AMDGPU: Add frexp_exp intrinsic

llvm-svn: 264944

2 files changed, 18 insertions, 7 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIInstructions.td b/llvm/lib/Target/AMDGPU/SIInstructions.td
index 2f7f908e4a5..bc0afa0a81c 100644
--- a/llvm/lib/Target/AMDGPU/SIInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SIInstructions.td
@@ -1344,7 +1344,7 @@ defm V_FFBH_U32 : VOP1Inst <vop1<0x39, 0x2d>, "v_ffbh_u32", VOP_I32_I32>;
 defm V_FFBL_B32 : VOP1Inst <vop1<0x3a, 0x2e>, "v_ffbl_b32", VOP_I32_I32>;
 defm V_FFBH_I32 : VOP1Inst <vop1<0x3b, 0x2f>, "v_ffbh_i32", VOP_I32_I32>;
 defm V_FREXP_EXP_I32_F64 : VOP1Inst <vop1<0x3c,0x30>, "v_frexp_exp_i32_f64",
-  VOP_I32_F64
+  VOP_I32_F64, int_amdgcn_frexp_exp
 >;
 
 let SchedRW = [WriteDoubleAdd] in {
@@ -1359,7 +1359,7 @@ defm V_FRACT_F64 : VOP1Inst <vop1<0x3e, 0x32>, "v_fract_f64",
 
 
 defm V_FREXP_EXP_I32_F32 : VOP1Inst <vop1<0x3f, 0x33>, "v_frexp_exp_i32_f32",
-  VOP_I32_F32
+  VOP_I32_F32, int_amdgcn_frexp_exp
 >;
 defm V_FREXP_MANT_F32 : VOP1Inst <vop1<0x40, 0x34>, "v_frexp_mant_f32",
   VOP_F32_F32, int_amdgcn_frexp_mant
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;
   }