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* [BasicAA] Use PhiValuesAnalysis if available when handling phi aliasJohn Brawn2018-07-301-2/+38
| | | | | | | | | | | | | | | | By using PhiValuesAnalysis we can get all the values reachable from a phi, so we can be more precise instead of giving up when a phi has phi operands. We can't make BaseicAA directly use PhiValuesAnalysis though, as the user of BasicAA may modify the function in ways that PhiValuesAnalysis can't cope with. For this optional usage to work correctly BasicAAWrapperPass now needs to be not marked as CFG-only (i.e. it is now invalidated even when CFG is preserved) due to how the legacy pass manager handles dependent passes being invalidated, namely the depending pass still has a pointer to the now-dead dependent pass. Differential Revision: https://reviews.llvm.org/D44564 llvm-svn: 338242
* [PM/AA] Port alias analysis evaluator to the new pass manager, and useChandler Carruth2016-02-201-0/+1
| | | | | | | | | | | | | | | | it to actually test the new pass manager AA wiring. This patch was extracted from the (somewhat too large) D12357 and rebosed on top of the slightly different design of the new pass manager AA wiring that I just landed. With this we can start testing the AA in a thorough way with the new pass manager. Some minor cleanups to the code in the pass was necessitated here, but otherwise it is a very minimal change. Differential Revision: http://reviews.llvm.org/D17372 llvm-svn: 261403
* [BasicAA] Fix the handling of sext and zext in the analysis of GEPs.Quentin Colombet2015-08-311-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hopefully this will end the GEPs saga! This commit reverts r245394, i.e., it reapplies r221876 while incorporating the fixes from D11847. r221876 was not reapplied alone because it was not safe and D11847 was not applied alone because it needs r221876 to produce correct results. This should fix PR24596. Original commit message for r221876: Let's try this again... This reverts r219432, plus a bug fix. Description of the bug in r219432 (by Nick): The bug was using AllPositive to break out of the loop; if the loop break condition i != e is changed to i != e && AllPositive then the test_modulo_analysis_with_global test I've added will fail as the Modulo will be calculated incorrectly (as the last loop iteration is skipped, so Modulo isn't updated with its Scale). Nick also adds this comment: ComputeSignBit is safe to use in loops as it takes into account phi nodes, and the == EK_ZeroEx check is safe in loops as, no matter how the variable changes between iterations, zero-extensions will always guarantee a zero sign bit. The isValueEqualInPotentialCycles check is therefore definitely not needed as all the variable analysis holds no matter how the variables change between loop iterations. And this patch also adds another enhancement to GetLinearExpression - basically to convert ConstantInts to Offsets (see test_const_eval and test_const_eval_scaled for the situations this improves). Original commit message: This reverts r218944, which reverted r218714, plus a bug fix. Description of the bug in r218714 (by Nick): The original patch forgot to check if the Scale in VariableGEPIndex flipped the sign of the variable. The BasicAA pass iterates over the instructions in the order they appear in the function, and so BasicAliasAnalysis::aliasGEP is called with the variable it first comes across as parameter GEP1. Adding a %reorder label puts the definition of %a after %b so aliasGEP is called with %b as the first parameter and %a as the second. aliasGEP later calculates that %a == %b + 1 - %idxprom where %idxprom >= 0 (if %a was passed as the first parameter it would calculate %b == %a - 1 + %idxprom where %idxprom >= 0) - ignoring that %idxprom is scaled by -1 here lead the patch to incorrectly conclude that %a > %b. Revised patch by Nick White, thanks! Thanks to Lang to isolating the bug. Slightly modified by me to add an early exit from the loop and avoid unnecessary, but expensive, function calls. Original commit message: Two related things: 1. Fixes a bug when calculating the offset in GetLinearExpression. The code previously used zext to extend the offset, so negative offsets were converted to large positive ones. 2. Enhance aliasGEP to deduce that, if the difference between two GEP allocations is positive and all the variables that govern the offset are also positive (i.e. the offset is strictly after the higher base pointer), then locations that fit in the gap between the two base pointers are NoAlias. Patch by Nick White! Message from D11847: Un-revert of r241981 and fix for PR23626. The 'Or' case of GetLinearExpression delegates to 'Add' if possible, and if not it returns an Opaque value. Unfortunately the Scale and Offsets weren't being set (and so defaulted to 0) - and a scale of zero effectively removes the variable from the GEP instruction. This meant that BasicAA would return MustAliases when it should have been returning PartialAliases (and PR23626 was an example of the GVN pass using an incorrect MustAlias to merge loads from what should have been different pointers). Differential Revision: http://reviews.llvm.org/D11847 Patch by Nick White <n.j.white@gmail.com>! llvm-svn: 246502
* [BasicAA] Revert r221876 because it can produce incorrect aliasingQuentin Colombet2015-08-191-1/+0
| | | | | | information: see PR24468. llvm-svn: 245394
* [opaque pointer type] Add textual IR support for explicit type parameter to ↵David Blaikie2015-02-271-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
* [opaque pointer type] Add textual IR support for explicit type parameter to ↵David Blaikie2015-02-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Revert r219432 - "Revert "[BasicAA] Revert "Revert r218714 - Make better use ↵Hal Finkel2014-11-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | of zext and sign information.""" Let's try this again... This reverts r219432, plus a bug fix. Description of the bug in r219432 (by Nick): The bug was using AllPositive to break out of the loop; if the loop break condition i != e is changed to i != e && AllPositive then the test_modulo_analysis_with_global test I've added will fail as the Modulo will be calculated incorrectly (as the last loop iteration is skipped, so Modulo isn't updated with its Scale). Nick also adds this comment: ComputeSignBit is safe to use in loops as it takes into account phi nodes, and the == EK_ZeroEx check is safe in loops as, no matter how the variable changes between iterations, zero-extensions will always guarantee a zero sign bit. The isValueEqualInPotentialCycles check is therefore definitely not needed as all the variable analysis holds no matter how the variables change between loop iterations. And this patch also adds another enhancement to GetLinearExpression - basically to convert ConstantInts to Offsets (see test_const_eval and test_const_eval_scaled for the situations this improves). Original commit message: This reverts r218944, which reverted r218714, plus a bug fix. Description of the bug in r218714 (by Nick): The original patch forgot to check if the Scale in VariableGEPIndex flipped the sign of the variable. The BasicAA pass iterates over the instructions in the order they appear in the function, and so BasicAliasAnalysis::aliasGEP is called with the variable it first comes across as parameter GEP1. Adding a %reorder label puts the definition of %a after %b so aliasGEP is called with %b as the first parameter and %a as the second. aliasGEP later calculates that %a == %b + 1 - %idxprom where %idxprom >= 0 (if %a was passed as the first parameter it would calculate %b == %a - 1 + %idxprom where %idxprom >= 0) - ignoring that %idxprom is scaled by -1 here lead the patch to incorrectly conclude that %a > %b. Revised patch by Nick White, thanks! Thanks to Lang to isolating the bug. Slightly modified by me to add an early exit from the loop and avoid unnecessary, but expensive, function calls. Original commit message: Two related things: 1. Fixes a bug when calculating the offset in GetLinearExpression. The code previously used zext to extend the offset, so negative offsets were converted to large positive ones. 2. Enhance aliasGEP to deduce that, if the difference between two GEP allocations is positive and all the variables that govern the offset are also positive (i.e. the offset is strictly after the higher base pointer), then locations that fit in the gap between the two base pointers are NoAlias. Patch by Nick White! llvm-svn: 221876
* Revert "[BasicAA] Revert "Revert r218714 - Make better use of zext and sign ↵Hal Finkel2014-10-091-1/+0
| | | | | | | | information."" This reverts commit r219135 -- still causing miscompiles in SPEC it seems... llvm-svn: 219432
* [BasicAA] Revert "Revert r218714 - Make better use of zext and sign ↵Hal Finkel2014-10-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | information." This reverts r218944, which reverted r218714, plus a bug fix. Description of the bug in r218714 (by Nick) The original patch forgot to check if the Scale in VariableGEPIndex flipped the sign of the variable. The BasicAA pass iterates over the instructions in the order they appear in the function, and so BasicAliasAnalysis::aliasGEP is called with the variable it first comes across as parameter GEP1. Adding a %reorder label puts the definition of %a after %b so aliasGEP is called with %b as the first parameter and %a as the second. aliasGEP later calculates that %a == %b + 1 - %idxprom where %idxprom >= 0 (if %a was passed as the first parameter it would calculate %b == %a - 1 + %idxprom where %idxprom >= 0) - ignoring that %idxprom is scaled by -1 here lead the patch to incorrectly conclude that %a > %b. Revised patch by Nick White, thanks! Thanks to Lang to isolating the bug. Slightly modified by me to add an early exit from the loop and avoid unnecessary, but expensive, function calls. Original commit message: Two related things: 1. Fixes a bug when calculating the offset in GetLinearExpression. The code previously used zext to extend the offset, so negative offsets were converted to large positive ones. 2. Enhance aliasGEP to deduce that, if the difference between two GEP allocations is positive and all the variables that govern the offset are also positive (i.e. the offset is strictly after the higher base pointer), then locations that fit in the gap between the two base pointers are NoAlias. Patch by Nick White! llvm-svn: 219135
* [BasicAA] Revert r218714 - Make better use of zext and sign information.Lang Hames2014-10-031-1/+0
| | | | | | | | | This patch broke 447.dealII on Darwin. I'm currently working on a reduced test-case, but reverting for now to keep the bots happy. <rdar://problem/18530107> llvm-svn: 218944
* [BasicAA] Make better use of zext and sign informationHal Finkel2014-09-301-0/+1
| | | | | | | | | | | | | | | | | Two related things: 1. Fixes a bug when calculating the offset in GetLinearExpression. The code previously used zext to extend the offset, so negative offsets were converted to large positive ones. 2. Enhance aliasGEP to deduce that, if the difference between two GEP allocations is positive and all the variables that govern the offset are also positive (i.e. the offset is strictly after the higher base pointer), then locations that fit in the gap between the two base pointers are NoAlias. Patch by Nick White! llvm-svn: 218714
* BasicAA: Use reachabilty instead of dominance for checking value equality in phiArnold Schwaighofer2014-01-031-7/+0
| | | | | | | | | | | | | | | | | | | | | cycles This allows the value equality check to work even if we don't have a dominator tree. Also add some more comments. I was worried about compile time impacts and did not implement reachability but used the dominance check in the initial patch. The trade-off was that the dominator tree was required. The llvm utility function isPotentiallyReachable cuts off the recursive search after 32 visits. Testing did not show any compile time regressions showing my worries unjustfied. No compile time or performance regressions at O3 -flto -mavx on test-suite + externals. Addresses review comments from r198290. llvm-svn: 198400
* BasicAA: Fix value equality and phi cyclesArnold Schwaighofer2014-01-021-0/+54
| | | | | | | | | | | | | | | | | | | | | | | | | When there are cycles in the value graph we have to be careful interpreting "Value*" identity as "value" equivalence. We interpret the value of a phi node as the value of its operands. When we check for value equivalence now we make sure that the "Value*" dominates all cycles (phis). %0 = phi [%noaliasval, %addr2] %l = load %ptr %addr1 = gep @a, 0, %l %addr2 = gep @a, 0, (%l + 1) store %ptr ... Before this patch we would return NoAlias for (%0, %addr1) which is wrong because the value of the load is from different iterations of the loop. Tested on x86_64 -mavx at O3 and O3 -flto with no performance or compile time regressions. PR18068 radar://15653794 llvm-svn: 198290
* Convert the uses of '|&' to use '2>&1 |' instead, which works on oldChandler Carruth2012-07-021-1/+1
| | | | | | | | | | versions of Bash. In addition, I can back out the change to the lit built-in shell test runner to support this. This should fix the majority of fallout on Darwin, but I suspect there will be a few straggling issues. llvm-svn: 159544
* FileCheck-ize these tests. Harden some of them.Bill Wendling2012-04-241-1/+3
| | | | llvm-svn: 155432
* Delete unneeded ssp attributes.Dan Gohman2010-11-111-1/+1
| | | | llvm-svn: 118836
* Replace test with a simpler hand crafted one.Evan Cheng2009-10-141-76/+19
| | | | llvm-svn: 84069
* Teach basic AA about PHI nodes. If all operands of a phi NoAlias another ↵Evan Cheng2009-10-131-0/+86
value than it's safe to declare the PHI NoAlias the value. Ditto for MustAlias. llvm-svn: 84038
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