This patch detects vector reductions before instruction selection. Vector
reductions are vectorized reduction operations, and for such operations we have
freedom to reorganize the elements of the result as long as the reduction of them
stay unchanged. This will enable some reduction pattern recognition during
instruction combine such as SAD/dot-product on X86. A flag is added to
SDNodeFlags to mark those vector reduction nodes to be checked during instruction
combine.
To detect those vector reductions, we search def-use chains starting from the
given instruction, and check if all uses fall into two categories:
1. Reduction with another vector.
2. Reduction on all elements.
in which 2 is detected by recognizing the pattern that the loop vectorizer
generates to reduce all elements in the vector outside of the loop, which
includes several ShuffleVector and one ExtractElement instructions.
Differential revision: http://reviews.llvm.org/D15250
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261070 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch skips DAG combine of fp_round (fp_round x) if it results in
an fp_round from f80 to f16.
fp_round from f80 to f16 always generates an expensive (and as yet,
unimplemented) libcall to __truncxfhf2. This prevents selection of
native f16 conversion instructions from f32 or f64. Moreover, the first
(value-preserving) fp_round from f80 to either f32 or f64 may become a
NOP in platforms like x86.
Reviewers: ab
Subscribers: srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D17221
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260769 91177308-0d34-0410-b5e6-96231b3b80d8
The code change is simple enough: instead of attaching an anonymous SDLoc to splatted
vector constants, use the scalar constant's existing SDLoc since that is what is passed
into getConstant() as a param. But this changes instruction scheduling, so I'll explain
why that happens.
The motivation for this patch starts near:
http://reviews.llvm.org/rL258833
...x86's getZeroVector() could be similarly cleaned up and I thought it would be 'NFC'.
But when I made that change locally, several x86 codegen tests wiggled.
It turns out that the lack of SDLoc consistency in getConstant() changes the way
ScheduleDAGRRList behaves. This is because the SDLoc contains 'IROrder' and some DAG
scheduler algorithms use IROrder for tie-breaking.
Differential Revision: http://reviews.llvm.org/D16972
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260582 91177308-0d34-0410-b5e6-96231b3b80d8
I reinvented this functionality in http://reviews.llvm.org/D16828 because it was
hidden away as a static function. The changes in x86 are not based on a complete
audit. I suspect there are other possible uses there, and there are almost certainly
more potential users in other targets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260295 91177308-0d34-0410-b5e6-96231b3b80d8
If a range has a lower bound of 0, add an AssertZext from the
nearest floor power of two.
This allows operations with some workitem intrinsics with known
maximum ranges to use fast 24-bit multiplies.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260109 91177308-0d34-0410-b5e6-96231b3b80d8
This patch consists of two parts: a performance fix in DAGCombiner.cpp
and a correctness fix in SelectionDAG.cpp.
The test case tests the bug that's uncovered by the performance fix, and
fixed by the correctness fix.
The performance fix keeps the containers required by the
hasPredecessorHelper (which is a lazy DFS) and reuse them. Since
hasPredecessorHelper is called in a loop, the overall efficiency reduced
from O(n^2) to O(n), where n is the number of SDNodes.
The correctness fix keeps iterating the neighbor list even if it's time
to early return. It will return after finishing adding all neighbors to
Worklist, so that no neighbors are discarded due to the original early
return.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259691 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is an extension to the existing implementation of r242436 which
restricts to only select inputs. This version fixes missed opportunities
in pr26084 by attempting to lower conditional compare sequences of
and/or trees with setcc leafs. This will additionaly handle the case
when a tree with select input is not a conjunction-disjunction tree
but some of the sub trees are conjunction-disjunction trees.
Reviewers: jmolloy, t.p.northover, mcrosier, MatzeB
Subscribers: mcrosier, llvm-commits, junbuml, haicheng, mssimpso, gberry
Differential Revision: http://reviews.llvm.org/D16291
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259387 91177308-0d34-0410-b5e6-96231b3b80d8
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259283 91177308-0d34-0410-b5e6-96231b3b80d8
While legalizing a 64-bit shift left by 1, the following occurs:
We split the shift operand in half: a high half and a low half.
We then create an ADDC with the low half and a ADDE with the high half +
the carry bit from the ADDC.
This is problematic if X is any_ext'd because the high half computation
is now undef + undef + carry bit and there is no way to ensure that the
two undef values had the same bitwise representation. This results in
the lowest bit in the high half turning into garbage.
Instead, do not try to turn shifts into arithmetic during type
legalization.
This fixes PR26350.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259065 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html
"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi
Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark
Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D16471
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258861 91177308-0d34-0410-b5e6-96231b3b80d8
When generating calls to memcpy, memmove, and memset, use void* as the return
type rather than void, to match the standard signatures for these functions.
This has no practical effect for most targets, since the return values of
these calls aren't being used anyway, and most calling conventions tolerate
this kind of mismatch. However, this change will help support future
optimizations to utilize the return value to avoid holding the argument
value live across a call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258691 91177308-0d34-0410-b5e6-96231b3b80d8
This reapplies r258296 and r258366, and also fixes an existing bug in
SelectionDAG.cpp's isMemSrcFromString, neglecting to account for the
offset in a GlobalAddressSDNode, which is uncovered by those patches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258482 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r258296 and the follow up r258366. With this change, we
miscompiled the following program on Windows:
#include <string>
#include <iostream>
static const char kData[] = "asdf jkl;";
int main() {
std::string s(kData + 3, sizeof(kData) - 3);
std::cout << s << '\n';
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258465 91177308-0d34-0410-b5e6-96231b3b80d8
SelectionDAG previously missed opportunities to fold constants into
GlobalAddresses in several areas. For example, given `(add (add GA, c1), y)`, it
would often reassociate to `(add (add GA, y), c1)`, missing the opportunity to
create `(add GA+c, y)`. This isn't often visible on targets such as X86 which
effectively reassociate adds in their complex address-mode folding logic,
however it is currently visible on WebAssembly since it currently has very
simple address mode folding code that doesn't reassociate anything.
This patch fixes this by making SelectionDAG fold offsets into GlobalAddresses
at the same times that it folds constants together, so that it doesn't miss any
opportunities to perform such folding.
Differential Revision: http://reviews.llvm.org/D16090
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258296 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
GEPOperator: provide getResultElementType alongside getSourceElementType.
This is made possible by adding a result element type field to GetElementPtrConstantExpr, which GetElementPtrInst already has.
GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.
Reviewers: mjacob, dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16275
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258145 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When SimplifySetCC sees a setcc node that compares the result of a
value extension operation with a constant, it tries to simplify the
setcc node by eliminating the extension and shrinking the constant.
If shrinking the inputs to setcc is deemed not desirable by the target
(e.g. the target does not want a setcc comparing i1 values), then it
is still possible to optimize this sequence in some cases.
This patch adds the following combines to SimplifySetCC when shrinking setcc
inputs is not desirable:
(setcc ([sz]ext (setcc x, y, cc)), 0, setne) -> (setcc (x, y, cc))
(setcc ([sz]ext (setcc x, y, cc)), 0, seteq) -> (setcc (x, Y, !cc))
There are no tests for this yet, but once AMDGPU correctly implements
TargetLowering::isTypeDesirableForOp(), this new combine will be
exercised by the existing CodeGen/AMDGPU/setcc-opt.ll test.
Reviewers: resistor, arsenm
Subscribers: jroelofs, arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D15034
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258067 91177308-0d34-0410-b5e6-96231b3b80d8
In the optimizer (GVN etc.) when eliminating redundant nodes with different
flags, the flags are ignored for the purposes of testing for congruence, and
then intersected for the purposes of producing a result that supports the union
of all the uses. This commit makes SelectionDAG's CSE do the same thing,
allowing it to CSE nodes in more cases. This fixes PR26063.
Differential Revision: http://reviews.llvm.org/D15957
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257940 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Rename to getCatchSwitchParentPad, to make it more clear which ancestor
the "parent" in question is. Add a comment pointing out the key feature
that the returned pad indicates which funclet contains the successor
block.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16222
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257933 91177308-0d34-0410-b5e6-96231b3b80d8
Since r230276, we support an improved legalization for f64->f16,
which goes through a temporary f32, improving codegen when
f32->f16 is legal but not f64->f16. This requires unsafe-fp-math.
However, that legalization assumed that the second step, producing
a pseudo-softened f16, had type i16. That's not true on targets
with illegal i16, such as ARM.
Use the initial f64->f16 result type instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257794 91177308-0d34-0410-b5e6-96231b3b80d8
We rely on HasOpaqueSPAdjustment not changing after we've calculated
things based on it. Things like whether or not we can use 'rep;movs' to
copy bytes around, that sort of thing. If it changes, invariants in the
backend will quietly break. This situation arose when we had a call to
memcpy *and* a COPY of the FLAGS register where we would attempt to
reference local variables using %esi, a register that was clobbered by
the 'rep;movs'.
This fixes PR26124.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257730 91177308-0d34-0410-b5e6-96231b3b80d8
This code isn't reachable if the GFI (GCFunctionInfo*) is null. Clarify this by adding an assert and removing an always taken if.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257724 91177308-0d34-0410-b5e6-96231b3b80d8
Previous implementation in http://reviews.llvm.org/D10522
created external references to __emutls_v.* variables.
Such references are inaccurate and cannot be handled by
all linkers, e.g. Android dynamic and gold linkers for aarch64.
Now a new LowerEmuTLS pass to go through all global variables,
and add emutls_v.* and emutls_t.* variables.
These __emutls* variables have the same linkage and
visibility as the associated user defined TLS variable.
Also removed old code that dump __emutls* variables in AsmPrinter.cpp,
and updated TLS unit tests.
Differential Revision: http://reviews.llvm.org/D15300
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257718 91177308-0d34-0410-b5e6-96231b3b80d8
