This SelectionDAG node will be attached to call nodes by LowerCall(),
and eventually becomes a MO_RegisterMask MachineOperand on the
MachineInstr representing the call instruction.
LowerCall() will attach a register mask that depends on the calling
convention.
llvm-svn: 148436
undefined result. This adds new ISD nodes for the new semantics,
selecting them when the LLVM intrinsic indicates that the undef behavior
is desired. The new nodes expand trivially to the old nodes, so targets
don't actually need to do anything to support these new nodes besides
indicating that they should be expanded. I've done this for all the
operand types that I could figure out for all the targets. Owners of
various targets, please review and let me know if any of these are
incorrect.
Note that the expand behavior is *conservatively correct*, and exactly
matches LLVM's current behavior with these operations. Ideally this
patch will not change behavior in any way. For example the regtest suite
finds the exact same instruction sequences coming out of the code
generator. That's why there are no new tests here -- all of this is
being exercised by the existing test suite.
Thanks to Duncan Sands for reviewing the various bits of this patch and
helping me get the wrinkles ironed out with expanding for each target.
Also thanks to Chris for clarifying through all the discussions that
this is indeed the approach he was looking for. That said, there are
likely still rough spots. Further review much appreciated.
llvm-svn: 146466
change, now you need a TargetOptions object to create a TargetMachine. Clang
patch to follow.
One small functionality change in PTX. PTX had commented out the machine
verifier parts in their copy of printAndVerify. That now calls the version in
LLVMTargetMachine. Users of PTX who need verification disabled should rely on
not passing the command-line flag to enable it.
llvm-svn: 145714
Conservatively returns zero when the GV does not specify an alignment nor is it
initialized. Previously it returns ABI alignment for type of the GV. However, if
the type is a "packed" type, then the under-specified alignments is attached to
the load / store instructions. In that case, the alignment of the type cannot be
trusted.
rdar://10464621
llvm-svn: 145300
When this field is true it means that the load is from constant (runt-time or compile-time) and so can be hoisted from loops or moved around other memory accesses
llvm-svn: 144100
fixes: Use a separate register, instead of SP, as the
calling-convention resource, to avoid spurious conflicts with
actual uses of SP. Also, fix unscheduling of calling sequences,
which can be triggered by pseudo-two-address dependencies.
llvm-svn: 143206
it fixes the dragonegg self-host (it looks like gcc is miscompiled).
Original commit messages:
Eliminate LegalizeOps' LegalizedNodes map and have it just call RAUW
on every node as it legalizes them. This makes it easier to use
hasOneUse() heuristics, since unneeded nodes can be removed from the
DAG earlier.
Make LegalizeOps visit the DAG in an operands-last order. It previously
used operands-first, because LegalizeTypes has to go operands-first, and
LegalizeTypes used to be part of LegalizeOps, but they're now split.
The operands-last order is more natural for several legalization tasks.
For example, it allows lowering code for nodes with floating-point or
vector constants to see those constants directly instead of seeing the
lowered form (often constant-pool loads). This makes some things
somewhat more complicated today, though it ought to allow things to be
simpler in the future. It also fixes some bugs exposed by Legalizing
using RAUW aggressively.
Remove the part of LegalizeOps that attempted to patch up invalid chain
operands on libcalls generated by LegalizeTypes, since it doesn't work
with the new LegalizeOps traversal order. Instead, define what
LegalizeTypes is doing to be correct, and transfer the responsibility
of keeping calls from having overlapping calling sequences into the
scheduler.
Teach the scheduler to model callseq_begin/end pairs as having a
physical register definition/use to prevent calls from having
overlapping calling sequences. This is also somewhat complicated, though
there are ways it might be simplified in the future.
This addresses rdar://9816668, rdar://10043614, rdar://8434668, and others.
Please direct high-level questions about this patch to management.
Delete #if 0 code accidentally left in.
llvm-svn: 143188
on every node as it legalizes them. This makes it easier to use
hasOneUse() heuristics, since unneeded nodes can be removed from the
DAG earlier.
Make LegalizeOps visit the DAG in an operands-last order. It previously
used operands-first, because LegalizeTypes has to go operands-first, and
LegalizeTypes used to be part of LegalizeOps, but they're now split.
The operands-last order is more natural for several legalization tasks.
For example, it allows lowering code for nodes with floating-point or
vector constants to see those constants directly instead of seeing the
lowered form (often constant-pool loads). This makes some things
somewhat more complicated today, though it ought to allow things to be
simpler in the future. It also fixes some bugs exposed by Legalizing
using RAUW aggressively.
Remove the part of LegalizeOps that attempted to patch up invalid chain
operands on libcalls generated by LegalizeTypes, since it doesn't work
with the new LegalizeOps traversal order. Instead, define what
LegalizeTypes is doing to be correct, and transfer the responsibility
of keeping calls from having overlapping calling sequences into the
scheduler.
Teach the scheduler to model callseq_begin/end pairs as having a
physical register definition/use to prevent calls from having
overlapping calling sequences. This is also somewhat complicated, though
there are ways it might be simplified in the future.
This addresses rdar://9816668, rdar://10043614, rdar://8434668, and others.
Please direct high-level questions about this patch to management.
llvm-svn: 143177
and the alignment is 0 (i.e., it's defined globally in one file and declared in
another file) it could get an alignment which is larger than the ABI allows for
that type, resulting in aligned moves being used for unaligned loads.
For instance, in file A.c:
struct S s;
In file B.c:
struct {
// something long
};
extern S s;
void foo() {
struct S p = s;
// ...
}
this copy is a 'memcpy' which is turned into a series of 'movaps' instructions
on X86. But this is wrong, because 'struct S' has alignment of 4, not 16.
llvm-svn: 140902
(The fix for the related failures on x86 is going to be nastier because we actually need Acquire memoperands attached to the atomic load instrs, etc.)
llvm-svn: 139221
with a vector condition); such selects become VSELECT codegen nodes.
This patch also removes VSETCC codegen nodes, unifying them with SETCC
nodes (codegen was actually often using SETCC for vector SETCC already).
This ensures that various DAG combiner optimizations kick in for vector
comparisons. Passes dragonegg bootstrap with no testsuite regressions
(nightly testsuite as well as "make check-all"). Patch mostly by
Nadav Rotem.
llvm-svn: 139159
init.trampoline and adjust.trampoline intrinsics, into two intrinsics
like in GCC. While having one combined intrinsic is tempting, it is
not natural because typically the trampoline initialization needs to
be done in one function, and the result of adjust trampoline is needed
in a different (nested) function. To get around this llvm-gcc hacks the
nested function lowering code to insert an additional parent variable
holding the adjust.trampoline result that can be accessed from the child
function. Dragonegg doesn't have the luxury of tweaking GCC code, so it
stored the result of adjust.trampoline in the memory GCC set aside for
the trampoline itself (this is always available in the child function),
and set up some new memory (using an alloca) to hold the trampoline.
Unfortunately this breaks Go which allocates trampoline memory on the
heap and wants to use it even after the parent has exited (!). Rather
than doing even more hacks to get Go working, it seemed best to just use
two intrinsics like in GCC. Patch mostly by Sanjoy Das.
llvm-svn: 139140
working on x86 (at least for trivial testcases); other architectures will
need more work so that they actually emit the appropriate instructions for
orderings stricter than 'monotonic'. (As far as I can tell, the ARM, PPC,
Mips, and Alpha backends need such changes.)
llvm-svn: 136457
hasPredecessorHelper function allows predecessors to be cached to speed up
repeated invocations. This fixes PR10186.
X.isPredecessorOf(Y) now just calls Y.hasPredecessor(X)
Y.hasPredecessor(X) calls Y.hasPredecessorHelper(X, Visited, Worklist) with
empty Visited and Worklist sets (i.e. no caching over invocations).
Y.hasPredecessorHelper(X, Visited, Worklist) caches search state in Visited
and Worklist to speed up repeated calls. The Visited set is searched for X
before going to the worklist to further search the DAG if necessary.
llvm-svn: 134592
non-zero.
- Teach X86 cmov optimization to eliminate the cmov from ctlz, cttz extension
when the source of X86ISD::BSR / X86ISD::BSF is proven to be non-zero.
rdar://9490949
llvm-svn: 131948
David Greene changed CannotYetSelect() to print the full DAG including multiple
copies of operands reached through different paths in the DAG. Unfortunately
this blows up exponentially in some cases. The depth limit of 100 is way too
high to prevent this -- I'm seeing a message string of 150MB with a depth of
only 40 in one particularly bad case, even though the DAG has less than 200
nodes. Part of the problem is that the printing code is following chain
operands, so if you fail to select an operation with a chain, the printer will
follow all the chained operations back to the entry node.
llvm-svn: 126899
have their low bits set to zero. This allows us to optimize
out explicit stack alignment code like in stack-align.ll:test4 when
it is redundant.
Doing this causes the code generator to start turning FI+cst into
FI|cst all over the place, which is general goodness (that is the
canonical form) except that various pieces of the code generator
don't handle OR aggressively. Fix this by introducing a new
SelectionDAG::isBaseWithConstantOffset predicate, and using it
in places that are looking for ADD(X,CST). The ARM backend in
particular was missing a lot of addressing mode folding opportunities
around OR.
llvm-svn: 125470
generating i8 shift amounts for things like i1024 types. Add
an assert in getNode to prevent this from occuring in the future,
fix the buggy transformation, revert my previous patch, and
document this gotcha in ISDOpcodes.h
llvm-svn: 125465
default implementation for x86, going through the stack in a similr
fashion to how the codegen implements BUILD_VECTOR. Eventually this
will get matched to VINSERTF128 if AVX is available.
llvm-svn: 124307
implementation of EXTRACT_SUBVECTOR for x86, going through the stack
in a similr fashion to how the codegen implements BUILD_VECTOR.
Eventually this will get matched to VEXTRACTF128 if AVX is available.
llvm-svn: 124292
clang's -Wuninitialized-experimental warning.
While these don't look like real bugs, clang's
-Wuninitialized-experimental analysis is stricter
than GCC's, and these fixes have the benefit
of being general nice cleanups.
llvm-svn: 124073
Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.
llvm-svn: 123107
up freebsd bootloader. However, this doesn't make much sense for Darwin, whose
-Os is meant to optimize for size only if it doesn't hurt performance.
rdar://8821501
llvm-svn: 122936
This allows us to compile:
void test(char *s, int a) {
__builtin_memset(s, a, 15);
}
into 1 mul + 3 stores instead of 3 muls + 3 stores.
llvm-svn: 122710
We could implement a DAGCombine to turn x * 0x0101 back into logic operations
on targets that doesn't support the multiply or it is slow (p4) if someone cares
enough.
Example code:
void test(char *s, int a) {
__builtin_memset(s, a, 4);
}
before:
_test: ## @test
movzbl 8(%esp), %eax
movl %eax, %ecx
shll $8, %ecx
orl %eax, %ecx
movl %ecx, %eax
shll $16, %eax
orl %ecx, %eax
movl 4(%esp), %ecx
movl %eax, 4(%ecx)
movl %eax, (%ecx)
ret
after:
_test: ## @test
movzbl 8(%esp), %eax
imull $16843009, %eax, %eax ## imm = 0x1010101
movl 4(%esp), %ecx
movl %eax, 4(%ecx)
movl %eax, (%ecx)
ret
llvm-svn: 122707
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.
llvm-svn: 121120
so don't claim they are. They are allocated using DAG.getNode, so attempts
to access MemSDNode fields results in reading off the end of the allocated
memory. This fixes crashes with "llc -debug" due to debug code trying to
print MemSDNode fields for these barrier nodes (since the crashes are not
deterministic, use valgrind to see this). Add some nasty checking to try
to catch this kind of thing in the future.
llvm-svn: 119901
to perform the copy, which may be of lots of memory [*]. It would be good if the
fall-back code generated something reasonable, i.e. did the copy in a loop, rather
than vast numbers of loads and stores. Add a note about this. Currently target
specific code seems to always kick in so this is more of a theoretical issue rather
than a practical one now that X86 has been fixed.
[*] It's amazing how often people pass mega-byte long arrays by copy...
llvm-svn: 118275
I think I've audited all uses, so it should be dependable for address spaces,
and the pointer+offset info should also be accurate when there.
llvm-svn: 114464
NO path to the destination containing side effects, not that SOME path contains no side effects.
In practice, this only manifests with CombinerAA enabled, because otherwise the chain has little
to no branching, so "any" is effectively equivalent to "all".
llvm-svn: 114268
-enable-no-nans-fp-math and -enable-no-infs-fp-math. All of the current codegen fp math optimizations only care whether the fp arithmetics arguments and results can never be NaN.
llvm-svn: 108465
when the condition is constant. This optimization shouldn't be
necessary, because codegen shouldn't be able to find dead control
paths that the IR-level optimizer can't find. And it's undesirable,
because it encourages bugpoint to leave "br i1 false" branches
in its output. And it wasn't updating the CFG.
I updated all the tests I could, but some tests are too reduced
and I wasn't able to meaningfully preserve them.
llvm-svn: 106748
that are too large. This causes the freebsd bootloader to be too
large apparently.
It's unclear if this should be an -Os or -Oz thing. Thoughts welcome.
llvm-svn: 105228
Move EmitTargetCodeForMemcpy, EmitTargetCodeForMemset, and
EmitTargetCodeForMemmove out of TargetLowering and into
SelectionDAGInfo to exercise this.
llvm-svn: 103481
getConstantFP to accept the two supported long double
target types. This was not the original intent, but
there are other places that assume this works and it's
easy enough to do.
llvm-svn: 103299
indexes could be of a different value type. Or not even using the same SDNode
for the constant (weird, I know). Compare the actual values instead of the
pointers.
llvm-svn: 102791
const_casts, and it reinforces the design of the Target classes being
immutable.
SelectionDAGISel::IsLegalToFold is now a static member function, because
PIC16 uses it in an unconventional way. There is more room for API
cleanup here.
And PIC16's AsmPrinter no longer uses TargetLowering.
llvm-svn: 101635
1. Introduce some enums and accessors in the InlineAsm class
that eliminate a ton of magic numbers when handling inline
asm SDNode.
2. Add a new MDNodeSDNode selection dag node type that holds
a MDNode (shocking!)
3. Add a new argument to ISD::INLINEASM nodes that hold !srcloc
metadata, propagating it to the instruction emitter, which
drops it.
No functionality change.
llvm-svn: 100605
Jakob Stoklund Olesen