis passes to recognize the
constsnt multiplication.
Disable those shl transformations, deferring them to DAGCombine time.
An 'shl X, C' instruction is now treated mostly the same was as 'mul X, C'.
These transformations are deferred:
(X >>? C) << C --> X & (-1 << C) (When X >> C has multiple uses)
(X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2) (When C2 > C1)
(X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2) (When C1 > C2)
The corresponding exact transformations are preserved, just like
div-exact + mul:
(X >>?,exact C) << C --> X
(X >>?,exact C1) << C2 --> X << (C2-C1)
(X >>?,exact C1) << C2 --> X >>?,exact (C1-C2)
The disabled transformations could also prevent the instruction selector
from recognizing rotate patterns in hash functions and cryptographic
primitives. I have a test case for that, but it is too fragile.
llvm-svn: 155136
symbolicated. These have and operand type of TYPE_RELv which was not handled
as isBranch in translateImmediate() in X86Disassembler.cpp. rdar://11268426
llvm-svn: 155074
commits have had several major issues pointed out in review, and those
issues are not being addressed in a timely fashion. Furthermore, this
was all committed leading up to the v3.1 branch, and we don't need piles
of code with outstanding issues in the branch.
It is possible that not all of these commits were necessary to revert to
get us back to a green state, but I'm going to let the Hexagon
maintainer sort that out. They can recommit, in order, after addressing
the feedback.
Reverted commits, with some notes:
Primary commit r154616: HexagonPacketizer
- There are lots of review comments here. This is the primary reason
for reverting. In particular, it introduced large amount of warnings
due to a bad construct in tablegen.
- Follow-up commits that should be folded back into this when
reposting:
- r154622: CMake fixes
- r154660: Fix numerous build warnings in release builds.
- Please don't resubmit this until the three commits above are
included, and the issues in review addressed.
Primary commit r154695: Pass to replace transfer/copy ...
- Reverted to minimize merge conflicts. I'm not aware of specific
issues with this patch.
Primary commit r154703: New Value Jump.
- Primarily reverted due to merge conflicts.
- Follow-up commits that should be folded back into this when
reposting:
- r154703: Remove iostream usage
- r154758: Fix CMake builds
- r154759: Fix build warnings in release builds
- Please incorporate these fixes and and review feedback before
resubmitting.
Primary commit r154829: Hexagon V5 (floating point) support.
- Primarily reverted due to merge conflicts.
- Follow-up commits that should be folded back into this when
reposting:
- r154841: Remove unused variable (fixing build warnings)
There are also accompanying Clang commits that will be reverted for
consistency.
llvm-svn: 155047
DenseMap's hash function uses slightly more entropy and reduces hash collisions
significantly. I also experimented with Hashing.h, but it didn't gave a lot of
improvement while being much more expensive to compute.
llvm-svn: 154996
If the loop contains invoke instructions, whose unwind edge escapes the loop,
then don't try to unswitch the loop. Doing so may cause the unwind edge to be
split, which not only is non-trivial but doesn't preserve loop simplify
information.
Fixes PR12573
llvm-svn: 154987
This introduces a threshold of 200 IV Users, which is very
conservative but should be sufficient to avoid serious compile time
sink or stack overflow. The llvm test-suite with LTO never exceeds 190
users per loop.
The bug doesn't relate to a specific type of loop. Checking in an
arbitrary giant loop as a unit test would be silly.
Fixes rdar://11262507.
llvm-svn: 154983
also fix SimplifyLibCalls to use TLI rather than compile-time conditionals to enable optimizations on floor, ceil, round, rint, and nearbyint
llvm-svn: 154960
transformation:
(X op C1) ^ C2 --> (X op C1) & ~C2 iff (C1&C2) == C2
should be done.
This change has been tested:
Using a debug+asserts build:
on the specific test case that brought this bug to light
make check-all
lnt nt
using this clang to build a release version of clang
Using the release+asserts clang-with-clang build:
on the specific test case that brought this bug to light
make check-all
lnt nt
Checking in because Evan wants it checked in. Test case forthcoming after
scrubbing.
llvm-svn: 154955
for the life of me remember why I wrote it this way, but I can't see any good
reason for it now. This patch replaces the custom linked list with an ilist.
This change should preserve the existing numberings exactly, so no generated code
should change (if it does, file a bug!).
llvm-svn: 154904
the MCJIT execution engine.
The GDB JIT debugging integration support works by registering a loaded
object image with a pre-defined function that GDB will monitor if GDB
is attached. GDB integration support is implemented for ELF only at this
time. This integration requires GDB version 7.0 or newer.
Patch by Andy Kaylor!
llvm-svn: 154868
both fallthrough and a conditional branch target the same successor.
Gracefully delete the conditional branch and introduce any unconditional
branch needed to reach the actual successor. This fixes memory
corruption in 2009-06-15-RegScavengerAssert.ll and possibly other tests.
Also, while I'm here fix a latent bug I spotted by inspection. I never
applied the same fundamental fix to this fallthrough successor finding
logic that I did to the logic used when there are no conditional
branches. As a consequence it would have selected landing pads had they
be aligned in just the right way here. I don't have a test case as
I spotted this by inspection, and the previous time I found this
required have of TableGen's source code to produce it. =/ I hate backend
bugs. ;]
Thanks to Jim Grosbach for helping me reason through this and reviewing
the fix.
llvm-svn: 154867
A trailing comma means no argument at all (i.e., as if the comma were not
present), not an empty argument to the invokee.
rdar://11252521
llvm-svn: 154863
