wangtao
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
64,676 Commits 29 Branches 0 Tags 2.2 GiB
Commit Graph

329 Commits

Author SHA1 Message Date
Chris Lattner 6510749050 invert to if's to make the logic simpler 
llvm-svn: 22641
 2005-08-04 00:40:47 +00:00
Chris Lattner a0102fbc4f When processing outer loops and we find uses of an IV in inner loops, make 
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

llvm-svn: 22640
 2005-08-04 00:14:11 +00:00
Chris Lattner fc62470466 Teach loop-reduce to see into nested loops, to pull out immediate values 
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

llvm-svn: 22639
 2005-08-03 23:44:42 +00:00
Chris Lattner bb78c97e24 improve debug output 
llvm-svn: 22638
 2005-08-03 23:30:08 +00:00
Chris Lattner db23c74e5e Move from Stage 0 to Stage 1. 
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

llvm-svn: 22635
 2005-08-03 22:51:21 +00:00
Chris Lattner 430d0022df Rename IVUse to IVUsersOfOneStride, use a struct instead of a pair to 
unify some parallel vectors and get field names more descriptive than
"first" and "second".  This isn't lisp afterall :)

llvm-svn: 22633
 2005-08-03 22:21:05 +00:00
Chris Lattner 84e9baa925 Fix a nasty dangling pointer issue. The ScalarEvolution pass would keep a 
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 :(

llvm-svn: 22632
 2005-08-03 21:36:09 +00:00
Chris Lattner 351b891cbc Like the comment says, do not insert cast instructions before phi nodes 
llvm-svn: 22586
 2005-08-02 03:31:14 +00:00
Chris Lattner 75a44e154e add a comment, make a check more lenient 
llvm-svn: 22581
 2005-08-02 02:52:02 +00:00
Chris Lattner dcce49e006 Simplify for loop, clear a per-loop map after processing each loop 
llvm-svn: 22580
 2005-08-02 02:44:31 +00:00
Chris Lattner 9ef1294210 Add a comment 
Make LSR ignore GEP's that have loop variant base values, as we currently
cannot codegen them

llvm-svn: 22576
 2005-08-02 01:32:29 +00:00
Chris Lattner 564900e5e5 Fix an iterator invalidation problem 
llvm-svn: 22575
 2005-08-02 00:41:11 +00:00
Jeff Cohen 546fd5944e Keep tabs and trailing spaces out. 
llvm-svn: 22565
 2005-07-30 18:33:25 +00:00
Jeff Cohen c500991055 Fix VC++ build problems. 
llvm-svn: 22564
 2005-07-30 18:22:27 +00:00
Nate Begeman 17a0e2afea Ack, typo 
llvm-svn: 22560
 2005-07-30 00:21:31 +00:00
Nate Begeman e68bcd1946 Commit a new LoopStrengthReduce pass that can use scalar evolutions and 
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.

llvm-svn: 22558
 2005-07-30 00:15:07 +00:00
Misha Brukman b1c9317bb4 Remove trailing whitespace 
llvm-svn: 21427
 2005-04-21 23:48:37 +00:00
Chris Lattner 8c79559443 fix a bug where we thought arguments were constants :( 
llvm-svn: 20506
 2005-03-06 22:52:29 +00:00
Chris Lattner 2ce303b406 Fix Regression/Transforms/LoopStrengthReduce/dont_insert_redundant_ops.ll, 
hopefully not breaking too many other things.

llvm-svn: 20505
 2005-03-06 22:36:12 +00:00
Chris Lattner 45403e5052 implement Transforms/LoopStrengthReduce/invariant_value_first_arg.ll 
llvm-svn: 20501
 2005-03-06 22:06:22 +00:00
Chris Lattner d3874fad44 minor simplifications of the code. 
llvm-svn: 20497
 2005-03-06 21:58:22 +00:00
Jeff Cohen 4abcea3a69 Reformat comments to fix 80 columns. 
llvm-svn: 20467
 2005-03-05 22:45:40 +00:00
Jeff Cohen be37fa07fd Reuse induction variables created for strength-reduced GEPs by other similar GEPs. 
llvm-svn: 20466
 2005-03-05 22:40:34 +00:00
Jeff Cohen a2c59b7423 Add support for not strength reducing GEPs where the element size is a small 
power of two.  This emphatically includes the zeroeth power of two.

llvm-svn: 20429
 2005-03-04 04:04:26 +00:00
Jeff Cohen 8ea6f9e821 Fixed the following LSR bugs: 
* 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.

llvm-svn: 20383
 2005-03-01 03:46:11 +00:00
Jeff Cohen dcaa48b5c4 Fix crash in LSR due to attempt to remove original induction variable. However, 
for reasons explained in the comments, I also deactivated this code as it needs
more thought.

llvm-svn: 20367
 2005-02-28 00:08:56 +00:00
Jeff Cohen fd63d3af0d PHI nodes were incorrectly placed when more than one GEP is reduced in a loop. 
llvm-svn: 20360
 2005-02-27 21:08:04 +00:00
Jeff Cohen 39751c3b7c First pass at improved Loop Strength Reduction. Still not yet ready for prime time. 
llvm-svn: 20358
 2005-02-27 19:37:07 +00:00
Nate Begeman b18121e6a9 Initial implementation of the strength reduction for GEP instructions in 
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

llvm-svn: 17134
 2004-10-18 21:08:22 +00:00