[HLSL] Reland; Make it possible to assign an array from a cbuffer #136580

spall · 2025-04-21T16:54:11Z

Reland #134174
Update Sema Checking to always do an HLSL Array RValue cast in the case we are dealing with hlsl constant array types
Instead of comparing canonical types, compare canonical unqualified types
Add a test to show it is possible to assign an array from a cbuffer.
Closes #133767

…r binding

llvmbot · 2025-04-21T16:54:44Z

@llvm/pr-subscribers-hlsl

Author: Sarah Spall (spall)

Changes

Reland #134174
Update Sema Checking to always do an HLSL Array RValue cast in the case we are dealing with hlsl constant array types
Instead of comparing canonical types, compare canonical unqualified types
Add a test to show it is possible to assign an array from a cbuffer.
Closes #133767

Full diff: https://github.com/llvm/llvm-project/pull/136580.diff

3 Files Affected:

(modified) clang/lib/Sema/SemaExprCXX.cpp (+4-10)
(modified) clang/lib/Sema/SemaOverload.cpp (+5-6)
(modified) clang/test/CodeGenHLSL/ArrayAssignable.hlsl (+62-1)

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index d46322d75721e..f5a10e0db85ad 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4745,19 +4745,13 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
   case ICK_HLSL_Array_RValue:
     if (ToType->isArrayParameterType()) {
       FromType = Context.getArrayParameterType(FromType);
-      From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
-                               /*BasePath=*/nullptr, CCK)
-                 .get();
-    } else { // FromType must be ArrayParameterType
-      assert(FromType->isArrayParameterType() &&
-             "FromType must be ArrayParameterType in ICK_HLSL_Array_RValue \
-              if it is not ToType");
+    } else if (FromType->isArrayParameterType()) {
       const ArrayParameterType *APT = cast<ArrayParameterType>(FromType);
       FromType = APT->getConstantArrayType(Context);
-      From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
-                               /*BasePath=*/nullptr, CCK)
-                 .get();
     }
+    From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
+                             /*BasePath=*/nullptr, CCK)
+               .get();
     break;
 
   case ICK_Function_To_Pointer:
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index e4ff8c5489df3..5b224b6c08fef 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -2275,17 +2275,16 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
     // handling here.
     if (ToType->isArrayParameterType()) {
       FromType = S.Context.getArrayParameterType(FromType);
-      SCS.First = ICK_HLSL_Array_RValue;
     } else if (FromType->isArrayParameterType()) {
       const ArrayParameterType *APT = cast<ArrayParameterType>(FromType);
       FromType = APT->getConstantArrayType(S.Context);
-      SCS.First = ICK_HLSL_Array_RValue;
-    } else {
-      SCS.First = ICK_Identity;
     }
 
-    if (S.Context.getCanonicalType(FromType) !=
-        S.Context.getCanonicalType(ToType))
+    SCS.First = ICK_HLSL_Array_RValue;
+
+    // Don't consider qualifiers, which include things like address spaces
+    if (FromType.getCanonicalType().getUnqualifiedType() !=
+        ToType.getCanonicalType().getUnqualifiedType())
       return false;
 
     SCS.setAllToTypes(ToType);
diff --git a/clang/test/CodeGenHLSL/ArrayAssignable.hlsl b/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
index e2ff2de68ed99..6374f91230546 100644
--- a/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
+++ b/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
@@ -1,4 +1,23 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s --enable-var-scope
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -finclude-default-header -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s
+
+struct S {
+  int x;
+  float f;
+};
+
+// CHECK: [[CBLayout:%.*]] = type <{ [2 x float], [2 x <4 x i32>], [2 x [2 x i32]], [1 x target("dx.Layout", %S, 8, 0, 4)] }>
+// CHECK: @CBArrays.cb = global target("dx.CBuffer", target("dx.Layout", [[CBLayout]], 136, 0, 32, 64, 128))
+// CHECK: @c1 = external addrspace(2) global [2 x float], align 4
+// CHECK: @c2 = external addrspace(2) global [2 x <4 x i32>], align 16
+// CHECK: @c3 = external addrspace(2) global [2 x [2 x i32]], align 4
+// CHECK: @c4 = external addrspace(2) global [1 x target("dx.Layout", %S, 8, 0, 4)], align 4
+
+cbuffer CBArrays : register(b0) {
+  float c1[2];
+  int4 c2[2];
+  int c3[2][2];
+  S c4[1];
+}
 
 // CHECK-LABEL: define void {{.*}}arr_assign1
 // CHECK: [[Arr:%.*]] = alloca [2 x i32], align 4
@@ -116,3 +135,45 @@ void arr_assign7() {
   int Arr2[2][2] = {{0, 0}, {1, 1}};
   (Arr = Arr2)[0] = {6, 6};
 }
+
+// Verify you can assign from a cbuffer array
+
+// CHECK-LABEL: define void {{.*}}arr_assign8
+// CHECK: [[C:%.*]] = alloca [2 x float], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[C]], ptr align 4 {{.*}}, i32 8, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p2.i32(ptr align 4 [[C]], ptr addrspace(2) align 4 @c1, i32 8, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign8() {
+  float C[2] = {1.0, 2.0};
+  C = c1;
+}
+
+// CHECK-LABEL: define void {{.*}}arr_assign9
+// CHECK: [[C:%.*]] = alloca [2 x <4 x i32>], align 16
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 16 [[C]], ptr align 16 {{.*}}, i32 32, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p2.i32(ptr align 16 [[C]], ptr addrspace(2) align 16 @c2, i32 32, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign9() {
+  int4 C[2] = {1,2,3,4,5,6,7,8};
+  C = c2;
+}
+
+// CHECK-LABEL: define void {{.*}}arr_assign10
+// CHECK: [[C:%.*]] = alloca [2 x [2 x i32]], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[C]], ptr align 4 {{.*}}, i32 16, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p2.i32(ptr align 4 [[C]], ptr addrspace(2) align 4 @c3, i32 16, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign10() {
+  int C[2][2] = {1,2,3,4};
+  C = c3;
+}
+
+// CHECK-LABEL: define void {{.*}}arr_assign11
+// CHECK: [[C:%.*]] = alloca [1 x %struct.S], align 4
+// CHECK: call void @llvm.memcpy.p0.p2.i32(ptr align 4 [[C]], ptr addrspace(2) align 4 @c4, i32 8, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign11() {
+  S s = {1, 2.0};
+  S C[1] = {s};
+  C = c4;
+}

llvmbot · 2025-04-21T16:54:46Z

@llvm/pr-subscribers-clang

Author: Sarah Spall (spall)

Changes

Reland #134174
Update Sema Checking to always do an HLSL Array RValue cast in the case we are dealing with hlsl constant array types
Instead of comparing canonical types, compare canonical unqualified types
Add a test to show it is possible to assign an array from a cbuffer.
Closes #133767

Full diff: https://github.com/llvm/llvm-project/pull/136580.diff

3 Files Affected:

(modified) clang/lib/Sema/SemaExprCXX.cpp (+4-10)
(modified) clang/lib/Sema/SemaOverload.cpp (+5-6)
(modified) clang/test/CodeGenHLSL/ArrayAssignable.hlsl (+62-1)

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index d46322d75721e..f5a10e0db85ad 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4745,19 +4745,13 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
   case ICK_HLSL_Array_RValue:
     if (ToType->isArrayParameterType()) {
       FromType = Context.getArrayParameterType(FromType);
-      From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
-                               /*BasePath=*/nullptr, CCK)
-                 .get();
-    } else { // FromType must be ArrayParameterType
-      assert(FromType->isArrayParameterType() &&
-             "FromType must be ArrayParameterType in ICK_HLSL_Array_RValue \
-              if it is not ToType");
+    } else if (FromType->isArrayParameterType()) {
       const ArrayParameterType *APT = cast<ArrayParameterType>(FromType);
       FromType = APT->getConstantArrayType(Context);
-      From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
-                               /*BasePath=*/nullptr, CCK)
-                 .get();
     }
+    From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
+                             /*BasePath=*/nullptr, CCK)
+               .get();
     break;
 
   case ICK_Function_To_Pointer:
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index e4ff8c5489df3..5b224b6c08fef 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -2275,17 +2275,16 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
     // handling here.
     if (ToType->isArrayParameterType()) {
       FromType = S.Context.getArrayParameterType(FromType);
-      SCS.First = ICK_HLSL_Array_RValue;
     } else if (FromType->isArrayParameterType()) {
       const ArrayParameterType *APT = cast<ArrayParameterType>(FromType);
       FromType = APT->getConstantArrayType(S.Context);
-      SCS.First = ICK_HLSL_Array_RValue;
-    } else {
-      SCS.First = ICK_Identity;
     }
 
-    if (S.Context.getCanonicalType(FromType) !=
-        S.Context.getCanonicalType(ToType))
+    SCS.First = ICK_HLSL_Array_RValue;
+
+    // Don't consider qualifiers, which include things like address spaces
+    if (FromType.getCanonicalType().getUnqualifiedType() !=
+        ToType.getCanonicalType().getUnqualifiedType())
       return false;
 
     SCS.setAllToTypes(ToType);
diff --git a/clang/test/CodeGenHLSL/ArrayAssignable.hlsl b/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
index e2ff2de68ed99..6374f91230546 100644
--- a/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
+++ b/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
@@ -1,4 +1,23 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s --enable-var-scope
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -finclude-default-header -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s
+
+struct S {
+  int x;
+  float f;
+};
+
+// CHECK: [[CBLayout:%.*]] = type <{ [2 x float], [2 x <4 x i32>], [2 x [2 x i32]], [1 x target("dx.Layout", %S, 8, 0, 4)] }>
+// CHECK: @CBArrays.cb = global target("dx.CBuffer", target("dx.Layout", [[CBLayout]], 136, 0, 32, 64, 128))
+// CHECK: @c1 = external addrspace(2) global [2 x float], align 4
+// CHECK: @c2 = external addrspace(2) global [2 x <4 x i32>], align 16
+// CHECK: @c3 = external addrspace(2) global [2 x [2 x i32]], align 4
+// CHECK: @c4 = external addrspace(2) global [1 x target("dx.Layout", %S, 8, 0, 4)], align 4
+
+cbuffer CBArrays : register(b0) {
+  float c1[2];
+  int4 c2[2];
+  int c3[2][2];
+  S c4[1];
+}
 
 // CHECK-LABEL: define void {{.*}}arr_assign1
 // CHECK: [[Arr:%.*]] = alloca [2 x i32], align 4
@@ -116,3 +135,45 @@ void arr_assign7() {
   int Arr2[2][2] = {{0, 0}, {1, 1}};
   (Arr = Arr2)[0] = {6, 6};
 }
+
+// Verify you can assign from a cbuffer array
+
+// CHECK-LABEL: define void {{.*}}arr_assign8
+// CHECK: [[C:%.*]] = alloca [2 x float], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[C]], ptr align 4 {{.*}}, i32 8, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p2.i32(ptr align 4 [[C]], ptr addrspace(2) align 4 @c1, i32 8, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign8() {
+  float C[2] = {1.0, 2.0};
+  C = c1;
+}
+
+// CHECK-LABEL: define void {{.*}}arr_assign9
+// CHECK: [[C:%.*]] = alloca [2 x <4 x i32>], align 16
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 16 [[C]], ptr align 16 {{.*}}, i32 32, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p2.i32(ptr align 16 [[C]], ptr addrspace(2) align 16 @c2, i32 32, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign9() {
+  int4 C[2] = {1,2,3,4,5,6,7,8};
+  C = c2;
+}
+
+// CHECK-LABEL: define void {{.*}}arr_assign10
+// CHECK: [[C:%.*]] = alloca [2 x [2 x i32]], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[C]], ptr align 4 {{.*}}, i32 16, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p2.i32(ptr align 4 [[C]], ptr addrspace(2) align 4 @c3, i32 16, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign10() {
+  int C[2][2] = {1,2,3,4};
+  C = c3;
+}
+
+// CHECK-LABEL: define void {{.*}}arr_assign11
+// CHECK: [[C:%.*]] = alloca [1 x %struct.S], align 4
+// CHECK: call void @llvm.memcpy.p0.p2.i32(ptr align 4 [[C]], ptr addrspace(2) align 4 @c4, i32 8, i1 false)
+// CHECK-NEXT: ret void
+void arr_assign11() {
+  S s = {1, 2.0};
+  S C[1] = {s};
+  C = c4;
+}

…vm#136580) Reland llvm#134174 Update Sema Checking to always do an HLSL Array RValue cast in the case we are dealing with hlsl constant array types Instead of comparing canonical types, compare canonical unqualified types Add a test to show it is possible to assign an array from a cbuffer. Closes llvm#133767

spall added 4 commits April 7, 2025 14:56

compare unqualified canonical types and add an hlsl array rvalue cast

5d81a4b

add comment about removing qualifiers

aa0c057

Merge branch 'main' into issue-133767

806df46

add a register to cbuffer in test to fix error about implicit registe…

ff36884

…r binding

llvmbot added clang Clang issues not falling into any other category clang:frontend Language frontend issues, e.g. anything involving "Sema" HLSL HLSL Language Support labels Apr 21, 2025

github-project-automation bot added this to HLSL Support Apr 21, 2025

bogner approved these changes Apr 21, 2025

View reviewed changes

farzonl approved these changes Apr 21, 2025

View reviewed changes

spall merged commit f02b285 into llvm:main Apr 21, 2025
15 checks passed

damyanp moved this to Closed in HLSL Support Apr 25, 2025

damyanp removed this from HLSL Support Jun 25, 2025

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[HLSL] Reland; Make it possible to assign an array from a cbuffer #136580

[HLSL] Reland; Make it possible to assign an array from a cbuffer #136580

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[HLSL] Reland; Make it possible to assign an array from a cbuffer #136580

[HLSL] Reland; Make it possible to assign an array from a cbuffer #136580

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