Feature/bit cast glsl (#808)

* First attempt at asint, asuint, asfloat intrinsics.

* Test with countbits

* Placing glsl definitions first makes them get picked up.

* Some more improvements around asint.

* Add support for vector versions of asint/asunit

* Fix some typos in asuint/asint intrinsics for glsl.
Simplified and increased coverage of as/u/int tests.

* Added bit-cast-double test.
Added notional support for asdouble bit casts to glsl - but couldn't test because glslang doesn't seem to support the extension.

* Try to get double bit casts working - doesn't work cos of block issue.

* Only output parents on intrinic replacement if return type is not void.

4 files changed, 79 insertions, 0 deletions

diff --git a/tests/compute/bit-cast-double.slang b/tests/compute/bit-cast-double.slang
new file mode 100644
index 000000000..27d0b48cf
--- /dev/null
+++ b/tests/compute/bit-cast-double.slang
@@ -0,0 +1,21 @@
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -dx12
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX:-vk -compute
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):dxbinding(0),glbinding(0),out
+
+RWStructuredBuffer<int> outputBuffer;
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    double d = double(dispatchThreadID.x);
+    
+    uint hi, low;
+    asuint(d, low, hi);
+    
+    // Reconstruct 
+    double r = asdouble(low, hi);
+    
+    outputBuffer[dispatchThreadID.x] = int(r);
+}
\ No newline at end of file
diff --git a/tests/compute/bit-cast-double.slang.expected.txt b/tests/compute/bit-cast-double.slang.expected.txt
new file mode 100644
index 000000000..bc856dafa
--- /dev/null
+++ b/tests/compute/bit-cast-double.slang.expected.txt
@@ -0,0 +1,4 @@
+0
+1
+2
+3
diff --git a/tests/compute/bit-cast.slang b/tests/compute/bit-cast.slang
new file mode 100644
index 000000000..050b84f30
--- /dev/null
+++ b/tests/compute/bit-cast.slang
@@ -0,0 +1,42 @@
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -dx12
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX:-vk -compute
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0 0 0 0 0 0 0 0], stride=4):dxbinding(0),glbinding(0),out
+
+RWStructuredBuffer<int> outputBuffer;
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    const int id = asint(dispatchThreadID.x);
+
+    {
+        int4 i4 = int4(id, id + 1, id + 2, id + 3);
+        uint3 u3 = asuint(i4.xyz);
+        int2 i2 = asint(u3.xy);
+        uint u1 = asuint(i2.x);
+        
+        outputBuffer[id + 0] = int(u1);
+    }
+    
+    {
+        uint v = asuint(id);
+        uint4 u4 = uint4(v, v + 1, v + 2, v + 3);
+        int3 i3 = asint(u4.xyz);
+        uint2 u2 = asuint(i3.xy);
+        int i1 = asint(u2.x);
+        
+        outputBuffer[id + 4] = i1;
+    }
+    
+    {
+        int4 i4 = int4(id, id + 1, id + 2, id + 3);
+        float4 f4 = asfloat(i4);
+        uint3 u3 = asuint(f4.xyz);
+        float2 f2 = asfloat(u3.xy);
+        int i1 = asint(id);
+        
+        outputBuffer[id + 8] = i1;
+    }
+}
\ No newline at end of file
diff --git a/tests/compute/bit-cast.slang.expected.txt b/tests/compute/bit-cast.slang.expected.txt
new file mode 100644
index 000000000..f5414793f
--- /dev/null
+++ b/tests/compute/bit-cast.slang.expected.txt
@@ -0,0 +1,12 @@
+0
+1
+2
+3
+0
+1
+2
+3
+0
+1
+2
+3
\ No newline at end of file