[llvm] r298453 - GlobalISel: respect BooleanContents when extending i1.

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Tue Mar 21 17:22:05 2017
New Revision: 298453

URL: http://llvm.org/viewvc/llvm-project?rev=298453&view=rev
Log:
GlobalISel: respect BooleanContents when extending i1.

The world isn't just x86 & ARM, some targets need to store -1 into the byte
when legalizing a bool store.

Modified:
    llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

Modified: llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp?rev=298453&r1=298452&r2=298453&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp Tue Mar 21 17:22:05 2017
@@ -428,12 +428,24 @@ LegalizerHelper::widenScalar(MachineInst
     return Legalized;
   }
   case TargetOpcode::G_STORE: {
-    assert(alignTo(MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(), 8) ==
-               WideTy.getSizeInBits() &&
-           "illegal to increase number of bytes modified by a store");
+    if (MRI.getType(MI.getOperand(0).getReg()) != LLT::scalar(1) ||
+        WideTy != LLT::scalar(8))
+      return UnableToLegalize;
+
+    auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
+    auto Content = TLI.getBooleanContents(false, false);
+
+    unsigned ExtOp = TargetOpcode::G_ANYEXT;
+    if (Content == TargetLoweringBase::ZeroOrOneBooleanContent)
+      ExtOp = TargetOpcode::G_ZEXT;
+    else if (Content == TargetLoweringBase::ZeroOrNegativeOneBooleanContent)
+      ExtOp = TargetOpcode::G_SEXT;
+    else
+      ExtOp = TargetOpcode::G_ANYEXT;
 
     unsigned SrcExt = MRI.createGenericVirtualRegister(WideTy);
-    MIRBuilder.buildZExt(SrcExt, MI.getOperand(0).getReg());
+    MIRBuilder.buildInstr(ExtOp).addDef(SrcExt).addUse(
+        MI.getOperand(0).getReg());
     MIRBuilder.buildStore(SrcExt, MI.getOperand(1).getReg(),
                           **MI.memoperands_begin());
     MI.eraseFromParent();