llvm-project/llvm/test/Analysis/BasicAA/2010-09-15-GEP-SignedArithm...

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; RUN: opt < %s -basicaa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s
; PR7959
target datalayout = "e-p:32:32:32"
[BasicAA] Use MayAlias instead of PartialAlias for fallback. Using various methods, BasicAA tries to determine whether two GetElementPtr memory locations alias when its base pointers are known to be equal. When none of its heuristics are applicable, it falls back to PartialAlias to, according to a comment, protect TBAA making a wrong decision in case of unions and malloc. PartialAlias is not correct, because a PartialAlias result implies that some, but not all, bytes overlap which is not necessarily the case here. AAResults returns the first analysis result that is not MayAlias. BasicAA is always the first alias analysis. When it returns PartialAlias, no other analysis is queried to give a more exact result (which was the intention of returning PartialAlias instead of MayAlias). For instance, ScopedAA could return a more accurate result. The PartialAlias hack was introduced in r131781 (and re-applied in r132632 after some reverts) to fix llvm.org/PR9971 where TBAA returns a wrong NoAlias result due to a union. A test case for the malloc case mentioned in the comment was not provided and I don't think it is affected since it returns an omnipotent char anyway. Since r303851 (https://reviews.llvm.org/D33328) clang does emit specific TBAA for unions anymore (but "omnipotent char" instead). Hence, the PartialAlias workaround is not required anymore. This patch passes the test-suite and check-llvm/check-clang of a self-hoisted build on x64. Reviewed By: hfinkel Differential Revision: https://reviews.llvm.org/D34318 llvm-svn: 305938
2017-06-22 02:25:37 +08:00
; CHECK: 1 may alias responses
define i32 @test(i32* %tab, i32 %indvar) nounwind {
%tmp31 = mul i32 %indvar, -2
%tmp32 = add i32 %tmp31, 30
[opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction One of several parallel first steps to remove the target type of pointers, replacing them with a single opaque pointer type. This adds an explicit type parameter to the gep instruction so that when the first parameter becomes an opaque pointer type, the type to gep through is still available to the instructions. * This doesn't modify gep operators, only instructions (operators will be handled separately) * Textual IR changes only. Bitcode (including upgrade) and changing the in-memory representation will be in separate changes. * geps of vectors are transformed as: getelementptr <4 x float*> %x, ... ->getelementptr float, <4 x float*> %x, ... Then, once the opaque pointer type is introduced, this will ultimately look like: getelementptr float, <4 x ptr> %x with the unambiguous interpretation that it is a vector of pointers to float. * address spaces remain on the pointer, not the type: getelementptr float addrspace(1)* %x ->getelementptr float, float addrspace(1)* %x Then, eventually: getelementptr float, ptr addrspace(1) %x Importantly, the massive amount of test case churn has been automated by same crappy python code. I had to manually update a few test cases that wouldn't fit the script's model (r228970,r229196,r229197,r229198). The python script just massages stdin and writes the result to stdout, I then wrapped that in a shell script to handle replacing files, then using the usual find+xargs to migrate all the files. update.py: import fileinput import sys import re ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") normrep = re.compile( r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") def conv(match, line): if not match: return line line = match.groups()[0] if len(match.groups()[5]) == 0: line += match.groups()[2] line += match.groups()[3] line += ", " line += match.groups()[1] line += "\n" return line for line in sys.stdin: if line.find("getelementptr ") == line.find("getelementptr inbounds"): if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("): line = conv(re.match(ibrep, line), line) elif line.find("getelementptr ") != line.find("getelementptr ("): line = conv(re.match(normrep, line), line) sys.stdout.write(line) apply.sh: for name in "$@" 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 After that, check-all (with llvm, clang, clang-tools-extra, lld, compiler-rt, and polly all checked out). The extra 'rm' in the apply.sh script is due to a few files in clang's test suite using interesting unicode stuff that my python script was throwing exceptions on. None of those files needed to be migrated, so it seemed sufficient to ignore those cases. Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7636 llvm-svn: 230786
2015-02-28 03:29:02 +08:00
%t.5 = getelementptr i32, i32* %tab, i32 %tmp32
%loada = load i32, i32* %tab
store i32 0, i32* %t.5
%loadb = load i32, i32* %tab
%rval = add i32 %loada, %loadb
ret i32 %rval
}