AMDGPU: Add frexp_exp intrinsic

llvm-svn: 264944

1 files changed, 16 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 19d81fac778..3132fe86c47 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1846,17 +1846,28 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
 
     break;
   }
-  case Intrinsic::amdgcn_frexp_mant: {
+  case Intrinsic::amdgcn_frexp_mant:
+  case Intrinsic::amdgcn_frexp_exp: {
     Value *Src = II->getArgOperand(0);
     if (const ConstantFP *C = dyn_cast<ConstantFP>(Src)) {
       int Exp;
       APFloat Significand = frexp(C->getValueAPF(), Exp,
                                   APFloat::rmNearestTiesToEven);
 
-      return replaceInstUsesWith(CI, ConstantFP::get(II->getContext(),
-                                                     Significand));
-    } else if (isa<UndefValue>(Src))
-      return replaceInstUsesWith(CI, Src);
+      if (II->getIntrinsicID() == Intrinsic::amdgcn_frexp_mant) {
+        return replaceInstUsesWith(CI, ConstantFP::get(II->getContext(),
+                                                       Significand));
+      }
+
+      // Match instruction special case behavior.
+      if (Exp == APFloat::IEK_NaN || Exp == APFloat::IEK_Inf)
+        Exp = 0;
+
+      return replaceInstUsesWith(CI, ConstantInt::get(II->getType(), Exp));
+    }
+
+    if (isa<UndefValue>(Src))
+      return replaceInstUsesWith(CI, UndefValue::get(II->getType()));
 
     break;
   }