The post-index matcher, before it queries the target legality, walks uses
of some instructions which in pathological cases can be massive. Since
no targets actually support indexed loads yet, disable this to stop wasting
compile time on something which is going to fail anyway.
Unwinders may only preserve the lower 64bits of Neon and SVE registers,
as only the registers in the base ABI are guaranteed to be preserved
over the exception edge. The caller will need to preserve additional
registers for when the call throws an exception and the unwinder has
tried to recover state.
For e.g.
svint32_t bar(svint32_t);
svint32_t foo(svint32_t x, bool *err) {
try { bar(x); } catch (...) { *err = true; }
return x;
}
`z0` needs to be spilled before the call to `bar(x)` and reloaded before
returning from foo, as the exception handler may have clobbered z0.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D84737
This is needed for an upcoming change to how we translate conditional branches
which might generate these.
Differential Revision: https://reviews.llvm.org/D86383
With gcc 6.3.0, I hit the following compilation error:
../lib/CodeGen/GlobalISel/Combiner.cpp: In member function
‘bool llvm::Combiner::combineMachineInstrs(llvm::MachineFunction&,
llvm::GISelCSEInfo*)’:
../lib/CodeGen/GlobalISel/Combiner.cpp:156:54: error: suggest parentheses
around ‘&&’ within ‘||’ [-Werror=parentheses]
assert(!CSEInfo || !errorToBool(CSEInfo->verify()) &&
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
"CSEInfo is not consistent. Likely missing calls to "
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"observer on mutations");
Fix the code as suggested by the compiler.
https://reviews.llvm.org/D83833
Patch adds two new GICombinerRules for G_SELECT. The rules include:
combining selects with undef comparisons into their first selectee value,
and to combine away selects with constant comparisons. Patch additionally
adds a new combiner test for the AArch64 target to test these new G_SELECT
combiner rules and the existing select_same_val combiner rule.
Patch by mkitzan
https://reviews.llvm.org/D86676
Sometimes we can have the following code
x:gpr(s32) = G_OP
Say we build G_OP2 to the same x and then delete the previous instruction. Using something like
Register X = ...;
auto NewMIB = CSEBuilder.buildOp2(X, ... args);
Currently there's a mismatch in how NewMIB is profiled and inserted into the CSEMap (ie it doesn't consider register bank/register class along with type).Unify the profiling by refactoring and calling the common method.
This was found by turning on the CSEInfo::verify in at the end of each of our GISel passes which turns inconsistent state/non determinism in CSEing into crashes which likely usually indicates missing calls to Observer on mutations (the most common case). Here non determinism usually means not cseing sometimes, but almost never about producing incorrect code.
Also this patch adds this verification at the end of the combiners as well.
AArch64, X86 and Mips currently directly consumes these and custom
lowering to produce a libcall, but really these should follow the
normal legalization process through the libcall/lower action.
This produces less work for addressing mode matching. I think this is
safe since I don't think machine IR is supposed to give the same
aliasing properties as getelementptr in the IR.
shl ([sza]ext x, y) => zext (shl x, y).
Turns expensive 64 bit shifts into 32 bit if it does not overflow the
source type:
This is a port of an AMDGPU DAG combine added in
5fa289f0d8. InstCombine does this
already, but we need to do it again here to apply it to shifts
introduced for lowered getelementptrs. This will help matching
addressing modes that use 32-bit offsets in a future patch.
TableGen annoyingly assumes only a single match data operand, so
introduce a reusable struct. However, this still requires defining a
separate GIMatchData for every combine which is still annoying.
Adds a morally equivalent function to the existing
getShiftAmountTy. Without this, we would have to do try to repeatedly
query the legalizer info and guess at what type to use for the shift.
Known bits for G_ANYEXT was incorrectly using KnownBits::zext, causing
us to treat the high bits as zero even though they're (by definition)
unknown.
Differential Revision: https://reviews.llvm.org/D86323
The check for the landingpad instructions was overly restrictive. In optimimized builds PHI nodes can appear
before the landingpad instructions, resulting in a fallback to SelectionDAG.
This change relaxes the check to allow PHI nodes.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D86141
If we have a mask, and a value x, where (x & mask) == x, we can drop the AND
and just use x.
This is about a 0.4% geomean code size improvement on CTMark at -O3 for AArch64.
In AArch64, this is most useful post-legalization. Patterns like this often
show up when legalizing s1s, which must be extended to larger types.
e.g.
```
%cmp:_(s32) = G_ICMP ...
%and:_(s32) = G_AND %cmp, 1
```
Since G_ICMP only produces a single bit, there's no reason to mask it with the
G_AND.
Differential Revision: https://reviews.llvm.org/D85463
It's annoying to have to maintain multiple, nearly identical chains of if
statements which all set the same attributes.
Add a helper function, `addFlagsUsingAttrFn` which performs the attribute
setting.
Then, use wrappers for that function in `lowerCall` and `setArgFlags`.
(Note that the flag-setting code in `setArgFlags` was missing the returned
attribute. There's no selection for this yet, so no test. It's an example of
the kind of thing this lets us avoid, though.)
Differential Revision: https://reviews.llvm.org/D86159
Similar to this commit:
faf8065a99
Testcase is pretty much the same as
test/CodeGen/AArch64/tailcall-explicit-sret.ll
Except it uses i64 (since we don't handle the i1024 return values yet), and
doesn't have indirect tail call testcases (because we can't translate those
yet).
Differential Revision: https://reviews.llvm.org/D86148
This is restricted to single use loads, which if we fold to sextloads we can
find more optimal addressing modes on AArch64.
This also fixes an overload the MachineFunction::getMachineMemOperand() method
which was incorrectly using the MF alignment instead of the MMO alignment.
Differential Revision: https://reviews.llvm.org/D85966
By detecting this sign extend pattern early, we can uncover opportunities for
more optimizations.
Differential Revision: https://reviews.llvm.org/D85965
We weren't looking through the parameters on calls at all.
E.g., say you had
```
declare i32 @zext(i32 zeroext %x)
...
%y = call i32 @zext(i32 %something)
...
```
At the point of the call, we wouldn't know that the %something should have the
zeroext attribute.
This sets flags in about the same way as
TargetLoweringBase::ArgListEntry::setAttributes.
Differential Revision: https://reviews.llvm.org/D86125
Some of the lower implementations were relying on this, however the
type was not set depending on which form .lower* helper form you were
using. For instance, if you used an unconditonal lower(), the type was
never set. Most of the lower actions do not benefit from a type
parameter, and just expand in terms of the original operation's types.
However, some lowerings could benefit from an additional type hint to
combine a promotion and an expansion. An example of this is for
add/sub sat. The DAG integer legalization tries to use smarter
expansions directly when promoting the integer type, and doesn't
always produce the same instruction with a wider type.
Treat this as an optional hint argument, that only means something for
specific lower actions. It may be useful to generalize this mechanism
to pass a full list of type indexes and desired types, but I haven't
run into a case like that yet.
These should really match either G_BUILD_VECTOR or
G_BUILD_VECTOR_TRUNC, but there doesn't seem to be an existing
mechanism for matching alternative opcodes. There is GIM_SwitchOpcode,
but it seems to assume it's oly only used for matcher optimization.
I could also omit any opcode check and rely on the matcher directly
checking the opcode, but the table optimizer currently assumes there
has to be an opcode check.
Also doesn't try to handle undef elements like the DAG version.
Volkan Keles