diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86InstrInfo.h')
| -rw-r--r-- | llvm/lib/Target/X86/X86InstrInfo.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h index 3f6b030c442..edd09d61759 100644 --- a/llvm/lib/Target/X86/X86InstrInfo.h +++ b/llvm/lib/Target/X86/X86InstrInfo.h @@ -264,6 +264,46 @@ public: bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1, unsigned &SrcOpIdx2) const override; + /// Returns true if the routine could find two commutable operands + /// in the given FMA instruction. Otherwise, returns false. + /// + /// \p SrcOpIdx1 and \p SrcOpIdx2 are INPUT and OUTPUT arguments. + /// The output indices of the commuted operands are returned in these + /// arguments. Also, the input values of these arguments may be preset either + /// to indices of operands that must be commuted or be equal to a special + /// value 'CommuteAnyOperandIndex' which means that the corresponding + /// operand index is not set and this method is free to pick any of + /// available commutable operands. + /// + /// For example, calling this method this way: + /// unsigned Idx1 = 1, Idx2 = CommuteAnyOperandIndex; + /// findFMA3CommutedOpIndices(MI, Idx1, Idx2); + /// can be interpreted as a query asking if the operand #1 can be swapped + /// with any other available operand (e.g. operand #2, operand #3, etc.). + /// + /// The returned FMA opcode may differ from the opcode in the given MI. + /// For example, commuting the operands #1 and #3 in the following FMA + /// FMA213 #1, #2, #3 + /// results into instruction with adjusted opcode: + /// FMA231 #3, #2, #1 + bool findFMA3CommutedOpIndices(MachineInstr *MI, + unsigned &SrcOpIdx1, + unsigned &SrcOpIdx2) const; + + /// Returns an adjusted FMA opcode that must be used in FMA instruction that + /// performs the same computations as the given MI but which has the operands + /// \p SrcOpIdx1 and \p SrcOpIdx2 commuted. + /// It may return 0 if it is unsafe to commute the operands. + /// + /// The returned FMA opcode may differ from the opcode in the given \p MI. + /// For example, commuting the operands #1 and #3 in the following FMA + /// FMA213 #1, #2, #3 + /// results into instruction with adjusted opcode: + /// FMA231 #3, #2, #1 + unsigned getFMA3OpcodeToCommuteOperands(MachineInstr *MI, + unsigned SrcOpIdx1, + unsigned SrcOpIdx2) const; + // Branch analysis. bool isUnpredicatedTerminator(const MachineInstr* MI) const override; bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB, |
