[clang] [llvm] [HLSL] Implement elementwise firstbitlow builtin (PR #116858)

[Ashley Coleman via llvm-commits]

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@@ -0,0 +1,168 @@
+; RUN: llc -verify-machineinstrs -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: [[glsl_450_ext:%.+]] = OpExtInstImport "GLSL.std.450"
+; CHECK-DAG: OpMemoryModel Logical GLSL450
+; CHECK-DAG: [[u32_t:%.+]] = OpTypeInt 32 0
+; CHECK-DAG: [[u32x2_t:%.+]] = OpTypeVector [[u32_t]] 2
+; CHECK-DAG: [[u32x3_t:%.+]] = OpTypeVector [[u32_t]] 3
+; CHECK-DAG: [[u32x4_t:%.+]] = OpTypeVector [[u32_t]] 4
+; CHECK-DAG: [[const_0:%.*]] = OpConstant [[u32_t]] 0
+; CHECK-DAG: [[const_0x2:%.*]] = OpConstantComposite [[u32x2_t]] [[const_0]] [[const_0]]
+; CHECK-DAG: [[const_0x3:%.*]] = OpConstantComposite [[u32x3_t]] [[const_0]] [[const_0]] [[const_0]]
+; CHECK-DAG: [[const_1:%.*]] = OpConstant [[u32_t]] 1
+; CHECK-DAG: [[const_32:%.*]] = OpConstant [[u32_t]] 32
+; CHECK-DAG: [[const_32x2:%.*]] = OpConstantComposite [[u32x2_t]] [[const_32]] [[const_32]]
+; CHECK-DAG: [[const_32x3:%.*]] = OpConstantComposite [[u32x3_t]] [[const_32]] [[const_32]] [[const_32]]
+; CHECK-DAG: [[const_neg1:%.*]] = OpConstant [[u32_t]] 4294967295
+; CHECK-DAG: [[const_neg1x2:%.*]] = OpConstantComposite [[u32x2_t]] [[const_neg1]] [[const_neg1]]
+; CHECK-DAG: [[const_neg1x3:%.*]] = OpConstantComposite [[u32x3_t]] [[const_neg1]] [[const_neg1]] [[const_neg1]]
+; CHECK-DAG: [[u16_t:%.+]] = OpTypeInt 16 0
+; CHECK-DAG: [[u16x2_t:%.+]] = OpTypeVector [[u16_t]] 2
+; CHECK-DAG: [[u16x3_t:%.+]] = OpTypeVector [[u16_t]] 3
+; CHECK-DAG: [[u16x4_t:%.+]] = OpTypeVector [[u16_t]] 4
+; CHECK-DAG: [[u64_t:%.+]] = OpTypeInt 64 0
+; CHECK-DAG: [[u64x2_t:%.+]] = OpTypeVector [[u64_t]] 2
+; CHECK-DAG: [[u64x3_t:%.+]] = OpTypeVector [[u64_t]] 3
+; CHECK-DAG: [[bool_t:%.+]] = OpTypeBool
+; CHECK-DAG: [[boolx2_t:%.+]] = OpTypeVector [[bool_t]] 2
+; CHECK-DAG: [[boolx3_t:%.+]] = OpTypeVector [[bool_t]] 3
+
+; CHECK-LABEL: Begin function firstbitlow_i32
+define noundef i32 @firstbitlow_i32(i32 noundef %a) {
+entry:
+; CHECK: [[a:%.+]] = OpFunctionParameter [[u32_t]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32_t]] [[glsl_450_ext]] FindILsb [[a]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call i32 @llvm.spv.firstbitlow.i32(i32 %a)
+  ret i32 %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v2xi32
+define noundef <2 x i32> @firstbitlow_v2xi32(<2 x i32> noundef %a) {
+entry:
+; CHECK: [[a:%.+]] = OpFunctionParameter [[u32x2_t]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32x2_t]] [[glsl_450_ext]] FindILsb [[a]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <2 x i32> @llvm.spv.firstbitlow.v2i32(<2 x i32> %a)
+  ret <2 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v3xi32
+define noundef <3 x i32> @firstbitlow_v3xi32(<3 x i32> noundef %a) {
+entry:
+; CHECK: [[a:%.+]] = OpFunctionParameter [[u32x3_t]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32x3_t]] [[glsl_450_ext]] FindILsb [[a]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <3 x i32> @llvm.spv.firstbitlow.v3i32(<3 x i32> %a)
+  ret <3 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v4xi32
+define noundef <4 x i32> @firstbitlow_v4xi32(<4 x i32> noundef %a) {
+entry:
+; CHECK: [[a:%.+]] = OpFunctionParameter [[u32x4_t]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32x4_t]] [[glsl_450_ext]] FindILsb [[a]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <4 x i32> @llvm.spv.firstbitlow.v4i32(<4 x i32> %a)
+  ret <4 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_i16
+define noundef i32 @firstbitlow_i16(i16 noundef %a) {
+entry:
+; CHECK: [[a16:%.+]] = OpFunctionParameter [[u16_t]]
+; CHECK: [[a32:%.+]] = OpUConvert [[u32_t]] [[a16]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32_t]] [[glsl_450_ext]] FindILsb [[a32]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call i32 @llvm.spv.firstbitlow.i16(i16 %a)
+  ret i32 %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v2i16
+define noundef <2 x i32> @firstbitlow_v2i16(<2 x i16> noundef %a) {
+entry:
+; CHECK: [[a16:%.+]] = OpFunctionParameter [[u16x2_t]]
+; CHECK: [[a32:%.+]] = OpUConvert [[u32x2_t]] [[a16]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32x2_t]] [[glsl_450_ext]] FindILsb [[a32]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <2 x i32> @llvm.spv.firstbitlow.v2i16(<2 x i16> %a)
+  ret <2 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v3xi16
+define noundef <3 x i32> @firstbitlow_v3xi16(<3 x i16> noundef %a) {
+entry:
+; CHECK: [[a16:%.+]] = OpFunctionParameter [[u16x3_t]]
+; CHECK: [[a32:%.+]] = OpUConvert [[u32x3_t]] [[a16]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32x3_t]] [[glsl_450_ext]] FindILsb [[a32]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <3 x i32> @llvm.spv.firstbitlow.v3i16(<3 x i16> %a)
+  ret <3 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v4xi16
+define noundef <4 x i32> @firstbitlow_v4xi16(<4 x i16> noundef %a) {
+entry:
+; CHECK: [[a16:%.+]] = OpFunctionParameter [[u16x4_t]]
+; CHECK: [[a32:%.+]] = OpUConvert [[u32x4_t]] [[a16]]
+; CHECK: [[ret:%.+]] = OpExtInst [[u32x4_t]] [[glsl_450_ext]] FindILsb [[a32]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <4 x i32> @llvm.spv.firstbitlow.v4i16(<4 x i16> %a)
+  ret <4 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_i64
+define noundef i32 @firstbitlow_i64(i64 noundef %a) {
+entry:
+; CHECK: [[a64:%.+]] = OpFunctionParameter [[u64_t]]
+; CHECK: [[a32x2:%.+]] = OpBitcast [[u32x2_t]] [[a64]]
+; CHECK: [[lsb_bits:%.+]] = OpExtInst [[u32x2_t]] [[glsl_450_ext]] FindILsb [[a32x2]]
+; CHECK: [[high_bits:%.+]] = OpVectorExtractDynamic [[u32_t]] [[lsb_bits]] [[const_0]]
+; CHECK: [[low_bits:%.+]] = OpVectorExtractDynamic [[u32_t]] [[lsb_bits]] [[const_1]]
+; CHECK: [[should_use_high:%.+]] = OpIEqual [[bool_t]] [[low_bits]] [[const_neg1]]
+; CHECK: [[ans_bits:%.+]] = OpSelect [[u32_t]] [[should_use_high]] [[high_bits]] [[low_bits]]
+; CHECK: [[ans_offset:%.+]] = OpSelect [[u32_t]] [[should_use_high]] [[const_32]] [[const_0]]
+; CHECK: [[ret:%.+]] = OpIAdd [[u32_t]] [[ans_offset]] [[ans_bits]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call i32 @llvm.spv.firstbitlow.i64(i64 %a)
+  ret i32 %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v2i64
+define noundef <2 x i32> @firstbitlow_v2i64(<2 x i64> noundef %a) {
+entry:
+; CHECK: [[a64x2:%.+]] = OpFunctionParameter [[u64x2_t]]
+; CHECK: [[a32x4:%.+]] = OpBitcast [[u32x4_t]] [[a64x2]]
+; CHECK: [[lsb_bits:%.+]] = OpExtInst [[u32x4_t]] [[glsl_450_ext]] FindILsb [[a32x4]]
+; CHECK: [[high_bits:%.+]] = OpVectorShuffle [[u32x2_t]] [[lsb_bits]] [[lsb_bits]] 0 2
+; CHECK: [[low_bits:%.+]] = OpVectorShuffle [[u32x2_t]] [[lsb_bits]] [[lsb_bits]] 1 3
+; CHECK: [[should_use_high:%.+]] = OpIEqual [[boolx2_t]] [[low_bits]] [[const_neg1x2]]
+; CHECK: [[ans_bits:%.+]] = OpSelect [[u32x2_t]] [[should_use_high]] [[high_bits]] [[low_bits]]
+; CHECK: [[ans_offset:%.+]] = OpSelect [[u32x2_t]] [[should_use_high]] [[const_32x2]] [[const_0x2]]
+; CHECK: [[ret:%.+]] = OpIAdd [[u32x2_t]] [[ans_offset]] [[ans_bits]]
+; CHECK: OpReturnValue [[ret]]
+  %elt.firstbitlow = call <2 x i32> @llvm.spv.firstbitlow.v2i64(<2 x i64> %a)
+  ret <2 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v3i64
+define noundef <3 x i32> @firstbitlow_v3i64(<3 x i64> noundef %a) {
+entry:
+  %elt.firstbitlow = call <3 x i32> @llvm.spv.firstbitlow.v3i64(<3 x i64> %a)
+  ret <3 x i32> %elt.firstbitlow
+}
+
+; CHECK-LABEL: Begin function firstbitlow_v4i64
+define noundef <4 x i32> @firstbitlow_v4i64(<4 x i64> noundef %a) {
+entry:
+  %elt.firstbitlow = call <4 x i32> @llvm.spv.firstbitlow.v4i64(<4 x i64> %a)
+  ret <4 x i32> %elt.firstbitlow
+}
----------------
V-FEXrt wrote:

These tests currently don't pass (in fact they seem to be crashing llc) but I'm out for the next two weeks and I wanted to push them before I was out

https://github.com/llvm/llvm-project/pull/116858