summaryrefslogtreecommitdiff
path: root/lib/Transforms/InstCombine/InstCombineShifts.cpp
Commit message (Collapse)AuthorAge
* Revert r174152. The shift amount may overflow and in that case this ↵Nadav Rotem2013-02-01
| | | | | | transformation is illegal. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174156 91177308-0d34-0410-b5e6-96231b3b80d8
* Optimize shift lefts of a constant by a value plus constant into a single shift.Nadav Rotem2013-02-01
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174152 91177308-0d34-0410-b5e6-96231b3b80d8
* Move all of the header files which are involved in modelling the LLVM IRChandler Carruth2013-01-02
| | | | | | | | | | | | | | | | | | | | | into their new header subdirectory: include/llvm/IR. This matches the directory structure of lib, and begins to correct a long standing point of file layout clutter in LLVM. There are still more header files to move here, but I wanted to handle them in separate commits to make tracking what files make sense at each layer easier. The only really questionable files here are the target intrinsic tablegen files. But that's a battle I'd rather not fight today. I've updated both CMake and Makefile build systems (I think, and my tests think, but I may have missed something). I've also re-sorted the includes throughout the project. I'll be committing updates to Clang, DragonEgg, and Polly momentarily. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
* Use m_OneUse pattern instead of hasOneUse() method.Jakub Staszak2012-12-09
| | | | | | | No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169703 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove trailing spaces.Jakub Staszak2012-12-09
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169701 91177308-0d34-0410-b5e6-96231b3b80d8
* Use the new script to sort the includes of every file under lib.Chandler Carruth2012-12-03
| | | | | | | | | | | | | | | | | Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 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
* Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. ↵Sylvestre Ledru2012-09-27
| | | | | | See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164768 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix a typo 'iff' => 'if'Sylvestre Ledru2012-09-27
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164767 91177308-0d34-0410-b5e6-96231b3b80d8
* PR12967: Don't crash when trying to fold a shift that's larger than the ↵Benjamin Kramer2012-05-27
| | | | | | type's size. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157548 91177308-0d34-0410-b5e6-96231b3b80d8
* Reapply r155136 after fixing PR12599.Jakob Stoklund Olesen2012-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Original commit message: Defer some shl transforms to DAGCombine. The shl instruction is used to represent multiplication by a constant power of two as well as bitwise left shifts. Some InstCombine transformations would turn an shl instruction into a bit mask operation, making it difficult for later analysis passes to recognize the constsnt multiplication. Disable those shl transformations, deferring them to DAGCombine time. An 'shl X, C' instruction is now treated mostly the same was as 'mul X, C'. These transformations are deferred: (X >>? C) << C --> X & (-1 << C) (When X >> C has multiple uses) (X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2) (When C2 > C1) (X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2) (When C1 > C2) The corresponding exact transformations are preserved, just like div-exact + mul: (X >>?,exact C) << C --> X (X >>?,exact C1) << C2 --> X << (C2-C1) (X >>?,exact C1) << C2 --> X >>?,exact (C1-C2) The disabled transformations could also prevent the instruction selector from recognizing rotate patterns in hash functions and cryptographic primitives. I have a test case for that, but it is too fragile. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155362 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r155136 "Defer some shl transforms to DAGCombine."Jakob Stoklund Olesen2012-04-20
| | | | | | | | | While the patch was perfect and defect free, it exposed a really nasty bug in X86 SelectionDAG that caused an llc crash when compiling lencod. I'll put the patch back in after fixing the SelectionDAG problem. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155181 91177308-0d34-0410-b5e6-96231b3b80d8
* Defer some shl transforms to DAGCombine.Jakob Stoklund Olesen2012-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The shl instruction is used to represent multiplication by a constant power of two as well as bitwise left shifts. Some InstCombine transformations would turn an shl instruction into a bit mask operation, making it difficult for later analysis passes to recognize the constsnt multiplication. Disable those shl transformations, deferring them to DAGCombine time. An 'shl X, C' instruction is now treated mostly the same was as 'mul X, C'. These transformations are deferred: (X >>? C) << C --> X & (-1 << C) (When X >> C has multiple uses) (X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2) (When C2 > C1) (X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2) (When C1 > C2) The corresponding exact transformations are preserved, just like div-exact + mul: (X >>?,exact C) << C --> X (X >>?,exact C1) << C2 --> X << (C2-C1) (X >>?,exact C1) << C2 --> X >>?,exact (C1-C2) The disabled transformations could also prevent the instruction selector from recognizing rotate patterns in hash functions and cryptographic primitives. I have a test case for that, but it is too fragile. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155136 91177308-0d34-0410-b5e6-96231b3b80d8
* Convert assert(0) to llvm_unreachableCraig Topper2012-02-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149967 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove pointless asserts.Nick Lewycky2012-01-04
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147529 91177308-0d34-0410-b5e6-96231b3b80d8
* Teach instcombine all sorts of great stuff about shifts that have exact, nuw orNick Lewycky2012-01-04
| | | | | | | nsw bits on them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147528 91177308-0d34-0410-b5e6-96231b3b80d8
* Make use of the exact bit when optimizing '(X >>exact 3) << 1' to eliminate theNick Lewycky2011-12-31
| | | | | | | | 'and' that would zero out the trailing bits, and to produce an exact shift ourselves. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147391 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix a few more places where TargetData/TargetLibraryInfo is not being passed.Chad Rosier2011-12-02
| | | | | | Add FIXMEs to places that are non-trivial to fix. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145661 91177308-0d34-0410-b5e6-96231b3b80d8
* Make sure to correctly clear the exact/nuw/nsw flags off of shifts when they ↵Eli Friedman2011-07-29
| | | | | | are combined together. <rdar://problem/9859829> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136435 91177308-0d34-0410-b5e6-96231b3b80d8
* Clean up includes of llvm/Analysis/ConstantFolding.h so it's included where ↵Eli Friedman2011-07-20
| | | | | | it's used and not included where it isn't. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135628 91177308-0d34-0410-b5e6-96231b3b80d8
* land David Blaikie's patch to de-constify Type, with a few tweaks.Chris Lattner2011-07-18
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
* Balance parentheses.Benjamin Kramer2011-04-29
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130489 91177308-0d34-0410-b5e6-96231b3b80d8
* InstCombine: turn (C1 << A) << C2) into (C1 << C2) << A)Benjamin Kramer2011-04-29
| | | | | | Fixes PR9809. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130485 91177308-0d34-0410-b5e6-96231b3b80d8
* Enhance a bunch of transformations in instcombine to start generatingChris Lattner2011-02-10
| | | | | | | | | | | | | exact/nsw/nuw shifts and have instcombine infer them when it can prove that the relevant properties are true for a given shift without them. Also, a variety of refactoring to use the new patternmatch logic thrown in for good luck. I believe that this takes care of a bunch of related code quality issues attached to PR8862. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125267 91177308-0d34-0410-b5e6-96231b3b80d8
* Teach instsimplify some tricks about exact/nuw/nsw shifts.Chris Lattner2011-02-09
| | | | | | | | improve interfaces to instsimplify to take this info. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125196 91177308-0d34-0410-b5e6-96231b3b80d8
* Null initialize a few variables flagged byTed Kremenek2011-01-23
| | | | | | | | | | clang's -Wuninitialized-experimental warning. While these don't look like real bugs, clang's -Wuninitialized-experimental analysis is stricter than GCC's, and these fixes have the benefit of being general nice cleanups. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124073 91177308-0d34-0410-b5e6-96231b3b80d8
* Move some shift transforms out of instcombine and into InstructionSimplify.Duncan Sands2011-01-14
| | | | | | | | | | | | | While there, I noticed that the transform "undef >>a X -> undef" was wrong. For example if X is 2 then the top two bits must be equal, so the result can not be anything. I fixed this in the constant folder as well. Also, I made the transform for "X << undef" stronger: it now folds to undef always, even though X might be zero. This is in accordance with the LangRef, but I must admit that it is fairly aggressive. Also, I added "i32 X << 32 -> undef" following the LangRef and the constant folder, likewise fairly aggressive. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123417 91177308-0d34-0410-b5e6-96231b3b80d8
* When determining if we can fold (x >> C1) << C2, the bits that we need to ↵Owen Anderson2010-12-23
| | | | | | | | | verify are zero are not the low bits of x, but the bits that WILL be the low bits after the operation completes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122529 91177308-0d34-0410-b5e6-96231b3b80d8
* Really check that the bits that will become zero are actually already zeroDan Gohman2010-12-09
| | | | | | | before eliminating the operation that zeros them. This fixes rdar://8739316. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121353 91177308-0d34-0410-b5e6-96231b3b80d8
* The srem -> urem transform is not safe for any divisor that's not a power of ↵Benjamin Kramer2010-11-23
| | | | | | | | | | | two. E.g. -5 % 5 is 0 with srem and 1 with urem. Also addresses Frits van Bommel's comments. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120049 91177308-0d34-0410-b5e6-96231b3b80d8
* InstCombine: Reduce "X shift (A srem B)" to "X shift (A urem B)" iff B is ↵Benjamin Kramer2010-11-23
| | | | | | | | | positive. This allows to transform the rem in "1 << ((int)x % 8);" to an and. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120028 91177308-0d34-0410-b5e6-96231b3b80d8
* When checking that the necessary bits are zero inDale Johannesen2010-11-10
| | | | | | | | | order to reduce ((x<<30)>>24) to x<<6, check the correct bits. PR 8547. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118665 91177308-0d34-0410-b5e6-96231b3b80d8
* When folding away a (shl (shr)) pair, we need to check that the bits that ↵Owen Anderson2010-11-01
| | | | | | | | | will BECOME the low bits are zero, not that the current low bits are zero. Fixes <rdar://problem/8606771>. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117953 91177308-0d34-0410-b5e6-96231b3b80d8
* optimize bitcasts from large integers to vector into vectorChris Lattner2010-08-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | element insertion from the pieces that feed into the vector. This handles a pattern that occurs frequently due to code generated for the x86-64 abi. We now compile something like this: struct S { float A, B, C, D; }; struct S g; struct S bar() { struct S A = g; ++A.A; ++A.C; return A; } into all nice vector operations: _bar: ## @bar ## BB#0: ## %entry movq _g@GOTPCREL(%rip), %rax movss LCPI1_0(%rip), %xmm1 movss (%rax), %xmm0 addss %xmm1, %xmm0 pshufd $16, %xmm0, %xmm0 movss 4(%rax), %xmm2 movss 12(%rax), %xmm3 pshufd $16, %xmm2, %xmm2 unpcklps %xmm2, %xmm0 addss 8(%rax), %xmm1 pshufd $16, %xmm1, %xmm1 pshufd $16, %xmm3, %xmm2 unpcklps %xmm2, %xmm1 ret instead of icky integer operations: _bar: ## @bar movq _g@GOTPCREL(%rip), %rax movss LCPI1_0(%rip), %xmm1 movss (%rax), %xmm0 addss %xmm1, %xmm0 movd %xmm0, %ecx movl 4(%rax), %edx movl 12(%rax), %esi shlq $32, %rdx addq %rcx, %rdx movd %rdx, %xmm0 addss 8(%rax), %xmm1 movd %xmm1, %eax shlq $32, %rsi addq %rax, %rsi movd %rsi, %xmm1 ret This resolves rdar://8360454 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112343 91177308-0d34-0410-b5e6-96231b3b80d8
* Enhance the shift propagator to handle the case when you have:Chris Lattner2010-08-27
| | | | | | | | | | | | | | | | | | A = shl x, 42 ... B = lshr ..., 38 which can be transformed into: A = shl x, 4 ... iff we can prove that the would-be-shifted-in bits are already zero. This eliminates two shifts in the testcase and allows eliminate of the whole i128 chain in the real example. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112314 91177308-0d34-0410-b5e6-96231b3b80d8
* Implement a pretty general logical shift propagationChris Lattner2010-08-27
| | | | | | | | | | | | | framework, which is good at ripping through bitfield operations. This generalize a bunch of the existing xforms that instcombine does, such as (x << c) >> c -> and to handle intermediate logical nodes. This is useful for ripping up the "promote to large integer" code produced by SRoA. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112304 91177308-0d34-0410-b5e6-96231b3b80d8
* remove some special shift cases that have been subsumed into theChris Lattner2010-08-27
| | | | | | | more general simplify demanded bits logic. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112291 91177308-0d34-0410-b5e6-96231b3b80d8
* use ArgOperand APIGabor Greif2010-06-24
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106707 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert 101465, it broke internal OpenGL testing.Eric Christopher2010-04-16
| | | | | | | | Probably the best way to know that all getOperand() calls have been handled is to replace that API instead of updating. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101579 91177308-0d34-0410-b5e6-96231b3b80d8
* reapply r101434Gabor Greif2010-04-16
| | | | | | | | | | | | | | with a fix for self-hosting rotate CallInst operands, i.e. move callee to the back of the operand array the motivation for this patch are laid out in my mail to llvm-commits: more efficient access to operands and callee, faster callgraph-construction, smaller compiler binary git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8
* back out r101423 and r101397, they break llvm-gcc self-host on darwin10Gabor Greif2010-04-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101434 91177308-0d34-0410-b5e6-96231b3b80d8
* reapply r101364, which has been backed out in r101368Gabor Greif2010-04-15
| | | | | | | | | | | | | | with a fix rotate CallInst operands, i.e. move callee to the back of the operand array the motivation for this patch are laid out in my mail to llvm-commits: more efficient access to operands and callee, faster callgraph-construction, smaller compiler binary git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101397 91177308-0d34-0410-b5e6-96231b3b80d8
* back out r101364, as it trips the linux nightlybot on some clang C++ testsGabor Greif2010-04-15
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101368 91177308-0d34-0410-b5e6-96231b3b80d8
* rotate CallInst operands, i.e. move callee to the backGabor Greif2010-04-15
| | | | | | | | | | | of the operand array the motivation for this patch are laid out in my mail to llvm-commits: more efficient access to operands and callee, faster callgraph-construction, smaller compiler binary git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101364 91177308-0d34-0410-b5e6-96231b3b80d8
* fix a potential overflow issue Eli pointed out.Chris Lattner2010-01-23
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94336 91177308-0d34-0410-b5e6-96231b3b80d8
* implement a simple instcombine xform that has been in theChris Lattner2010-01-23
| | | | | | | readme forever. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94318 91177308-0d34-0410-b5e6-96231b3b80d8
* my instcombine transformations to make extension elimination moreChris Lattner2010-01-18
| | | | | | | | | aggressive changed the canonical form from sext(trunc(x)) to ashr(lshr(x)), make sure to transform a couple more things into that canonical form, and catch a case where we missed turning zext/shl/ashr into a single sext. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93787 91177308-0d34-0410-b5e6-96231b3b80d8
* change the preferred canonical form for a sign extension to beChris Lattner2010-01-10
| | | | | | | | | lshr+ashr instead of trunc+sext. We want to avoid type conversions whenever possible, it is easier to codegen expressions without truncates and extensions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93107 91177308-0d34-0410-b5e6-96231b3b80d8
* fix indentation of switch statements, no functionality change.Chris Lattner2010-01-10
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93106 91177308-0d34-0410-b5e6-96231b3b80d8
* teach instcombine to delete sign extending shift pairs (sra(shl X, C), C) whenChris Lattner2010-01-08
| | | | | | | the input is already sign extended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93019 91177308-0d34-0410-b5e6-96231b3b80d8
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-13 03:05:33 +0000