diff options
| author | Chris Lattner <sabre@nondot.org> | 2005-12-23 05:37:50 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2005-12-23 05:37:50 +0000 |
| commit | c8547d856d3459a61ca9e35b5342288fe626c295 (patch) | |
| tree | ad63f1598ca842ffd23ac170dd5ef2bec21bebd3 /lib/CodeGen/SelectionDAG/SelectionDAG.cpp | |
| parent | 94683777aee436a0e5f12e08a4b3827a11265fb2 (diff) | |
Fold bitconv(bitconv(x)) -> x. We now compile this:
void foo(double);
void bar(double X) { foo(X); }
to this:
bar:
save -96, %o6, %o6
or %g0, %i0, %o0
or %g0, %i1, %o1
call foo
nop
restore %g0, %g0, %g0
retl
nop
instead of this:
bar:
save -112, %o6, %o6
st %i1, [%i6+-4]
st %i0, [%i6+-8]
ldd [%i6+-8], %f0
std %f0, [%i6+-16]
ld [%i6+-12], %o1
ld [%i6+-16], %o0
call foo
nop
restore %g0, %g0, %g0
retl
nop
on V8.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24981 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 76d983f57e..b510f1cd95 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -916,6 +916,8 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, assert(MVT::getSizeInBits(VT)==MVT::getSizeInBits(Operand.getValueType()) && "Cannot BIT_CONVERT between two different types!"); if (VT == Operand.getValueType()) return Operand; // noop conversion. + if (OpOpcode == ISD::BIT_CONVERT) // bitconv(bitconv(x)) -> bitconv(x) + return getNode(ISD::BIT_CONVERT, VT, Operand.getOperand(0)); break; case ISD::FNEG: if (OpOpcode == ISD::FSUB) // -(X-Y) -> (Y-X) |