[llvm] r204748 - [PowerPC] Correct commutable indices for VSX FMA instructions

[Hal Finkel]

Author: hfinkel
Date: Tue Mar 25 14:26:43 2014
New Revision: 204748

URL: http://llvm.org/viewvc/llvm-project?rev=204748&view=rev
Log:
[PowerPC] Correct commutable indices for VSX FMA instructions

Although the first two operands are the ones that can be swapped, the tied
input operand is listed before them, so we need to adjust for that.

I have a test case for this, but it goes along with an upcoming commit (so it
will come soon).

Modified:
    llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
    llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h

Modified: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp?rev=204748&r1=204747&r2=204748&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp Tue Mar 25 14:26:43 2014
@@ -282,6 +282,21 @@ PPCInstrInfo::commuteInstruction(Machine
   return MI;
 }
 
+bool PPCInstrInfo::findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
+                                         unsigned &SrcOpIdx2) const {
+  // For VSX A-Type FMA instructions, it is the first two operands that can be
+  // commuted, however, because the non-encoded tied input operand is listed
+  // first, the operands to swap are actually the second and third.
+
+  int AltOpc = PPC::getAltVSXFMAOpcode(MI->getOpcode());
+  if (AltOpc == -1)
+    return TargetInstrInfo::findCommutedOpIndices(MI, SrcOpIdx1, SrcOpIdx2);
+
+  SrcOpIdx1 = 2;
+  SrcOpIdx2 = 3;
+  return true;
+}
+
 void PPCInstrInfo::insertNoop(MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator MI) const {
   // This function is used for scheduling, and the nop wanted here is the type

Modified: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h?rev=204748&r1=204747&r2=204748&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h Tue Mar 25 14:26:43 2014
@@ -119,6 +119,9 @@ public:
   // rotate amt is zero.  We also have to munge the immediates a bit.
   virtual MachineInstr *commuteInstruction(MachineInstr *MI, bool NewMI) const;
 
+  virtual bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
+                                     unsigned &SrcOpIdx2) const;
+
   virtual void insertNoop(MachineBasicBlock &MBB,
                           MachineBasicBlock::iterator MI) const;