Allow derivatives in coalescing nodes (#7942)

Per the spec (
https://github.com/microsoft/DirectX-Specs/blob/master/d3d/WorkGraphs.md#quad-and-derivative-operation-semantics
) derivatives are allowed in all but thread launch nodes, but the
validator disallowed them in coalescing nodes.

This changes the validator to allow derivatives in coalescind nodes and
adds testing for derivatives in coalescing and broadcast nodes.

Fixes #7723

Author: pow2clk

docs/DXIL.rst

@@ -3304,7 +3304,7 @@ SM.HSINPUTCONTROLPOINTCOUNTRANGE                              HS input control p
 SM.HULLPASSTHRUCONTROLPOINTCOUNTMATCH                         For pass thru hull shader, input control point count must match output control point count
 SM.INCOMPATIBLECALLINENTRY                                    Features used in internal function calls must be compatible with entry
 SM.INCOMPATIBLEDERIVINCOMPUTESHADERMODEL                      Derivatives in compute-model shaders require shader model 6.6 and above
-SM.INCOMPATIBLEDERIVLAUNCH                                    Node shaders only support derivatives in broadcasting launch mode
+SM.INCOMPATIBLEDERIVLAUNCH                                    Node shaders only support derivatives in broadcasting and coalescing launch modes
 SM.INCOMPATIBLEOPERATION                                      Operations used in entry function must be compatible with shader stage and other properties
 SM.INCOMPATIBLEREQUIRESGROUP                                  Functions requiring groupshared memory must be called from shaders with a visible group
 SM.INCOMPATIBLESHADERMODEL                                    Functions may only use features available in the current shader model

lib/DxilValidation/DxilValidation.cpp

@@ -5463,12 +5463,11 @@ struct CompatibilityChecker {
       MaskForDeriv |=
           static_cast<uint32_t>(ConflictFlags::DerivInComputeShaderModel);
     } else if (ShaderKind == DXIL::ShaderKind::Node) {
-      // Only broadcasting launch supports derivatives.
-      if (Props.Node.LaunchType != DXIL::NodeLaunchType::Broadcasting)
-        MaskForDeriv |= static_cast<uint32_t>(ConflictFlags::DerivLaunch);
-      // Thread launch node has no group.
-      if (Props.Node.LaunchType == DXIL::NodeLaunchType::Thread)
+      // Thread launch node has no group and doesn't support derivatives.
+      if (Props.Node.LaunchType == DXIL::NodeLaunchType::Thread) {
         MaskForGroup |= static_cast<uint32_t>(ConflictFlags::RequiresGroup);
+        MaskForDeriv |= static_cast<uint32_t>(ConflictFlags::DerivLaunch);
+      }
     }
 
     if (ShaderKind == DXIL::ShaderKind::Mesh ||

tools/clang/test/HLSLFileCheck/hlsl/objects/Texture/derivatives_in_csmsas.hlsl

@@ -1,13 +1,17 @@
 // RUN: %dxc -DSTAGE=1 -T cs_6_6 %s | FileCheck %s
 // RUN: %dxc -DSTAGE=2 -T as_6_6 %s | FileCheck %s -check-prefixes=CHECK,ASMSCHECK
 // RUN: %dxc -DSTAGE=3 -T ms_6_6 %s | FileCheck %s -check-prefixes=CHECK,ASMSCHECK
+// RUN: %dxc -DSTAGE=4 -T lib_6_8 %s | FileCheck %s
+// RUN: %dxc -DSTAGE=5 -T lib_6_8 %s | FileCheck %s
 // RUN: %dxilver 1.6 | %dxc -DSTAGE=1 -T cs_6_5 -Wno-hlsl-availability %s | FileCheck %s -check-prefix=ERRCHECK
 // RUN: %dxilver 1.6 | %dxc -DSTAGE=2 -T as_6_5 -Wno-hlsl-availability %s | FileCheck %s -check-prefix=ERRCHECK
 // RUN: %dxilver 1.6 | %dxc -DSTAGE=3 -T ms_6_5 -Wno-hlsl-availability %s | FileCheck %s -check-prefix=ERRCHECK
 
 #define CS 1
 #define AS 2
 #define MS 3
+#define BNS 4
+#define CNS 5
 
 // Test 6.6 feature allowing derivative operations in compute shaders
 
@@ -20,13 +24,26 @@ SamplerState samp : register(s5);
 SamplerComparisonState cmpSamp : register(s6);
 float cmpVal;
 
+
+struct NodeRecord {
+   uint w, h;
+};
+
+
 [numthreads( 8, 8, 1 )]
 #if STAGE==MS
 [outputtopology("triangle")]
+#elif STAGE==BNS
+[Shader("node")]
+[NodeLaunch("broadcasting")]
+[NodeDispatchGrid(1, 1, 1)]
+#elif STAGE==CNS
+[Shader("node")]
+[NodeLaunch("coalescing")]
 #endif
-void main( uint GI : SV_GroupIndex, uint3 DTid : SV_DispatchThreadID )
-{
-  float2 uv = DTid.xy/float2(8, 8);
+void main( uint GI : SV_GroupIndex, uint2 GTid : SV_GroupThreadID
+           ) {
+  float2 uv = GTid.xy/float2(8, 8);
   float4 res = 0;
   uint status = 0;
 
@@ -100,8 +117,8 @@ void main( uint GI : SV_GroupIndex, uint3 DTid : SV_DispatchThreadID )
   // ERRCHECK: error: opcode 'Derivatives in CS/MS/AS' should only be used in 'Shader Model 6.6+'
   res += input.SampleCmp(cmpSamp, uv, cmpVal);
   res += input.SampleCmp(cmpSamp, uv, cmpVal, uint2(-3, 4));
-  res += input.SampleCmp(cmpSamp, uv, cmpVal, uint2(-4, 6), DTid.z);
-  res += input.SampleCmp(cmpSamp, uv, cmpVal, uint2(-5, 7), DTid.z, status);
+  res += input.SampleCmp(cmpSamp, uv, cmpVal, uint2(-4, 6), GI);
+  res += input.SampleCmp(cmpSamp, uv, cmpVal, uint2(-5, 7), GI, status);
   res *= status;
 
 #if STAGE == AS

tools/clang/test/HLSLFileCheck/validation/callgraph/deriv-in-nested-fn-node-lib68-launch.ll

@@ -3,7 +3,7 @@
 ; Sample called from node shader is not allowed with thread launch.
 
 ; CHECK: Function: main: error: Entry function calls one or more functions using incompatible features.  See other errors for details.
-; CHECK: Function: {{.*}}fn_sample{{.*}}: error: Function called from Thread launch node shader uses derivatives; only broadcasting launch supports derivatives.
+; CHECK: Function: {{.*}}fn_sample{{.*}}: error: Function called from Thread launch node shader uses derivatives; only broadcasting and coalescing launch modes support derivatives.
 ; CHECK: Function: {{.*}}fn_sample{{.*}}: error: Function uses derivatives in compute-model shader with NumThreads (1, 1, 1); derivatives require NumThreads to be 1D and a multiple of 4, or 2D/3D with X and Y both being a multiple of 2.
 
 target datalayout = "e-m:e-p:32:32-i1:32-i8:32-i16:32-i32:32-i64:64-f16:32-f32:32-f64:64-n8:16:32:64"

utils/hct/hctdb.py

@@ -8668,8 +8668,8 @@ def build_valrules(self):
         )
         self.add_valrule_msg(
             "Sm.IncompatibleDerivLaunch",
-            "Node shaders only support derivatives in broadcasting launch mode",
-            "Function called from %0 launch node shader uses derivatives; only broadcasting launch supports derivatives.",
+            "Node shaders only support derivatives in broadcasting and coalescing launch modes",
+            "Function called from %0 launch node shader uses derivatives; only broadcasting and coalescing launch modes support derivatives.",
         )
 
         # Assign sensible category names and build up an enumeration description