Implement 8.14-8.19 of OpenGL-GLSL specification

The following PR implements 8.14-8.19 of the [OpenGL-GLSL specification](https://registry.khronos.org/OpenGL/specs/gl/GLSLangSpec.4.60.pdf).

Fully implements all functions and built-in type's, resolves https://github.com/shader-slang/slang/issues/3692 for GLSL & SPRI-V targets.

_Notes:_
Testing Tools:
* Fragment shaders cannot test computational results. Only OpCodes are checked for proper emitting.

Implementation Notes:
* SubpassInput requires an unknown image format.
* SubpassInput is disjoint from TextureType: __SubpassImpl (.slang) & SubpassInputType (Compiler) to reduce code generation required.
* SubpassInput required an additional input layout modifier, input_attachment_index, this was added as a new parameter binding attribute. Since the following qualifiers can overlap with different resources (`layout(input_attachment_index = 0, binding = 0, set = 0)`) input_attachment_index is checked for overlapping resource bindings separately from other qualifiers with `LayoutResourceKind::InputAttachmentIndex`.
* `GLSLInputAttachmentIndexLayoutModifier` was added to enforce function parameters only accepting `in` decorated variables.
* `in` decorated variables needed to have emitting modified to allow directly emitting the variable into function calls if used as a parameter, normally Slang has a "global variable" shadow as a "global parameter" through a copy. This does not work and is solved using `GlobalVariableShadowingGlobalParameterDecoration` to build a relationship of "global variable" to "global parameter", we then resolve this relationship and replace "global variable" uses later in compile.
* `AtomicCounterMemory` memory-constraint requires `OpCapability AtomicStorage`, `AtomicStorage` is invalid for Vulkan targets. glslang outputs for `barrier`, `memoryBarrier`, and `groupMemoryBarrier` `AtomicCounterMemory` as a memory constraint. This compiles as valid SPIR-V for Vulkan since `OpCapability AtomicStorage` is not declared. This behavior of glslang is undefined as per [3.31.Capability of the SPIR-V specification](https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#_capability). We will omit `AtomicCounterMemory` from our barrier calls.

13 files changed, 656 insertions, 0 deletions

diff --git a/tests/glsl-intrinsic/fragment-processing/fragment-processing-interpolate-simple.slang b/tests/glsl-intrinsic/fragment-processing/fragment-processing-interpolate-simple.slang
new file mode 100644
index 000000000..fb1c72ed7
--- /dev/null
+++ b/tests/glsl-intrinsic/fragment-processing/fragment-processing-interpolate-simple.slang
@@ -0,0 +1,28 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+#version 450
+// CHECK_SPV-DAG: OpEntryPoint
+// CHECK_GLSL-DAG: void main(
+
+layout(location = 0) out ivec4 outColorActual;
+
+layout (location = 0) in float inDataV1;
+
+bool isOk(float a, float b)   { return (a == b); }
+
+bool testFragmentProcessingInterpolateFunctions()
+{
+    float tmpStore = inDataV1;
+    return true
+        && interpolateAtCentroid(inDataV1) != -1.0f
+        && (tmpStore + inDataV1) != -0.1f
+        && isOk(inDataV1, tmpStore)
+        && inDataV1 != -1.0f
+        ;
+}
+
+void main() {
+    outColorActual = ivec4(true
+        && testFragmentProcessingInterpolateFunctions()
+        );
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/fragment-processing/fragment-processing-non-input-param-error.slang b/tests/glsl-intrinsic/fragment-processing/fragment-processing-non-input-param-error.slang
new file mode 100644
index 000000000..638dd0ea7
--- /dev/null
+++ b/tests/glsl-intrinsic/fragment-processing/fragment-processing-non-input-param-error.slang
@@ -0,0 +1,20 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+#version 450
+// CHECK_SPV-DAG: error 31208
+// CHECK_GLSL-DAG: error 31208
+
+layout(location = 0) out ivec4 outColorActual;
+
+layout (location = 0) in float inDataV1;
+bool testFragmentProcessingInterpolateFunctions()
+{
+    float v = 1.0f;
+    return interpolateAtCentroid(v) != -1.0f;
+}
+
+void main() {
+    outColorActual = ivec4(true
+        && testFragmentProcessingInterpolateFunctions()
+        );
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/fragment-processing/fragment-processing.slang b/tests/glsl-intrinsic/fragment-processing/fragment-processing.slang
new file mode 100644
index 000000000..909679bbe
--- /dev/null
+++ b/tests/glsl-intrinsic/fragment-processing/fragment-processing.slang
@@ -0,0 +1,137 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+#version 450
+
+layout(location = 0) out ivec4 outColorActual;
+
+layout (location = 0) in float inDataV1;
+layout (location = 1) in vec2 inDataV2;
+layout (location = 2) in vec3 inDataV3;
+layout (location = 3) in vec4 inDataV4;
+
+bool testFragmentProcessingDerivativeFunctionsScalar()
+{
+// CHECK_SPV: OpDPdx
+// CHECK_GLSL: dFdx
+// CHECK_SPV: OpDPdy
+// CHECK_GLSL: dFdy
+// CHECK_SPV: OpDPdxFine
+// CHECK_GLSL: dFdxFine
+// CHECK_SPV: OpDPdyFine
+// CHECK_GLSL: dFdyFine
+// CHECK_SPV: OpDPdxCoarse
+// CHECK_GLSL: dFdxCoarse
+// CHECK_SPV: OpDPdyCoarse
+// CHECK_GLSL: dFdyCoarse
+// CHECK_SPV: OpFwidth
+// CHECK_GLSL: fwidth
+// CHECK_SPV: OpFwidthFine
+// CHECK_GLSL: fwidthFine
+// CHECK_SPV: OpFwidthCoarse
+// CHECK_GLSL: fwidthCoarse
+    return true
+        && dFdx(1.0f) != -1.0f
+        && dFdy(1.0f) != -1.0f
+        && dFdxFine(1.0f) != -1.0f
+        && dFdyFine(1.0f) != -1.0f
+        && dFdxCoarse(1.0f) != -1.0f
+        && dFdyCoarse(1.0f) != -1.0f
+        && fwidth(1.0f) != -1.0f
+        && fwidthFine(1.0f) != -1.0f
+        && fwidthCoarse(1.0f) != -1.0f
+        ;
+}
+__generic<let N:int>
+bool testFragmentProcessingDerivativeFunctionsVector()
+{
+// CHECK_SPV: OpDPdx
+// CHECK_GLSL: dFdx
+// CHECK_SPV: OpDPdy
+// CHECK_GLSL: dFdy
+// CHECK_SPV: OpDPdxFine
+// CHECK_GLSL: dFdxFine
+// CHECK_SPV: OpDPdyFine
+// CHECK_GLSL: dFdyFine
+// CHECK_SPV: OpDPdxCoarse
+// CHECK_GLSL: dFdxCoarse
+// CHECK_SPV: OpDPdyCoarse
+// CHECK_GLSL: dFdyCoarse
+// CHECK_SPV: OpFwidth
+// CHECK_GLSL: fwidth
+// CHECK_SPV: OpFwidthFine
+// CHECK_GLSL: fwidthFine
+// CHECK_SPV: OpFwidthCoarse
+// CHECK_GLSL: fwidthCoarse
+    return true
+        && dFdx(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && dFdy(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && dFdxFine(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && dFdyFine(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && dFdxCoarse(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && dFdyCoarse(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && fwidth(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && fwidthFine(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        && fwidthCoarse(vector<float,N>(1.0f)) != vector<float,N>(-1.0f)
+        ;
+}
+bool testFragmentProcessingInterpolateFunctions()
+{
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtCentroid %inDataV1
+// CHECK_GLSL: interpolateAtCentroid{{.*}}inDataV1
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtSample %inDataV1 {{.*}}
+// CHECK_GLSL: interpolateAtSample{{.*}}inDataV1
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtOffset %inDataV1 {{.*}}
+// CHECK_GLSL: interpolateAtOffset{{.*}}inDataV1
+
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtCentroid %inDataV2
+// CHECK_GLSL: interpolateAtCentroid{{.*}}inDataV2
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtSample %inDataV2 {{.*}}
+// CHECK_GLSL: interpolateAtSample{{.*}}inDataV2
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtOffset %inDataV2 {{.*}}
+// CHECK_GLSL: interpolateAtOffset{{.*}}inDataV2
+
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtCentroid %inDataV3
+// CHECK_GLSL: interpolateAtCentroid{{.*}}inDataV3
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtSample %inDataV3 {{.*}}
+// CHECK_GLSL: interpolateAtSample{{.*}}inDataV3
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtOffset %inDataV3 {{.*}}
+// CHECK_GLSL: interpolateAtOffset{{.*}}inDataV3
+
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtCentroid %inDataV4
+// CHECK_GLSL: interpolateAtCentroid{{.*}}inDataV4
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtSample %inDataV4 {{.*}}
+// CHECK_GLSL: interpolateAtSample{{.*}}inDataV4
+// CHECK_SPV: {{.*}} = OpExtInst {{.*}} {{.*}} InterpolateAtOffset %inDataV4 {{.*}}
+// CHECK_GLSL: interpolateAtOffset{{.*}}inDataV4
+    return true
+        && interpolateAtCentroid(inDataV1) != -1.0f
+        && interpolateAtSample(inDataV1, 0) != -1.0f
+        && interpolateAtOffset(inDataV1, vec2(0.0f)) != -1.0f
+        && interpolateAtCentroid(inDataV2) != vector<float,2>(-1.0f)
+        && interpolateAtSample(inDataV2, 0) != vector<float,2>(-1.0f)
+        && interpolateAtOffset(inDataV2, vec2(0.0f)) != vector<float,2>(-1.0f)
+        && interpolateAtCentroid(inDataV3) != vector<float,3>(-1.0f)
+        && interpolateAtSample(inDataV3, 0) != vector<float,3>(-1.0f)
+        && interpolateAtOffset(inDataV3, vec2(0.0f)) != vector<float,3>(-1.0f)
+        && interpolateAtCentroid(inDataV4) != vector<float,4>(-1.0f)
+        && interpolateAtSample(inDataV4, 0) != vector<float,4>(-1.0f)
+        && interpolateAtOffset(inDataV4, vec2(0.0f)) != vector<float,4>(-1.0f)
+        ;
+}
+bool testFragmentProcessingFunctions()
+{
+    return true
+        && testFragmentProcessingDerivativeFunctionsScalar()
+        && testFragmentProcessingDerivativeFunctionsVector<2>()
+        && testFragmentProcessingDerivativeFunctionsVector<3>()
+        && testFragmentProcessingDerivativeFunctionsVector<4>()
+        && testFragmentProcessingInterpolateFunctions()
+        ;
+    ;
+}
+
+void main() {
+    outColorActual = ivec4(true
+        && testFragmentProcessingFunctions()
+        );
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/noise-functions/noise-functions.slang b/tests/glsl-intrinsic/noise-functions/noise-functions.slang
new file mode 100644
index 000000000..f7d04b987
--- /dev/null
+++ b/tests/glsl-intrinsic/noise-functions/noise-functions.slang
@@ -0,0 +1,50 @@
+//TEST:SIMPLE(filecheck=CHECK):  -allow-glsl -stage compute -entry computeMain -target glsl
+//TEST:SIMPLE(filecheck=CHECK):  -allow-glsl -stage compute -entry computeMain -target spirv -emit-spirv-directly
+#version 460
+// CHECK: warning 31200
+
+buffer MyBlockName2
+{
+    uint data[];
+} outputBuffer;
+
+layout(local_size_x = 4) in;
+
+bool testNoiseScalar()
+{
+    return true
+        && noise1(1.0f) == 0.0f
+        && noise2(1.0f) == vec2(0.0f)
+        && noise3(1.0f) == vec3(0.0f)
+        && noise4(1.0f) == vec4(0.0f)
+        ;
+}
+
+__generic<let N:int>
+bool testNoiseVector()
+{
+    return true
+        && noise1(vector<float, N>(1.0f)) == 0.0f
+        && noise2(vector<float, N>(1.0f)) == vec2(0.0f)
+        && noise3(vector<float, N>(1.0f)) == vec3(0.0f)
+        && noise4(vector<float, N>(1.0f)) == vec4(0.0f)
+        ;
+}
+
+bool testNoiseFunctions()
+{
+    return true
+        && testNoiseScalar()
+        && testNoiseVector<2>()
+        && testNoiseVector<3>()
+        && testNoiseVector<4>()
+        ;
+}
+
+void computeMain()
+{
+    outputBuffer.data[0] = true
+        && testNoiseFunctions()
+        ;
+    // BUF: 1
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/shader-invocation-control/shader-invocation-control.slang b/tests/glsl-intrinsic/shader-invocation-control/shader-invocation-control.slang
new file mode 100644
index 000000000..4edb249f8
--- /dev/null
+++ b/tests/glsl-intrinsic/shader-invocation-control/shader-invocation-control.slang
@@ -0,0 +1,40 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL):  -allow-glsl -stage compute -entry computeMain -target glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV):  -allow-glsl -stage compute -entry computeMain -target spirv -emit-spirv-directly
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=BUF):-vk -compute -entry computeMain -allow-glsl
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=BUF):-vk -compute -entry computeMain -allow-glsl -emit-spirv-directly
+
+#version 460
+
+groupshared uint raceConditionShared;
+
+//TEST_INPUT:ubuffer(data=[0], stride=4):out,name=outputBuffer
+buffer MyBlockName2
+{
+    uint data[];
+} outputBuffer;
+
+layout(local_size_x = 4) in;
+bool testBarrier()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        raceConditionShared = 3;
+        barrier();
+        raceConditionShared = 1;
+        if (raceConditionShared != 1)
+            return false;
+    }
+    return true
+        && raceConditionShared == 1
+        ;
+}
+
+void computeMain()
+{
+    outputBuffer.data[0] = true
+        && testBarrier()
+        ;
+    // CHECK_GLSL: void main(
+    // CHECK_SPV: OpEntryPoint
+    // BUF: 1
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/shader-invocation-group/shader-invocation-group.slang b/tests/glsl-intrinsic/shader-invocation-group/shader-invocation-group.slang
new file mode 100644
index 000000000..201f33ea2
--- /dev/null
+++ b/tests/glsl-intrinsic/shader-invocation-group/shader-invocation-group.slang
@@ -0,0 +1,47 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL):  -allow-glsl -stage compute -entry computeMain -target glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV):  -allow-glsl -stage compute -entry computeMain -target spirv -emit-spirv-directly
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=BUF):-vk -compute -entry computeMain -allow-glsl
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=BUF):-vk -compute -entry computeMain -allow-glsl -emit-spirv-directly
+
+#version 460
+
+//TEST_INPUT:ubuffer(data=[0], stride=4):out,name=outputBuffer
+buffer MyBlockName2
+{
+    uint data[];
+} outputBuffer;
+
+layout(local_size_x = 4) in;
+
+bool testAnyInvocation()
+{
+    return true
+        && anyInvocation(gl_GlobalInvocationID.x == 0)
+        && anyInvocation(gl_GlobalInvocationID.x == 8) == false
+        ;
+}
+bool testAllInvocations()
+{
+    return true
+        && allInvocations(true)
+        && allInvocations(gl_GlobalInvocationID.x == 0) == false
+        ;
+}
+bool testAllInvocationsEqual()
+{
+    return true
+        && allInvocationsEqual(false)
+        && allInvocationsEqual(gl_GlobalInvocationID.x == 0) == false
+        ;
+}
+void computeMain()
+{
+    outputBuffer.data[0] = true
+        && testAnyInvocation()
+        && testAllInvocations()
+        && testAllInvocationsEqual()
+        ;
+    // CHECK_GLSL: void main(
+    // CHECK_SPV: OpEntryPoint
+    // BUF: 1
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/shader-memory-control/shader-memory-control.slang b/tests/glsl-intrinsic/shader-memory-control/shader-memory-control.slang
new file mode 100644
index 000000000..e6d9b7984
--- /dev/null
+++ b/tests/glsl-intrinsic/shader-memory-control/shader-memory-control.slang
@@ -0,0 +1,137 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL):  -allow-glsl -stage compute -entry computeMain -target glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV):  -allow-glsl -stage compute -entry computeMain -target spirv -emit-spirv-directly
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=BUF):-vk -compute -entry computeMain -allow-glsl
+//TEST(compute, vulkan):COMPARE_COMPUTE(filecheck-buffer=BUF):-vk -compute -entry computeMain -allow-glsl -emit-spirv-directly
+#version 460
+
+// CHECK_GLSL: void main(
+// CHECK_SPV: OpEntryPoint
+
+//TEST_INPUT:ubuffer(data=[2 2 2 2], stride=4):out,name=raceCondition
+buffer MyBlockName1
+{
+    uint data[];
+} raceCondition;
+
+groupshared uint raceConditionShared;
+
+//TEST_INPUT: set raceConditionImage = RWTexture1D(format=R32_SINT, size=4, content=one, mipMaps = 1)
+uniform layout(binding=0,r32i) iimage1D raceConditionImage;
+
+//TEST_INPUT:ubuffer(data=[0], stride=4):out,name=outputBuffer
+buffer MyBlockName2
+{
+    uint data[];
+} outputBuffer;
+
+layout(local_size_x = 32) in;
+
+bool testMemoryBarrier()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        raceCondition.data[0] = gl_GlobalInvocationID.x;
+        memoryBarrier();
+        raceCondition.data[0] = 1;
+        memoryBarrier();
+        if (raceCondition.data[0] != 1)
+            return false;
+    }
+    return true
+        && raceCondition.data[0] == 1
+        ;
+}
+bool testMemoryBarrierAtomicCounter()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        atomicExchange(raceCondition.data[1], 2);
+        memoryBarrierAtomicCounter();
+        atomicExchange(raceCondition.data[1], 1);
+        memoryBarrierAtomicCounter();
+        if (raceCondition.data[1] != 1)
+            return false;
+    }
+    return true
+        && raceCondition.data[1] == 1
+        ;
+}
+bool testMemoryBarrierBuffer()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        raceCondition.data[2] = gl_GlobalInvocationID.x;
+        memoryBarrierBuffer();
+        raceCondition.data[2] = 1;
+        memoryBarrierBuffer();
+        if (raceCondition.data[2] != 1)
+            return false;
+    }
+    return true
+        && raceCondition.data[2] == 1
+        ;
+}
+bool testMemoryBarrierShared()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        raceConditionShared = 2;
+        memoryBarrierShared();
+        raceConditionShared = 1;
+        memoryBarrierShared();
+        if (raceConditionShared != 1)
+            return false;
+    }
+    return true
+        && raceConditionShared == 1
+        ;
+}
+bool testMemoryBarrierImage()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        imageStore(raceConditionImage, 0, 2);
+        memoryBarrierShared();
+        imageStore(raceConditionImage, 0, 1);
+        memoryBarrierShared();
+        if (imageLoad(raceConditionImage, 0).x != 1)
+            return false;
+    }
+    return true
+        && imageLoad(raceConditionImage, 0).x == 1
+        ;
+}
+bool testGroupMemoryBarrier()
+{
+    for (int i = 0; i < 4; i++)
+    {
+        raceCondition.data[3] = gl_GlobalInvocationID.x;
+        groupMemoryBarrier();
+        raceCondition.data[3] = 1;
+        groupMemoryBarrier();
+        if (raceCondition.data[3] != 1)
+            return false;
+    }
+    return true
+        && raceCondition.data[3] == 1
+        ;
+}
+bool testMemoryBarriers()
+{
+    return true
+        && testMemoryBarrier()
+        && testMemoryBarrierAtomicCounter()
+        && testMemoryBarrierBuffer()
+        && testMemoryBarrierShared()
+        && testMemoryBarrierImage()
+        && testGroupMemoryBarrier()
+        ;
+}
+
+void computeMain()
+{
+    outputBuffer.data[0] = true
+        && testMemoryBarriers()
+        ;
+    // BUF: 1
+}
diff --git a/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error1.slang b/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error1.slang
new file mode 100644
index 000000000..82b56f872
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error1.slang
@@ -0,0 +1,23 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+#version 450
+// CHECK: warning 39001
+buffer MyBlockName
+{
+    uvec4 idata[2];
+} keepAliveBuffer;
+
+layout(location = 0) in highp vec4 a_position;
+layout(location = 0) in highp vec4 b_position;
+
+layout (input_attachment_index = 2, set = 0, binding = 0) uniform isubpassInput isubpass;
+layout (input_attachment_index = 2, set = 0, binding = 1) uniform isubpassInputMS isubpassMS;
+
+layout (location = 0) out vec4 outColor;
+
+void main() {
+    keepAliveBuffer.idata[0] = subpassLoad(isubpass);
+    keepAliveBuffer.idata[1] = subpassLoad(isubpassMS, 0);
+
+    outColor = vec4(0);
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error2.slang b/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error2.slang
new file mode 100644
index 000000000..d70377660
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error2.slang
@@ -0,0 +1,20 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+#version 450
+// CHECK: warning 39001
+buffer MyBlockName
+{
+    uvec4 idata[2];
+} keepAliveBuffer;
+
+layout (input_attachment_index = 0, set = 0, binding = 1) uniform isubpassInput isubpass;
+layout (input_attachment_index = 1, set = 0, binding = 1) uniform isubpassInputMS isubpassMS;
+
+layout (location = 0) out vec4 outColor;
+
+void main() {
+    keepAliveBuffer.idata[0] = subpassLoad(isubpass);
+    keepAliveBuffer.idata[1] = subpassLoad(isubpassMS, 0);
+
+    outColor = vec4(0);
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error3.slang b/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error3.slang
new file mode 100644
index 000000000..c2396dbfe
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/input-attachment-index-overlapping-error3.slang
@@ -0,0 +1,20 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+#version 450
+// CHECK: warning 39001
+buffer MyBlockName
+{
+    uvec4 idata[2];
+} keepAliveBuffer;
+
+layout (input_attachment_index = 0, binding = 1) uniform isubpassInput isubpass;
+layout (input_attachment_index = 1, binding = 1) uniform isubpassInputMS isubpassMS;
+
+layout (location = 0) out vec4 outColor;
+
+void main() {
+    keepAliveBuffer.idata[0] = subpassLoad(isubpass);
+    keepAliveBuffer.idata[1] = subpassLoad(isubpassMS, 0);
+
+    outColor = vec4(0);
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/subpass-input/input-attachment-index-use-error.slang b/tests/glsl-intrinsic/subpass-input/input-attachment-index-use-error.slang
new file mode 100644
index 000000000..889a4e205
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/input-attachment-index-use-error.slang
@@ -0,0 +1,11 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage fragment -entry main -allow-glsl
+#version 450
+
+// CHECK: error 31207
+layout (input_attachment_index = 1, set = 0, binding = 1) uniform vec3 image;
+
+layout (location = 0) out vec4 outColor;
+
+void main() {
+    outColor = vec4(0);
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/subpass-input/subpass-input-as-parameter.slang b/tests/glsl-intrinsic/subpass-input/subpass-input-as-parameter.slang
new file mode 100644
index 000000000..a415fcf81
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/subpass-input-as-parameter.slang
@@ -0,0 +1,35 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+
+#version 450
+
+// CHECK_SPV-DAG: InputAttachmentIndex 0
+// CHECK_SPV-DAG: OpTypeImage %float SubpassData 2 0 0 2 Unknown
+// CHECK_GLSL: subpassInput
+
+layout (input_attachment_index = 0, set = 0, binding = 0) uniform subpassInput subpass;
+
+// CHECK_SPV-DAG: InputAttachmentIndex 1
+// CHECK_SPV-DAG: OpTypeImage %float SubpassData 2 0 1 2 Unknown
+// CHECK_GLSL: subpassInputMS
+layout (input_attachment_index = 1, set = 0, binding = 1) uniform subpassInputMS subpassMS;
+
+layout (location = 0) out vec4 outColor;
+
+void someSideEffect(subpassInput subpassTmp)
+{
+    outColor.xy = subpassLoad(subpassTmp).xy;
+}
+
+void someSideEffectMS(subpassInputMS subpassTmp)
+{
+    outColor.zw = subpassLoad(subpassTmp, 0).zw;
+}
+
+// CHECK_GLSL-DAG: void main(
+// CHECK_SPV-DAG: OpEntryPoint
+
+void main() {
+    someSideEffect(subpass);
+    someSideEffectMS(subpassMS);
+}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/subpass-input/subpass-input.slang b/tests/glsl-intrinsic/subpass-input/subpass-input.slang
new file mode 100644
index 000000000..0597cc06c
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/subpass-input.slang
@@ -0,0 +1,88 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_HLSL): -target hlsl -stage fragment -entry main -allow-glsl
+
+#version 450
+// CHECK_SPV-DAG: OpEntryPoint
+
+// CHECK_SPV-DAG: InputAttachmentIndex 0
+// CHECK_SPV-DAG: InputAttachmentIndex 1
+// CHECK_SPV-DAG: InputAttachmentIndex 2
+// CHECK_SPV-DAG: InputAttachmentIndex 3
+// CHECK_SPV-DAG: InputAttachmentIndex 4
+// CHECK_SPV-DAG: InputAttachmentIndex 5
+
+// CHECK_SPV-DAG: OpTypeImage %float SubpassData 2 0 0 2 Unknown
+// CHECK_GLSL-DAG: input_attachment_index = 0
+// CHECK_GLSL-DAG: subpassInput
+// CHECK_HLSL-DAG: vk::input_attachment_index(0)
+// CHECK_HLSL-DAG: SubpassInput<float4>
+layout (input_attachment_index = 0, set = 0, binding = 0) uniform subpassInput subpass;
+
+// CHECK_SPV-DAG: OpTypeImage %float SubpassData 2 0 1 2 Unknown
+// CHECK_GLSL-DAG: input_attachment_index = 1
+// CHECK_GLSL-DAG: subpassInputMS
+// CHECK_HLSL-DAG: vk::input_attachment_index(1)
+// CHECK_HLSL-DAG: SubpassInputMS<float4>
+layout (input_attachment_index = 1, set = 0, binding = 1) uniform subpassInputMS subpassMS;
+
+// CHECK_SPV-DAG: OpTypeImage %uint SubpassData 2 0 0 2 Unknown
+// CHECK_GLSL-DAG: input_attachment_index = 2
+// CHECK_GLSL-DAG: usubpassInput
+// CHECK_HLSL-DAG: vk::input_attachment_index(2)
+// CHECK_HLSL-DAG: SubpassInput<uint4>
+layout (input_attachment_index = 2, set = 0, binding = 2) uniform usubpassInput usubpass;
+
+// CHECK_SPV-DAG: OpTypeImage %uint SubpassData 2 0 1 2 Unknown
+// CHECK_GLSL-DAG: input_attachment_index = 3
+// CHECK_GLSL-DAG: usubpassInputMS
+// CHECK_HLSL-DAG: vk::input_attachment_index(3)
+// CHECK_HLSL-DAG: SubpassInputMS<uint4>
+layout (input_attachment_index = 3, set = 0, binding = 3) uniform usubpassInputMS usubpassMS;
+
+// CHECK_SPV-DAG: OpTypeImage %int SubpassData 2 0 0 2 Unknown
+// CHECK_GLSL-DAG: input_attachment_index = 4
+// CHECK_GLSL-DAG: isubpassInput
+// CHECK_HLSL-DAG: vk::input_attachment_index(4)
+// CHECK_HLSL-DAG: SubpassInput<int4>
+layout (input_attachment_index = 4, set = 0, binding = 4) uniform isubpassInput isubpass;
+
+// CHECK_SPV-DAG: OpTypeImage %int SubpassData 2 0 1 2 Unknown
+// CHECK_GLSL-DAG: input_attachment_index = 5
+// CHECK_GLSL-DAG: isubpassInputMS
+// CHECK_HLSL-DAG: vk::input_attachment_index(5)
+// CHECK_HLSL-DAG: SubpassInputMS<int4>
+layout (input_attachment_index = 5, set = 0, binding = 5) uniform isubpassInputMS isubpassMS;
+
+layout (location = 0) out vec4 outColor;
+
+// CHECK_GLSL-DAG: void main()
+// CHECK_HLSL-DAG: main()
+void main() {
+// CHECK_SPV: OpImageRead
+// CHECK_GLSL: subpassLoad
+// CHECK_HLSL: SubpassLoad
+// CHECK_SPV: OpImageRead
+// CHECK_GLSL: subpassLoad
+// CHECK_HLSL: SubpassLoad
+// CHECK_SPV: OpImageRead
+// CHECK_GLSL: subpassLoad
+// CHECK_HLSL: SubpassLoad
+// CHECK_SPV: OpImageRead
+// CHECK_GLSL: subpassLoad
+// CHECK_HLSL: SubpassLoad
+// CHECK_SPV: OpImageRead
+// CHECK_GLSL: subpassLoad
+// CHECK_HLSL: SubpassLoad
+// CHECK_SPV: OpImageRead
+// CHECK_GLSL: subpassLoad
+// CHECK_HLSL: SubpassLoad
+    outColor = vec4(true
+        && subpassLoad(subpass) == vec4(1)
+        && subpassLoad(subpassMS, 0) == vec4(1)
+        && subpassLoad(isubpass) == ivec4(1)
+        && subpassLoad(isubpassMS, 0) == ivec4(1)
+        && subpassLoad(usubpass) == uvec4(1)
+        && subpassLoad(usubpassMS, 0) == uvec4(1)
+    );
+}
\ No newline at end of file