[llvm] [DXIL] Add lowering for `ceil` (PR #87039)

[Helena Kotas via llvm-commits]

https://github.com/hekota created https://github.com/llvm/llvm-project/pull/87039

Add lowering of `llvm.ceil` intrinsics to DXIL ops.

Fixes #86984

>From e9235ed9c9c7cb39c649e5ecc97ae40ad8dc36c8 Mon Sep 17 00:00:00 2001
From: Helena Kotas <hekotas at microsoft.com>
Date: Fri, 29 Mar 2024 00:31:11 -0700
Subject: [PATCH] [DXIL] Add lowering for ceil

---
 llvm/lib/Target/DirectX/DXIL.td         |  3 +++
 llvm/test/CodeGen/DirectX/ceil.ll       | 20 ++++++++++++++++++++
 llvm/test/CodeGen/DirectX/ceil_error.ll | 10 ++++++++++
 3 files changed, 33 insertions(+)
 create mode 100644 llvm/test/CodeGen/DirectX/ceil.ll
 create mode 100644 llvm/test/CodeGen/DirectX/ceil_error.ll

diff --git a/llvm/lib/Target/DirectX/DXIL.td b/llvm/lib/Target/DirectX/DXIL.td
index 1fd6f3ed044ecd..9d41f6fb5181d2 100644
--- a/llvm/lib/Target/DirectX/DXIL.td
+++ b/llvm/lib/Target/DirectX/DXIL.td
@@ -292,6 +292,9 @@ def Round : DXILOpMapping<26, unary, int_round,
 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 FMax : DXILOpMapping<35, binary, int_maxnum,
                          "Float maximum. FMax(a,b) = a > b ? a : b">;
 def FMin : DXILOpMapping<36, binary, int_minnum,
diff --git a/llvm/test/CodeGen/DirectX/ceil.ll b/llvm/test/CodeGen/DirectX/ceil.ll
new file mode 100644
index 00000000000000..ac451824367aad
--- /dev/null
+++ b/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 ceil @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)
diff --git a/llvm/test/CodeGen/DirectX/ceil_error.ll b/llvm/test/CodeGen/DirectX/ceil_error.ll
new file mode 100644
index 00000000000000..1b554d8715566e
--- /dev/null
+++ b/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
+}