In our test pool, the max entry point RT was improved by this change:
1'181 seconds (~19.7 minutes) -> 94 seconds (1.6 minutes)
BTW, the 1.6 minutes is still really bad. But a few orders of magnitude
better than it was before.
This was the most servere RT edge-case as you can see from the numbers.
There are are more known RT bottlenecks, such as:
- Large environment sizes, and `removeDead`. See more about the failed
attempt on improving it at:
https://discourse.llvm.org/t/unsuccessful-attempts-to-fix-a-slow-analysis-case-related-to-removedead-and-environment-size/84650
- Large chunk of time could be spend inside `assume`, to reach a fixed
point. This is something we want to look into a bit later if we have
time.
We have 3'075'607 entry points in our test set.
About 393'352 entry points ran longer than 1 second when measured.
To give a sense of the distribution, if we ignore the slowest 500 entry
points, then the maximum entry point runs for about 14 seconds. These
500 slow entry points are in 332 translation units.
By this patch, out of the slowest 500 entry points, 72 entry points were
improved by at least 10x after this change.
We measured no RT regression on the "usual" entry points.
(The dashed lines represent the maximum of their RT)
CPP-6092
Summary:
CompoundLiteralRegions have been properly modeled before, but
'getBindingForElement` was not changed to accommodate this change
properly.
rdar://problem/46144644
Differential Revision: https://reviews.llvm.org/D78990
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368942
Default RegionStore bindings represent values that can be obtained by loading
from anywhere within the region, not just the specific offset within the region
that they are said to be bound to. For example, default-binding a character \0
to an int (eg., via memset()) means that the whole int is 0, not just
that its lower byte is 0.
Even though memset and bzero were modeled this way, it didn't work correctly
when applied to simple variables. Eg., in
int x;
memset(x, 0, sizeof(x));
we did produce a default binding, but were unable to read it later, and 'x'
was perceived as an uninitialized variable even after memset.
At the same time, if we replace 'x' with a variable of a structure or array
type, accessing fields or elements of such variable was working correctly,
which was enough for most cases. So this was only a problem for variables of
simple integer/enumeration/floating-point/pointer types.
Fix loading default bindings from RegionStore for regions of simple variables.
Add a unit test to document the API contract as well.
Differential Revision: https://reviews.llvm.org/D60742
llvm-svn: 358722
