we were losing a node, causing an assertion to fail. Now we eagerly delete
discovered CSE's, and provide an optional vector to keep track of these
discovered equivalences.
llvm-svn: 23255
from the binary ops map, even if they had multiple results. This latent bug
caused a few failures with the dag isel last night.
To prevent stuff like this from happening in the future, add some really
strict checking to make sure that the CSE maps always match up with reality!
llvm-svn: 23221
over to DAGCombiner.cpp
1. Don't assume that SetCC returns i1 when folding (xor (setcc) constant)
2. Don't duplicate code in folding AND with AssertZext that is handled by
MaskedValueIsZero
llvm-svn: 23196
them. This allows for elminination of redundant extends in the entry
blocks of functions on PowerPC.
Add support for i32 x i32 -> i64 multiplies, by recognizing when the inputs
to ISD::MUL in ExpandOp are actually just extended i32 values and not real
i64 values. this allows us to codegen
int mulhs(int a, int b) { return ((long long)a * b) >> 32; }
as:
_mulhs:
mulhw r3, r4, r3
blr
instead of:
_mulhs:
mulhwu r2, r4, r3
srawi r5, r3, 31
mullw r5, r4, r5
add r2, r2, r5
srawi r4, r4, 31
mullw r3, r4, r3
add r3, r2, r3
blr
with a similar improvement on x86.
llvm-svn: 23147
putting it into the constant pool. This allows the isel machinery to
create constants that it will end up deciding are not needed, without them
ending up in the resultant function constant pool.
llvm-svn: 23081
select. Also teach it that the bit count instructions can only set the low bits
of the result, depending on the size of the input.
This allows us to compile this:
int %eq0(int %a) {
%tmp.1 = seteq int %a, 0 ; <bool> [#uses=1]
%tmp.2 = cast bool %tmp.1 to int ; <int> [#uses=1]
ret int %tmp.2
}
To this:
_eq0:
cntlzw r2, r3
srwi r3, r2, 5
blr
instead of this:
_eq0:
cntlzw r2, r3
rlwinm r3, r2, 27, 31, 31
blr
when setcc is marked illegal on ppc (which restores parity to non-illegal
setcc). Thanks to Nate for pointing this out.
llvm-svn: 23013
used to tack a register number onto the node.
Instead of doing this, make a new node, RegisterSDNode, which is a leaf
containing a register number. These three operations just become normal
DAG nodes now, instead of requiring special handling.
Note that with this change, it is no longer correct to make illegal
CopyFromReg/CopyToReg nodes. The legalizer will not touch them, and this
is bad, so don't do it. :)
llvm-svn: 22806
