essential problem was that the DAG can contain
random unused nodes which were never analyzed.
When remapping a value of a node being processed,
such a node may become used and need to be analyzed;
however due to operands being transformed during
analysis the node may morph into a different one.
Users of the morphing node need to be updated, and
this wasn't happening. While there I added a bunch
of documentation and sanity checks, so I (or some
other poor soul) won't have to scratch their head
over this stuff so long trying to remember how it
was all supposed to work next time some obscure
problem pops up! The extra sanity checking exposed
a few places where invariants weren't being preserved,
so those are fixed too. Since some of the sanity
checking is expensive, I added a flag to turn it
on. It is also turned on when building with
ENABLE_EXPENSIVE_CHECKS=1.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60797 91177308-0d34-0410-b5e6-96231b3b80d8
1. ppcf128 select is expanded to f64 select's.
2. f64 select operand 0 is an i1 truncate, it's promoted to i32 zero_extend.
3. f64 select is updated. It's changed back to a "NewNode" and being re-analyzed.
4. f64 select operands are being processed. Operand 0 is a "NewNode". It's being expunged out of ReplacedValues map.
5. ExpungeNode tries to remap f64 select and notice it's a "NewNode" and assert.
Duncan, please take a look. Thanks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60443 91177308-0d34-0410-b5e6-96231b3b80d8
ReplaceNodeResults: rather than returning a node which
must have the same number of results as the original
node (which means mucking around with MERGE_VALUES,
and which is also easy to get wrong since SelectionDAG
folding may mean you don't get the node you expect),
return the results in a vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60348 91177308-0d34-0410-b5e6-96231b3b80d8
(this doesn't happen that often, since most code
does not use illegal types) then follow it by a
DAG combiner run that is allowed to generate
illegal operations but not illegal types. I didn't
modify the target combiner code to distinguish like
this between illegal operations and illegal types,
so it will not produce illegal operations as well
as not producing illegal types.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59960 91177308-0d34-0410-b5e6-96231b3b80d8
is morphed by AnalyzeNewNode into a previously
processed node, and different result values of
that node are remapped to values with different
nodes, then we could end up using wrong values
here [we were assuming that all results remap
to values with the same underlying node]. This
seems theoretically possible, but I don't have
a testcase. The meat of the patch is in the
changes to AnalyzeNewNode/AnalyzeNewValue and
ReplaceNodeWith. While there, I changed names
like RemapNode to RemapValue, since it really
remaps values. To tell the truth, I would be
much happier if we were only remapping nodes
(it would simplify a bunch of logic, and allow
for some cute speedups) but I haven't yet worked
out how to do that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58372 91177308-0d34-0410-b5e6-96231b3b80d8
id could end up being wrong mostly because of
forgetting to remap new nodes that morphed into
processed nodes through CSE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58323 91177308-0d34-0410-b5e6-96231b3b80d8
worklist twice: UpdateNodeOperands could morph
a new node into a node already on the worklist.
We would then recalculate the NodeId for this
existing node and add it to the worklist. The
testcase is ARM/cse-libcalls.ll, the problem
showing up once UpdateNodeOperands is taught to
do CSE for calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58246 91177308-0d34-0410-b5e6-96231b3b80d8
its size). Adjust various lowering functions to
pass this info through from CallInst. Use it to
implement sseregparm returns on X86. Remove
X86_ssecall calling convention.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56677 91177308-0d34-0410-b5e6-96231b3b80d8
- Add linkage to SymbolSDNode (default to external).
- Change ISD::ExternalSymbol to ISD::Symbol.
- Change ISD::TargetExternalSymbol to ISD::TargetSymbol
These changes pave the way to allowing SymbolSDNodes with non-external linkage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56249 91177308-0d34-0410-b5e6-96231b3b80d8
The first can update the SDNode in an SDValue
while the second is called with SDNode* and
returns a possibly updated SDNode*.
This patch has no intended functional impact,
but helps eliminating ugly temporary SDValues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55608 91177308-0d34-0410-b5e6-96231b3b80d8
parallel its analogue, Value::value_use_iterator. The operator* method
now returns the user, rather than the use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54127 91177308-0d34-0410-b5e6-96231b3b80d8
that include useful information like the name of the
block being viewed and the current phase of compilation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53872 91177308-0d34-0410-b5e6-96231b3b80d8
are used for passing huge immediates in inline ASM
from the front-end straight down to the ASM writer.
Of course this is a hack, but it is simple, limited
in scope, works in practice, and is what LegalizeDAG
does.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53553 91177308-0d34-0410-b5e6-96231b3b80d8
integer of the same type. Before it was "promotion",
but this is confusing because it is quite different
to promotion of integers. Call it "softening" instead,
inspired by "soft float".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52546 91177308-0d34-0410-b5e6-96231b3b80d8
rather than bundling them together. Rename FloatToInt
to PromoteFloat (better, if not perfect). Reorganize
files by types rather than by operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52408 91177308-0d34-0410-b5e6-96231b3b80d8
maps can be deleted. This happens when RAUW
replaces a node N with another equivalent node
E, deleting the first node. Solve this by
adding (N, E) to ReplacedNodes, which is already
used to remap nodes to replacements. This means
that deleted nodes are being allowed in maps,
which can be delicate: the memory may be reused
for a new node which might get confused with the
old deleted node pointer hanging around in the
maps, so detect this and flush out maps if it
occurs (ExpungeNode). The expunging operation
is expensive, however it never occurs during
a llvm-gcc bootstrap or anywhere in the nightly
testsuite. It occurs three times in "make check":
Alpha/illegal-element-type.ll,
PowerPC/illegal-element-type.ll and
X86/mmx-shift.ll. If expunging proves to be too
expensive then there are other more complicated
ways of solving the problem.
In the normal case this patch adds the overhead
of a few more map lookups, which is hopefully
negligable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52214 91177308-0d34-0410-b5e6-96231b3b80d8
and better control the abstraction. Rename the type
to MVT. To update out-of-tree patches, the main
thing to do is to rename MVT::ValueType to MVT, and
rewrite expressions like MVT::getSizeInBits(VT) in
the form VT.getSizeInBits(). Use VT.getSimpleVT()
to extract a MVT::SimpleValueType for use in switch
statements (you will get an assert failure if VT is
an extended value type - these shouldn't exist after
type legalization).
This results in a small speedup of codegen and no
new testsuite failures (x86-64 linux).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52044 91177308-0d34-0410-b5e6-96231b3b80d8
rather than having it suck them out of a node. Add
a bunch of new libcalls, and remove dead softfloat
code (dead, because FloatToInt is used not Expand
in this case). Note that indexed stores probably
aren't handled properly, likewise for loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49915 91177308-0d34-0410-b5e6-96231b3b80d8
Rename SDOperandImpl back to SDOperand.
Introduce the SDUse class that represents a use of the SDNode referred by
an SDOperand. Now it is more similar to Use/Value classes.
Patch is approved by Dan Gohman.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49795 91177308-0d34-0410-b5e6-96231b3b80d8
much simpler than in LegalizeDAG because calls are
not yet expanded into call sequences: that happens
after type legalization has finished.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49634 91177308-0d34-0410-b5e6-96231b3b80d8
in its maps. Add some sanity checks that catch
this kind of thing. Hopefully these can be
removed one day (once all problems are fixed!)
but for the moment it seems wise to have them in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49612 91177308-0d34-0410-b5e6-96231b3b80d8
on any current target and aren't optimized in DAGCombiner. Instead
of using intermediate nodes, expand the operations, choosing between
simple loads/stores, target-specific code, and library calls,
immediately.
Previously, the code to emit optimized code for these operations
was only used at initial SelectionDAG construction time; now it is
used at all times. This fixes some cases where rep;movs was being
used for small copies where simple loads/stores would be better.
This also cleans up code that checks for alignments less than 4;
let the targets make that decision instead of doing it in
target-independent code. This allows x86 to use rep;movs in
low-alignment cases.
Also, this fixes a bug that resulted in the use of rep;stos for
memsets of 0 with non-constant memory size when the alignment was
at least 4. It's better to use the library in this case, which
can be significantly faster when the size is large.
This also preserves more SourceValue information when memory
intrinsics are lowered into simple loads/stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49572 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM Value/Use does and MachineRegisterInfo/MachineOperand does.
This allows constant time for all uses list maintenance operations.
The idea was suggested by Chris. Reviewed by Evan and Dan.
Patch is tested and approved by Dan.
On normal use-cases compilation speed is not affected. On very big basic
blocks there are compilation speedups in the range of 15-20% or even better.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48822 91177308-0d34-0410-b5e6-96231b3b80d8
the fcopysign expansion from LegalizeDAG to get rid of
what seems to be a bug: the use of sign extension means
that when copying the sign bit from an f32 to an f64,
the upper 32 bits of the f64 (now an i64) are set, not
just the top bit... I also generalized it to work for
any sized floating point types, and removed the bogosity:
SDOperand Mask1 = (SrcVT == MVT::f64)
? DAG.getConstantFP(BitsToDouble(1ULL << 63), SrcVT)
: DAG.getConstantFP(BitsToFloat(1U << 31), SrcVT);
Mask1 = DAG.getNode(ISD::BIT_CONVERT, SrcNVT, Mask1);
(here SrcNVT is an integer with the same size as SrcVT).
As far as I can see this takes a 1 << 63, converts to
a double, converts that to a floating point constant
then converts that to an integer constant, ending up
with... 1 << 63 as an integer constant! So I just
generate this integer constant directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48305 91177308-0d34-0410-b5e6-96231b3b80d8
approach taken is different to that in LegalizeDAG
when it is a question of expanding or promoting the
result type: for example, if extracting an i64 from
a <2 x i64>, when i64 needs expanding, it bitcasts
the vector to <4 x i32>, extracts the appropriate
two i32's, and uses those for the Lo and Hi parts.
Likewise, when extracting an i16 from a <4 x i16>,
and i16 needs promoting, it bitcasts the vector to
<2 x i32>, extracts the appropriate i32, twiddles
the bits if necessary, and uses that as the promoted
value. This puts more pressure on bitcast legalization,
and I've added the appropriate cases. They needed to
be added anyway since users can generate such bitcasts
too if they want to. Also, when considering various
cases (Legal, Promote, Expand, Scalarize, Split) it is
a pain that expand can correspond to Expand, Scalarize
or Split, so I've changed the LegalizeTypes enum so it
lists those different cases - now Expand only means
splitting a scalar in two.
The code produced is the same as by LegalizeDAG for
all relevant testcases, except for
2007-10-31-extractelement-i64.ll, where the code seems
to have improved (see below; can an expert please tell
me if it is better or not).
Before < vs after >.
< subl $92, %esp
< movaps %xmm0, 64(%esp)
< movaps %xmm0, (%esp)
< movl 4(%esp), %eax
< movl %eax, 28(%esp)
< movl (%esp), %eax
< movl %eax, 24(%esp)
< movq 24(%esp), %mm0
< movq %mm0, 56(%esp)
---
> subl $44, %esp
> movaps %xmm0, 16(%esp)
> pshufd $1, %xmm0, %xmm1
> movd %xmm1, 4(%esp)
> movd %xmm0, (%esp)
> movq (%esp), %mm0
> movq %mm0, 8(%esp)
< subl $92, %esp
< movaps %xmm0, 64(%esp)
< movaps %xmm0, (%esp)
< movl 12(%esp), %eax
< movl %eax, 28(%esp)
< movl 8(%esp), %eax
< movl %eax, 24(%esp)
< movq 24(%esp), %mm0
< movq %mm0, 56(%esp)
---
> subl $44, %esp
> movaps %xmm0, 16(%esp)
> pshufd $3, %xmm0, %xmm1
> movd %xmm1, 4(%esp)
> movhlps %xmm0, %xmm0
> movd %xmm0, (%esp)
> movq (%esp), %mm0
> movq %mm0, 8(%esp)
< subl $92, %esp
< movaps %xmm0, 64(%esp)
---
> subl $44, %esp
< movl 16(%esp), %eax
< movl %eax, 48(%esp)
< movl 20(%esp), %eax
< movl %eax, 52(%esp)
< movaps %xmm0, (%esp)
< movl 4(%esp), %eax
< movl %eax, 60(%esp)
< movl (%esp), %eax
< movl %eax, 56(%esp)
---
> pshufd $1, %xmm0, %xmm1
> movd %xmm1, 4(%esp)
> movd %xmm0, (%esp)
> movd %xmm1, 12(%esp)
> movd %xmm0, 8(%esp)
< subl $92, %esp
< movaps %xmm0, 64(%esp)
---
> subl $44, %esp
< movl 24(%esp), %eax
< movl %eax, 48(%esp)
< movl 28(%esp), %eax
< movl %eax, 52(%esp)
< movaps %xmm0, (%esp)
< movl 12(%esp), %eax
< movl %eax, 60(%esp)
< movl 8(%esp), %eax
< movl %eax, 56(%esp)
---
> pshufd $3, %xmm0, %xmm1
> movd %xmm1, 4(%esp)
> movhlps %xmm0, %xmm0
> movd %xmm0, (%esp)
> movd %xmm1, 12(%esp)
> movd %xmm0, 8(%esp)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47672 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen/PowerPC/illegal-element-type.ll): suppose
a node X is processed, and processing maps it to
a node Y. Then X continues to exist in the DAG,
but with no users. While processing some other
node, a new node may be created that happens to
be equal to X, and thus X will be reused rather
than a truly new node. This can cause X to
"magically reappear", and since it is in the
Processed state in will not be reprocessed, so
at the end of type legalization the illegal node
X can still be present. The solution is to replace
X with Y whenever X gets resurrected like this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47601 91177308-0d34-0410-b5e6-96231b3b80d8
ReadyToProcess node - add an assertion to check
this. Add an assertion to NodeDeleted that checks
that processed/ready nodes are indeed not deleted.
It is because they are never deleted that none of
the maps can have a deleted node as the source of
a mapping. It does however seem to be possible in
theory to have a deleted value as the target of a
mapping, however this has not yet been spotted in
the wild. Still mulling on what to do about this.
[The theoretical situation is this: a node A is
expanded/promoted/whatever to a newly created node
B. Thus A->B is added to a map. When the subtree
rooted at B is legalized it is conceivable that B
is deleted due to RAUW on a node somewhere above
it].
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46705 91177308-0d34-0410-b5e6-96231b3b80d8
