Commit Graph

5 Commits

Author SHA1 Message Date
Michael Kruse 225f0d1ee2 Load/Store scalar accesses before/after the statement itself
Instead of generating implicit loads within basic blocks, put them 
before the instructions of the statment itself, including non-affine 
subregions. The region's entry node is dominating all blocks in the 
region and therefore the loaded value will be available there.

Implicit writes in block-stmts were already stored back at the end of 
the block. Now, also generate the stores of non-affine subregions when 
leaving the statement, i.e. in the exiting block.

This change is required for array-mapped implicits ("De-LICM") to 
ensure that there are no dependencies of demoted scalars within 
statments. Statement load all required values, operator on copied in 
registers, and then write back the changed value to the demoted memory. 
Lifetimes analysis within statements becomes unecessary.

Differential Revision: http://reviews.llvm.org/D13487

llvm-svn: 250625
2015-10-17 21:36:00 +00:00
Tobias Grosser f4ee371e60 tests: Drop -polly-detect-unprofitable and -polly-no-early-exit
These flags are now always passed to all tests and need to be disabled if
not needed. Disabling these flags, rather than passing them to almost all
tests, significantly simplfies our RUN: lines.

llvm-svn: 249422
2015-10-06 15:36:44 +00:00
Tobias Grosser c0091a77f9 Store scalar dependences from outside the scop into alloca locations
We already modeled read-only dependences to scalar values defined outside the
scop as memory reads and also generated read accesses from the corresponding
alloca instructions that have been used to pass these scalar values around
during code generation. However, besides for PHI nodes that have already been
handled, we failed to store the orignal read-only scalar values into these
alloc. This commit extends the initialization of scalar values to all read-only
scalar values used within the scop.

llvm-svn: 246394
2015-08-30 19:19:34 +00:00
Tobias Grosser ed21a1fc7e Do not detect Scops with only one loop.
If a region does not have more than one loop, we do not identify it as
a Scop in ScopDetection. The main optimizations Polly is currently performing
(tiling, preparation for outer-loop vectorization and loop fusion) are unlikely
to have a positive impact on individual loops. In some cases, Polly's run-time
alias checks or conditional hoisting may still have a positive impact, but those
are mostly enabling transformations which LLVM already performs for individual
loops. As we do not focus on individual loops, we leave them untouched to not
introduce compile time regressions and execution time noise. This results in
good compile time reduction (oourafft: -73.99%, smg2000: -56.25%).

Contributed-by: Pratik Bhatu <cs12b1010@iith.ac.in>

Reviewers: grosser

Differential Revision: http://reviews.llvm.org/D12268

llvm-svn: 246161
2015-08-27 16:55:18 +00:00
Tobias Grosser 0164b8ff70 Enable code generation of scalar dependences from function arguments
This change extends the BlockGenerator to not only allow Instructions as
base elements of scalar dependences, but any llvm::Value. This allows
us to code-generate scalar dependences which reference function arguments, as
they arise when moddeling read-only scalar dependences.

llvm-svn: 244874
2015-08-13 08:07:39 +00:00