Add a flag to getPredicateAt() that allows making use of the block
value. This allows us to take into account range information from
the current block, rather than only information that is threaded
over edges, making the icmp simplification in CVP a lot more
powerful.
I'm not changing getPredicateAt() to use the block value
unconditionally to avoid any impact on the JumpThreading pass,
which is somewhat picky about LVI query order.
Most test changes here are just icmps that now get dropped (while
previously only a result used in a return was replaced). The three
tests in icmp.ll show some representative improvements. Some of
the folds this enables have been covered by IPSCCP in the meantime,
but LVI can reason about some cases which are hard to support in
IPSCCP, such as in test_br_cmp_with_offset.
The compile-time time cost of doing this is fairly minimal, with
a ~0.05% CTMark regression for ReleaseThinLTO:
https://llvm-compile-time-tracker.com/compare.php?from=709d03f8af4da4204849a70f01798e7cebba2e32&to=6236fd503761f43c99f4537121e057a01056f185&stat=instructions
This is because the block values will typically already be queried
and cached by other CVP optimizations anyway.
Differential Revision: https://reviews.llvm.org/D69686
If -enable-constraint-elimination is specified, add it to the -O2/-O3 pipeline.
(-O1 uses a separate function now.)
Reviewed By: fhahn, aeubanks
Differential Revision: https://reviews.llvm.org/D88365
D69686 will be able to determine that the icmp is always false.
As this is not the purpose of the test, use a different modulus
that doesn't trivialize the condition.
The lattice value returned by getValueInBlock() holds at the start
of the block, not at the end. Also make it clearer what the
difference between getValueInBlock() and getValueAt() is.
Require CxtI in getConstant() and getConstantRange() APIs.
Accordingly drop the BB parameter, as it is implied by
CxtI->getParent().
This makes sure we don't forget to pass the context instruction,
and makes the API contract clearer (also clean up the comments to
that effect -- the value holds at the context instruction, not
the end of the block).
This fold was the only place not passing the context instruction.
The tests worked around that fact by introducing a basic block split,
which is now no longer necessary.
As discussed in D87877, instcombine already has this fold,
but it was missing from the more general ValueTracking logic.
https://alive2.llvm.org/ce/z/PumYZP
Remove usages of special error reporting functions(error(),
reportError()). This patch is extracted from D87987.
Errors are reported as Expected<>/Error returning values.
This part is for COFF subfolder of llvm-objcopy.
Testing: check-all.
Differential Revision: https://reviews.llvm.org/D88213
RegInfoBasedABI::GetRegisterInfoByName was failing because mips/mips64 ABIs
don't use ConstString in their register info array.
Reviewed By: #lldb, teemperor
Differential Revision: https://reviews.llvm.org/D88375
This was supposed to be done in the first place as is currently the case for
G_ASHR and G_LSHR but was forgotten when the original shift legalization
overhaul was done last year.
This was exposed because we started falling back on s32 = s32, s64 SHLs
due to a recent combiner change.
Gives a very minor (0.1%) code size -O0 improvement on consumer-typeset.
Use +/-Inf or +/-Largest as neutral element for nnan fmin/fmax
reductions. This avoids dropping any FMF flags. Preserving the
nnan flag in particular is important to get a good lowering on X86.
Differential Revision: https://reviews.llvm.org/D87586
It is not a good idea to expose raw constants in the LLVM C API. Replace this with an explicit getter.
Differential Revision: https://reviews.llvm.org/D88367
Previous description didn't actually state the effect the attribute has on
thread safety analysis (causing analysis to assume the capability is held).
Previous description was also ambiguous about (or slightly overstated) the
noreturn assumption made by thread safety analysis, implying the assumption had
to be true about the function's behavior in general, and not just its behavior
in places where it's used. Stating the assumption specifically should avoid a
perceived need to disable thread safety analysis in places where only asserting
that a specific capability is held would be better.
Reviewed By: aaronpuchert, vasild
Differential Revision: https://reviews.llvm.org/D87629
SAVE statement, according to 8.6.14, must apply to the same scoping
unit, that excludes nested scoping units. For example, if the SAVE
statement is found in a MODULE, the functions contained in that module
should not inherit the SAVE attribute. I think that the code was doing
this, failing the following source:
```
MODULE pippo
SAVE
CONTAINS
PURE FUNCTION fft_stick_index( )
IMPLICIT NONE
INTEGER :: fft_stick_index
INTEGER :: mc !error: A pure subprogram may not have a variable with the SAVE attribute
END FUNCTION
END MODULE
```
Differential Revision: https://reviews.llvm.org/D88279
There appears to be a mis-compile with MemorySSA-backed DSE in
combination with llvm.lifetime.end. It currently appears like
DSE is doing the right thing and the llvm.lifetime.end markers
are incorrect. The reverted patch uncovers the mis-compile.
This patch temporarily switches back to the legacy DSE
implementation, while we investigate.
This reverts commit 9d172c8e9c.
If we're multiplying all elements of a vector by '0' or '1' then we can more efficiently perform this as a clearing mask (that is likely to further simplify to a shuffle blend).
This was noticed when reviewing D87502 but seems to help idiv/irem by constant cases even more as '0'/'1' values are often used for 'passthrough' cases.
Differential Revision: https://reviews.llvm.org/D88225
When looking for memory defs killed by memory terminators the code
currently incorrectly ignores the size argument of llvm.lifetime.end.
This patch updates the code to use isMemTerminator and updates
isMemTerminator to use isOverwrite() to make sure locations that are
outside the range marked as dead by llvm.lifetime.end are not
considered. Note that isOverwrite is only used for llvm.lifetime.end,
because free-like functions make the whole underlying object dead.
llvm.lifetime.end accepts a size parameters to limit the size of the
location marked as dead. Add a few tests with stores to locations after
the part that has been marked as dead.
The change implements evaluation of constant floating point expressions
under non-default rounding modes. The main objective was to support
evaluation of global variable initializers, where constant rounding mode
may be specified by `#pragma STDC FENV_ROUND`.
Differential Revision: https://reviews.llvm.org/D87822
This is a fix for PR47630. The regression is caused by the D78011. After
this change the code starts to call the `emitGlobalConstantLargeInt` even
for constants which requires eight bytes to store.
Differential revision: https://reviews.llvm.org/D88261
This is like FastMathFlagGuard in IR. Since we use SDAG instance to get
values, it's with SelectionDAG. By creating a FlagInserter in current
scope, all values created by getNode will get the flags if no Flags
argument provided.
In this patch, I applied it to floating point operations folding part in
DAG combiner, and removed Flags passing to getNode to show its effect.
Other places in DAG combiner and other helper methods similar to getNode
also need this. They can be done in follow-up patches.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D87361
Nikita Popov