Fix Varying Variable Location Assignments With Hull Shaders (#4915)

* Fix Varying Variable Location Assignments With Hull Shaders

Fixes: #4913
Fixes: #4540

Changes:
1. Added `kIROp_ControlBarrier` to HLSL/GLSL emitting.
2. Added a method to track 'used' and 'unused' varyings for when legalizing GLSL. This allows us to assign correct offsets to automatically added varyings
    * Added a `ZeroLSB` check to UIntSet for this purpose

* add missing return

* code comment adjustment

* cleanup

* comment and HLSL controlBarrier mistake

* assume space for glsl/spriv varying is irrelevant

2 files changed, 109 insertions, 0 deletions

diff --git a/tests/hlsl/simple-hull-shader-1.slang b/tests/hlsl/simple-hull-shader-1.slang
new file mode 100644
index 000000000..20033ed37
--- /dev/null
+++ b/tests/hlsl/simple-hull-shader-1.slang
@@ -0,0 +1,53 @@
+//TEST:SIMPLE(filecheck=HLSL):-target hlsl -entry hullMain -stage hull -allow-glsl
+//TEST:SIMPLE(filecheck=GLSL):-target glsl -entry hullMain -stage hull -allow-glsl
+// Currently SPIR-V fails to compile this hull shader (#4914)
+//DISABLE_TEST:SIMPLE(filecheck=SPIRV):-target spirv -entry hullMain -stage hull -allow-glsl
+
+//HLSL: hullMain
+
+//GLSL-DAG: location = 0
+//GLSL-DAG: location = 1
+//GLSL-DAG: location = 2
+
+//SPIRV-DAG: location 0
+//SPIRV-DAG: location 1
+//SPIRV-DAG: location 2
+
+struct HsOut
+{
+    float2 pos;
+    float2 hm;
+};
+
+struct HscOut
+{
+    float EdgeTessFactor[4] : SV_TessFactor;
+    float InsideTessFactor[2] : SV_InsideTessFactor;
+    uint instanceId;
+};
+
+[domain("quad")]
+[partitioning("integer")]
+[outputtopology("triangle_ccw")]
+[outputcontrolpoints(4)]
+[patchconstantfunc("constants")]
+HsOut hullMain()
+{
+    HsOut o;
+    o.pos = 1;
+    o.hm = 2;
+    return o;
+}
+
+HscOut constants()
+{
+    HscOut o;
+    o.instanceId = 123;
+    o.EdgeTessFactor[0] = 1;
+    o.EdgeTessFactor[1] = 2;
+    o.EdgeTessFactor[2] = 3;
+    o.EdgeTessFactor[3] = 4;
+    o.InsideTessFactor[0] = 0.5;
+    o.InsideTessFactor[1] = 0.5;
+    return o;
+}
\ No newline at end of file
diff --git a/tests/hlsl/simple-hull-shader-2.slang b/tests/hlsl/simple-hull-shader-2.slang
new file mode 100644
index 000000000..bc3b34971
--- /dev/null
+++ b/tests/hlsl/simple-hull-shader-2.slang
@@ -0,0 +1,56 @@
+//TEST:SIMPLE(filecheck=GLSL):-target glsl -entry hullMain -stage hull -allow-glsl
+
+// Currently SPIR-V fails to compile this hull shader (#4914)
+//DISABLE_TEST:SIMPLE(filecheck=SPIRV):-target spirv -entry hullMain -stage hull -allow-glsl
+
+//GLSL-DAG: location = 0
+//GLSL-DAG: location = 1
+//GLSL-DAG: location = 2
+//GLSL-DAG: location = 3
+
+//SPIRV-DAG: location 0
+//SPIRV-DAG: location 1
+//SPIRV-DAG: location 2
+//SPIRV-DAG: location 3
+
+
+struct HsOut
+{
+    float2 pos;
+    float2 hm;
+};
+
+struct HscOut
+{
+    uint roundingFactor;
+    float EdgeTessFactor[4] : SV_TessFactor;
+    float InsideTessFactor[2] : SV_InsideTessFactor;
+    uint instanceId;
+};
+
+[domain("quad")]
+[partitioning("integer")]
+[outputtopology("triangle_ccw")]
+[outputcontrolpoints(4)]
+[patchconstantfunc("constants")]
+HsOut hullMain()
+{
+    HsOut o;
+    o.pos = 1;
+    o.hm = 2;
+    return o;
+}
+
+HscOut constants()
+{
+    HscOut o;
+    o.instanceId = 123;
+    o.roundingFactor = 6;
+    o.EdgeTessFactor[0] = 1;
+    o.EdgeTessFactor[1] = 2;
+    o.EdgeTessFactor[2] = 3;
+    o.EdgeTessFactor[3] = 4;
+    o.InsideTessFactor[0] = 0.5;
+    o.InsideTessFactor[1] = 0.5;
+    return o;
+}
\ No newline at end of file