[clang] [llvm] [HLSL][DXIL] Implement WaveGetLaneIndex Intrinsic (PR #111576)

via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 8 15:18:46 PDT 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-codegen

Author: Finn Plummer (inbelic)

<details>
<summary>Changes</summary>

    - add additional lowering for directx backend in CGBuiltin.cpp
    - add directx intrinsic to IntrinscsDirectX.td
    - add semantic check of arguments in SemaHLSL.cpp
    - add mapping to DXIL op in DXIL.td

    - add testing of semantics in WaveGetLaneIndex-errors.hlsl
    - add testing of dxil lowering in WaveGetLaneIndex.ll
  
Resolves #<!-- -->70105 

---
Full diff: https://github.com/llvm/llvm-project/pull/111576.diff


7 Files Affected:

- (modified) clang/lib/CodeGen/CGBuiltin.cpp (+15-3) 
- (modified) clang/lib/Sema/SemaHLSL.cpp (+5) 
- (modified) clang/test/CodeGenHLSL/builtins/wave_get_lane_index_simple.hlsl (+14-6) 
- (added) clang/test/SemaHLSL/BuiltIns/WaveGetLaneIndex-errors.hlsl (+6) 
- (modified) llvm/include/llvm/IR/IntrinsicsDirectX.td (+1) 
- (modified) llvm/lib/Target/DirectX/DXIL.td (+9) 
- (added) llvm/test/CodeGen/DirectX/WaveGetLaneIndex.ll (+10) 


``````````diff
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index da3eca73bfb575..803bdbaa0e7e01 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -18827,9 +18827,21 @@ case Builtin::BI__builtin_hlsl_elementwise_isinf: {
         ArrayRef<Value *>{Op0, Op1}, nullptr, "hlsl.step");
   }
   case Builtin::BI__builtin_hlsl_wave_get_lane_index: {
-    return EmitRuntimeCall(CGM.CreateRuntimeFunction(
-        llvm::FunctionType::get(IntTy, {}, false), "__hlsl_wave_get_lane_index",
-        {}, false, true));
+    // Since we don't define a SPIR-V intrinsic for the SPIR-V built-in from
+    // SPIRVBuiltins.td, manually get the matching name for the DirectX
+    // intrinsic and the demangled builtin name
+    switch (CGM.getTarget().getTriple().getArch()) {
+    case llvm::Triple::dxil:
+      return EmitRuntimeCall(Intrinsic::getDeclaration(
+          &CGM.getModule(), Intrinsic::dx_waveGetLaneIndex));
+    case llvm::Triple::spirv:
+      return EmitRuntimeCall(CGM.CreateRuntimeFunction(
+          llvm::FunctionType::get(IntTy, {}, false),
+          "__hlsl_wave_get_lane_index", {}, false, true));
+    default:
+      llvm_unreachable(
+          "Intrinsic WaveGetLaneIndex not supported by target architecture");
+    }
   }
   case Builtin::BI__builtin_hlsl_wave_is_first_lane: {
     Intrinsic::ID ID = CGM.getHLSLRuntime().getWaveIsFirstLaneIntrinsic();
diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp
index 43cc6c81ae5cb0..7d93f41bb2d7a0 100644
--- a/clang/lib/Sema/SemaHLSL.cpp
+++ b/clang/lib/Sema/SemaHLSL.cpp
@@ -1956,6 +1956,11 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
       return true;
     break;
   }
+  case Builtin::BI__builtin_hlsl_wave_get_lane_index: {
+    if (SemaRef.checkArgCount(TheCall, 0))
+      return true;
+    break;
+  }
   case Builtin::BI__builtin_elementwise_acos:
   case Builtin::BI__builtin_elementwise_asin:
   case Builtin::BI__builtin_elementwise_atan:
diff --git a/clang/test/CodeGenHLSL/builtins/wave_get_lane_index_simple.hlsl b/clang/test/CodeGenHLSL/builtins/wave_get_lane_index_simple.hlsl
index 8f52d81091c180..e76d35a86e512a 100644
--- a/clang/test/CodeGenHLSL/builtins/wave_get_lane_index_simple.hlsl
+++ b/clang/test/CodeGenHLSL/builtins/wave_get_lane_index_simple.hlsl
@@ -1,14 +1,22 @@
 // RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -x hlsl -triple \
-// RUN:   spirv-pc-vulkan-library %s -emit-llvm -disable-llvm-passes -o - | FileCheck %s
+// RUN:   spirv-pc-vulkan-library %s -emit-llvm -disable-llvm-passes -o - | FileCheck %s \
+// RUN:   --check-prefixes=CHECK,CHECK-SPIRV
+// RUN: %clang_cc1 -finclude-default-header \
+// RUN:   -triple dxil-pc-shadermodel6.3-library %s \
+// RUN:   -emit-llvm -disable-llvm-passes -o - | FileCheck %s \
+// RUN:   --check-prefixes=CHECK,CHECK-DXIL
 
-// CHECK: define spir_func noundef i32 @_Z6test_1v() [[A0:#[0-9]+]] {
-// CHECK: %[[CI:[0-9]+]] = call token @llvm.experimental.convergence.entry()
-// CHECK: call i32 @__hlsl_wave_get_lane_index() [ "convergencectrl"(token %[[CI]]) ]
-uint test_1() {
+// CHECK-SPIRV: define spir_func noundef i32 @{{.*test_1.*}}() [[A0:#[0-9]+]] {
+// CHECK-DXIL: define noundef i32 @{{.*test_1.*}}() [[A0:#[0-9]+]] {
+// CHECK-SPIRV: %[[CI:[0-9]+]] = call token @llvm.experimental.convergence.entry()
+// CHECK-SPIRV: call i32 @__hlsl_wave_get_lane_index() [ "convergencectrl"(token %[[CI]]) ]
+// CHECK-DXIL: call i32 @llvm.dx.waveGetLaneIndex()
+int test_1() {
   return WaveGetLaneIndex();
 }
 
-// CHECK: declare i32 @__hlsl_wave_get_lane_index() [[A1:#[0-9]+]]
+// CHECK-SPIRV: declare i32 @__hlsl_wave_get_lane_index() [[A1:#[0-9]+]]
+// CHECK-DXIL: declare i32 @llvm.dx.waveGetLaneIndex() [[A1:#[0-9]+]]
 
 // CHECK-DAG: attributes [[A0]] = { {{.*}}convergent{{.*}} }
 // CHECK-DAG: attributes [[A1]] = { {{.*}}convergent{{.*}} }
diff --git a/clang/test/SemaHLSL/BuiltIns/WaveGetLaneIndex-errors.hlsl b/clang/test/SemaHLSL/BuiltIns/WaveGetLaneIndex-errors.hlsl
new file mode 100644
index 00000000000000..94cfd0662b5fc3
--- /dev/null
+++ b/clang/test/SemaHLSL/BuiltIns/WaveGetLaneIndex-errors.hlsl
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm-only -disable-llvm-passes -verify -verify-ignore-unexpected
+
+int test_too_many_arg(int x) {
+  return __builtin_hlsl_wave_get_lane_index(x);
+  // expected-error at -1 {{too many arguments to function call, expected 0, have 1}}
+}
diff --git a/llvm/include/llvm/IR/IntrinsicsDirectX.td b/llvm/include/llvm/IR/IntrinsicsDirectX.td
index 555877e7aaf0e5..585cb2b7b300df 100644
--- a/llvm/include/llvm/IR/IntrinsicsDirectX.td
+++ b/llvm/include/llvm/IR/IntrinsicsDirectX.td
@@ -82,6 +82,7 @@ def int_dx_imad : DefaultAttrsIntrinsic<[llvm_anyint_ty], [LLVMMatchType<0>, LLV
 def int_dx_umad : DefaultAttrsIntrinsic<[llvm_anyint_ty], [LLVMMatchType<0>, LLVMMatchType<0>, LLVMMatchType<0>], [IntrNoMem]>;
 def int_dx_normalize : DefaultAttrsIntrinsic<[LLVMMatchType<0>], [llvm_anyfloat_ty], [IntrNoMem]>;
 def int_dx_rsqrt  : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>], [IntrNoMem]>;
+def int_dx_waveGetLaneIndex : DefaultAttrsIntrinsic<[llvm_i32_ty], [], [IntrConvergent, IntrNoMem]>;
 def int_dx_wave_is_first_lane : DefaultAttrsIntrinsic<[llvm_i1_ty], [], [IntrConvergent]>;
 def int_dx_sign : DefaultAttrsIntrinsic<[LLVMScalarOrSameVectorWidth<0, llvm_i32_ty>], [llvm_any_ty], [IntrNoMem]>;
 def int_dx_step : DefaultAttrsIntrinsic<[LLVMMatchType<0>], [llvm_anyfloat_ty, LLVMMatchType<0>], [IntrNoMem]>;
diff --git a/llvm/lib/Target/DirectX/DXIL.td b/llvm/lib/Target/DirectX/DXIL.td
index 9aa0af3e3a6b17..f0db3b4c165e41 100644
--- a/llvm/lib/Target/DirectX/DXIL.td
+++ b/llvm/lib/Target/DirectX/DXIL.td
@@ -801,3 +801,12 @@ def WaveIsFirstLane :  DXILOp<110, waveIsFirstLane> {
   let stages = [Stages<DXIL1_0, [all_stages]>];
   let attributes = [Attributes<DXIL1_0, [ReadNone]>];
 }
+
+def WaveGetLaneIndex : DXILOp<111, waveGetLaneIndex> {
+  let Doc = "returns the index of the current lane in the wave";
+  let LLVMIntrinsic = int_dx_waveGetLaneIndex;
+  let arguments = [];
+  let result = Int32Ty;
+  let stages = [Stages<DXIL1_0, [all_stages]>];
+  let attributes = [Attributes<DXIL1_0, [ReadNone]>];
+}
diff --git a/llvm/test/CodeGen/DirectX/WaveGetLaneIndex.ll b/llvm/test/CodeGen/DirectX/WaveGetLaneIndex.ll
new file mode 100644
index 00000000000000..0b1c96976f594a
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/WaveGetLaneIndex.ll
@@ -0,0 +1,10 @@
+; RUN: opt -S  -dxil-op-lower  -mtriple=dxil-pc-shadermodel6.3-compute %s | FileCheck %s
+
+define void @main() {
+entry:
+; CHECK: call i32 @dx.op.waveGetLaneIndex(i32 111)
+  %0 = call i32 @llvm.dx.waveGetLaneIndex()
+  ret void
+}
+
+declare i32 @llvm.dx.waveGetLaneIndex()

``````````

</details>


https://github.com/llvm/llvm-project/pull/111576


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