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path: root/lib/Analysis/InstructionSimplify.cpp
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2012-03-21Teach instsimplify to gracefully degrade in the presence of instructionsChandler Carruth
not attched to a basic block or function. There are conservatively correct answers in these cases, and this makes the analysis more useful in contexts where we have a partially formed bit of IR. I don't have any way to test this directly... suggestions welcome here, but I'm not seeing anything sadly. I only found this using a subsequent patch to the inliner which runs instsimplify on partially inlined instructions, and even then only on a quite large program. I never got a reasonable testcase out of it, and anything I do get is likely to be quite fragile due to requiring an interaction of two different passes, and the only result being a segfault if it goes wrong. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153176 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-15Type sizes and fields offsets inside structs are unsigned. This is a highlyDuncan Sands
theoretical fix since it only matters for types with >= 2^63 bits (!) and also only matters if pointers have more than 64 bits, which is not supported anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152831 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-13Generalize the "trunc(ptrtoint(x)) - trunc(ptrtoint(y)) ->Duncan Sands
trunc(ptrtoint(x-y))" optimization introduced by Chandler. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152626 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-13Uniformize the InstructionSimplify interface by ensuring that all routinesDuncan Sands
take a TargetLibraryInfo parameter. Internally, rather than passing TD, TLI and DT parameters around all over the place, introduce a struct for holding them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152623 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-13Fix regression from r151466: an we can't replace uses of an instruction ↵Eli Friedman
reachable from the entry block with uses of an instruction not reachable from the entry block. PR12231. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152595 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-13Address some review comments from Duncan. This moves the iterativeChandler Carruth
offset accumulation to use a boring APInt instead of ConstantExprs. I didn't go all the way to an 'int64_t' because I wanted APInt to handle any magic required to properly wrap the arithmetic when the pointer width is <64 bits. If there is a significant penalty from using APInt here, first off WTF, and secondly let me know and I'll do the math by hand. I've left one layer still operating w/ ConstantExpr because it makes the interface quite a bit simpler, and that one isn't iterative so has much lower cost. I suppose this may potentially speed up some strang compilation situations, but I don't really expect much. It should have no functional impact either way. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152590 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-12Teach instsimplify how to constant fold pointer differences.Chandler Carruth
Typically instcombine has handled this, but pointer differences show up in several contexts where we would like to get constant folding, and cannot afford to run instcombine. Specifically, I'm working on improving the constant folding of arguments used in inline cost analysis with instsimplify. Doing this in instsimplify implies some algorithm changes. We have to handle multiple layers of all-constant GEPs because instsimplify cannot fold them into a single GEP the way instcombine can. Also, we're only interested in all-constant GEPs. The result is that this doesn't really replace the instcombine logic, it's just complimentary and focused on constant folding. Reviewed on IRC by Benjamin Kramer. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152555 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-10As Duncan pointed out, pointers tend not to be in floating point ↵Bill Wendling
format...for now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152499 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-10Make this transformation slightly less agressive and more correct.Bill Wendling
The 'CmpInst::isFalseWhenEqual' function returns 'false' for values other than simply equality. For instance, it returns 'false' for <= or >=. This isn't the correct behavior for this transformation, which is checking for strict equality and non-equality. It was causing the gcc.c-torture/execute/frame-address.c test to fail because it would completely (and incorrectly) optimize a whole function into a 'ret i32 0'. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152497 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-10Refactor some methods to look through bitcasts and GEPs on pointers intoChandler Carruth
a common collection of methods on Value, and share their implementation. We had two variations in two different places already, and I need the third variation for inline cost estimation. Reviewed by Duncan Sands on IRC, but further comments here welcome. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152490 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-26Reinstate the optimization from r151449 with a fix to not turn 'gep %x' intoNick Lewycky
'gep null' when the icmp predicate is unsigned (or is signed without inbounds). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151467 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-26Don't call dominates on unreachable instructions.Rafael Espindola
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151466 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-25Roll these back to r151448 until I figure out how they're breakingNick Lewycky
MultiSource/Applications/lua. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151463 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-25An argument and a local identified object (eg. a noalias call) could turn outNick Lewycky
equal if both are null. In the test, scope type %t and global @y by adding a 'gep' prefix to them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151452 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-25Fix five-letter typo in comment.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151450 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-25Teach instsimplify to be more aggressive when analyzing comparisons of pointersNick Lewycky
by using llvm::isIdentifiedObject. Also teach it to handle GEPs that have the same base pointer and constant operands. Fixes PR11238! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151449 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-24fix PR12075, a regression in a recent transform I added. In unreachable ↵Chris Lattner
code, gep chains can be infinite. Just like "stripPointerCasts", use a set to keep track of visited instructions so we don't recurse infinitely. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151383 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-20fold comparisons of gep'd alloca points with null to false,Chris Lattner
implementing PR12013. We now compile the testcase to: __Z4testv: ## @_Z4testv ## BB#0: ## %_ZN4llvm15SmallVectorImplIiE9push_backERKi.exit pushq %rbx subq $64, %rsp leaq 32(%rsp), %rbx movq %rbx, (%rsp) leaq 64(%rsp), %rax movq %rax, 16(%rsp) movl $1, 32(%rsp) leaq 36(%rsp), %rax movq %rax, 8(%rsp) leaq (%rsp), %rdi callq __Z1gRN4llvm11SmallVectorIiLj8EEE movq (%rsp), %rdi cmpq %rbx, %rdi je LBB0_2 ## BB#1: callq _free LBB0_2: ## %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit addq $64, %rsp popq %rbx ret instead of: __Z4testv: ## @_Z4testv ## BB#0: pushq %rbx subq $64, %rsp xorl %eax, %eax leaq (%rsp), %rbx addq $32, %rbx movq %rbx, (%rsp) movq %rbx, 8(%rsp) leaq 64(%rsp), %rcx movq %rcx, 16(%rsp) je LBB0_2 ## BB#1: movl $1, 32(%rsp) movq %rbx, %rax LBB0_2: ## %_ZN4llvm15SmallVectorImplIiE9push_backERKi.exit addq $4, %rax movq %rax, 8(%rsp) leaq (%rsp), %rdi callq __Z1gRN4llvm11SmallVectorIiLj8EEE movq (%rsp), %rdi cmpq %rbx, %rdi je LBB0_4 ## BB#3: callq _free LBB0_4: ## %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit addq $64, %rsp popq %rbx ret This doesn't shrink clang noticably though. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150944 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-18Fix a rather nasty regression from r150690: LHS != RHS does not imply ↵Eli Friedman
LHS->stripPointerCasts() != RHS->stripPointerCasts(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150863 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16Revert "InstSimplify: Strip pointer casts early."Benjamin Kramer
Turns out this isn't safe, because the code below depends on LHS and RHS having the same type. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150695 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16InstSimplify: Strip pointer casts early.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150694 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16InstSimplify: Ignore pointer casts when constant folding compares between ↵Benjamin Kramer
pointers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150690 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-10Fix PR11948: the result type of an icmp may be a vector of boolean -Duncan Sands
don't assume it is a boolean. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150247 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-07Convert assert(0) to llvm_unreachableCraig Topper
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149967 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-01PatternMatch: Introduce a matcher for instructions with the "exact" bit. Use ↵Benjamin Kramer
it to simplify a few matchers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147403 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-05Add support for vectors of pointers.Nadav Rotem
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145801 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-01Propagate TargetLibraryInfo throughout ConstantFolding.cpp and Chad Rosier
InstructionSimplify.cpp. Other fixups as needed. Part of rdar://10500969 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145559 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-01Make use of "getScalarType()". No functionality change.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145556 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-08Fix code to match comment. Fixes PR11340, a regression from r143209.Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144121 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-04Teach instsimplify to simplify calls to undef.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143719 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-30Reapply commit 143214 with a fix: m_ICmp doesn't match conditionsDuncan Sands
with the given predicate, it matches any condition and returns the predicate - d'oh! Original commit message: The expression icmp eq (select (icmp eq x, 0), 1, x), 0 folds to false. Spotted by my super-optimizer in 186.crafty and 450.soplex. We really need a proper infrastructure for handling generalizations of this kind of thing (which occur a lot), however this case is so simple that I decided to go ahead and implement it directly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143318 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-29Revert r143214; it's breaking a bunch of stuff.Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143265 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-28The expression icmp eq (select (icmp eq x, 0), 1, x), 0 folds to false.Duncan Sands
Spotted by my super-optimizer in 186.crafty and 450.soplex. We really need a proper infrastructure for handling generalizations of this kind of thing (which occur a lot), however this case is so simple that I decided to go ahead and implement it directly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143214 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-28Fold icmp ugt (udiv X, Y), X to false. Spotted by my super-optimizerDuncan Sands
in 186.crafty. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143209 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-27Reapply commit 143028 with a fix: the problem was casting a ConstantExpr MulDuncan Sands
using BinaryOperator (which only works for instructions) when it should have been a cast to OverflowingBinaryOperator (which also works for constants). While there, correct a few other dubious looking uses of BinaryOperator. Thanks to Chad Rosier for the testcase. Original commit message: My super-optimizer noticed that we weren't folding this expression to true: (x *nsw x) sgt 0, where x = (y | 1). This occurs in 464.h264ref. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143125 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-26The maximum power of 2 dividing a power of 2 is itself. This occursDuncan Sands
in 403.gcc and was spotted by my super-optimizer. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143054 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-05InstSimplify: Don't try to replace an extractvalue/insertvalue pair with the ↵Benjamin Kramer
original value if types don't match. Fixes clang selfhost. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139120 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-05Add some simple insertvalue simplifications, for the purpose of cleaningDuncan Sands
up do-nothing exception handling code produced by dragonegg. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139113 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-17Revert r137781; I agree with Duncan's comment that the situation in question ↵Eli Friedman
is clearly impossible given the current structure of the code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137853 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16Extend the undef ^ undef idiom once more. No testcase: I can't figure out ↵Eli Friedman
how to actually trigger the codepath in question at the moment, but it might get exposed in the future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137781 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-04Fix what seems an obvious typo. Patch by Ivan Krasin. ProblemDuncan Sands
reported at http://habrahabr.ru/blogs/compilers/125626/. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136865 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-26Add helper function for getting true/false constants in a uniformDuncan Sands
way for i1 and vector of i1 types. Use these to make some code more self-documenting. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136079 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-25Convert GetElementPtrInst to use ArrayRef.Jay Foad
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135904 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-21Convert ConstantExpr::getGetElementPtr andJay Foad
ConstantExpr::getInBoundsGetElementPtr to use ArrayRef. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135673 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19Convert SimplifyGEPInst to use ArrayRef.Jay Foad
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135482 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19Use ArrayRef in ConstantFoldInstOperands and ConstantFoldCall.Jay Foad
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135477 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18land David Blaikie's patch to de-constify Type, with a few tweaks.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-01Improve constant folding of undef for cmp and select operators.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134223 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-07The comparision "max(x,y)==x" is equivalent to "x>=y". Since the max isDuncan Sands
often expressed as "x >= y ? x : y", there is a good chance we can extract the existing "x >= y" from it and use that as a replacement for "max(x,y)==x". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131049 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-05PR9838: Fix transform introduced in r127064 to not trigger when only one ↵Eli Friedman
side of the icmp is an exact shift. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130954 91177308-0d34-0410-b5e6-96231b3b80d8
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