Update GATHER instructions to support 2 read-write operands. Patch from myself and Manman Ren.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160110 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 5 deletions

diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index 3079dfa7cf..977cc50c13 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -935,8 +935,15 @@ void Emitter<CodeEmitter>::emitVEXOpcodePrefix(uint64_t TSFlags,
   // Classify VEX_B, VEX_4V, VEX_R, VEX_X
   unsigned NumOps = Desc->getNumOperands();
   unsigned CurOp = 0;
-  if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) != -1)
+  if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) == 0)
     ++CurOp;
+  else if (NumOps > 3 && Desc->getOperandConstraint(2, MCOI::TIED_TO) == 0) {
+    assert(Desc->getOperandConstraint(NumOps - 1, MCOI::TIED_TO) == 1);
+    // Special case for GATHER with 2 TIED_TO operands
+    // Skip the first 2 operands: dst, mask_wb
+    CurOp += 2;
+  }
+
   switch (TSFlags & X86II::FormMask) {
     case X86II::MRMInitReg:
       // Duplicate register.
@@ -1117,11 +1124,14 @@ void Emitter<CodeEmitter>::emitInstruction(MachineInstr &MI,
   // If this is a two-address instruction, skip one of the register operands.
   unsigned NumOps = Desc->getNumOperands();
   unsigned CurOp = 0;
-  if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) != -1)
+  if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) == 0)
     ++CurOp;
-  else if (NumOps > 2 && Desc->getOperandConstraint(NumOps-1,MCOI::TIED_TO)== 0)
-    // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32
-    --NumOps;
+  else if (NumOps > 3 && Desc->getOperandConstraint(2, MCOI::TIED_TO) == 0) {
+    assert(Desc->getOperandConstraint(NumOps - 1, MCOI::TIED_TO) == 1);
+    // Special case for GATHER with 2 TIED_TO operands
+    // Skip the first 2 operands: dst, mask_wb
+    CurOp += 2;
+  }
 
   uint64_t TSFlags = Desc->TSFlags;