Same as https://github.com/llvm/llvm-project/pull/177988, but for
fminimum_num/fmaximum_num. Directly canonicalize these to the
corresponding intrinsics, and let the shrinking happen directly on the
intrinsics.
Drop the custom shrinking code, which we'll also do for intrinsics.
Having libcall-only optimizations is confusing, as these are typically
directly emitted as intrinsics by the frontend.
This was propagating the callee's attributes instead of just the
callsite. It's illegal to set denormal_fpenv on a callsite. This
was also losing callsite attributes which may have been more useful;
there's no point in setting the callee's attributes on the callsite.
When rewriting operator new calls to their hot/cold variants for PGHO,
`!alloc_token` metadata was being dropped. This metadata is required by
the AllocToken pass to correctly instrument the optimized allocation.
Fix it by preserving all metadata.
The collection of library function names in TargetLibraryInfo faces
similar challenges as RuntimeLibCalls in the IR component. The number of
function names is large, there are numerous customizations based on the
triple (including alternate names), and there is a lot of replicated
data in the signature table.
The ultimate goal would be to capture all lbrary function related
information in a .td file. This PR brings the current .def file to
TableGen, almost as a 1:1 replacement. However, there are some
improvements which are not possible in the current implementation:
- the function names are now stored as a long string together with an
offset table.
- the table of signatures is now deduplicated, using an offset table for
access.
The size of the object file decreases about 34kB with these changes. The
hash table of all function names is still constructed dynamically. A
static table like for RuntimeLibCalls is the next logical step.
The main motivation for this change is that I have to add a large number
of custom names for z/OS (like in RuntimeLibCalls.td), and the current
infrastructur does not support this very well.
Apply hints even if the attribute is the default "notcold" or
"ambiguous", to enable better tracking through the allocator.
Add an option to control the ambiguous allocation hint value.
Explicit calls to ::operator new are marked nobuiltin and cannot be
elided or updated as they may call user defined versions. However,
existing calls to the hot/cold versions of new only need their hint
parameter value updated, which does not mutate the call.
This makes the optimization in optimizeStringLength for strlen(gep
@glob, %x) -> sub endof@glob, %x a little more resilient, and maybe a
bit more correct for geps with non-array types.
When matching integers, `m_ConstantInt` is a convenient alternative to
`m_APInt` for matching unsigned 64-bit integers, allowing one to
simplify
```cpp
const APInt *IntC;
if (match(V, m_APInt(IntC))) {
if (IntC->ule(UINT64_MAX)) {
uint64_t Int = IntC->getZExtValue();
// ...
}
}
```
to
```cpp
uint64_t Int;
if (match(V, m_ConstantInt(Int))) {
// ...
}
```
However, this simplification is only true if `V` is a scalar type.
Specifically, `m_APInt` also matches integer splats, but `m_ConstantInt`
does not.
This patch ensures that the matching behaviour of `m_ConstantInt`
parallels that of `m_APInt`, and also incorporates it in some obvious
places.
Having a finite Depth (or recursion limit) for computeKnownBits is very
limiting, but is currently a load-bearing necessity, as all KnownBits
are recomputed on each call and there is no caching. As a prerequisite
for an effort to remove the recursion limit altogether, either using a
clever caching technique, or writing a easily-invalidable KnownBits
analysis, make the Depth argument in APIs in ValueTracking uniformly the
last argument with a default value. This would aid in removing the
argument when the time comes, as many callers that currently pass 0
explicitly are now updated to omit the argument altogether.
This optimization already exists, but for the libcall versions of these
functions and not for their intrinsic form.
Solves https://github.com/llvm/llvm-project/issues/139044.
There are probably more opportunities for other intrinsics, because the
switch-case in `LibCallSimplifier::optimizeCall` covers only `pow`,
`exp2`, `log`, `log2`, `log10`, `sqrt`, `memset`, `memcpy` and
`memmove`.
This PR removes the old `nocapture` attribute, replacing it with the new
`captures` attribute introduced in #116990. This change is
intended to be essentially NFC, replacing existing uses of `nocapture`
with `captures(none)` without adding any new analysis capabilities.
Making use of non-`none` values is left for a followup.
Some notes:
* `nocapture` will be upgraded to `captures(none)` by the bitcode
reader.
* `nocapture` will also be upgraded by the textual IR reader. This is to
make it easier to use old IR files and somewhat reduce the test churn in
this PR.
* Helper APIs like `doesNotCapture()` will check for `captures(none)`.
* MLIR import will convert `captures(none)` into an `llvm.nocapture`
attribute. The representation in the LLVM IR dialect should be updated
separately.
When using non-integral pointer types, such as on CHERI targets, size_t
is equivalent
to the index size, which is allowed to be smaller than the size of the
pointer.
Writing a test for this transitively exposed a number of places in
BuildLibCalls where
we were failing to propagate address spaces properly, which are
additionally fixed.
In a variety of places we change the bitwidth of a parameter but don't
update the attributes.
The issue in this case is from the `range` attribute when inlining
`__memset_chk`. `optimizeMemSetChk` will replace an `i32` with an
`i8`, and if the `i32` had a `range` attr assosiated it will cause an
error.
Fixes#112633
Rename the function to reflect its correct behavior and to be consistent
with `Module::getOrInsertFunction`. This is also in preparation of
adding a new `Intrinsic::getDeclaration` that will have behavior similar
to `Module::getFunction` (i.e, just lookup, no creation).
Similar to 112aac4e8961b9626bb84f36deeaa5a674f03f5a, this converts log
libcalls to llvm.log.f64 intrinsics if we know they do not set errno, as
the input is not zero and not negative. As log will produce errno if the
input is 0 (returning -inf) or if the input is negative (returning nan),
we also perform the conversion when we have noinf and nonan.
This attempts to fix the ASan buildbot, which is detecting that CI is used
after it is removed in substituteInParent. The idea was to make sure it was
removed even if it had side-effects writing errno, but that appears to happen
if we return FRem directly as usual.
fmod will be folded to frem in clang under -fno-math-errno and can be constant
folded in llvm if the operands are known. It can be relatively common to have
fp code that handles special values before doing some calculation:
```
if (isnan(f))
return handlenan;
if (isinf(f))
return handleinf;
..
fmod(f, 2.0)
```
This patch enables the folding of fmod to frem in instcombine if the first
parameter is not inf and the second is not zero. Other combinations do not set
errno.
The same transform is performed for fmod with the nnan flag, which implies the
input is known to not be inf/zero.
The `ch` argument of memcmp should be truncated to `unsigned char`
before using it in comparisons. This didn't happen on all code paths.
The following program miscompiled at -O1 and higher:
```C++
#include <cstring>
#include <iostream>
char ch = '\x81';
int main() {
bool found = std::strchr("\x80\x81\x82", ch) != nullptr;
std::cout << std::boolalpha << found << '\n';
}
```
This is a helper to avoid writing `getModule()->getDataLayout()`. I
regularly try to use this method only to remember it doesn't exist...
`getModule()->getDataLayout()` is also a common (the most common?)
reason why code has to include the Module.h header.
Uses the new InsertPosition class (added in #94226) to simplify some of
the IRBuilder interface, and removes the need to pass a BasicBlock
alongside a BasicBlock::iterator, using the fact that we can now get the
parent basic block from the iterator even if it points to the sentinel.
This patch removes the BasicBlock argument from each constructor or call
to setInsertPoint.
This has no functional effect, but later on as we look to remove the
`Instruction *InsertBefore` argument from instruction-creation
(discussed
[here](https://discourse.llvm.org/t/psa-instruction-constructors-changing-to-iterator-only-insertion/77845)),
this will simplify the process by allowing us to deprecate the
InsertPosition constructor directly and catch all the cases where we use
instructions rather than iterators.
Do not require a libm ldexp libcall to emit the ldexp intrinsic when
transforming pow(2, x) -> ldexp(1, x)
This enables the half intrinsic case to fold.
When folding exp2(itofp(x)) to ldexp(1, x), don't require an ldexp
libcall to emit the intrinsic.
The intrinsic needs to be handled regardless of whether the system has a
libcall, and we have an inline implementation of ldexp already. This
fixes the instance in the exp2->ldexp fold. Another instance exists for
the pow(2) -> ldexp case
The LTO test change isn't ideal, since it's just moving the problem to
another instance where we're relying on implied libm behavior for an
intrinsic transform. Use exp10 since that's a harder case to solve in
the libcall house of cards we have.
