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path: root/lib/Transforms/InstCombine/InstCombineCompares.cpp
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2011-07-11De-constify Types in FunctionType::get().Jay Foad
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134888 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-04PR10267: Don't combine an equality compare with an AND into an inequality ↵Benjamin Kramer
compare when the AND has more than one use. This can pessimize code, inequalities are generally more expensive. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134379 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-13InstCombine: Fold A-b == C --> b == A-C if A and C are constants.Benjamin Kramer
The backend already knew this trick. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132915 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-12InstCombine: Shrink ((zext X) & C1) == C2 to fold away the cast if the ↵Benjamin Kramer
"zext" and the "and" have one use. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132897 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-12Simplify code. No functionality changes, name changes aside.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132896 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-25PR9998: ashr exact %x, 31 is not equivalent to sdiv exact %x, -2147483648.Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132097 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18More instcombine simplifications towards better debug locations.Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131596 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-14Avoid combining GEPs that might overflow at runtime.Stuart Hastings
rdar://problem/9267970 Patch by Julien Lerouge! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131339 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
2011-04-26Transform: "icmp eq (trunc (lshr(X, cst1)), cst" to "icmp (and X, mask), cst"Chris Lattner
when X has multiple uses. This is useful for exposing secondary optimizations, but the X86 backend isn't ready for this when X has a single use. For example, this can disable load folding. This is inching towards resolving PR6627. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130238 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-26some random cleanups, no functionality change.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130237 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-15Fix a ton of comment typos found by codespell. Patch byChris Lattner
Luis Felipe Strano Moraes! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129558 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31InstCombine: APFloat can't perform arithmetic on PPC double doubles, don't ↵Benjamin Kramer
even try. Thanks Eli! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128676 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31InstCombine: Fix transform to use the swapped predicate.Benjamin Kramer
Thanks Frits! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128628 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31InstCombine: fold fcmp (fneg x), (fneg y) -> fcmp x, yBenjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128627 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31InstCombine: fold fcmp pred (fneg x), C -> fcmp swap(pred) x, -CBenjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128626 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31InstCombine: Shrink "fcmp (fpext x), C" to "fcmp x, C" if C can be ↵Benjamin Kramer
losslessly converted to the type of x. Fixes PR9592. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128625 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31InstCombine: fold fcmp (fpext x), (fpext y) -> fcmp x, y.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128624 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08Reorder comments to put them the right way around.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127220 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-06ConstantInt has some getters which return ConstantInt's or ConstantVector's ofNick Lewycky
the value splatted into every element. Extend this to getTrue and getFalse which by providing new overloads that take Types that are either i1 or <N x i1>. Use it in InstCombine to add vector support to some code, fixing PR8469! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127116 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw wheneverNick Lewycky
possible. This goes into instcombine and instsimplify because instsimplify doesn't need to check hasOneUse since it returns (almost exclusively) constants. This fixes PR9343 #4 #5 and #8! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127064 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05Try once again to optimize "icmp (srem X, Y), Y" by turning the comparison intoNick Lewycky
true/false or "icmp slt/sge Y, 0". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127063 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28srem doesn't actually have the same resulting sign as its numerator, you couldNick Lewycky
also have a zero when numerator = denominator. Reverts parts of r126635 and r126637. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126644 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28Teach InstCombine to fold "(shr exact X, Y) == 0" --> X == 0, fixing #1 fromNick Lewycky
PR9343. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126643 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28The sign of an srem instruction is the sign of its dividend (the firstNick Lewycky
argument), regardless of the divisor. Teach instcombine about this and fix test7 in PR9343! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126635 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18Add some transforms of the kind X-Y>X -> 0>Y which are valid when there is noDuncan Sands
overflow. These subsume some existing equality transforms, so zap those. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125843 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-17Transform "A + B >= A + C" into "B >= C" if the adds do not wrap. Likewise ↵Duncan Sands
for some variations (some of these were already present so I unified the code). Spotted by my auto-simplifier as occurring a lot. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125734 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13remove a now-unneccesary cast.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125464 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13implement instcombine folding for things like (x >> c) < 42.Chris Lattner
We were previously simplifying divisions, but not right shifts! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125454 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13refactor some code out into a helper method.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125451 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-11Also fold (A+B) == A -> B == 0 when the add is commuted.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125411 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10Enhance the "compare with shift" and "compare with div" Chris Lattner
optimizations to be much more aggressive in the face of exact/nsw/nuw div and shifts. For example, these (which are the same except the first is 'exact' sdiv: define i1 @sdiv_icmp4_exact(i64 %X) nounwind { %A = sdiv exact i64 %X, -5 ; X/-5 == 0 --> x == 0 %B = icmp eq i64 %A, 0 ret i1 %B } define i1 @sdiv_icmp4(i64 %X) nounwind { %A = sdiv i64 %X, -5 ; X/-5 == 0 --> x == 0 %B = icmp eq i64 %A, 0 ret i1 %B } compile down to: define i1 @sdiv_icmp4_exact(i64 %X) nounwind { %1 = icmp eq i64 %X, 0 ret i1 %1 } define i1 @sdiv_icmp4(i64 %X) nounwind { %X.off = add i64 %X, 4 %1 = icmp ult i64 %X.off, 9 ret i1 %1 } This happens when you do something like: (ptr1-ptr2) == 42 where the pointers are pointers to non-unit types. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125266 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-30Recognize and simplifyAnders Carlsson
(A+B) == A -> B == 0 A == (A+B) -> B == 0 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124567 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-20At -O123 the early-cse pass is run before instcombine has run. According to myDuncan Sands
auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0. This patch adds this transform and some related logic to InstructionSimplify and removes some of the logic from instcombine (unfortunately not all because there are several situations in which instcombine can improve things by making new instructions, whereas instsimplify is not allowed to do this). At -O2 this often results in more than 15% more simplifications by early-cse, and results in hundreds of lines of bitcode being eliminated from the testsuite. I did see some small negative effects in the testsuite, for example a few additional instructions in three programs. One program, 483.xalancbmk, got an additional 35 instructions, which seems to be due to a function getting an additional instruction and then being inlined all over the place. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123911 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16remove the AllowAggressive argument to FoldOpIntoPhi. It is forced to false ↵Chris Lattner
in the first line of the function because it isn't a good idea, even for compares. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123566 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15fix typoChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123516 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15Catch ~x < cst just like ~x < ~y, we currently handle this throughChris Lattner
means that are about to disappear. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123515 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11Remove dead variable, const-ref-ize an APInt.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123248 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11Fix a random missed optimization by making InstCombine more aggressive when ↵Owen Anderson
determining which bits are demanded by a comparison against a constant. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123203 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19recognize an unsigned add with overflow idiom into uadd.Chris Lattner
This resolves a README entry and technically resolves PR4916, but we still get poor code for the testcase in that PR because GVN isn't CSE'ing uadd with add, filed as PR8817. Previously we got: _test7: ## @test7 addq %rsi, %rdi cmpq %rdi, %rsi movl $42, %eax cmovaq %rsi, %rax ret Now we get: _test7: ## @test7 addq %rsi, %rdi movl $42, %eax cmovbq %rsi, %rax ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122182 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19use IC.ReplaceInstUsesWith instead of a raw RAUW so that uses ofChris Lattner
the old thing end up on the instcombine worklist. Not doing this can cause an extra top-level iteration of instcombine, burning compile time. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122179 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19generalize the sadd creation code to not require that theChris Lattner
sadd formed is half the size of the original type. We can now compile this into a sadd.i8: unsigned char X(char a, char b) { int res = a+b; if ((unsigned )(res+128) > 255U) abort(); return res; } git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122178 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19fix another miscompile in the llvm.sadd formation logic: it wasn't Chris Lattner
checking to see if the high bits of the original add result were dead. Inserting a smaller add and zexting back to that size is not good enough. This is likely to be the fix for 8816. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122177 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19fix a bug (possibly 8816) in the sadd forming xform: it isn'tChris Lattner
profitable (or safe) to promote code when the add-with-constant has other uses. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122175 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19rework the code added in r122072 to pull it out to its ownChris Lattner
helper function, clean up comments, and reduce indentation. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122174 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17Reapply r121905 (automatic synthesis of @llvm.sadd.with.overflow) with a fix ↵Owen Anderson
for a bug that manifested itself on the DragonEgg self-host bot. Unfortunately, the testcase is pretty messy and doesn't reduce well due to interactions with other parts of InstCombine. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122072 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-16Speculatively revert commit 121905 since it looks like it might have broken theDuncan Sands
dragonegg self-host buildbot. Original commit message: Add an InstCombine transform to recognize instances of manual overflow-safe addition (performing the addition in a wider type and explicitly checking for overflow), and fold them down to intrinsics. This currently only supports signed-addition, but could be generalized if someone works out the magic constant formulas for other operations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121965 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15Add an InstCombine transform to recognize instances of manual overflow-safe ↵Owen Anderson
addition (performing the addition in a wider type and explicitly checking for overflow), and fold them down to intrinsics. This currently only supports signed-addition, but could be generalized if someone works out the magic constant formulas for other operations. Fixes <rdar://problem/8558713>. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121905 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() andJay Foad
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method trunc(), to be const and to return a new value instead of modifying the object in place. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121120 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-01PR5207: Rename overloaded APInt methods set(), clear(), flip() toJay Foad
setAllBits(), setBit(unsigned), etc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120564 91177308-0d34-0410-b5e6-96231b3b80d8
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