Commit Graph

22 Commits

Author SHA1 Message Date
Chandler Carruth
7a34c8b602 Delete a dead member. Dunno if this was ever used, but the current code
directly manipulates the weights inside of the BranchProbabilityInfo
that is passed in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142163 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-16 22:27:54 +00:00
Benjamin Kramer
26eb870d7e Use canonical forms for the branch probability zero heutistic.
- Drop support for X >u 0, it's equivalent to X != 0 and should be canonicalized into the latter.
- Add X < 1 -> unlikely, which is what instcombine canonicalizes X <= 0 into.
- Add X > -1 -> likely, which is what instcombine canonicalizes X >= 0 into.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139110 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-04 23:53:04 +00:00
Jakub Staszak
b137f16936 Change SmallVector to SmallPtrSet in BranchProbabilityInfo. Handle cases where
one than one successor goes to the same block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136638 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-01 19:16:26 +00:00
Jakub Staszak
6762dc1fb3 Do not handle cases with >= and <= predicates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136588 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-31 05:54:04 +00:00
Jakub Staszak
4faf553d50 Remove untrue comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136587 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-31 04:51:14 +00:00
Jakub Staszak
a385c20d42 Do not handle case where LHS is equal to zero, because InstCombiner always moves
it to RHS anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136586 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-31 04:47:20 +00:00
Jakub Staszak
a5dd550588 Add Zero Heurestics to BranchProbabilityInfo. If we compare value to zero we
decide whether condition is likely to be true this way:

x == 0  ->  false
x <  0  ->  false
x <= 0  ->  false
x != 0  ->  true
x >  0  ->  true
x >= 0  ->  true


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136583 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-31 03:27:24 +00:00
Jakub Staszak
6f6baf1bdd Add more constantness in BranchProbabilityInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136502 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-29 19:30:00 +00:00
Jakub Staszak
e0058b4b0c Remove incEdgeWeight and decEdgeWeight. Set edge weight directly to avoid
rounding errors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136456 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-29 02:36:53 +00:00
Jakub Staszak
3d8b15ea70 Change LBH_TAKEN_WEIGHT to 124 (from 128). Right now, sum of
LBH_TAKEN_WEIGHT + LBH_NONTAKEN_WEIGHT = 128 which in _most_ cases reduce
number of rounding errors.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136428 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-28 23:42:08 +00:00
Jakub Staszak
7241caf7b8 Heuristics are in descending priority now. If we use one of them, skip the rest.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136402 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-28 21:45:07 +00:00
Jakub Staszak
fa44725233 Add InEdges (edges from header to the loop) in Loop Branch Heuristics, so
there is no frequency difference whether condition is in the header or in
the latch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136398 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-28 21:33:46 +00:00
Jakub Staszak
12af93ae86 Remove "LoopInfo.h" include from BranchProbabilityInfo.h.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135353 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-16 20:31:15 +00:00
Jakub Staszak
d7932ca962 Fix pointer heuristic. Check whether predicator is ICMP_NE instead of if it is
not isEquality().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135296 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-15 20:51:06 +00:00
Jakub Staszak
66dddd1da3 Calculate backedge probability correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133776 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-23 23:52:11 +00:00
Jakub Staszak
44eb49c2a1 Introduce BlockFrequency analysis for BasicBlocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133766 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-23 21:45:20 +00:00
Jakub Staszak
7cc2b07437 Introduce MachineBranchProbabilityInfo class, which has similar API to
BranchProbabilityInfo (expect setEdgeWeight which is not available here).
Branch Weights are kept in MachineBasicBlocks. To turn off this analysis
set -use-mbpi=false.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133184 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-16 20:22:37 +00:00
Benjamin Kramer
afa88eaf65 Move class into an anonymous namespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132925 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-13 18:38:56 +00:00
Andrew Trick
f289df2d95 Branch profiling: floating-point avoidance.
Patch by: Jakub Staszak!

Introduces BranchProbability. Changes unsigned to uint32_t all over and
uint64_t only when overflow is expected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132867 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-11 01:05:22 +00:00
Nick Lewycky
404b53e38c Fold assert-only-used variable into the assert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132620 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 02:07:10 +00:00
Andrew Trick
b4528c3d7e Missing include of climits in the new BranchProbability pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132616 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 01:30:52 +00:00
Andrew Trick
9e76422b96 New BranchProbabilityInfo analysis. Patch by Jakub Staszak!
BranchProbabilityInfo provides an interface for IR passes to query the
likelihood that control follows a CFG edge. This patch provides an
initial implementation of static branch predication that will populate
BranchProbabilityInfo for branches with no external profile
information using very simple heuristics. It currently isn't hooked up
to any external profile data, so static prediction does all the work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132613 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 01:16:30 +00:00