09f86993bd
Take advantage of undefined behavior if the source program tries to GEP
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beyond the end of an alloca to make FastDSE faster and more aggressive.
llvm-svn: 39945
2007-07-16 23:34:39 +00:00
7fcaaadf1c
Add support for walking up memory def chains, which enables finding many more
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dead stores on 400.perlbench.
llvm-svn: 39929
2007-07-16 21:52:50 +00:00
d975efab16
Handle GEPs with all-zero indices in the same way we handle pointer-pointer bitcasts. Also, fix a potentia infinite loop.
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This brings FastDSE to parity with old DSE on 175.vpr.
llvm-svn: 39839
2007-07-13 22:50:48 +00:00
9c9ef21432
Be more aggressive in removing dead stores, and in removing instructions trivially dead after DSE.
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This drastically improves the effect of FastDSE on kimwitu++.
llvm-svn: 39819
2007-07-13 18:26:26 +00:00
32c4a05dd4
Reimplement removing stores to allocas at the end of a function. This should be safe now.
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llvm-svn: 39790
2007-07-12 21:41:30 +00:00
d4451dee1e
Make the condition-checking for free with non-trivial dependencies more correct.
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llvm-svn: 39789
2007-07-12 18:08:51 +00:00
5e06995b3d
Remove the end-block handling code. It was unsafe, and making it safe would have resulted in falling back to the slow DSE case. I need to think some more about the right way to handle this.
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llvm-svn: 39788
2007-07-12 17:52:20 +00:00
b8bca52c7d
checked in as obvious,
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thanks Benoit Boissinot!
llvm-svn: 39774
2007-07-12 13:31:38 +00:00
1e1bace52b
Let MemoryDependenceAnalysis take care of updating AliasAnalysis.
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llvm-svn: 39769
2007-07-12 00:06:21 +00:00
aa07172340
Handle the case where an entire structure is freed, and its dependency is a store to a field within
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that structure.
Also, refactor the runOnBasicBlock() function, splitting some of the special cases into separate functions.
llvm-svn: 39762
2007-07-11 23:19:17 +00:00
1441470be8
Add support for eliminate stores to stack-allocated memory locations at the end
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of a function.
llvm-svn: 39754
2007-07-11 21:06:56 +00:00
e720144837
Handle eliminating stores that occur right before a free.
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llvm-svn: 39753
2007-07-11 20:38:34 +00:00
bf971aafb6
Clean up a few things based on Chris' feedback.
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llvm-svn: 39747
2007-07-11 19:03:09 +00:00
5e72db3f7f
Add FastDSE, a new algorithm for doing dead store elimination. This algorithm is not as accurate
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as the current DSE, but it only a linear scan over each block, rather than quadratic. Eventually
(once it has been improved somewhat), this will replace the current DSE.
NOTE: This has not yet been extensively tested.
llvm-svn: 38517
2007-07-11 00:46:18 +00:00
Owen Anderson