[DXIL] Add lowering for ceil (#87043)

Add lowering of llvm.ceil intrinsics to DXIL ops.

Fixes #86984

Author: hekota

llvm/lib/Target/DirectX/DXIL.td

@@ -292,6 +292,9 @@ def Round : DXILOpMapping<26, unary, int_roundeven,
 def Floor : DXILOpMapping<27, unary, int_floor,
                          "Returns the largest integer that is less than or equal to the input.",
                          [llvm_halforfloat_ty, LLVMMatchType<0>]>;
+def Ceil : DXILOpMapping<28, unary, int_ceil,
+                         "Returns the smallest integer that is greater than or equal to the input.",
+                         [llvm_halforfloat_ty, LLVMMatchType<0>]>;
 def Trunc : DXILOpMapping<29, unary, int_trunc,
                          "Returns the specified value truncated to the integer component.",
                          [llvm_halforfloat_ty, LLVMMatchType<0>]>;

llvm/test/CodeGen/DirectX/ceil.ll

@@ -0,0 +1,20 @@
+; RUN: opt -S -dxil-op-lower < %s | FileCheck %s
+
+; Make sure dxil operation function calls for ceil are generated for float and half.
+
+define noundef float @ceil_float(float noundef %a) {
+entry:
+; CHECK:call float @dx.op.unary.f32(i32 28, float %{{.*}})
+  %elt.ceil = call float @llvm.ceil.f32(float %a)
+  ret float %elt.ceil
+}
+
+define noundef half @ceil_half(half noundef %a) {
+entry:
+; CHECK:call half @dx.op.unary.f16(i32 28, half %{{.*}})
+  %elt.ceil = call half @llvm.ceil.f16(half %a)
+  ret half %elt.ceil
+}
+
+declare half @llvm.ceil.f16(half)
+declare float @llvm.ceil.f32(float)

llvm/test/CodeGen/DirectX/ceil_error.ll

@@ -0,0 +1,10 @@
+; RUN: not opt -S -dxil-op-lower %s 2>&1 | FileCheck %s
+
+; DXIL operation ceil does not support double overload type
+; CHECK: LLVM ERROR: Invalid Overload Type
+
+define noundef double @ceil_double(double noundef %a) {
+entry:
+  %elt.ceil = call double @llvm.ceil.f64(double %a)
+  ret double %elt.ceil
+}