[llvm] [SPIRV] Add trig function lowering (PR #95973)

[Helena Kotas via llvm-commits]

================
@@ -0,0 +1,45 @@
+; RUN: llc -O0 -mtriple=spirv-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-DAG: %[[#op_ext_glsl:]] = OpExtInstImport "GLSL.std.450"
+; CHECK-DAG: %[[#float_32:]] = OpTypeFloat 32
+; CHECK-DAG: %[[#float_16:]] = OpTypeFloat 16
+; CHECK-DAG: %[[#vec4_float_32:]] = OpTypeVector %[[#float_32]] 4
+; CHECK-DAG: %[[#vec4_float_16:]] = OpTypeVector %[[#float_16]] 4
+
+define noundef float @acos_float(float noundef %a) {
+entry:
+; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#]]
+; CHECK: %[[#]] = OpExtInst %[[#float_32]] %[[#op_ext_glsl]] Acos %[[#arg0]]
+  %elt.acos = call float @llvm.acos.f32(float %a)
+  ret float %elt.acos
+}
+
+define noundef half @acos_half(half noundef %a) {
+entry:
+; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#]]
+; CHECK: %[[#]] = OpExtInst %[[#float_16]] %[[#op_ext_glsl]] Acos %[[#arg0]]
+  %elt.acos = call half @llvm.acos.f16(half %a)
+  ret half %elt.acos
+}
+
+define noundef <4 x float> @acos_float4(<4 x float> noundef %a) {
+entry:
+  ; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#]]
+  ; CHECK: %[[#]] = OpExtInst %[[#vec4_float_32]] %[[#op_ext_glsl]] Acos %[[#arg0]]
+  %elt.acos = call <4 x float> @llvm.acos.v4f32(<4 x float> %a)
+  ret <4 x float> %elt.acos
+}
+
+define noundef <4 x half> @acos_half4(<4 x half> noundef %a) {
+entry:
+  ; CHECK: %[[#arg0:]] = OpFunctionParameter %[[#]]
+  ; CHECK: %[[#]] = OpExtInst %[[#vec4_float_16]] %[[#op_ext_glsl]] Acos %[[#arg0]]
+  %elt.acos = call <4 x half> @llvm.acos.v4f16(<4 x half> %a)
+  ret <4 x half> %elt.acos
+}
+
+declare half @llvm.acos.f16(half)
+declare float @llvm.acos.f32(float)
+declare <4 x half> @llvm.acos.v4f16(<4 x half>)
+declare <4 x float> @llvm.acos.v4f32(<4 x float>)
----------------
hekota wrote:

Does SPIR-V support these for `double`? If yes, it would be good to add test cases for that too.

https://github.com/llvm/llvm-project/pull/95973