[IR] Rename `comdat noduplicates` to `comdat nodeduplicate`

In the textual format, `noduplicates` means no COMDAT/section group
deduplication is performed. Therefore, if both sets of sections are re

[IR] Rename `comdat noduplicates` to `comdat nodeduplicate`

In the textual format, `noduplicates` means no COMDAT/section group
deduplication is performed. Therefore, if both sets of sections are retained, and
they happen to define strong external symbols with the same names,
there will be a duplicate definition linker error.

In PE/COFF, the selection kind lowers to `IMAGE_COMDAT_SELECT_NODUPLICATES`.
The name describes the corollary instead of the immediate semantics. The name
can cause confusion to other binary formats (ELF, wasm) which have implemented/
want to implement the "no deduplication" selection kind. Rename it to be clearer.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D106319

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[Internalize] Simplify comdat renaming with noduplicates after D103043

I realized that we can use `comdat noduplicates` which is available on ELF.
Add a special case for wasm which doesn't support t

[Internalize] Simplify comdat renaming with noduplicates after D103043

I realized that we can use `comdat noduplicates` which is available on ELF.
Add a special case for wasm which doesn't support the feature.

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[Internalize] Rename instead of removal if a to-be-internalized comdat has more than one member

Beside the `comdat any` deduplication feature, instrumentations use comdat to
establish dependencies a

[Internalize] Rename instead of removal if a to-be-internalized comdat has more than one member

Beside the `comdat any` deduplication feature, instrumentations use comdat to
establish dependencies among a group of sections, to prevent section based
linker garbage collection from discarding some members without discarding all.
LangRef acknowledges this usage with the following wording:

> All global objects that specify this key will only end up in the final object file if the linker chooses that key over some other key.

On ELF, for PGO instrumentation, a `__llvm_prf_cnts` section and its associated
`__llvm_prf_data` section are placed in the same GRP_COMDAT group. A
`__llvm_prf_data` is usually not referenced and expects the liveness of its
associated `__llvm_prf_cnts` to retain it.

The `setComdat(nullptr)` code (added by D10679) in InternalizePass can break the
use case (a `__llvm_prf_data` may be dropped with its associated `__llvm_prf_cnts` retained).
The main goal of this patch is to fix the dependency relationship.

I think it makes sense for InternalizePass to internalize a comdat and thus
suppress the deduplication feature, e.g. a relocatable link of a regular LTO can
create an object file affected by InternalizePass.
If a non-internal comdat in a.o is prevailed by an internal comdat in b.o, the
a.o references to the comdat definitions will be non-resolvable (references
cannot bind to STB_LOCAL definitions in b.o).

On PE-COFF, for a non-external selection symbol, deduplication is naturally
suppressed with link.exe and lld-link. However, this is fuzzy on ELF and I tend
to believe the spec creator has not thought about this use case (see D102973).

GNU ld and gold are still using the "signature is name based" interpretation.
So even if D102973 for ld.lld is accepted, for portability, a better approach is
to rename the comdat. A comdat with one single member is the common case,
leaving the comdat can waste (sizeof(Elf64_Shdr)+4*2) bytes, so we optimize by
deleting the comdat; otherwise we rename the comdat.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D103043

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Revert "Temporarily Revert "Add basic loop fusion pass.""

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

[opaque pointer type] Add textual IR support for explicit type parameter for global aliases

update.py:
import fileinput
import sys
import re

alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(

[opaque pointer type] Add textual IR support for explicit type parameter for global aliases

update.py:
import fileinput
import sys
import re

alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(?:private|internal|linkonce|linkonce_odr|weak|weak_odr|common|appending|extern_weak|available_externally) )?(?:default |hidden |protected )?(?:dllimport |dllexport )?(?:unnamed_addr |)(?:thread_local(?:\([a-z]*\))? )?alias"
plain = re.compile(alias_match_prefix + r" (.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|addrspacecast|\[\[[a-zA-Z]|\{\{).*$)")
cast = re.compile(alias_match_prefix + r") ((?:bitcast|inttoptr|addrspacecast)\s*\(.* to (.*?)(| addrspace\(\d+\) *)\*\)\s*(?:;.*)?$)")
gep = re.compile(alias_match_prefix + r") ((?:getelementptr)\s*(?:inbounds)?\s*\((?P<type>.*), (?P=type)(?:\s*addrspace\(\d+\)\s*)?\* .*\)\s*(?:;.*)?$)")

def conv(line):
m = re.match(cast, line)
if m:
return m.group(1) + " " + m.group(3) + ", " + m.group(2)
m = re.match(gep, line)
if m:
return m.group(1) + " " + m.group(3) + ", " + m.group(2)
m = re.match(plain, line)
if m:
return m.group(1) + ", " + m.group(2) + m.group(3) + "*" + m.group(4) + "\n"
return line

for line in sys.stdin:
sys.stdout.write(conv(line))

apply.sh:
for name in "$@"
do
python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

llvm-svn: 247378

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Internalize: internalize comdat members as a group, and drop comdat on such members.

Internalizing an individual comdat group member without also internalizing
the other members of the comdat can br

Internalize: internalize comdat members as a group, and drop comdat on such members.

Internalizing an individual comdat group member without also internalizing
the other members of the comdat can break comdat semantics. For example,
if a module contains a reference to an internalized comdat member, and the
linker chooses a comdat group from a different object file, this will break
the reference to the internalized member.

This change causes the internalizer to only internalize comdat members if all
other members of the comdat are not externally visible. Once a comdat group
has been fully internalized, there is no need to apply comdat rules to its
members; later optimization passes (e.g. globaldce) can legally drop individual
members of the comdat. So we drop the comdat attribute from all comdat members.

Differential Revision: http://reviews.llvm.org/D10679

llvm-svn: 242423

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