diff options
Diffstat (limited to 'lib/Target/X86/X86ISelDAGToDAG.cpp')
| -rw-r--r-- | lib/Target/X86/X86ISelDAGToDAG.cpp | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp index d836c29d6b..88cfe10dfa 100644 --- a/lib/Target/X86/X86ISelDAGToDAG.cpp +++ b/lib/Target/X86/X86ISelDAGToDAG.cpp @@ -204,6 +204,9 @@ namespace { bool SelectAddr(SDNode *Parent, SDValue N, SDValue &Base, SDValue &Scale, SDValue &Index, SDValue &Disp, SDValue &Segment); + bool SelectSingleRegAddr(SDNode *Parent, SDValue N, SDValue &Base, + SDValue &Scale, SDValue &Index, SDValue &Disp, + SDValue &Segment); bool SelectLEAAddr(SDValue N, SDValue &Base, SDValue &Scale, SDValue &Index, SDValue &Disp, SDValue &Segment); @@ -1319,6 +1322,31 @@ bool X86DAGToDAGISel::SelectAddr(SDNode *Parent, SDValue N, SDValue &Base, return true; } +/// SelectSingleRegAddr - Like SelectAddr, but reject any address that would +/// require more than one allocatable register. +/// +/// This is used for a TCRETURNmi64 instruction when used to tail call a +/// variadic function with 6 arguments: Only %r11 is available from GR64_TC. +/// The other scratch register, %rax, is needed to pass in the number of vector +/// registers used in the variadic arguments. +/// +bool X86DAGToDAGISel::SelectSingleRegAddr(SDNode *Parent, SDValue N, + SDValue &Base, + SDValue &Scale, SDValue &Index, + SDValue &Disp, SDValue &Segment) { + if (!SelectAddr(Parent, N, Base, Scale, Index, Disp, Segment)) + return false; + // Anything %RIP relative is fine. + if (RegisterSDNode *Reg = dyn_cast<RegisterSDNode>(Base)) + if (Reg->getReg() == X86::RIP) + return true; + // Check that the index register is 0. + if (RegisterSDNode *Reg = dyn_cast<RegisterSDNode>(Index)) + if (Reg->getReg() == 0) + return true; + return false; +} + /// SelectScalarSSELoad - Match a scalar SSE load. In particular, we want to /// match a load whose top elements are either undef or zeros. The load flavor /// is derived from the type of N, which is either v4f32 or v2f64. |