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* Revert "InstCombine: merge constants in both operands of icmp."Erik Verbruggen2014-03-28
| | | | | | | | | | | This reverts commit r204912, and follow-up commit r204948. This introduced a performance regression, and the fix is not completely clear yet. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205010 91177308-0d34-0410-b5e6-96231b3b80d8
* InstCombine: merge constants in both operands of icmp.Erik Verbruggen2014-03-27
| | | | | | | | | | Transform: icmp X+Cst2, Cst into: icmp X, Cst-Cst2 when Cst-Cst2 does not overflow, and the add has nsw. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204912 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove two popcount patterns which we are already able to recognize.Shuxin Yang2012-12-13
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170158 91177308-0d34-0410-b5e6-96231b3b80d8
* Move TargetData to DataLayout.Micah Villmow2012-10-08
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
* Fabs folding is implemented.Benjamin Kramer2012-08-19
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162186 91177308-0d34-0410-b5e6-96231b3b80d8
* Test revert of test changes.Micah Villmow2012-07-23
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160632 91177308-0d34-0410-b5e6-96231b3b80d8
* Test commit.Micah Villmow2012-07-23
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160631 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a microoptimization note.Benjamin Kramer2012-06-23
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159082 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove README entry obsoleted by register masks.Benjamin Kramer2012-04-12
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154588 91177308-0d34-0410-b5e6-96231b3b80d8
* Add another note about a missed compare with nsw arithmetic instcombine.Benjamin Kramer2012-03-28
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153574 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a note about a cute little fabs optimization.Benjamin Kramer2012-03-27
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153543 91177308-0d34-0410-b5e6-96231b3b80d8
* Add two missed instcombines related to compares with nsw arithmetic.Benjamin Kramer2012-03-27
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153542 91177308-0d34-0410-b5e6-96231b3b80d8
* Add two notes for correlated-expression optimizations.Benjamin Kramer2011-09-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139263 91177308-0d34-0410-b5e6-96231b3b80d8
* Don't emit a bit test if there is only one case the test can yield false. A ↵Benjamin Kramer2011-07-14
| | | | | | simple SETNE is sufficient. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135126 91177308-0d34-0410-b5e6-96231b3b80d8
* InstCombine: Fold A-b == C --> b == A-C if A and C are constants.Benjamin Kramer2011-06-13
| | | | | | The backend already knew this trick. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132915 91177308-0d34-0410-b5e6-96231b3b80d8
* clarify this, apparently it is confusing :)Chris Lattner2011-05-23
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131916 91177308-0d34-0410-b5e6-96231b3b80d8
* add a note.Chris Lattner2011-05-22
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131863 91177308-0d34-0410-b5e6-96231b3b80d8
* move PR9408 here.Chris Lattner2011-05-22
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131841 91177308-0d34-0410-b5e6-96231b3b80d8
* Transform: "icmp eq (trunc (lshr(X, cst1)), cst" to "icmp (and X, mask), cst"Chris Lattner2011-04-26
| | | | | | | | | | | | 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
* add a missed bitfield instcombine.Chris Lattner2011-04-25
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130137 91177308-0d34-0410-b5e6-96231b3b80d8
* DAGCombine: fold "(zext x) == C" into "x == (trunc C)" if the trunc is lossless.Benjamin Kramer2011-04-22
| | | | | | | | | | | | On x86 this allows to fold a load into the cmp, greatly reducing register pressure. movzbl (%rdi), %eax cmpl $47, %eax -> cmpb $47, (%rdi) This shaves 8k off gcc.o on i386. I'll leave applying the patch in README.txt to Chris :) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130005 91177308-0d34-0410-b5e6-96231b3b80d8
* add a minor missed dag combine that is blocking mid-level optimizationChris Lattner2011-04-14
| | | | | | | | improvements, that will lead to fixing PR6627. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129504 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a note.Benjamin Kramer2011-03-25
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128286 91177308-0d34-0410-b5e6-96231b3b80d8
* A bit more analysis of a memset-related README entry.Eli Friedman2011-03-22
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128107 91177308-0d34-0410-b5e6-96231b3b80d8
* This README entry was fixed recently.Eli Friedman2011-03-21
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127982 91177308-0d34-0410-b5e6-96231b3b80d8
* add a noteChris Lattner2011-03-01
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126719 91177308-0d34-0410-b5e6-96231b3b80d8
* Add some DAGCombines for (adde 0, 0, glue), which are useful to optimize ↵Benjamin Kramer2011-02-26
| | | | | | | | | | | legalized code for large integer arithmetic. 1. Inform users of ADDEs with two 0 operands that it never sets carry 2. Fold other ADDs or ADDCs into the ADDE if possible It would be neat if we could do the same thing for SETCC+ADD eventually, but we can't do that in target independent code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126557 91177308-0d34-0410-b5e6-96231b3b80d8
* add a missed loop deletion case.Chris Lattner2011-02-21
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126103 91177308-0d34-0410-b5e6-96231b3b80d8
* add an idiom that loop idiom could theoretically catch.Chris Lattner2011-02-21
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126101 91177308-0d34-0410-b5e6-96231b3b80d8
* This has been implemented.Duncan Sands2011-02-17
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125738 91177308-0d34-0410-b5e6-96231b3b80d8
* add some notes on compares + binops. Remove redundant entries.Chris Lattner2011-02-17
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125702 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a few missed xforms from GCC PR14753Chris Lattner2011-02-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125681 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove outdated README entry.Eli Friedman2011-02-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125660 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove outdated README entry.Eli Friedman2011-02-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125659 91177308-0d34-0410-b5e6-96231b3b80d8
* Update README entry.Eli Friedman2011-02-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125658 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove a virtual inheritance case that clang can devirtualize fully now.Anders Carlsson2011-02-06
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124989 91177308-0d34-0410-b5e6-96231b3b80d8
* SimplifyCFG: Turn switches into sub+icmp+branch if possible.Benjamin Kramer2011-02-02
| | | | | | | | | | | | | | | | | This makes the job of the later optzn passes easier, allowing the vast amount of icmp transforms to chew on it. We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting binary on i386-linux. The testcase from README.txt now compiles into decl %edi cmpl $3, %edi sbbl %eax, %eax andl $1, %eax ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124724 91177308-0d34-0410-b5e6-96231b3b80d8
* add a note, progress unblocked by PR8575 being fixed.Chris Lattner2011-01-31
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124599 91177308-0d34-0410-b5e6-96231b3b80d8
* Teach DAGCombine to fold fold (sra (trunc (sr x, c1)), c2) -> (trunc (sra x, ↵Benjamin Kramer2011-01-30
| | | | | | | | | | | | | | | | | | | c1+c2) when c1 equals the amount of bits that are truncated off. This happens all the time when a smul is promoted to a larger type. On x86-64 we now compile "int test(int x) { return x/10; }" into movslq %edi, %rax imulq $1717986919, %rax, %rax movq %rax, %rcx shrq $63, %rcx sarq $34, %rax <- used to be "shrq $32, %rax; sarl $2, %eax" addl %ecx, %eax This fires 96 times in gcc.c on x86-64. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124559 91177308-0d34-0410-b5e6-96231b3b80d8
* this isn't a memset, we do convert dest[i] to one though :)Chris Lattner2011-01-24
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124097 91177308-0d34-0410-b5e6-96231b3b80d8
* with recent work, we now optimize this into:Chris Lattner2011-01-24
| | | | | | | | | | | | | define i32 @foo(i32 %x) nounwind readnone ssp { entry: %tobool = icmp eq i32 %x, 0 %tmp5 = select i1 %tobool, i32 2, i32 1 ret i32 %tmp5 } git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124091 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a memset loop that LoopIdiomRecognize doesn't recognize.Anders Carlsson2011-01-23
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124082 91177308-0d34-0410-b5e6-96231b3b80d8
* add a noteChris Lattner2011-01-18
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123752 91177308-0d34-0410-b5e6-96231b3b80d8
* Update README.txt to remove the DAE enhancement.Anders Carlsson2011-01-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123597 91177308-0d34-0410-b5e6-96231b3b80d8
* add some commentaryChris Lattner2011-01-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123572 91177308-0d34-0410-b5e6-96231b3b80d8
* Simplify a README.txt entry significantly to expose the core issue.Chandler Carruth2011-01-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123556 91177308-0d34-0410-b5e6-96231b3b80d8
* typoChris Lattner2011-01-13
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123406 91177308-0d34-0410-b5e6-96231b3b80d8
* memcpy + metadata = bliss :)Chris Lattner2011-01-13
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123405 91177308-0d34-0410-b5e6-96231b3b80d8
* Teach constant folding to perform conversions from constant floatingChandler Carruth2011-01-11
| | | | | | | | point values to their integer representation through the SSE intrinsic calls. This is the last part of a README.txt entry for which I have real world examples. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123206 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix a random missed optimization by making InstCombine more aggressive when ↵Owen Anderson2011-01-11
| | | | | | | | | 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
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