Complete loop unrolling can make some loads constant, thus enabling a
lot of other optimizations. To catch such cases, we look for loads that
might become constants and estimate number of instructions that would be
simplified or become dead after substitution.
Example:
Suppose we have:
int a[] = {0, 1, 0};
v = 0;
for (i = 0; i < 3; i ++)
v += b[i]*a[i];
If we completely unroll the loop, we would get:
v = b[0]*a[0] + b[1]*a[1] + b[2]*a[2]
Which then will be simplified to:
v = b[0]* 0 + b[1]* 1 + b[2]* 0
And finally:
v = b[1]
llvm-svn: 228265
Summary: When evaluating floating point instructions in the inliner, ask the TTI whether it is an expensive operation. By default, it's not an expensive operation. This keeps the default behavior the same as before. The ARM TTI has been updated to return back TCC_Expensive for targets which don't have hardware floating point.
Reviewers: chandlerc, echristo
Reviewed By: echristo
Subscribers: t.p.northover, aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D6936
llvm-svn: 228263
Add some API to `APSInt` to make it easier to compare with `int64_t`.
- `APSInt::compareValues(APSInt, APSInt)` returns 1, -1 or 0 for
greater, lesser, or equal, doing the right thing for mismatched
"has-sign" and bitwidths. This is just like `isSameValue()` (and is
now the implementation of it).
- `APSInt::get(int64_t)` gets a signed `APSInt`.
- `operator<(int64_t)`, etc., are implemented trivially via `get()`
and `compareValues()`.
- Also added `APSInt::getUnsigned(uint64_t)` to make it easier to test
`compareValues()`.
llvm-svn: 228239
Split out `LineField`, which restricts the legal line numbers. This
will make it easier to be consistent between different node parsers.
llvm-svn: 228226
Summary:
Handle LLVM_USE_SANITIZER=Address;Undefined to enable ASan and UBSan
If UBSan is compatible with more of the other sanitizers, maybe we should
deal with this in a better way where we allow combining UBSan with any of
the other sanitizers.
Reviewers: samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7024
llvm-svn: 228219
Move all the types of `MDField` to an anonymous namespace in the source
file. This also eliminates the duplication of `ParseMDField()`
declarations in the header for each new field type.
llvm-svn: 228211
Parts of llvm were not expecting it and we wouldn't print
the entity size of the section.
Given what comdats are used for, having SHF_MERGE sections would be
just a small improvement, so just disable it for now.
Fixes pr22463.
llvm-svn: 228196
v2i32, i32, trunc i32 to i16, and truc i32 to i8 stores are legal for
all address spaces. We had marked them as custom in order to lower
them for the private address space, but this is no longer necessary.
This enables lowering of misaligned stores of these types in the
DAGLegalizer.
llvm-svn: 228189
We were previously doing a post-order traversal and operating on the
list in reverse, however this would occasionaly cause backedges for
loops to be visited before some of the other blocks in the loop.
We know use a reverse post-order traversal, which avoids this issue.
The reverse post-order traversal is not completely ideal, so we need
to manually fixup the list to ensure that inner loop backedges are
visited before outer loop backedges.
llvm-svn: 228186
Track unresolved nodes under distinct `MDNode`s during `MapMetadata()`,
and resolve them at the end. Previously, these cycles wouldn't get
resolved.
llvm-svn: 228180
In case CSE reuses a previoulsy unused register the dead-def flag has to
be cleared on the def operand, as exposed by the arm64-cse.ll test.
This fixes PR22439 and the corresponding rdar://19694987
Differential Revision: http://reviews.llvm.org/D7395
llvm-svn: 228178
