[clang] [llvm] [HLSL][SPIRV][DXIL] Implement `WaveActiveMax` intrinsic (PR #123428)

[Ashley Coleman via llvm-commits]

================
@@ -0,0 +1,46 @@
+// RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -triple \
+// RUN:   dxil-pc-shadermodel6.3-compute %s -emit-llvm -disable-llvm-passes -o - | \
+// RUN:   FileCheck %s --check-prefixes=CHECK,CHECK-DXIL
+// RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -triple \
+// RUN:   spirv-pc-vulkan-compute %s -emit-llvm -disable-llvm-passes -o - | \
+// RUN:   FileCheck %s --check-prefixes=CHECK,CHECK-SPIRV
+
+// Test basic lowering to runtime function call.
+
+// CHECK-LABEL: test_int
+int test_int(int expr) {
+  // CHECK-SPIRV:  %[[RET:.*]] = call spir_func [[TY:.*]] @llvm.spv.wave.reduce.max.i32([[TY]] %[[#]])
+  // CHECK-DXIL:  %[[RET:.*]] = call [[TY:.*]] @llvm.dx.wave.reduce.max.i32([[TY]] %[[#]])
+  // CHECK:  ret [[TY]] %[[RET]]
+  return WaveActiveMax(expr);
+}
+
+// CHECK-DXIL: declare [[TY]] @llvm.dx.wave.reduce.max.i32([[TY]]) #[[#attr:]]
+// CHECK-SPIRV: declare spir_func [[TY]] @llvm.spv.wave.reduce.max.i32([[TY]]) #[[#attr:]]
+
+// CHECK-LABEL: test_uint64_t
+uint64_t test_uint64_t(uint64_t expr) {
+  // CHECK-SPIRV:  %[[RET:.*]] = call spir_func [[TY:.*]] @llvm.spv.wave.reduce.umax.i64([[TY]] %[[#]])
+  // CHECK-DXIL:  %[[RET:.*]] = call [[TY:.*]] @llvm.dx.wave.reduce.umax.i64([[TY]] %[[#]])
+  // CHECK:  ret [[TY]] %[[RET]]
+  return WaveActiveMax(expr);
+}
+
+// CHECK-DXIL: declare [[TY]] @llvm.dx.wave.reduce.umax.i64([[TY]]) #[[#attr:]]
+// CHECK-SPIRV: declare spir_func [[TY]] @llvm.spv.wave.reduce.umax.i64([[TY]]) #[[#attr:]]
+
+// Test basic lowering to runtime function call with array and float value.
+
+// CHECK-LABEL: test_floatv4
+float4 test_floatv4(float4 expr) {
+  // CHECK-SPIRV:  %[[RET1:.*]] = call reassoc nnan ninf nsz arcp afn spir_func [[TY1:.*]] @llvm.spv.wave.reduce.max.v4f32([[TY1]] %[[#]]
+  // CHECK-DXIL:  %[[RET1:.*]] = call reassoc nnan ninf nsz arcp afn [[TY1:.*]] @llvm.dx.wave.reduce.max.v4f32([[TY1]] %[[#]])
+  // CHECK:  ret [[TY1]] %[[RET1]]
+  return WaveActiveMax(expr);
+}
+
+// CHECK-DXIL: declare [[TY1]] @llvm.dx.wave.reduce.max.v4f32([[TY1]]) #[[#attr]]
+// CHECK-SPIRV: declare spir_func [[TY1]] @llvm.spv.wave.reduce.max.v4f32([[TY1]]) #[[#attr]]
+
+// CHECK: attributes #[[#attr]] = {{{.*}} convergent {{.*}}}
+
----------------
V-FEXrt wrote:

oh wait nvm, I got confused. This is the post function stuff I think

https://github.com/llvm/llvm-project/pull/123428