ComputeMaskedBits knows about cttz, ctlz, and ctpop. Teach
SelectionDAG's ComputeMaskedBits what InstCombine's knows
about SRem. And teach them both some things about high bits
in Mul, UDiv, URem, and Sub. This allows instcombine and
dagcombine to eliminate sign-extension operations in
several new cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50358 91177308-0d34-0410-b5e6-96231b3b80d8
getelementptr-seteq.ll into:
define i1 @test(i64 %X, %S* %P) {
%C = icmp eq i64 %X, -1 ; <i1> [#uses=1]
ret i1 %C
}
instead of:
define i1 @test(i64 %X, %S* %P) {
%A.idx.mask = and i64 %X, 4611686018427387903 ; <i64> [#uses=1]
%C = icmp eq i64 %A.idx.mask, 4611686018427387903 ; <i1> [#uses=1]
ret i1 %C
}
And fixes the second half of PR2235. This speeds up the insertion sort
case by 45%, from 1.12s to 0.77s. In practice, this will significantly
speed up for loops structured like:
for (double *P = Base + N; P != Base; --P)
...
Which happens frequently for C++ iterators.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50079 91177308-0d34-0410-b5e6-96231b3b80d8
in addition to integer expressions. Rewrite GetOrEnforceKnownAlignment
as a ComputeMaskedBits problem, moving all of its special alignment
knowledge to ComputeMaskedBits as low-zero-bits knowledge.
Also, teach ComputeMaskedBits a few basic things about Mul and PHI
instructions.
This improves ComputeMaskedBits-based simplifications in a few cases,
but more noticeably it significantly improves instcombine's alignment
detection for loads, stores, and memory intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49492 91177308-0d34-0410-b5e6-96231b3b80d8
simplify things like (X & 4) >> 1 == 2 --> (X & 4) == 4.
since it is obvious that the shift doesn't remove any bits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48631 91177308-0d34-0410-b5e6-96231b3b80d8
the type instead of the byte size. This was causing troublesome mis-compilations.
True to form, this took 2 days to find and is a one-line fix. :-P
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48354 91177308-0d34-0410-b5e6-96231b3b80d8
was incorrectly simplifying "x == (gep x, 1, i)" into false, even
though i could be negative. As it turns out, all the code to
handle this already existed, we just need to disable the incorrect
optimization case and let the general case handle it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46739 91177308-0d34-0410-b5e6-96231b3b80d8
drop attributes on varargs call arguments. Also, it could generate
invalid IR if the transformed call already had the 'nest' attribute
somewhere (this can never happen for code coming from llvm-gcc,
but it's a theoretical possibility). Fix both problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45973 91177308-0d34-0410-b5e6-96231b3b80d8
a load/store of i64. The later prevents promotion/scalarrepl of the
source and dest in many cases.
This fixes the 300% performance regression of the byval stuff on
stepanov_v1p2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45945 91177308-0d34-0410-b5e6-96231b3b80d8
realize that ne & sgt was a signed comparison (it was only
looking at whether the left compare was signed).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45937 91177308-0d34-0410-b5e6-96231b3b80d8
if this becomes a varargs call then deal correctly with any
parameter attributes on the newly vararg call arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45931 91177308-0d34-0410-b5e6-96231b3b80d8
direct calls bails out unless caller and callee have essentially
equivalent parameter attributes. This is illogical - the callee's
attributes should be of no relevance here. Rework the logic, which
incidentally fixes a crash when removed arguments have attributes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45658 91177308-0d34-0410-b5e6-96231b3b80d8
a direct call with cast parameters and cast return
value (if any), instcombine was prepared to cast any
non-void return value into any other, whether castable
or not. Add a new predicate for testing whether casting
is valid, and check it both for the return value and
(as a cleanup) for the parameters.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45657 91177308-0d34-0410-b5e6-96231b3b80d8
