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++.
llvm-svn: 25075
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:$src2). But that's a more distruptive change. Adding
'let noResults = 1' is the workaround to tell tblgen that the instruction does
not produces a result. It works for now since tblgen does not support
instructions which produce multiple results.
llvm-svn: 25017
use too much stack space, overflowing the stack for large functions. Instead
of emitting new SDOperands in each match block, we emit some common ones at
the top of SelectCode then reuse them when possible.
This reduces the stack size of SelectCode from 28K to 21K. Note that GCC
compiles it to 512 bytes :-/
I've filed GCC PR 25505 to track this.
llvm-svn: 24882
if (!N.Val->hasOneUse()) {
std::map<SDOperand, SDOperand>::iterator CGMI = CodeGenMap.find(N);
if (CGMI != CodeGenMap.end()) return CGMI->second;
}
Suppose a DAG like this:
X
^ ^
/ \
USE1 USE2
Suppose USE1 is being selected first and during which X is selected and
returned a new node. After this, USE1 is no longer an use of X. During USE2
selection, X will be selected again since it has only one use!
The fix is to always query CodeGenMap.
llvm-svn: 24679
it has more than one real use (non-chain uses).
* Record folded chain producing node in CodeGenMap.
* Do not fold a chain producing node if it has already been selected as an
operand of a chain use.
llvm-svn: 24647
matching code that is not currently auto-generated by tblgen, e.g. X86
addressing mode. Selection routines for complex patterns can return multiple operands, e.g. X86 addressing mode returns 4.
llvm-svn: 24634
* Enhanced tblgen to handle instructions which have chain operand and writes a
chain result.
* Enhanced tblgen to handle instructions which produces no results. Part of
the change is a temporary hack which relies on instruction property (e.g.
isReturn, isBranch). The proper fix would be to change the .td syntax to
separate results dag from ops dag.
llvm-svn: 24587
def SHL8rCL : I<0xD2, MRM4r, (ops R8 :$dst, R8 :$src),
"shl{b} {%cl, $dst|$dst, %CL}",
[(set R8:$dst, (shl R8:$src, CL))]>, Imp<[CL],[]>;
This generates a CopyToReg operand and added its 2nd result to the shl as
a flag operand.
llvm-svn: 24557
Jeff Cohen