Defer immutable buffer loads when emitting spirv. (#7579)

* Defer immutable buffer loads when emitting spirv.

* Fix.

* Fix.

* Fix.

* Fix tests.

* Fix test.

7 files changed, 39 insertions, 15 deletions

diff --git a/tests/spirv/aligned-load-store.slang b/tests/spirv/aligned-load-store.slang
index e8bee779e..c2f50b66c 100644
--- a/tests/spirv/aligned-load-store.slang
+++ b/tests/spirv/aligned-load-store.slang
@@ -3,8 +3,8 @@
 // CHECK: OpLoad {{.*}} Aligned 8
 // CHECK: OpStore {{.*}} Aligned 16
 
-// CHECK: OpLoad {{.*}} Aligned 8
-// CHECK: OpLoad {{.*}} Aligned 8
+// CHECK: OpLoad {{.*}} Aligned 16
+// CHECK: OpLoad {{.*}} Aligned 16
 // CHECK: OpStore {{.*}} Aligned 16
 // CHECK: OpStore {{.*}} Aligned 16
 
@@ -20,6 +20,7 @@ void computeMain()
     var v = loadAligned<8>((float2x4*)data);
     storeAligned<16>((float2x4*)data+1, v);
 
-    var v1 = loadAligned<8>(data2);
+    var v1 = loadAligned<16>(data2);
+    v1.v0 += 1.0f;
     storeAligned<16>(data2, v1);
 }
\ No newline at end of file
diff --git a/tests/spirv/fetch-array-from-parameter-block.slang b/tests/spirv/fetch-array-from-parameter-block.slang
new file mode 100644
index 000000000..4a86bfb8d
--- /dev/null
+++ b/tests/spirv/fetch-array-from-parameter-block.slang
@@ -0,0 +1,22 @@
+//TEST:SIMPLE(filecheck=CHECK):-target spirv
+
+//CHECK-NOT: OpCompositeConstruct
+//CHECK-COUNT-1: OpStore
+
+struct Data
+{
+    int bigArray[8];
+    int fetch(int i)
+    {
+        return bigArray[i];
+    }
+}
+
+ParameterBlock<Data> pData;
+uniform int* result;
+
+[numthreads(16,1,1)]
+void main(int id : SV_DispatchThreadID)
+{
+    *result = pData.fetch(id);
+}
\ No newline at end of file
diff --git a/tests/spirv/large-struct.slang b/tests/spirv/large-struct.slang
index 7738a5fcf..2d79c0aaf 100644
--- a/tests/spirv/large-struct.slang
+++ b/tests/spirv/large-struct.slang
@@ -3,9 +3,8 @@
 //TEST(compute, vulkan):COMPARE_COMPUTE_EX(filecheck-buffer=BUF):-d3d12 -compute -output-using-type
 //TEST(compute, vulkan):COMPARE_COMPUTE_EX(filecheck-buffer=BUF):-cpu -compute -output-using-type
 
-// Check that when generating spirv directly, we use a loop
-// to copy large arrays in input data out into a local variable, instead of emitting
-// unrolled code that reads each element of the array individually.
+// Check that when generating spirv directly, we do not load the entire big array
+// from the constant buffer into registers.
 
 struct WorkData
 {
@@ -21,7 +20,9 @@ ConstantBuffer<WorkData> input;
 //TEST_INPUT:set resultBuffer = out ubuffer(data=[0 0 0 0], stride=4)
 RWStructuredBuffer<float> resultBuffer;
 
-// CHECK: OpLoopMerge
+// CHECK-NOT: OpLoopMerge
+// CHECK-NOT: OpCompositeConstruct
+// CHECK-COUNT-1: OpStore
 
 [numthreads(2, 1, 1)]
 void computeMain(uint3 tid: SV_DispatchThreadID)
diff --git a/tests/spirv/pointer-data-marshal.slang b/tests/spirv/pointer-data-marshal.slang
index 3ad6c373b..a07a365ce 100644
--- a/tests/spirv/pointer-data-marshal.slang
+++ b/tests/spirv/pointer-data-marshal.slang
@@ -8,9 +8,9 @@ struct Params {
   Foo *foo;
 };
 
-// CHECK: %[[PTR0:[A-Za-z0-9_]+]] = OpAccessChain %_ptr_PhysicalStorageBuffer__arr_v3float_int_2 %{{.*}} %int_0
-// CHECK: %[[PTR1:[A-Za-z0-9_]+]]  = OpAccessChain %_ptr_PhysicalStorageBuffer_v3float %[[PTR0]] %int_1
-// CHECK: %[[PTR2:[A-Za-z0-9_]+]]  = OpAccessChain %_ptr_PhysicalStorageBuffer_float %[[PTR1]] %int_2
+// CHECK: %[[PTR0:[A-Za-z0-9_]+]] = Op{{.*}}AccessChain %_ptr_PhysicalStorageBuffer__arr_v3float_int_2 %{{.*}} %int_0
+// CHECK: %[[PTR1:[A-Za-z0-9_]+]]  = Op{{.*}}AccessChain %_ptr_PhysicalStorageBuffer_v3float %[[PTR0]] %int_1
+// CHECK: %[[PTR2:[A-Za-z0-9_]+]]  = Op{{.*}}AccessChain %_ptr_PhysicalStorageBuffer_float %[[PTR1]] %int_2
 
 ConstantBuffer<Params> params;
 
diff --git a/tests/spirv/ptr-unsized-array-2.slang b/tests/spirv/ptr-unsized-array-2.slang
index ac0911d76..eb653d0a6 100644
--- a/tests/spirv/ptr-unsized-array-2.slang
+++ b/tests/spirv/ptr-unsized-array-2.slang
@@ -3,7 +3,7 @@
 // CHECK-DAG: %[[cbuffer__t:[A-Za-z0-9_]+]] = OpTypeStruct %_ptr_PhysicalStorageBuffer_uint 
 // CHECK-DAG: %light_buffer = OpVariable %_ptr_PushConstant_[[cbuffer__t]] PushConstant
 
-// CHECK: OpAccessChain %_ptr_PushConstant
+// CHECK: Op{{.*}}AccessChain %_ptr_PushConstant
 // CHECK-NEXT: OpLoad
 // CHECK-NEXT: OpBitcast %_ptr_PhysicalStorageBuffer
 
diff --git a/tests/spirv/ref-this.slang b/tests/spirv/ref-this.slang
index de4263975..890e1451f 100644
--- a/tests/spirv/ref-this.slang
+++ b/tests/spirv/ref-this.slang
@@ -1,6 +1,6 @@
 //TEST:SIMPLE(filecheck=CHECK): -target spirv
 
-// CHECK: %[[PTR:[0-9a-zA-Z_]+]] = OpAccessChain %_ptr_PhysicalStorageBuffer_uint %{{.*}} %int_0
+// CHECK: %[[PTR:[0-9a-zA-Z_]+]] = Op{{.*}}AccessChain %_ptr_PhysicalStorageBuffer_uint %{{.*}} %int_0
 // CHECK: %{{.*}} = OpAtomicIAdd %uint %[[PTR]] %uint_1 %uint_0 %uint_1
 
 struct Buf
diff --git a/tests/spirv/subgroup-size-2.slang b/tests/spirv/subgroup-size-2.slang
index 500bd63c8..f7376f584 100644
--- a/tests/spirv/subgroup-size-2.slang
+++ b/tests/spirv/subgroup-size-2.slang
@@ -15,12 +15,12 @@ uint3 f() { return WorkgroupSize(); }
 void compute1()
 {
     // CHECK_EXPERIMENTAL-DAG: %[[VAR:[A-Za-z0-9_]+]] = OpTypePointer Function %v3int
-    // CHECK_EXPERIMENTAL: OpAccessChain %[[VAR]]
+    // CHECK_EXPERIMENTAL: Op{{.*}}AccessChain %[[VAR]]
     //
     // CHECK_EXPERIMENTAL-DAG: %[[CALL_RS:[A-Za-z0-9_]+]] = OpFunctionCall %v3uint %f
     // CHECK_EXPERIMENTAL: OpCompositeExtract %uint %[[CALL_RS]] 0
     //
-    // CHECK_EXPERIMENTAL-DAG: %[[PTR:[A-Za-z0-9_]+]] = OpAccessChain %_ptr_StorageBuffer_int %outputBuffer %int_0 %int_1
+    // CHECK_EXPERIMENTAL-DAG: %[[PTR:[A-Za-z0-9_]+]] = Op{{.*}}AccessChain %_ptr_StorageBuffer_int %outputBuffer %int_0 %int_1
     // CHECK_EXPERIMENTAL: OpStore %[[PTR]] %int_2
 
     // CHECK-DAG: %[[VAR:[A-Za-z0-9_]+]] = OpVariable %_ptr_Private_v3int Private
@@ -29,7 +29,7 @@ void compute1()
     // CHECK-DAG: %[[CALL_RS:[A-Za-z0-9_]+]] = OpFunctionCall %v3uint %f
     // CHECK: OpCompositeExtract %uint %[[CALL_RS]] 0
     //
-    // CHECK-DAG: %[[PTR:[A-Za-z0-9_]+]] = OpAccessChain %_ptr_StorageBuffer_int %outputBuffer %int_0 %int_1
+    // CHECK-DAG: %[[PTR:[A-Za-z0-9_]+]] = Op{{.*}}AccessChain %_ptr_StorageBuffer_int %outputBuffer %int_0 %int_1
     // CHECK: OpStore %[[PTR]] %int_2
 
     const int x = f().x;