Commit Graph

4695 Commits

Author SHA1 Message Date
Chris Lattner 2c2dd15a85 Introduce a new array_pod_sort function and switch LSR to use it
instead of std::sort.  This shrinks the release-asserts LSR.o file
by 1100 bytes of code on my system.

We should start using array_pod_sort where possible.

llvm-svn: 60335
2008-12-01 06:49:59 +00:00
Chris Lattner 2aebea5735 Eliminate use of setvector for the DeadInsts set, just use a smallvector.
This is a lot cheaper and conceptually simpler.

llvm-svn: 60332
2008-12-01 06:27:41 +00:00
Chris Lattner 4da78e3774 DeleteTriviallyDeadInstructions is always passed the
DeadInsts ivar, just use it directly.

llvm-svn: 60330
2008-12-01 06:14:28 +00:00
Chris Lattner a68a5a4784 simplify DeleteTriviallyDeadInstructions again, unlike my previous
buggy rewrite, this notifies ScalarEvolution of a pending instruction
about to be removed and then erases it, instead of erasing it then 
notifying.

llvm-svn: 60329
2008-12-01 06:11:32 +00:00
Chris Lattner 9e6b243428 simplify these patterns using m_Specific. No need to grep for
xor in testcase (or is a substring).

llvm-svn: 60328
2008-12-01 05:16:26 +00:00
Chris Lattner 88a1f0213d Teach jump threading to clean up after itself, DCE and constfolding the
new instructions it simplifies.  Because we're threading jumps on edges
with constants coming in from PHI's, we inherently are exposing a lot more
constants to the new block.  Folding them and deleting dead conditions
allows the cost model in jump threading to be more accurate as it iterates.

llvm-svn: 60327
2008-12-01 04:48:07 +00:00
Chris Lattner 084b3a47d3 Change instcombine to use FoldPHIArgGEPIntoPHI to fold two operand PHIs
instead of using FoldPHIArgBinOpIntoPHI.  In addition to being more
obvious, this also fixes a problem where instcombine wouldn't merge two
phis that had different variable indices.  This prevented instcombine
from factoring big chunks of code in 403.gcc.  For example:

 insn_cuid.exit:                
-       %tmp336 = load i32** @uid_cuid, align 4      
-       %tmp337 = getelementptr %struct.rtx_def* %insn_addr.0.ph.i, i32 0, i32 3    
-       %tmp338 = bitcast [1 x %struct.rtunion]* %tmp337 to i32*               
-       %tmp339 = load i32* %tmp338, align 4           
-       %tmp340 = getelementptr i32* %tmp336, i32 %tmp339     
        br label %bb62
 
 bb61:       
-       %tmp341 = load i32** @uid_cuid, align 4     
-       %tmp342 = getelementptr %struct.rtx_def* %insn, i32 0, i32 3        
-       %tmp343 = bitcast [1 x %struct.rtunion]* %tmp342 to i32*           
-       %tmp344 = load i32* %tmp343, align 4        
-       %tmp345 = getelementptr i32* %tmp341, i32 %tmp344          
        br label %bb62
 
 bb62:      
-       %iftmp.62.0.in = phi i32* [ %tmp345, %bb61 ], [ %tmp340, %insn_cuid.exit ]         
+       %insn.pn2 = phi %struct.rtx_def* [ %insn, %bb61 ], [ %insn_addr.0.ph.i, %insn_cuid.exit ]         
+       %tmp344.pn.in.in = getelementptr %struct.rtx_def* %insn.pn2, i32 0, i32 3     
+       %tmp344.pn.in = bitcast [1 x %struct.rtunion]* %tmp344.pn.in.in to i32*  
+       %tmp341.pn = load i32** @uid_cuid     
+       %tmp344.pn = load i32* %tmp344.pn.in 
+       %iftmp.62.0.in = getelementptr i32* %tmp341.pn, i32 %tmp344.pn   
        %iftmp.62.0 = load i32* %iftmp.62.0.in     

llvm-svn: 60325
2008-12-01 03:42:51 +00:00
Chris Lattner 9d02a70a7d Teach inst combine to merge GEPs through PHIs. This is really
important because it is sinking the loads using the GEPs, but
not the GEPs themselves.  This triggers 647 times on 403.gcc
and makes the .s file much much nicer.  For example before:

        je      LBB1_87 ## bb78
LBB1_62:        ## bb77
        leal    84(%esi), %eax
LBB1_63:        ## bb79
        movl    (%eax), %eax
...
LBB1_87:        ## bb78
        movl    $0, 4(%esp)
        movl    %esi, (%esp)
        call    L_make_decl_rtl$stub
        jmp     LBB1_62 ## bb77


after:

        jne     LBB1_63 ## bb79
LBB1_62:        ## bb78
        movl    $0, 4(%esp)
        movl    %esi, (%esp)
        call    L_make_decl_rtl$stub
LBB1_63:        ## bb79
        movl    84(%esi), %eax

The input code was (and the GEPs are merged and
the PHI is now eliminated by instcombine):

        br i1 %tmp233, label %bb78, label %bb77
bb77:           
        %tmp234 = getelementptr %struct.tree_node* %t_addr.3, i32 0, i32 0, i32 22              
        br label %bb79
bb78:           
        call void @make_decl_rtl(%struct.tree_node* %t_addr.3, i8* null) nounwind
        %tmp235 = getelementptr %struct.tree_node* %t_addr.3, i32 0, i32 0, i32 22              
        br label %bb79
bb79:           
        %iftmp.12.0.in = phi %struct.rtx_def** [ %tmp235, %bb78 ], [ %tmp234, %bb77 ]           
        %iftmp.12.0 = load %struct.rtx_def** %iftmp.12.0.in             

llvm-svn: 60322
2008-12-01 02:34:36 +00:00
Chris Lattner 9ce8995d24 Make GVN be more intelligent about redundant load
elimination: when finding dependent load/stores, realize that
they are the same if aliasing claims must alias instead of relying
on the pointers to be exactly equal.  This makes load elimination
more aggressive.  For example, on 403.gcc, we had:

<     68 gvn    - Number of instructions PRE'd
< 152718 gvn    - Number of instructions deleted
<  49699 gvn    - Number of loads deleted
<   6153 memdep - Number of dirty cached non-local responses
< 169336 memdep - Number of fully cached non-local responses
< 162428 memdep - Number of uncached non-local responses

now we have:

>     64 gvn    - Number of instructions PRE'd
> 153623 gvn    - Number of instructions deleted
>  49856 gvn    - Number of loads deleted
>   5022 memdep - Number of dirty cached non-local responses
> 159030 memdep - Number of fully cached non-local responses
> 162443 memdep - Number of uncached non-local responses

That's an extra 157 loads deleted and extra 905 other instructions nuked.

This slows down GVN very slightly, from 3.91 to 3.96s.

llvm-svn: 60314
2008-12-01 01:31:36 +00:00
Chris Lattner 7e61dafc95 Reimplement the non-local dependency data structure in terms of a sorted
vector instead of a densemap.  This shrinks the memory usage of this thing
substantially (the high water mark) as well as making operations like
scanning it faster.  This speeds up memdep slightly, gvn goes from
3.9376 to 3.9118s on 403.gcc

This also splits out the statistics for the cached non-local case to
differentiate between the dirty and clean cached case.  Here's the stats
for 403.gcc:

  6153 memdep - Number of dirty cached non-local responses
169336 memdep - Number of fully cached non-local responses
162428 memdep - Number of uncached non-local responses

yay for caching :)

llvm-svn: 60313
2008-12-01 01:15:42 +00:00
Bill Wendling 5b902c5b1e Implement ((A|B)&1)|(B&-2) -> (A&1) | B transformation. This also takes care of
permutations of this pattern.

llvm-svn: 60312
2008-12-01 01:07:11 +00:00
Chris Lattner 8541edec44 Cache analyses in ivars and add some useful DEBUG output.
This speeds up GVN from 4.0386s to 3.9376s.

llvm-svn: 60310
2008-12-01 00:40:32 +00:00
Chris Lattner 80c7d81e81 improve indentation, do cheap checks before expensive ones,
remove some fixme's.  This speeds up GVN very slightly on 403.gcc 
(4.06->4.03s)

llvm-svn: 60309
2008-11-30 23:39:23 +00:00
Eli Friedman 11c15a5de7 Minor cleanup: use getTrue and getFalse where appropriate. No
functional change.

llvm-svn: 60307
2008-11-30 22:48:49 +00:00
Eli Friedman 55e4becba9 Some minor cleanups to instcombine; no functionality change.
Note that the FoldOpIntoPhi call is dead because it's impossible for the 
first operand of a subtraction to be both a ConstantInt and a PHINode.

llvm-svn: 60306
2008-11-30 21:09:11 +00:00
Bill Wendling de89bc275c Add instruction combining for ((A&~B)|(~A&B)) -> A^B and all permutations.
llvm-svn: 60291
2008-11-30 13:52:49 +00:00
Bill Wendling 9eef421e12 Implement (A&((~A)|B)) -> A&B transformation in the instruction combiner. This
takes care of all permutations of this pattern.

llvm-svn: 60290
2008-11-30 13:08:13 +00:00
Bill Wendling 2fe3229824 Forgot one remaining call to getSExtValue().
llvm-svn: 60289
2008-11-30 12:41:09 +00:00
Bill Wendling 2d2e7861b5 getSExtValue() doesn't work for ConstantInts with bitwidth > 64 bits. Use all
APInt calls instead.

This fixes PR3144.

llvm-svn: 60288
2008-11-30 12:38:24 +00:00
Eli Friedman 09bc610945 Optimize memmove and memset into the LLVM builtins. Note that these
only show up in code from front-ends besides llvm-gcc, like clang.

llvm-svn: 60287
2008-11-30 08:32:11 +00:00
Bill Wendling 7abf352f44 Don't make TwoToExp signed by default.
llvm-svn: 60279
2008-11-30 05:29:33 +00:00
Bill Wendling af200e9237 From Hacker's Delight:
"For signed integers, the determination of overflow of x*y is not so simple. If
x and y have the same sign, then overflow occurs iff xy > 2**31 - 1. If they
have opposite signs, then overflow occurs iff xy < -2**31."

In this case, x == -1.

llvm-svn: 60278
2008-11-30 05:01:05 +00:00
Bill Wendling 70635adea3 Instcombine was illegally transforming -X/C into X/-C when either X or C
overflowed on negation. This commit checks to make sure that neithe C nor X
overflows. This requires that the RHS of X (a subtract instruction) be a
constant integer.

llvm-svn: 60275
2008-11-30 03:42:12 +00:00
Chris Lattner 3ff6d01586 Fix a fixme by making memdep's handling of allocations more logical.
If we see that a load depends on the allocation of its memory with no
intervening stores, we now return a 'None' depedency instead of "Normal".
This tweaks GVN to do its optimization with the new result.

llvm-svn: 60267
2008-11-30 01:39:32 +00:00
Chris Lattner 63bd586d35 Eliminate the dropInstruction method, which is not needed any more.
Fix a subtle iterator invalidation bug I introduced in the last commit.

llvm-svn: 60258
2008-11-29 23:30:39 +00:00
Chris Lattner 1c6b62eb4d Change MemDep::getNonLocalDependency to return its results as
a smallvector instead of a DenseMap.  This speeds up GVN by 5%
on 403.gcc.

llvm-svn: 60255
2008-11-29 21:33:22 +00:00
Chris Lattner f280b0c729 reimplement getNonLocalDependency with a simpler worklist
formulation that is faster and doesn't require nonLazyHelper.
Much less code.

llvm-svn: 60253
2008-11-29 21:22:42 +00:00
Chris Lattner 8c5ff516c6 Fix a thinko that manifested as a crash on clamav last night.
llvm-svn: 60251
2008-11-29 20:29:04 +00:00
Chris Lattner 51ba8d0630 Split getDependency into getDependency and getDependencyFrom, the
former does caching, the later doesn't.  This dramatically simplifies
the logic in getDependency and getDependencyFrom.

llvm-svn: 60234
2008-11-29 03:47:00 +00:00
Bill Wendling 469e3aa696 Temporarily revert r60195. It's causing an optimized bootstrap of llvm-gcc to fail.
llvm-svn: 60233
2008-11-29 03:43:04 +00:00
Chris Lattner 7f9c8a0f05 Introduce and use a new MemDepResult class to hold the results of a memdep
query.  This makes it crystal clear what cases can escape from MemDep that
the clients have to handle.  This also gives the clients a nice simplified
interface to it that is easy to poke at.

This patch also makes DepResultTy and MemoryDependenceAnalysis::DepType
private, yay.

llvm-svn: 60231
2008-11-29 02:29:27 +00:00
Chris Lattner de04e1173a Reimplement the internal abstraction used by MemDep in terms
of a pointer/int pair instead of a manually bitmangled pointer.
This forces clients to think a little more about checking the 
appropriate pieces and will be useful for internal 
implementation improvements later.

I'm not particularly happy with this.  After going through this
I don't think that the clients of memdep should be exposed to
the internal type at all.  I'll fix this in a subsequent commit.

This has no functionality change.

llvm-svn: 60230
2008-11-29 01:43:36 +00:00
Chris Lattner f3f6a801cc don't revisit instructions off the beginning of the block.
llvm-svn: 60221
2008-11-28 22:50:08 +00:00
Chris Lattner f2a8ba4cf0 simplify some code, remove escaped newline.
llvm-svn: 60213
2008-11-28 21:29:52 +00:00
Chris Lattner 8a172daa55 don't call MergeBasicBlockIntoOnlyPred on a block whose only
predecessor is itself.  This doesn't make sense, and this is
a dead infinite loop anyway.

llvm-svn: 60210
2008-11-28 19:54:49 +00:00
Chris Lattner e9f6c355bf rewrite RecursivelyDeleteTriviallyDeadInstructions to use a more efficient
formulation that doesn't require set lookups or scanning a set.

llvm-svn: 60203
2008-11-28 01:20:46 +00:00
Chris Lattner d4b5ba615e remove some weirdness that came from the LSR code that has
nothing to do with dead instruction elimination.  No tests in
dejagnu depend on this, so I don't know what it was needed for.

llvm-svn: 60202
2008-11-28 00:58:15 +00:00
Chris Lattner 1adb6759ef rewrite a big chunk of how DSE does recursive dead operand
elimination to use more modern infrastructure.  Also do a bunch
of small cleanups.

llvm-svn: 60201
2008-11-28 00:27:14 +00:00
Chris Lattner 8e84c129ce delete ErasePossiblyDeadInstructionTree, replacing uses of it with
RecursivelyDeleteTriviallyDeadInstructions.

llvm-svn: 60196
2008-11-27 23:25:44 +00:00
Chris Lattner c077a2a535 Simplify LoopStrengthReduce::DeleteTriviallyDeadInstructions by
making it use RecursivelyDeleteTriviallyDeadInstructions to do
the heavy lifting.

llvm-svn: 60195
2008-11-27 23:23:35 +00:00
Chris Lattner a1bbdff933 enhance RecursivelyDeleteTriviallyDeadInstructions to make
PHIs dead if they are single-value.

llvm-svn: 60194
2008-11-27 23:18:11 +00:00
Chris Lattner 1cb4f72706 Enhance RecursivelyDeleteTriviallyDeadInstructions to optionally
return a list of deleted instructions.

llvm-svn: 60193
2008-11-27 23:14:34 +00:00
Chris Lattner 96e2dbe008 use continue to reduce indentation
llvm-svn: 60192
2008-11-27 23:00:20 +00:00
Chris Lattner c6c481cdfc remove doConstantPropagation and dceInstruction, they are just
wrappers around the interesting code and use an obscure iterator
abstraction that dates back many many years.

Move EraseDeadInstructions to Transforms/Utils and name it
RecursivelyDeleteTriviallyDeadInstructions.

llvm-svn: 60191
2008-11-27 22:57:53 +00:00
Chris Lattner 5ef9ebf787 simplify code.
llvm-svn: 60190
2008-11-27 22:56:14 +00:00
Chris Lattner c92fa42ddd simplify this logic.
llvm-svn: 60189
2008-11-27 22:46:09 +00:00
Nick Lewycky 4ab50b93c8 Chris prefers icmp/select over udiv!
llvm-svn: 60187
2008-11-27 22:41:10 +00:00
Nick Lewycky 69941fd0a0 Add a couple of missed optimizations on integer vectors. Multiply and divide
by 1, as well as multiply by -1.

llvm-svn: 60182
2008-11-27 20:21:08 +00:00
Chris Lattner 4059f43b74 defensive patch: if CGP is merging a block with the entry block, make sure
it ends up being the entry block.

llvm-svn: 60180
2008-11-27 19:29:14 +00:00
Chris Lattner 5dfbfcd80d Fix PR3138: if we merge the entry block into another block, make sure to
move the other block back up into the entry position!

llvm-svn: 60179
2008-11-27 19:25:19 +00:00