Summary:
When the backedge taken codition is computed from an icmp, SCEV can
deduce the backedge taken count only if one of the sides of the icmp
is an AddRecExpr. However, due to sign/zero extensions, we sometimes
end up with something that is not an AddRecExpr.
However, we can use SCEV predicates to produce a 'guarded' expression.
This change adds a method to SCEV to get this expression, and the
SCEV predicate associated with it.
In HowManyGreaterThans and HowManyLessThans we will now add a SCEV
predicate associated with the guarded backedge taken count when the
analyzed SCEV expression is not an AddRecExpr. Note that we only do
this as an alternative to returning a 'CouldNotCompute'.
We use new feature in Loop Access Analysis and LoopVectorize to analyze
and transform more loops.
Reviewers: anemet, mzolotukhin, hfinkel, sanjoy
Subscribers: flyingforyou, mcrosier, atrick, mssimpso, sanjoy, mzolotukhin, llvm-commits
Differential Revision: http://reviews.llvm.org/D17201
llvm-svn: 265535
AArch64InstrInfo::optimizeCompareInstr has a bug which causes generation of incorrect code (PR#27158).
The patch refactors the function to simplify reviewing the fix of the bug.
1. Function name ‘modifiesConditionCode’ is changed to ‘areCFlagsAccessedBetweenInstrs’
to reflect that the function can check modifying accesses, reading accesses or both.
2. Function ‘AArch64InstrInfo::optimizeCompareInstr’
- Documented the function
- Cmp_NZCV is DeadNZCVIdx to reflect that it is an operand index of dead NZCV
- The code for the case of substituting CmpInstr is put into separate
functions the main of them is ‘substituteCmpInstr’.
Differential Revision: http://reviews.llvm.org/D18609
llvm-svn: 265531
To quote the langref "Unlike sqrt in libm, however, llvm.sqrt has
undefined behavior for negative numbers other than -0.0 (which allows
for better optimization, because there is no need to worry about errno
being set). llvm.sqrt(-0.0) is defined to return -0.0 like IEEE sqrt."
This means that it's unsafe to replace sqrt with llvm.sqrt unless the
call is annotated with nnan.
Thanks to Hal Finkel for pointing this out!
llvm-svn: 265521
Instead of copying arguments from the source function to the
destination, steal them. This has a few advantages.
- The ValueMap doesn't need to be seeded with (or cleared of)
Arguments.
- Often the destination function won't have created any arguments yet,
so this avoids malloc traffic.
- Argument names don't need to be copied.
Because argument lists are lazy, this required a new
Function::stealArgumentListFrom helper.
llvm-svn: 265519
We must remove all aliased registers which may be more than the all sub
and super registers combined.
Bug found while reading the code. The bug does not affect any existing
target as the only use of register aliases I could found were control
registers on ARM and Hexagon which are all reserved.
llvm-svn: 265510
r265273 added Mapper::mapBlockAddress, which delays mapping a
blockaddress value until the function has a body. The condition was
backwards, and should be checking Function::empty instead of
GlobalValue::isDeclaration.
llvm-svn: 265508
Instead of crashing, give a nice error. As a drive-by, fix the location
associated with the errors for unresolved metadata (the location was off
by one token).
llvm-svn: 265507
This patch enable sibling call optimization on ppc64 ELFv1/ELFv2 abi, and
add a couple of test cases. This patch also passed llvm/clang bootstrap
test, and spec2006 build/run/result validation.
Original issue: https://llvm.org/bugs/show_bug.cgi?id=25617
Great thanks to Tom's (tjablin) help, he contributed a lot to this patch.
Thanks Hal and Kit's invaluable opinions!
Reviewers: hfinkel kbarton
http://reviews.llvm.org/D16315
llvm-svn: 265506
This patch implements the following BookII and Book III instructions:
- copy copy_first cp_abort paste paste. paste_last
- msgsync
- slbieg slbsync
- stop
Total 10 instructions
Reviewers: nemanjai hfinkel tjablin amehsan kbarton
llvm-svn: 265504
While preserving the return value for @llvm.experimental.deoptimize at
the IR level is useful during mid-level optimization, doing so at the
machine instruction level requires generating some extra code and a
return that is non-ideal. This change has LLVM lower
```
%val = call @llvm.experimental.deoptimize
ret %val
```
to effectively
```
call @__llvm_deoptimize()
unreachable
```
instead.
llvm-svn: 265502
Summary:
Address space mapping is described in lib/Target/AMDGPU/AMDGPU.h in
Doxygen comments. This patch adds the description to user guide for
AMDGPU back-end.
Patch By: Vedran Miletić
Reviewers: tstellarAMD, arsenm
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D17046
llvm-svn: 265500
As part of the TRI argument of addRegBankCoverage we already have access to
the TargetRegisterClass through the ID of that register class.
Therefore, there is no point in needing a TargetRegisterClass instance,
the ID is enough to get to it.
llvm-svn: 265487
Don't emit a gc.result for a statepoint lowered from
@llvm.experimental.deoptimize since the call into __llvm_deoptimize is
effectively noreturn. Instead follow the corresponding gc.statepoint
with an "unreachable".
llvm-svn: 265485
Bionic has a defined thread-local location for the stack protector
cookie. Emit a direct load instead of going through __stack_chk_guard.
llvm-svn: 265481
Prior to this patch, CFLAA wouldn't tag arguments/globals properly if
it didn't find any "interesting" edges on them. This means that, if all
you do is store constants to a global or argument, we would never
actually treat it as a global/argument.
Test case:
define void @foo(i32* %A, i32* %B) #0 {
entry:
store i32 0, i32* %A, align 4
store i32 0, i32* %B, align 4
ret void
}
CFLAA would say that %A can't alias %B, because neither pointer was
used in an interesting way. This patch makes us note whether something
is an argument, global, ... regardless of how interesting CFLAA thinks
its uses are.
(For the record, using a value in an interesting way means loading
from it, using it in a GEP, ...)
llvm-svn: 265474
Add a common parent class for ConstantArray, ConstantVector, and
ConstantStruct called ConstantAggregate. These are the aggregate
subclasses of Constant that take operands.
This is mainly a cleanup, adding common `isa` target and removing
duplicated code. However, it also simplifies caching which constants
point transitively at `GlobalValue` (a possible future direction).
llvm-svn: 265466
Change the default constructor to create invalid object.
The target will have to properly initialize the register banks before
using them.
llvm-svn: 265460
