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.
Prior to #85863, the required parameters of llvm::isKnownNonZero were
Value and DataLayout. After, they are Value, Depth, and SimplifyQuery,
where SimplifyQuery is implicitly constructible from DataLayout. The
change to move Depth before SimplifyQuery needed callers to be updated
unnecessarily, and as commented in #85863, we actually want Depth to be
after SimplifyQuery anyway so that it can be defaulted and the caller
does not need to specify it.
optimizeTan has been renamed to optimizeTrigInversionPairs as a result.
Sadly, this is not mathematically true that all inverse pairs fold to x.
For example, asin(sin(x)) does not fold to x if x is over 2pi.
Under fast-math flags it's possible to convert `sqrt(exp(X)) `into
`exp(X * 0.5)`. I suppose that this transformation is always profitable.
This is similar to the optimization existing in GCC.
This patch refactors the interface of the `computeKnownFPClass` family
to pass `SimplifyQuery` directly.
The motivation of this patch is to compute known fpclass with
`DomConditionCache`, which was introduced by
https://github.com/llvm/llvm-project/pull/73662. With
`DomConditionCache`, we can do more optimization with context-sensitive
information.
Example (extracted from
[fmt/format.h](e17bc67547/include/fmt/format.h (L3555-L3566))):
```
define float @test(float %x, i1 %cond) {
%i32 = bitcast float %x to i32
%cmp = icmp slt i32 %i32, 0
br i1 %cmp, label %if.then1, label %if.else
if.then1:
%fneg = fneg float %x
br label %if.end
if.else:
br i1 %cond, label %if.then2, label %if.end
if.then2:
br label %if.end
if.end:
%value = phi float [ %fneg, %if.then1 ], [ %x, %if.then2 ], [ %x, %if.else ]
%ret = call float @llvm.fabs.f32(float %value)
ret float %ret
}
```
We can prove the signbit of `%value` is always zero. Then the fabs can
be eliminated.
Fixes https://github.com/llvm/llvm-project/issues/76549
The cause of the optimization miss was -
1. `optimizePow` converting almost integer FP exponents to integer, and
turning `pow` to `powi`.
2. `optimizeLog` not accepting `Intrinsic::powi` as a target.
This patch converts constantInt back to constantFP where applicable and
adds a test.
The current code for reprocessing the result of fortified libcall
simplifications is not correct, because we might simplify to an
argument of the original call, and if that is again a libcall,
mistakenly think that this is actually the simplification result.
Instead of trying to fix this, simply remove the code entirely,
because InstCombine nowadays correctly handles reprocessing of
SimplifyLibCall results.
Fixes https://github.com/llvm/llvm-project/issues/77064.
Given the transition into using opaque pointers we no longer need to
add casts to handle "mismatched pointer types" as all pointers types
involved now are the same.
This reverts commit 5dde755188e34c0ba5304365612904476c8adfda,
cbfcf90152de5392a36d0a0241eef25f5e159eef and
8981520b19f2d2fe3d2bc80cf26318ee6b5b7473 due to a miscompile introduced in
8981520b19f2d2fe3d2bc80cf26318ee6b5b7473 (see
https://reviews.llvm.org/D154725#4568845 for details)
Differential Revision: https://reviews.llvm.org/D157430
Move `AttributeMask` out of `llvm/IR/Attributes.h` to a new file
`llvm/IR/AttributeMask.h`. After doing this we can remove the
`#include <bitset>` and `#include <set>` directives from `Attributes.h`.
Since there are many headers including `Attributes.h`, but not needing
the definition of `AttributeMask`, this causes unnecessary bloating of
the translation units and slows down compilation.
This commit adds in the include directive for `llvm/IR/AttributeMask.h`
to the handful of source files that need to see the definition.
This reduces the total number of preprocessing tokens across the LLVM
source files in lib from (roughly) 1,917,509,187 to 1,902,982,273 - a
reduction of ~0.76%. This should result in a small improvement in
compilation time.
Differential Revision: https://reviews.llvm.org/D153728
In preparation for removing the `#include "llvm/ADT/StringExtras.h"`
from the header to source file of `llvm/Support/Error.h`, first add in
all the missing includes that were previously included transitively
through this header.
Partial progress towards replacing in-tree uses of
`Type::getPointerTo()`.
If `getPointerTo()` is used solely to support an unnecessary bitcast,
remove the bitcast.
Reviewed By: barannikov88, nikic
Differential Revision: https://reviews.llvm.org/D153307
Adds support to set the hot/cold new hint values with an option. Change
the defaults slightly to make it easier to distinguish between compiler
synthesized vs manually inserted calls to the interface.
Differential Revision: https://reviews.llvm.org/D150488
