[llvm] [DirectX] Add support for vector type checking in DXIL Shader Flag Analysis (PR #150532)

via llvm-commits llvm-commits at lists.llvm.org
Thu Jul 24 14:46:31 PDT 2025


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-directx

Author: Deric C. (Icohedron)

<details>
<summary>Changes</summary>

Fixes #<!-- -->150482 by replacing all `Instruction.getType()` in DXILShaderFlags.cpp with `Instruction.getType()->getScalarType()` to account for vectors types as suggested by @<!-- -->bogner 

---
Full diff: https://github.com/llvm/llvm-project/pull/150532.diff


2 Files Affected:

- (modified) llvm/lib/Target/DirectX/DXILShaderFlags.cpp (+8-7) 
- (added) llvm/test/CodeGen/DirectX/ShaderFlags/rawbuffer-low-precision.ll (+44) 


``````````diff
diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
index eb4adfea5aed6..e7e7f2ce66ae8 100644
--- a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
+++ b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp
@@ -106,11 +106,11 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
                                             DXILResourceTypeMap &DRTM,
                                             const ModuleMetadataInfo &MMDI) {
   if (!CSF.Doubles)
-    CSF.Doubles = I.getType()->isDoubleTy();
+    CSF.Doubles = I.getType()->getScalarType()->isDoubleTy();
 
   if (!CSF.Doubles) {
     for (const Value *Op : I.operands()) {
-      if (Op->getType()->isDoubleTy()) {
+      if (Op->getType()->getScalarType()->isDoubleTy()) {
         CSF.Doubles = true;
         break;
       }
@@ -130,12 +130,13 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
   }
 
   if (!CSF.LowPrecisionPresent)
-    CSF.LowPrecisionPresent =
-        I.getType()->isIntegerTy(16) || I.getType()->isHalfTy();
+    CSF.LowPrecisionPresent = I.getType()->getScalarType()->isIntegerTy(16) ||
+                              I.getType()->getScalarType()->isHalfTy();
 
   if (!CSF.LowPrecisionPresent) {
     for (const Value *Op : I.operands()) {
-      if (Op->getType()->isIntegerTy(16) || Op->getType()->isHalfTy()) {
+      if (Op->getType()->getScalarType()->isIntegerTy(16) ||
+          Op->getType()->getScalarType()->isHalfTy()) {
         CSF.LowPrecisionPresent = true;
         break;
       }
@@ -150,11 +151,11 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
   }
 
   if (!CSF.Int64Ops)
-    CSF.Int64Ops = I.getType()->isIntegerTy(64);
+    CSF.Int64Ops = I.getType()->getScalarType()->isIntegerTy(64);
 
   if (!CSF.Int64Ops && !isa<LifetimeIntrinsic>(&I)) {
     for (const Value *Op : I.operands()) {
-      if (Op->getType()->isIntegerTy(64)) {
+      if (Op->getType()->getScalarType()->isIntegerTy(64)) {
         CSF.Int64Ops = true;
         break;
       }
diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/rawbuffer-low-precision.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/rawbuffer-low-precision.ll
new file mode 100644
index 0000000000000..ec4b87fd81799
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ShaderFlags/rawbuffer-low-precision.ll
@@ -0,0 +1,44 @@
+; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s
+; RUN: llc %s --filetype=obj -o - | obj2yaml | FileCheck %s --check-prefix=DXC
+
+target triple = "dxil-pc-shadermodel6.7-library"
+
+; CHECK: ; Combined Shader Flags for Module
+; CHECK-NEXT: ; Shader Flags Value: 0x00800030
+; CHECK-NEXT: ;
+; CHECK-NEXT: ; Note: shader requires additional functionality:
+; CHECK-NEXT: ;       Native low-precision data types
+; CHECK-NEXT: ; Note: extra DXIL module flags:
+; CHECK-NEXT: ;       Raw and structured buffers
+; CHECK-NEXT: ;       Low-precision data types present
+; CHECK-NEXT: ;       Enable native low-precision data types
+; CHECK-NEXT: ;
+; CHECK-NEXT: ; Shader Flags for Module Functions
+
+; CHECK: Function rawbuf : 0x00800030
+define void @rawbuf() "hlsl.export" {
+  %halfrb = tail call target("dx.RawBuffer", <4 x half>, 0, 0)
+    @llvm.dx.resource.handlefrombinding.tdx.RawBuffer_v4f16_0_0t(i32 0, i32 0, i32 1, i32 0, i1 false, ptr null)
+  %i16rb = tail call target("dx.RawBuffer", <4 x i16>, 1, 0)
+    @llvm.dx.resource.handlefrombinding.tdx.RawBuffer_v4i16_1_0t(i32 0, i32 1, i32 1, i32 0, i1 false, ptr null)
+  %loadhalfrb = call { <4 x i16>, i1 }
+    @llvm.dx.resource.load.rawbuffer.v4i16.tdx.RawBuffer_v4f16_0_0t(target("dx.RawBuffer", <4 x half>, 0, 0) %halfrb, i32 0, i32 0)
+  %storei16rb = extractvalue { <4 x i16>, i1 } %loadhalfrb, 0
+  call void @llvm.dx.resource.store.rawbuffer.tdx.RawBuffer_v4i16_1_0t.v4i16(target("dx.RawBuffer", <4 x i16>, 1, 0) %i16rb, i32 0, i32 0, <4 x i16> %storei16rb)
+  ret void
+}
+
+; Metadata to avoid adding flags not currently of interest to this test, and
+; enable native low precision data types
+!dx.valver = !{!0}
+!0 = !{i32 1, i32 8}
+!llvm.module.flags = !{!1, !2}
+!1 = !{i32 1, !"dx.nativelowprec", i32 1}
+!2 = !{i32 1, !"dx.resmayalias", i32 1}
+
+; DXC: - Name:            SFI0
+; DXC-NEXT:     Size:            8
+; DXC-NEXT:     Flags:
+; DXC:      MinimumPrecision: false
+; DXC:      NativeLowPrecision: true
+; DXC: ...

``````````

</details>


https://github.com/llvm/llvm-project/pull/150532


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