Rebased dxil_td/precise-overload-specification branch and

to create this branch

Reverted classification of valid overload specification based on
Shader Model version for sin. Will specify minimum DXIL Version
for DXIL Ops.

Author: bharadwajy

llvm/lib/Target/DirectX/DXIL.td

@@ -111,9 +111,10 @@ let OpClass = unary in {
 
   def Cos  : DXILOpMapping<12, int_cos, [DXILOpOverload<SM6_0, [llvm_half_ty, llvm_float_ty]>],
                           "Returns cosine(theta) for theta in radians.">;
-  def Sin  : DXILOpMapping<13, int_sin, [DXILOpOverload<SM6_2, [llvm_half_ty, llvm_float_ty]>,
-                                         DXILOpOverload<SM6_0, [llvm_float_ty]>],
+  def Sin  : DXILOpMapping<13, int_sin, [DXILOpOverload<SM6_0, [llvm_half_ty, llvm_float_ty]>],
                            "Returns sine(theta) for theta in radians.">;
+  def Tan  : DXILOpMapping<14, int_tan, [DXILOpOverload<SM6_0, [llvm_half_ty, llvm_float_ty]>],
+                           "Returns tangent(theta) for theta in radians.">;
   def Exp2 : DXILOpMapping<21, int_exp2, [DXILOpOverload<SM6_0, [llvm_half_ty, llvm_float_ty]>],
                            "Returns the base 2 exponential, or 2**x, of the"
                            " specified value. exp2(x) = 2**x.">;

llvm/test/CodeGen/DirectX/sin_sm_62.ll renamed to llvm/test/CodeGen/DirectX/sin.ll

@@ -1,5 +1,4 @@
 ; RUN: opt -S -dxil-op-lower -mtriple=dxil-pc-shadermodel6.3-library %s | FileCheck %s -check-prefix=SM6_3
-; Half and float are valid for SM6.2 and later
 ; SM6_3: call half @dx.op.unary.f16(i32 13, half %{{.*}})
 ; SM6_3: call float @dx.op.unary.f32(i32 13, float %{{.*}})
 

llvm/test/CodeGen/DirectX/sin_sm_60.ll

@@ -1,4 +1,4 @@
-; RUN: opt -S -dxil-op-lower < %s | FileCheck %s
+; RUN: opt -S -dxil-op-lower -mtriple=dxil-pc-shadermodel6.0-library %s | FileCheck %s
 
 ; Make sure dxil operation function calls for tan are generated for float and half.
 

llvm/test/CodeGen/DirectX/sin_sm_60_error.ll

@@ -1,4 +1,4 @@
-; RUN: not opt -S -dxil-op-lower %s 2>&1 | FileCheck %s
+; RUN: not opt -S -dxil-op-lower -mtriple=dxil-pc-shadermodel6.0-library %s 2>&1 | FileCheck %s
 
 ; DXIL operation tan does not support double overload type
 ; CHECK: LLVM ERROR: Invalid Overload