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path: root/lib/Transforms/Scalar/LoopStrengthReduce.cpp
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2005-08-04* Refactor some code into a new BasedUser::RewriteInstructionToUseNewBaseChris Lattner
method. * Fix a crash on 178.galgel, where we would insert expressions before PHI nodes instead of into the PHI node predecessor blocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22657 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04Fix a case that caused this to crash on 178.galgelChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22653 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04Teach LSR about loop-variant expressions, such as loops like this:Chris Lattner
for (i = 0; i < N; ++i) A[i][foo()] = 0; here we still want to strength reduce the A[i] part, even though foo() is l-v. This also simplifies some of the 'CanReduce' logic. This implements Transforms/LoopStrengthReduce/ops_after_indvar.ll git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22652 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04Remove some more dead code.Nate Begeman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22650 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04Refactor this code substantially with the following improvements:Chris Lattner
1. We only analyze instructions once, guaranteed 2. AnalyzeGetElementPtrUsers has been ripped apart and replaced with something much simpler. The next step is to handle expressions that are not all indvar+loop-invariant values (e.g. handling indvar+loopvariant). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22649 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04refactor some codeChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22643 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04invert to if's to make the logic simplerChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22641 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04When processing outer loops and we find uses of an IV in inner loops, makeChris Lattner
sure to handle the use, just don't recurse into it. This permits us to generate this code for a simple nested loop case: .LBB_foo_0: ; entry stwu r1, -48(r1) stw r29, 44(r1) stw r30, 40(r1) mflr r11 stw r11, 56(r1) lis r2, ha16(L_A$non_lazy_ptr) lwz r30, lo16(L_A$non_lazy_ptr)(r2) li r29, 1 .LBB_foo_1: ; no_exit.0 bl L_bar$stub li r2, 1 or r3, r30, r30 .LBB_foo_2: ; no_exit.1 lfd f0, 8(r3) stfd f0, 0(r3) addi r4, r2, 1 addi r3, r3, 8 cmpwi cr0, r2, 100 or r2, r4, r4 bne .LBB_foo_2 ; no_exit.1 .LBB_foo_3: ; loopexit.1 addi r30, r30, 800 addi r2, r29, 1 cmpwi cr0, r29, 100 or r29, r2, r2 bne .LBB_foo_1 ; no_exit.0 .LBB_foo_4: ; return lwz r11, 56(r1) mtlr r11 lwz r30, 40(r1) lwz r29, 44(r1) lwz r1, 0(r1) blr instead of this: _foo: .LBB_foo_0: ; entry stwu r1, -48(r1) stw r28, 44(r1) ;; uses an extra register. stw r29, 40(r1) stw r30, 36(r1) mflr r11 stw r11, 56(r1) li r30, 1 li r29, 0 or r28, r29, r29 .LBB_foo_1: ; no_exit.0 bl L_bar$stub mulli r2, r28, 800 ;; unstrength-reduced multiply lis r3, ha16(L_A$non_lazy_ptr) ;; loop invariant address computation lwz r3, lo16(L_A$non_lazy_ptr)(r3) add r2, r2, r3 mulli r4, r29, 800 ;; unstrength-reduced multiply addi r3, r3, 8 add r3, r4, r3 li r4, 1 .LBB_foo_2: ; no_exit.1 lfd f0, 0(r3) stfd f0, 0(r2) addi r5, r4, 1 addi r2, r2, 8 ;; multiple stride 8 IV's addi r3, r3, 8 cmpwi cr0, r4, 100 or r4, r5, r5 bne .LBB_foo_2 ; no_exit.1 .LBB_foo_3: ; loopexit.1 addi r28, r28, 1 ;;; Many IV's with stride 1 addi r29, r29, 1 addi r2, r30, 1 cmpwi cr0, r30, 100 or r30, r2, r2 bne .LBB_foo_1 ; no_exit.0 .LBB_foo_4: ; return lwz r11, 56(r1) mtlr r11 lwz r30, 36(r1) lwz r29, 40(r1) lwz r28, 44(r1) lwz r1, 0(r1) blr git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22640 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03Teach loop-reduce to see into nested loops, to pull out immediate valuesChris Lattner
pushed down by SCEV. In a nested loop case, this allows us to emit this: lis r3, ha16(L_A$non_lazy_ptr) lwz r3, lo16(L_A$non_lazy_ptr)(r3) add r2, r2, r3 li r3, 1 .LBB_foo_2: ; no_exit.1 lfd f0, 8(r2) ;; Uses offset of 8 instead of 0 stfd f0, 0(r2) addi r4, r3, 1 addi r2, r2, 8 cmpwi cr0, r3, 100 or r3, r4, r4 bne .LBB_foo_2 ; no_exit.1 instead of this: lis r3, ha16(L_A$non_lazy_ptr) lwz r3, lo16(L_A$non_lazy_ptr)(r3) add r2, r2, r3 addi r3, r3, 8 li r4, 1 .LBB_foo_2: ; no_exit.1 lfd f0, 0(r3) stfd f0, 0(r2) addi r5, r4, 1 addi r2, r2, 8 addi r3, r3, 8 cmpwi cr0, r4, 100 or r4, r5, r5 bne .LBB_foo_2 ; no_exit.1 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22639 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03improve debug outputChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22638 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03Move from Stage 0 to Stage 1.Chris Lattner
Only emit one PHI node for IV uses with identical bases and strides (after moving foldable immediates to the load/store instruction). This implements LoopStrengthReduce/dont_insert_redundant_ops.ll, allowing us to generate this PPC code for test1: or r30, r3, r3 .LBB_test1_1: ; Loop li r2, 0 stw r2, 0(r30) stw r2, 4(r30) bl L_pred$stub addi r30, r30, 8 cmplwi cr0, r3, 0 bne .LBB_test1_1 ; Loop instead of this code: or r30, r3, r3 or r29, r3, r3 .LBB_test1_1: ; Loop li r2, 0 stw r2, 0(r29) stw r2, 4(r30) bl L_pred$stub addi r30, r30, 8 ;; Two iv's with step of 8 addi r29, r29, 8 cmplwi cr0, r3, 0 bne .LBB_test1_1 ; Loop git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22635 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03Rename IVUse to IVUsersOfOneStride, use a struct instead of a pair toChris Lattner
unify some parallel vectors and get field names more descriptive than "first" and "second". This isn't lisp afterall :) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22633 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03Fix a nasty dangling pointer issue. The ScalarEvolution pass would keep aChris Lattner
map from instruction* to SCEVHandles. When we delete instructions, we have to tell it about it. We would run into nasty cases where new instructions were reallocated at old instruction addresses and get the old map values. Bad bad bad :( git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22632 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02Like the comment says, do not insert cast instructions before phi nodesChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22586 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02add a comment, make a check more lenientChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22581 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02Simplify for loop, clear a per-loop map after processing each loopChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22580 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02Add a commentChris Lattner
Make LSR ignore GEP's that have loop variant base values, as we currently cannot codegen them git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22576 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02Fix an iterator invalidation problemChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22575 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30Keep tabs and trailing spaces out.Jeff Cohen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22565 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30Fix VC++ build problems.Jeff Cohen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22564 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30Ack, typoNate Begeman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22560 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30Commit a new LoopStrengthReduce pass that can use scalar evolutions andNate Begeman
target data to decide which loop induction variables to strength reduce and how to do so. This work is mostly by Chris Lattner, with tweaks by me to get it working on some of MultiSource. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22558 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-21Remove trailing whitespaceMisha Brukman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21427 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-06fix a bug where we thought arguments were constants :(Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20506 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-06Fix Regression/Transforms/LoopStrengthReduce/dont_insert_redundant_ops.ll,Chris Lattner
hopefully not breaking too many other things. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20505 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-06implement Transforms/LoopStrengthReduce/invariant_value_first_arg.llChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20501 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-06minor simplifications of the code.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20497 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-05Reformat comments to fix 80 columns.Jeff Cohen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20467 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-05Reuse induction variables created for strength-reduced GEPs by other similar ↵Jeff Cohen
GEPs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20466 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-04Add support for not strength reducing GEPs where the element size is a smallJeff Cohen
power of two. This emphatically includes the zeroeth power of two. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20429 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-01Fixed the following LSR bugs:Jeff Cohen
* Loop invariant code does not dominate the loop header, but rather the end of the loop preheader. * The base for a reduced GEP isn't a constant unless all of its operands (preceding the induction variable) are constant. * Allow induction variable elimination for the simple case after all. Also made changes recommended by Chris for properly deleting instructions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20383 91177308-0d34-0410-b5e6-96231b3b80d8
2005-02-28Fix crash in LSR due to attempt to remove original induction variable. However,Jeff Cohen
for reasons explained in the comments, I also deactivated this code as it needs more thought. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20367 91177308-0d34-0410-b5e6-96231b3b80d8
2005-02-27PHI nodes were incorrectly placed when more than one GEP is reduced in a loop.Jeff Cohen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20360 91177308-0d34-0410-b5e6-96231b3b80d8
2005-02-27First pass at improved Loop Strength Reduction. Still not yet ready for ↵Jeff Cohen
prime time. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20358 91177308-0d34-0410-b5e6-96231b3b80d8
2004-10-18Initial implementation of the strength reduction for GEP instructions inNate Begeman
loops. This optimization is not turned on by default yet, but may be run with the opt tool's -loop-reduce flag. There are many FIXMEs listed in the code that will make it far more applicable to a wide range of code, but you have to start somewhere :) This limited version currently triggers on the following tests in the MultiSource directory: pcompress2: 7 times cfrac: 5 times anagram: 2 times ks: 6 times yacr2: 2 times git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17134 91177308-0d34-0410-b5e6-96231b3b80d8
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