When emitting TBAA information for enums in C code we currently just
treat the data as an 'omnipotent char'. However, with C strict aliasing
this means we fail to optimise certain cases. For example, in the
SPEC2017 xz benchmark there are structs that contain arrays of enums,
and clang pessmistically assumes that accesses to those enums could
alias with other struct members that have a different type.
According to
https://en.cppreference.com/w/c/language/enum
enums should be treated as 'int' types unless explicitly specified (C23)
or if 'int' would not be large enough to hold all the enumerated values.
In the latter case the compiler is free to choose a suitable integer
that would hold all such values.
When compiling C code this patch generates TBAA information for the enum
by using an equivalent integer of the size clang has already chosen for
the enum. I have ignored C++ for now because the rules are more complex.
New test added here:
clang/test/CodeGen/tbaa.c
…ndling.
Returns an error *and* a benchmark rather than an error *or* a
benchmark. This allows users to have custom error handling while still
being able to inspect the benchmark.
Apart from this small API change, this is an NFC.
This is an alternative to #74211.
Fix loop unroll fail caused by branches folding.
For example:
SimplifyCFG foldloop branches then cause loop unroll failed for "#program unroll" loop.
```
#program unroll
for (int I = 0; I < ConstNum; ++I) { // folding "I < ConstNum" and "Cond2"
if (Cond2) {
break;
}
xxx loop body;
}
```
The pragma unroll metadata only takes effect if there is an exact trip
count, but not if there is an upper bound trip count. This patch make it
work with an upper bound trip count as well in shouldPragmaUnroll().
Loop unroll is important in stack nervous devices (e.g. GPU, and that is
why a lot of GPU code mark loop with "#program unroll").
It usually much simplify the address (offset) calculations in old
iterations, then we can do a lot of others optimizations, e.g, SROA, for
these simplifed address (escape alloca the whole aggregates).
Fixes https://github.com/llvm/llvm-project/issues/57372
Previously some work has already been done on this. A PR was generated
but it remained in review:
https://reviews.llvm.org/D136462
In short previous approach was following:
Changing the symbol names (making the searched part colorized) ->
printing them -> restoring the symbol names back in their original form.
The reviewers suggested that instead of changing the symbol table, this
colorization should be done in the dump functions itself. Our strategy
involves passing the searched regex pattern to the existing dump
functions responsible for printing information about the searched
symbol. This pattern is propagated until it reaches the line in the dump
functions responsible for displaying symbol information on screen.
At this point, we've introduced a new function called
"PutCStringColorHighlighted," which takes the searched pattern, a prefix and suffix,
and the text and applies colorization to highlight the pattern in the
output. This approach aims to streamline the symbol search process to
improve readability of search results.
Co-authored-by: José L. Junior <josejunior@10xengineers.ai>
`nsw` is a flag for LLVM arithmetic operations meaning "no signed wrap".
If this keyword is present, the result of the operation is a poison
value if overflow occurs. Adding this keyword permits LLVM to re-order
integer arithmetic more aggressively.
In
https://discourse.llvm.org/t/rfc-changes-to-fircg-xarray-coor-codegen-to-allow-better-hoisting/75257/16
@vzakhari observed that adding nsw is useful to enable hoisting of
address calculations after some loops (or is at least a step in that
direction).
Classic flang also adds nsw to address calculations.
We have a bunch of folds that basically perform X pred Y to ~Y pred ~X
for various special cases where this saves an instruction.
Generalize these folds to use isFreeToInvert(). We have to make sure
that we consume an instruction in either of the inversions, otherwise
we're just going to swap the icmp back and forth.
Fixes https://github.com/llvm/llvm-project/issues/74302.
opt accepts the -march command-line argument, but this argument only
makes sense in conjunction with -mtriple. Fix a couple of tests under
LoopVectorize that invoke opt with -march but without -mtriple, to avoid
confusing users.
Declare `getPreservedProducerResults` function which helps to get the
preserved results of the producer linalg generic operation as a result
of elementwise fusion.
This MR fix the argument name of GEPOp builder from `basePtrType` to
`elementType` to avoid confusion.
Co-authored-by: Xiaolei Shi <xiaoleis@nvidia.com>
Do not add the previous users of replaced ops to the worklist during
`notifyOperationReplaced`.
The previous users are modified inplace as part of
`PatternRewriter::replaceOp`, which calls
`PatternRewriter::replaceAllUsesWith`. The latter function updates all
users with `updateRootInPlace`, which already puts all previous users of
the replaced op on the worklist. No further worklist management work is
needed in the `notifyOperationReplaced` callback.
