Cost model support for lowered math builtins.

We make the cost for calling libm functions extremely high as emitting the
calls is expensive and causes spills (on x86) so performance suffers. We still
vectorize important calls like ceilf and friends on SSE4.1. and fabs.

Differential Revision: http://llvm-reviews.chandlerc.com/D466

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176287 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/CostModel.cpp

@@ -23,6 +23,7 @@
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Value.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/Debug.h"
@@ -189,6 +190,16 @@ unsigned CostModelAnalysis::getInstructionCost(const Instruction *I) const {
                                  0);
     return -1;
   }
+  case Instruction::Call:
+    if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
+      SmallVector<Type*, 4> Tys;
+      for (unsigned J = 0, JE = II->getNumArgOperands(); J != JE; ++J)
+        Tys.push_back(II->getArgOperand(J)->getType());
+
+      return TTI->getIntrinsicInstrCost(II->getIntrinsicID(), II->getType(),
+                                        Tys);
+    }
+    return -1;
   default:
     // We don't have any information on this instruction.
     return -1;