Count the number of computational steps that have been used to solve the
dependence problem and abort in case we reach the "compute-out". This ensures we
do not hang forever in cases the dependence problem is too difficult to solve.
There is just a single case in the LLVM test-suite that runs into the
compute-out. Even in this case, we can probably coalesce some of the parameters
(i32 b, i32 b zext i64, ...) to simplify the problem enough to not hit the
compute out. However, for now we set the compute out in place to address the
general issue. The compute out was choosen such that it stops on a recent laptop
after about 8 seconds.
llvm-svn: 200156
This includes the following very useful isl commit:
commit d962967ab42323ea5ca0398956fbff6a98c782fa
Author: Sven Verdoolaege <skimo@kotnet.org>
Date: Wed Dec 18 12:05:32 2013 +0100
allow the user to impose a bound on the number of low-level operations
This should allow the user to deterministically limit the effort spent on a
computation.
llvm-svn: 200155
This removes the last isl_int dependency in the default build. There are
still some in OpenScop and Scoplib. For those isl-0.12.2 still needs to be used.
llvm-svn: 199585
This ModulePass schedules the set of Polly canonicalization passes. It is a
debugging tool that can be used to preoptimize .ll files for Polly processing.
llvm-svn: 198376
Also the code makes the impression this was happening, shouldEnablePolly()
always returns false for optlevel equal to zero. This was previously different,
but was accidentally changed by a commit a couple of months ago. As this
behavior was mainly a debugging tool and adding this to clang never really made
sense, we just remove the last traces.
llvm-svn: 198370
This fixes a crash that appeared when generating dotty graphs for functions
without loops (for which we do not calculate polyhedral information).
llvm-svn: 198364
We now report the following:
$ polly-clang -O3 -mllvm -polly -mllvm -polly-report test.c -c \
-gline-tables-only
note: Polly detected an optimizable loop region (scop) in function 'foo'
test.c:2: Start of scop
test.c:3: End of scop
note: Polly detected an optimizable loop region (scop) in function 'bar'
test.c:9: Start of scop
test.c:13: End of scop
llvm-svn: 197558
For for-nodes that are translated to a set of vector lanes, we already know the
overall number of iterations. Calculating the upper bound is consequently not
necessary. This change removes the code for upper bound calculation, which was
probably copy/pasted from the code generation for the normal for-loop.
This issue was found by Sylvestre's scan-build server.
llvm-svn: 193925
When constructing a scop sometimes the exact representation of a statement or
condition would be very complex, but there is a common case which is a lot
simpler, but which is only valid under certain assumptions. The assumed context
records the assumptions taken during the construction of this scop and that need
to be code generated as a run-time test.
At the moment, we do not yet model any assumptions, but only added the
AssumedContext as well as the isl-ast generation support. As a next step,
this needs to be hooked up with the isl code generation.
if (1) /* run-time condition */
{ /* optimized code */ }
else
{ /* original code */ }
llvm-svn: 193652
Instead of defining the relevant functions inline, we now just keep the
declarations in the class itself. This makes the class declaration a lot
easier to read as all functions can be seen at once. We also use this
opportunity to privatize all functions not used in the public interface of the
class.
llvm-svn: 190841
Use 0 >= 1 instead of 0 != 0 to represent 'false'. This might be slightly more
efficient as isl may create a union of sets for 0 != 0, whereas this is never
needed for the expression 0 >= 1.
Contributed-by: Alexandre Isoard <alexandre.isoard@gmail.com>
llvm-svn: 190384
SCoP invariant parameters with the different start value would deter parameter
sharing. For example, when compiling the following C code:
void foo(float *input) {
for (long j = 0; j < 8; j++) {
// SCoP begin
for (long i = 0; i < 8; i++) {
float x = input[j * 64 + i + 1];
input[j * 64 + i] = x * x;
}
}
}
Polly would creat two parameters for these memory accesses:
p_0: {0,+,256}
p_2: {4,+,256}
[j * 64 + i + 1] => MemRef_input[o0] : 4o0 = p_1 + 4i0
[j * 64 + i] => MemRef_input[o0] : 4o0 = p_0 + 4i0
These parameters only differ from start value. To enable parameter sharing,
we split the start value from SCEVAddRecExpr, so they would share a single
parameter that always has zero start value:
p0: {0,+,256}<%for.cond1.preheader>
[j * 64 + i + 1] => MemRef_input[o0] : 4o0 = 4 + p_1 + 4i0
[j * 64 + i] => MemRef_input[o0] : 4o0 = p_0 + 4i0
Such translation can make the polly-dependence much faster.
Contributed-by: Star Tan <tanmx_star@yeah.net>
llvm-svn: 187728
In case we detect that the schedule the user wants to import is invalid we
refuse it _and_ free the isl_maps containing it.
Another bug found thanks to Rafael.
llvm-svn: 187339
We now use __isl_take to annotate the uses of the isl_set where we got the
memory management wrong.
Thanks to Rafael! His pipefail work hardened our test environment and exposed
this bug nicely.
llvm-svn: 187338
Split the old getNewValue into two parts:
1. The function "lookupAvailableValue" that return the new version of
the instruction which is already available.
2. The function calls "lookupAvailableValue", and tries to generate
the new version if it is not available yet.
llvm-svn: 187114
String operations resulted by raw_string_ostream in the INVALID macro can lead
to significant compile-time overhead when compiling large size source code.
This is because raw_string_ostream relies on TypeFinder class, whose
compile-time cost increases as the size of the module increases. This patch
targets to ensure that it only track detection failures if actually needed.
In this way, we can avoid expensive string operations in normal execution.
With this patch file, the relative compile-time cost of Polly-detect pass does
not increase even when compiling very large size source code.
Contributed-by: Star Tan <tanmx_star@yeah.net>
llvm-svn: 187102
Ensure that the scalar write access corresponds to the result of a load
instruction appears after the generic read access corresponds to the load
instruction.
llvm-svn: 186419
Tobias Grosser