Extend the vcmp/fcmp LLVM IR instructions to take vectors as arguments

and, if so, to return a vector of boolean as a result;

Extend the select LLVM IR instruction to allow you to specify a result
type which is a vector of boolean, in which case the result will be an
element-wise selection instead of choosing one vector or the other; and

Update LangRef.html to describe these changes.

This patch was contributed by Preston Gurd!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55969 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 44 insertions, 3 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 0d6b6f2..eeba0e5 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1499,8 +1499,19 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
       Value *TrueVal, *FalseVal, *Cond;
       if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
           getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
-          getValue(Record, OpNum, Type::Int1Ty, Cond))
+          getValue(Record, OpNum, 0 /*skip type check*/, Cond))
         return Error("Invalid SELECT record");
+
+      // select condition can be either i1 or [N x i1]
+      if (const VectorType* vector_type = dyn_cast<const VectorType>(Cond->getType())) {
+        // expect <n x i1>
+        if (vector_type->getElementType() != Type::Int1Ty) 
+          return Error("Invalid SELECT condition type");
+      } else {
+        // expect i1
+        if (Cond->getType() != Type::Int1Ty) 
+          return Error("Invalid SELECT condition type");
+      } 
       
       I = SelectInst::Create(Cond, TrueVal, FalseVal);
       break;
@@ -1563,6 +1574,22 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
         I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
       break;
     }
+    case bitc::FUNC_CODE_INST_VCMP: { // VCMP: [opty, opval, opval, pred]
+      // Fcmp/ICmp returning vector of bool
+      unsigned OpNum = 0;
+      Value *LHS, *RHS;
+      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
+          getValue(Record, OpNum, LHS->getType(), RHS) ||
+          OpNum+1 != Record.size())
+        return Error("Invalid VCMP record");
+      
+      // will always be vector
+      if (LHS->getType()->isFPOrFPVector())
+        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
+      else 
+        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
+      break;
+    }
     case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
       if (Record.size() != 2)
         return Error("Invalid GETRESULT record");
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index b8aab5a..19f5bea 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -641,7 +641,14 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
       case Instruction::FCmp:
       case Instruction::VICmp:
       case Instruction::VFCmp:
-        Code = bitc::CST_CODE_CE_CMP;
+        if (isa<VectorType>(C->getOperand(0)->getType())
+            && (CE->getOpcode() == Instruction::ICmp
+                || CE->getOpcode() == Instruction::FCmp)) {
+          // compare returning vector of Int1Ty
+          assert(0 && "Unsupported constant!");
+        } else {
+          Code = bitc::CST_CODE_CE_CMP;
+        }
         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
         Record.push_back(VE.getValueID(C->getOperand(0)));
         Record.push_back(VE.getValueID(C->getOperand(1)));
@@ -765,7 +772,14 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
   case Instruction::FCmp:
   case Instruction::VICmp:
   case Instruction::VFCmp:
-    Code = bitc::FUNC_CODE_INST_CMP;
+    if (isa<VectorType>(I.getOperand(0)->getType())
+        && (I.getOpcode() == Instruction::ICmp
+            || I.getOpcode() == Instruction::FCmp)) {
+      // compare returning vector of Int1Ty
+      Code = bitc::FUNC_CODE_INST_VCMP;
+    } else {
+      Code = bitc::FUNC_CODE_INST_CMP;
+    }
     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
     Vals.push_back(VE.getValueID(I.getOperand(1)));
     Vals.push_back(cast<CmpInst>(I).getPredicate());