that there were two input operands before the variable operand portion. This
*happened* to be true for all call instructions, which took a chain and a
destination, but was not true for the PPC BCTRL instruction, whose destination
is implicit.
Making this code more general allows elimination of the custom selection logic
for BCTRL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31732 91177308-0d34-0410-b5e6-96231b3b80d8
X86ISD::CMP, etc.) instead of SDNode names (add, x86cmp, etc). We now allow
multiple SDNodes to map to the same SelectionDAG node (e.g. store, indexed
store).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31575 91177308-0d34-0410-b5e6-96231b3b80d8
way to reach the load via any nodes that would be folded. Start from the
root of the matched sub-tree.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30956 91177308-0d34-0410-b5e6-96231b3b80d8
chain operand to point to the load being folded. Now we relax this, traversing
up the chain, if it doesn't reach the load, then it's ok. We will create a
TokenFactor (of all the chain operands and the load's chain) to capture all
the control flow dependencies.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30897 91177308-0d34-0410-b5e6-96231b3b80d8
The dag/inst combiners often 'simplify' the masked value based on whether
or not the bits are live or known zero/one. This is good and dandy, but
often causes special case patterns to fail, such as alpha's CMPBGE pattern,
which looks like "(set GPRC:$RC, (setuge (and GPRC:$RA, 255), (and GPRC:$RB, 255)))".
Here the pattern for (and X, 255) should match actual dags like (and X, 254) if
the dag combiner proved that the missing bits are already zero (one for 'or').
For CodeGen/Alpha/cmpbge.ll:test2 for example, this results in:
sll $16,1,$0
cmpbge $0,$17,$0
ret $31,($26),1
instead of:
sll $16,1,$0
and $0,254,$0
and $17,255,$1
cmpule $1,$0,$0
ret $31,($26),1
... and requires no target-specific code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30871 91177308-0d34-0410-b5e6-96231b3b80d8
the branch's chain is also produced by cmp.
[ch, r : ld]
^ ^
| |
[XX]--/ \- [flag : cmp]
^ ^
| |
\---[br flag]-
Remove an isel check which prevents loads from being folded into cmp / test
instructions.
2) Whenever possible, delete a selected node to allow more load folding
opportunities. Note not all nodes can be deleted after it has been
selected. Some may have simply morphed; some have not changed at all (e.g.
EntryToken).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30242 91177308-0d34-0410-b5e6-96231b3b80d8
- Clean up the code generated by tablegen:
* AddToISelQueue now takes one argument.
* ComplexPattern matching condition can now be shared.
* Eliminate passing unnecessary arguments to emit routines.
* Eliminate some unneeded SDOperand declarations in select routines.
* Other minor clean ups.
- This reduces foot print slightly: X86ISelDAGToDAG.o is reduced from 971k
to 823k.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29892 91177308-0d34-0410-b5e6-96231b3b80d8
introduced by previous commit.
- SelectCode now returns a SDNode*. If it is not null, the selected node
produces the same number of results as the input node. The seletion loop
is responsible for calling ReplaceAllUsesWith() to replace the input node
with the output target node. For other cases, e.g. when load is folded,
the selection code is responsible for calling ReplaceAllUsesOfValueWith()
and SelectCode returns NULL.
- Other clean ups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29602 91177308-0d34-0410-b5e6-96231b3b80d8
