From: Hal Finkel <hfinkel@anl.gov>
Date: Tue, 25 Mar 2014 19:26:43 +0000 (+0000)
Subject: [PowerPC] Correct commutable indices for VSX FMA instructions
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=7e77dabbd08f5822a8b95fe98ee1a48072aa0f1c;p=oota-llvm.git

[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 6b5d78b5814..1f98fe62126 100644
--- 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 7876703584d..3c8117cb639 100644
--- 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;