due to ordering issue. i.e. they were selected for chain use first.
Now at load select time, check if it is being selected for a chain use and if
it has only a single real use. If so, return a HANDLENODE (with the load as
its operand) in its place and record it.
When it is folded or the load is selected for a real use, the isel records it
as the replacement for the HANDLENODE. The replacement is done when all nodes
are selected.
This scheme exposed a couple of problems where cycles can happen. (See comments
in EmitMatchCode() for descriptions of the problems and their workaround /
solutions.) These problems have been resolved with a small compile time
penality.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25995 91177308-0d34-0410-b5e6-96231b3b80d8
X86 backend attempts to match small-immediate versions of instructions before
the full size immediate versions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25937 91177308-0d34-0410-b5e6-96231b3b80d8
Chain is initially set to the chain operand of store node, when it reaches
load, if it matches the load then Chain is set to the chain operand of the
load.
However, if the matching code that follows this fails, isel moves on to the
next pattern but it does not restore Chain to the chain operand of the store.
So when it tries to match the next store / op / load pattern it would fail on
the Chain == load.getOperand(0) test.
The solution is for each chain operand to get a unique name. e.g. Chain10.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25931 91177308-0d34-0410-b5e6-96231b3b80d8
"if" statements (indenting it appropriately, of course) instead of using goto's.
This inverts the logic for all of the if statements, which makes things simpler
to understand in addition to making the generated code easier to read.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25757 91177308-0d34-0410-b5e6-96231b3b80d8
directly to the output file. This makes things simple because the code doesn't
have to worry about indentation or the case when there is no goto. It also
allows us to indent the code better without touching everything :)
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If store's chain operand is load, then use load's chain operand instead. If
it isn't (likely a TokenFactor), then do not allow the folding.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25708 91177308-0d34-0410-b5e6-96231b3b80d8
has already been selected. The number of use check is not strong enough since
a node can be replaced with newly created target node. e.g. If the original
node has two uses, when it is selected for one of the uses it is replaced with
another. Each node now has a single use but isel still should not fold it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25651 91177308-0d34-0410-b5e6-96231b3b80d8
instruction to produce a result. e.g MUL8m, the instruction does not
produce a explicit result. However it produces an implicit result in
AL which would be copied to a temp. The root operator of the matching
pattern is a mul so the use would expect it to produce a result.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25458 91177308-0d34-0410-b5e6-96231b3b80d8
SNDPOutFlag to DAG nodes. These properties do not belong to target specific
instructions.
* Added DAG node property SNDPOptInFlag. It's same as SNDPInFlag except it's
optional. Used by ret / call, etc.
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SDOperand Tmp0,Tmp1,Tmp2,Tmp3,;
GCC has a bug (24907) in which is fails to catch this, but VC++ correctly
notes its illegality, so tblgen must be taught to only generate legal C++.
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Currently tblgen cannot tell which operands in the operand list are results so
it assumes the first one is a result. This is bad. Ideally we would fix this
by separating results from inputs, e.g. (res R32:$dst),
(ops R32:$src1, R32:$src2). But that's a more distruptive change. Adding
'let noResults = 1' is the workaround to tell tblgen that the instruction does
not produces a result. It works for now since tblgen does not support
instructions which produce multiple results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25017 91177308-0d34-0410-b5e6-96231b3b80d8
