Detect and deduplicate read-only resource access. (#2680)

* Detect and deduplicate read-only resource access.

* Fix tests.

* Fix tests.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

8 files changed, 87 insertions, 60 deletions

diff --git a/tests/autodiff/global-param-hoisting.slang b/tests/autodiff/global-param-hoisting.slang
new file mode 100644
index 000000000..72a9494fe
--- /dev/null
+++ b/tests/autodiff/global-param-hoisting.slang
@@ -0,0 +1,42 @@
+// Test that the compiler can hoist the texture sample out of the loop.
+// We currently have no way to verify the hoist actually take place, but this test
+// allows us to manually inspect the generated code to see that happen.
+// TODO: use a pattern checker on the resulting code to make sure there is only
+// one call to `SampleLevel`.
+
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj -output-using-type
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX:-vk -compute -shaderobj -output-using-type
+//TEST(compute):COMPARE_COMPUTE_EX:-cpu -compute -output-using-type -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+struct Params : IDifferentiable
+{
+    Texture2D tex;
+    SamplerState sampler;
+}
+
+//TEST_INPUT:set gParams = new Params{Texture2D(size=4, content=one), Sampler}
+ParameterBlock<Params> gParams;
+
+[BackwardDifferentiable]
+float f(float x)
+{
+    float sum = 0.0;
+    for (int i = 0; i < 3; i++)
+    {
+        float t = (no_diff gParams.tex.SampleLevel(gParams.sampler, float2(0.0), 0)).x;
+        sum += t * x * x;
+    }
+    return sum;
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    var dpa = diffPair(3.0);
+
+    __bwd_diff(f)(dpa, 1.0);
+    outputBuffer[0] = dpa.d.x; // Expect: 18
+}
diff --git a/tests/autodiff/global-param-hoisting.slang.expected.txt b/tests/autodiff/global-param-hoisting.slang.expected.txt
new file mode 100644
index 000000000..05d0a2ffd
--- /dev/null
+++ b/tests/autodiff/global-param-hoisting.slang.expected.txt
@@ -0,0 +1,6 @@
+type: float
+18.000000
+0.000000
+0.000000
+0.000000
+0.000000
diff --git a/tests/bindings/glsl-parameter-blocks.slang.glsl b/tests/bindings/glsl-parameter-blocks.slang.glsl
index a27fbb3db..03e4e8774 100644
--- a/tests/bindings/glsl-parameter-blocks.slang.glsl
+++ b/tests/bindings/glsl-parameter-blocks.slang.glsl
@@ -1,52 +1,31 @@
-//TEST_IGNORE_FILE:
-#version 450 core
-
-#define Test Test_0
-#define a a_0
-
-#define gTest gTest_0
-#define gTest_t gTest_t_0
-#define gTest_s gTest_s_0
-
-#define ParameterBlock_gTest _S1
-
-#define main_result _S2
-#define uv _S3
-
-#define temp_a _S4
-#define temp_sample _S5
-#define temp_add _S2
-
-struct Test
+#version 450
+layout(row_major) uniform;
+layout(row_major) buffer;
+struct Test_0
 {
-    vec4 a;
+    vec4 a_0;
 };
 
 layout(binding = 0)
-uniform ParameterBlock_gTest
+layout(std140) uniform _S1
 {
-    Test _data;
-} gTest;
-
+    Test_0 _data;
+} gTest_0;
 layout(binding = 1)
-uniform texture2D gTest_t;
+uniform texture2D gTest_t_0;
 
 layout(binding = 2)
-uniform sampler gTest_s;
+uniform sampler gTest_s_0;
 
 layout(location = 0)
-out vec4 main_result;
+out vec4 _S2;
 
 layout(location = 0)
-in vec2 uv;
+in vec2 _S3;
 
 void main()
 {
-	vec4 temp_a = gTest._data.a;
-
-    vec4 temp_sample = texture(sampler2D(gTest_t, gTest_s), uv);
-
-    main_result = temp_a + temp_sample;
-
-	return;
+    vec4 _S4 = (texture(sampler2D(gTest_t_0,gTest_s_0), (_S3)));
+    _S2 = gTest_0._data.a_0 + _S4;
+    return;
 }
diff --git a/tests/bindings/multiple-parameter-blocks.slang b/tests/bindings/multiple-parameter-blocks.slang
index 29eea6766..0f247319d 100644
--- a/tests/bindings/multiple-parameter-blocks.slang
+++ b/tests/bindings/multiple-parameter-blocks.slang
@@ -39,10 +39,11 @@ SamplerState p1_s_0 : register(s0, space1);
 
 float4 main(float v : V) : SV_TARGET
 {
-	return use(p_t_0,         	p_s_0)
-		 + use(p_ta_0[int(v)],  p_s_0)
-		 + use(p1_t_0,         	p1_s_0)
-		 + use(p1_ta_0[int(v)], p1_s_0);
+    int _S2 = int(v);
+    return use(p_t_0, p_s_0)
+		 + use(p_ta_0[_S2], p_s_0)
+		 + use(p1_t_0, p1_s_0)
+		 + use(p1_ta_0[_S2], p1_s_0);
 }
 
 #endif
diff --git a/tests/bugs/texture2d-ms.hlsl b/tests/bugs/texture2d-ms.hlsl
index 1d8293937..3fb84f72d 100644
--- a/tests/bugs/texture2d-ms.hlsl
+++ b/tests/bugs/texture2d-ms.hlsl
@@ -3,8 +3,10 @@
 [[vk::binding(0, 0)]]
 Texture2DMS tex : register(t1);
 
+RWStructuredBuffer<float4> outBuffer;
+
 [numthreads(4, 4, 1)]
 void main(uint3 groupId : SV_GroupID)
 {
-    tex.Load(int2(groupId.xy), 0);
+    outBuffer[0] = tex.Load(int2(groupId.xy), 0);
 }
diff --git a/tests/bugs/texture2d-ms.hlsl.glsl b/tests/bugs/texture2d-ms.hlsl.glsl
index ba0d571dd..40ce5f9de 100644
--- a/tests/bugs/texture2d-ms.hlsl.glsl
+++ b/tests/bugs/texture2d-ms.hlsl.glsl
@@ -1,16 +1,17 @@
-// texture2d-ms.hlsl.glsl
-//TEST_IGNORE_FILE:
-
 #version 450
+#extension GL_EXT_samplerless_texture_functions : require
 layout(row_major) uniform;
 layout(row_major) buffer;
-#extension GL_EXT_samplerless_texture_functions : require
 layout(binding = 0)
 uniform texture2DMS tex_0;
 
-layout(local_size_x = 4, local_size_y = 4, local_size_z = 1) in;void main()
+layout(std430, binding = 1) buffer _S1 {
+    vec4 _data[];
+} outBuffer_0;
+layout(local_size_x = 4, local_size_y = 4, local_size_z = 1) in;
+void main()
 {
-    vec4 _S1 = (texelFetch((tex_0), (ivec2(gl_WorkGroupID.xy)), (0)));
+    vec4 _S2 = (texelFetch((tex_0), (ivec2(gl_WorkGroupID.xy)), (0)));
+    ((outBuffer_0)._data[(0U)]) = _S2;
     return;
 }
-
diff --git a/tests/cross-compile/array-of-buffers.slang.glsl b/tests/cross-compile/array-of-buffers.slang.glsl
index 21961afd1..4ff86f36e 100644
--- a/tests/cross-compile/array-of-buffers.slang.glsl
+++ b/tests/cross-compile/array-of-buffers.slang.glsl
@@ -36,11 +36,9 @@ out vec4 _S6;
 
 void main()
 {
-    vec4 _S7 = cb_0[C_0._data.index_0]._data.f_0;
-    S_0 _S8 = ((sb1_0[C_0._data.index_0])._data[(C_0._data.index_0)]);
-    vec4 _S9 = _S7 + _S8.f_0;
-    vec4 _S10 = _S9 + ((sb2_0[C_0._data.index_0])._data[(C_0._data.index_0)]);
-    uint _S11 = ((bb_0[C_0._data.index_0])._data[(int(C_0._data.index_0 * 4U))/4]);
-    _S6 = _S10 + vec4(float(_S11));
+    S_0 _S7 = ((sb1_0[C_0._data.index_0])._data[(C_0._data.index_0)]);
+    vec4 _S8 = cb_0[C_0._data.index_0]._data.f_0 + _S7.f_0;
+    uint _S9 = ((bb_0[C_0._data.index_0])._data[(int(C_0._data.index_0 * 4U))/4]);
+    _S6 = _S8 + ((sb2_0[C_0._data.index_0])._data[(C_0._data.index_0)]) + vec4(float(_S9));
     return;
 }
diff --git a/tests/cross-compile/array-of-buffers.slang.hlsl b/tests/cross-compile/array-of-buffers.slang.hlsl
index 960957789..e709d323a 100644
--- a/tests/cross-compile/array-of-buffers.slang.hlsl
+++ b/tests/cross-compile/array-of-buffers.slang.hlsl
@@ -27,10 +27,8 @@ RWStructuredBuffer<float4 >  sb2_0[int(5)] : register(u0);
 ByteAddressBuffer  bb_0[int(6)] : register(t4);
 float4 main() : SV_TARGET
 {
-    float4 _S1 = cb_0[C_0.index_0].f_0;
-    S_0 _S2 = sb1_0[C_0.index_0][C_0.index_0];
-    float4 _S3 = _S1 + _S2.f_0;
-    float4 _S4 = _S3 + sb2_0[C_0.index_0][C_0.index_0];
-    uint _S5 = bb_0[C_0.index_0].Load(int(C_0.index_0 * 4U));
-    return _S4 + (float4)float(_S5);
+    S_0 _S1 = sb1_0[C_0.index_0][C_0.index_0];
+    float4 _S2 = cb_0[C_0.index_0].f_0 + _S1.f_0;
+    uint _S3 = bb_0[C_0.index_0].Load(int(C_0.index_0 * 4U));
+    return _S2 + sb2_0[C_0.index_0][C_0.index_0] + (float4)float(_S3);
 }