[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).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204748 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index 6b5d78b58149431e7cd897990c908c420b018357..1f98fe62126b0cfa28f433f00c8234873d26086b 100644 (file)
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -282,6 +282,21 @@ PPCInstrInfo::commuteInstruction(MachineInstr *MI, bool NewMI) const {
   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

diff --git a/lib/Target/PowerPC/PPCInstrInfo.h b/lib/Target/PowerPC/PPCInstrInfo.h
index 7876703584db77ae56a4cc11701659bc5e873da0..3c8117cb6398f3b06b4131fdfe596e596d4ba677 100644 (file)
--- a/lib/Target/PowerPC/PPCInstrInfo.h
+++ b/lib/Target/PowerPC/PPCInstrInfo.h
@@ -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;