This fixes Bugzilla #1835 (http://llvm.org/bugs/show_bug.cgi?id=1835).
This patched is reviewed by Tanya and Dan. Dan tested and approved it.
The reason for the bad performance of the old algorithm is that it is very naive and scans every
time all nodes of the DAG in the worst case.
This patch introduces a new algorithm based on the paper "Online algorithms
for maintaining the topological order of a directed acyclic graph" by
David J.Pearce and Paul H.J.Kelly. This is the MNR algorithm. It has a
linear time worst-case and performs much better in most situations.
The paper can be found here:
http://fano.ics.uci.edu/cites/Document/Online-algorithms-for-maintaining-the-topological-order-of-a-directed-acyclic-graph.html
The main idea of the new algorithm is to compute the topological ordering of the SNodes in the
DAG and to maintain it even after DAG modifications. The topological ordering allows for very fast
node reachability checks.
Tests on very big input files with tens of thousands of instructions in a BB indicate huge
speed-ups (up to 10x compilation time improvement) compared to the old version.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48817 91177308-0d34-0410-b5e6-96231b3b80d8
flags. This is needed by the new legalize types
infrastructure which wants to expand the 64 bit
constants previously used to hold the flags on
32 bit machines. There are two functional changes:
(1) in LowerArguments, if a parameter has the zext
attribute set then that is marked in the flags;
before it was being ignored; (2) PPC had some bogus
code for handling two word arguments when using the
ELF 32 ABI, which was hard to convert because of
the bogusness. As suggested by the original author
(Nicolas Geoffray), I've disabled it for the moment.
Tested with "make check" and the Ada ACATS testsuite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48640 91177308-0d34-0410-b5e6-96231b3b80d8
Use getIntPtrConstant in a couple places to shorten stuff up
Handle splitting vector shuffles with undefs in the mask
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48351 91177308-0d34-0410-b5e6-96231b3b80d8
the fcopysign expansion from LegalizeDAG to get rid of
what seems to be a bug: the use of sign extension means
that when copying the sign bit from an f32 to an f64,
the upper 32 bits of the f64 (now an i64) are set, not
just the top bit... I also generalized it to work for
any sized floating point types, and removed the bogosity:
SDOperand Mask1 = (SrcVT == MVT::f64)
? DAG.getConstantFP(BitsToDouble(1ULL << 63), SrcVT)
: DAG.getConstantFP(BitsToFloat(1U << 31), SrcVT);
Mask1 = DAG.getNode(ISD::BIT_CONVERT, SrcNVT, Mask1);
(here SrcNVT is an integer with the same size as SrcVT).
As far as I can see this takes a 1 << 63, converts to
a double, converts that to a floating point constant
then converts that to an integer constant, ending up
with... 1 << 63 as an integer constant! So I just
generate this integer constant directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48305 91177308-0d34-0410-b5e6-96231b3b80d8
getCopyToParts problem was noticed by the new
LegalizeTypes infrastructure. In order to avoid
this kind of thing in the future I've added a
check that EXTRACT_ELEMENT is only used with
integers. Once LegalizeTypes is up and running
most likely BUILD_PAIR and EXTRACT_ELEMENT can
be removed, in favour of using apints instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48294 91177308-0d34-0410-b5e6-96231b3b80d8
X86 lowering normalize vector 0 to v4i32. However DAGCombine can fold (sub x, x) -> 0 after legalization. It can create a zero vector of a type that's not expected (e.g. v8i16). We don't want to disable the optimization since leaving a (sub x, x) is really bad. Add isel patterns for other types of vector 0 to ensure correctness. It's highly unlikely to happen other than in bugpoint reduced test cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48279 91177308-0d34-0410-b5e6-96231b3b80d8
and it's the result that requires expansion. This code is a little confusing
because the TargetLoweringInfo tables for [US]INT_TO_FP use the operand type
(the integer type) rather than the result type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48206 91177308-0d34-0410-b5e6-96231b3b80d8
return ValueType can depend its operands' ValueType.
This is a cosmetic change, no functionality impacted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48145 91177308-0d34-0410-b5e6-96231b3b80d8
