[llvm-branch-commits] [llvm] [DirectX] Add missing verifications during `validate` of `DXILRootSignature` (PR #147111)
Finn Plummer via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Fri Jul 4 14:23:25 PDT 2025
https://github.com/inbelic created https://github.com/llvm/llvm-project/pull/147111
This pr resolves some discrepancies in verification during `validate` in `DXILRootSignature.cpp`.
Namely,
- `verifyDescriptorFlag` should be updated to check what flags are valid based on the root signature version, as reflected here https://github.com/llvm/wg-hlsl/pull/297.
- There is currently no verification that `numDescriptors > 0` which should be added to be compliant with DXC: https://github.com/microsoft/DirectXShaderCompiler/blob/4fcf67f78f7d6ffd286316112694a3ae000860e2/lib/DxilRootSignature/DxilRootSignatureValidator.cpp#L197.
- Updates `verifyDescriptorFlag` to check for valid flags based on version
- Add test to demonstrate updated flag verifications
- Adds `verifyNumDescriptors` to the validation of `DescriptorRange`s
- Add a test to demonstrate `numDescriptors` verification
- Updates a number of tests that mistakenly had an invalid `numDescriptors` specified
Resolves: https://github.com/llvm/llvm-project/issues/147107
>From ab274d239bd12e39fc91d7cc2fc7e899be274e55 Mon Sep 17 00:00:00 2001
From: Finn Plummer <canadienfinn at gmail.com>
Date: Fri, 4 Jul 2025 20:54:50 +0000
Subject: [PATCH 1/3] [HLSL][DirectX] Add `verifyNumDescriptors`
---
.../Frontend/HLSL/RootSignatureValidations.h | 1 +
.../HLSL/RootSignatureValidations.cpp | 4 ++++
llvm/lib/Target/DirectX/DXILRootSignature.cpp | 3 +++
...-DescriptorTable-Invalid-NumDescriptors.ll | 19 +++++++++++++++++++
4 files changed, 27 insertions(+)
create mode 100644 llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-NumDescriptors.ll
diff --git a/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h b/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h
index 9b68a524432cc..bcef20530559d 100644
--- a/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h
+++ b/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h
@@ -31,6 +31,7 @@ bool verifyDescriptorFlag(uint32_t Flags);
bool verifyRangeType(uint32_t Type);
bool verifyDescriptorRangeFlag(uint32_t Version, uint32_t Type,
uint32_t FlagsVal);
+bool verifyNumDescriptors(uint32_t NumDescriptors);
bool verifySamplerFilter(uint32_t Value);
bool verifyAddress(uint32_t Address);
bool verifyMipLODBias(float MipLODBias);
diff --git a/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp b/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp
index b5b5fc0c74d83..6c238e0f04468 100644
--- a/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp
+++ b/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp
@@ -108,6 +108,10 @@ bool verifyDescriptorRangeFlag(uint32_t Version, uint32_t Type,
return (Flags & ~Mask) == FlagT::None;
}
+bool verifyNumDescriptors(uint32_t NumDescriptors) {
+ return NumDescriptors > 0;
+}
+
bool verifySamplerFilter(uint32_t Value) {
switch (Value) {
#define FILTER(Num, Val) case llvm::to_underlying(dxbc::SamplerFilter::Val):
diff --git a/llvm/lib/Target/DirectX/DXILRootSignature.cpp b/llvm/lib/Target/DirectX/DXILRootSignature.cpp
index e46b184a353f1..edad63bfe7ea7 100644
--- a/llvm/lib/Target/DirectX/DXILRootSignature.cpp
+++ b/llvm/lib/Target/DirectX/DXILRootSignature.cpp
@@ -447,6 +447,9 @@ static bool validate(LLVMContext *Ctx, const mcdxbc::RootSignatureDesc &RSD) {
if (!llvm::hlsl::rootsig::verifyRegisterSpace(Range.RegisterSpace))
return reportValueError(Ctx, "RegisterSpace", Range.RegisterSpace);
+ if (!llvm::hlsl::rootsig::verifyNumDescriptors(Range.NumDescriptors))
+ return reportValueError(Ctx, "NumDescriptors", Range.NumDescriptors);
+
if (!llvm::hlsl::rootsig::verifyDescriptorRangeFlag(
RSD.Version, Range.RangeType, Range.Flags))
return reportValueError(Ctx, "DescriptorFlag", Range.Flags);
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-NumDescriptors.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-NumDescriptors.ll
new file mode 100644
index 0000000000000..99d126ee95443
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-NumDescriptors.ll
@@ -0,0 +1,19 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: error: Invalid value for NumDescriptors: 0
+; CHECK-NOT: Root Signature Definitions
+
+define void @main() #0 {
+entry:
+ ret void
+}
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+
+
+!dx.rootsignatures = !{!2} ; list of function/root signature pairs
+!2 = !{ ptr @main, !3, i32 2 } ; function, root signature
+!3 = !{ !5 } ; list of root signature elements
+!5 = !{ !"DescriptorTable", i32 0, !6}
+!6 = !{ !"SRV", i32 0, i32 0, i32 10, i32 -1, i32 4 }
>From 56ae9d9316fd02b588ba67ddf1820c9bd80bae49 Mon Sep 17 00:00:00 2001
From: Finn Plummer <canadienfinn at gmail.com>
Date: Fri, 4 Jul 2025 20:59:09 +0000
Subject: [PATCH 2/3] fix up testcases using invalid num descriptors
---
...ootSignature-DescriptorTable-AllValidFlagCombinationsV1.ll | 4 ++--
.../RootSignature-DescriptorTable-Invalid-Flag.ll | 2 +-
.../RootSignature-DescriptorTable-Invalid-RangeType.ll | 2 +-
.../RootSignature-DescriptorTable-Invalid-RegisterSpace.ll | 2 +-
.../DirectX/ContainerData/RootSignature-DescriptorTable.ll | 4 ++--
.../CodeGen/DirectX/ContainerData/RootSignature-Parameters.ll | 4 ++--
6 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-AllValidFlagCombinationsV1.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-AllValidFlagCombinationsV1.ll
index 9d89dbdd9107b..053721de1eb1f 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-AllValidFlagCombinationsV1.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-AllValidFlagCombinationsV1.ll
@@ -13,7 +13,7 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
!2 = !{ ptr @main, !3, i32 1 } ; function, root signature
!3 = !{ !5 } ; list of root signature elements
!5 = !{ !"DescriptorTable", i32 0, !6, !7 }
-!6 = !{ !"Sampler", i32 0, i32 1, i32 0, i32 -1, i32 1 }
+!6 = !{ !"Sampler", i32 1, i32 1, i32 0, i32 -1, i32 1 }
!7 = !{ !"UAV", i32 5, i32 1, i32 10, i32 5, i32 3 }
@@ -33,7 +33,7 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
; DXC-NEXT: RangesOffset: 44
; DXC-NEXT: Ranges:
; DXC-NEXT: - RangeType: 3
-; DXC-NEXT: NumDescriptors: 0
+; DXC-NEXT: NumDescriptors: 1
; DXC-NEXT: BaseShaderRegister: 1
; DXC-NEXT: RegisterSpace: 0
; DXC-NEXT: OffsetInDescriptorsFromTableStart: 4294967295
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-Flag.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-Flag.ll
index 41101c1f1fe8e..58056c5d4ba94 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-Flag.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-Flag.ll
@@ -16,5 +16,5 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
!2 = !{ ptr @main, !3, i32 2 } ; function, root signature
!3 = !{ !5 } ; list of root signature elements
!5 = !{ !"DescriptorTable", i32 0, !6, !7 }
-!6 = !{ !"SRV", i32 0, i32 1, i32 0, i32 -1, i32 22 }
+!6 = !{ !"SRV", i32 1, i32 1, i32 0, i32 -1, i32 22 }
!7 = !{ !"UAV", i32 5, i32 1, i32 10, i32 5, i32 2 }
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RangeType.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RangeType.ll
index b7e99ae7cd27b..0f7116307c315 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RangeType.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RangeType.ll
@@ -16,5 +16,5 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
!2 = !{ ptr @main, !3, i32 2 } ; function, root signature
!3 = !{ !5 } ; list of root signature elements
!5 = !{ !"DescriptorTable", i32 0, !6, !7 }
-!6 = !{ !"Invalid", i32 0, i32 0, i32 -1, i32 -1, i32 4 }
+!6 = !{ !"Invalid", i32 1, i32 0, i32 -1, i32 -1, i32 4 }
!7 = !{ !"UAV", i32 5, i32 1, i32 10, i32 5, i32 2 }
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RegisterSpace.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RegisterSpace.ll
index 4cef5d86a980b..94cd25b06a127 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RegisterSpace.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable-Invalid-RegisterSpace.ll
@@ -16,5 +16,5 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
!2 = !{ ptr @main, !3, i32 2 } ; function, root signature
!3 = !{ !5 } ; list of root signature elements
!5 = !{ !"DescriptorTable", i32 0, !6, !7 }
-!6 = !{ !"SRV", i32 0, i32 0, i32 10, i32 -1, i32 4 }
+!6 = !{ !"SRV", i32 1, i32 0, i32 10, i32 -1, i32 4 }
!7 = !{ !"UAV", i32 5, i32 1, i32 4294967280, i32 5, i32 2 }
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable.ll
index b516d66180247..8e9b4b43b11a6 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-DescriptorTable.ll
@@ -16,7 +16,7 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
!2 = !{ ptr @main, !3, i32 2 } ; function, root signature
!3 = !{ !5 } ; list of root signature elements
!5 = !{ !"DescriptorTable", i32 0, !6, !7 }
-!6 = !{ !"SRV", i32 0, i32 1, i32 0, i32 -1, i32 4 }
+!6 = !{ !"SRV", i32 1, i32 1, i32 0, i32 -1, i32 4 }
!7 = !{ !"UAV", i32 5, i32 1, i32 10, i32 5, i32 2 }
; DXC: - Name: RTS0
@@ -35,7 +35,7 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
; DXC-NEXT: RangesOffset: 44
; DXC-NEXT: Ranges:
; DXC-NEXT: - RangeType: 0
-; DXC-NEXT: NumDescriptors: 0
+; DXC-NEXT: NumDescriptors: 1
; DXC-NEXT: BaseShaderRegister: 1
; DXC-NEXT: RegisterSpace: 0
; DXC-NEXT: OffsetInDescriptorsFromTableStart: 4294967295
diff --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Parameters.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Parameters.ll
index d0a58bc34ffa4..a8444c6079a85 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Parameters.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Parameters.ll
@@ -17,7 +17,7 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
!5 = !{ !"RootConstants", i32 0, i32 1, i32 2, i32 3 }
!6 = !{ !"RootSRV", i32 1, i32 4, i32 5, i32 6 }
!7 = !{ !"DescriptorTable", i32 0, !8, !9 }
-!8 = !{ !"SRV", i32 0, i32 1, i32 0, i32 -1, i32 4 }
+!8 = !{ !"SRV", i32 1, i32 1, i32 0, i32 -1, i32 4 }
!9 = !{ !"UAV", i32 5, i32 1, i32 10, i32 5, i32 2 }
;CHECK-LABEL: Definition for 'main':
@@ -41,7 +41,7 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
;CHECK-NEXT: - Range Type: 0
;CHECK-NEXT: Register Space: 0
;CHECK-NEXT: Base Shader Register: 1
-;CHECK-NEXT: Num Descriptors: 0
+;CHECK-NEXT: Num Descriptors: 1
;CHECK-NEXT: Offset In Descriptors From Table Start: 4294967295
;CHECK-NEXT: Flags: 4
;CHECK-NEXT: - Range Type: 1
>From b6ac185f96beb673660f68e22ffd16bdcf023e46 Mon Sep 17 00:00:00 2001
From: Finn Plummer <canadienfinn at gmail.com>
Date: Fri, 4 Jul 2025 21:11:47 +0000
Subject: [PATCH 3/3] [HLSL][DirectX] update `verifyRootDescriptorFlag` to
match the spec
---
.../Frontend/HLSL/RootSignatureValidations.h | 2 +-
.../HLSL/RootSignatureValidations.cpp | 19 ++++++++++++++++++-
llvm/lib/Target/DirectX/DXILRootSignature.cpp | 3 ++-
3 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h b/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h
index bcef20530559d..03f4e2cf5bb8f 100644
--- a/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h
+++ b/llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h
@@ -27,7 +27,7 @@ bool verifyRootFlag(uint32_t Flags);
bool verifyVersion(uint32_t Version);
bool verifyRegisterValue(uint32_t RegisterValue);
bool verifyRegisterSpace(uint32_t RegisterSpace);
-bool verifyDescriptorFlag(uint32_t Flags);
+bool verifyRootDescriptorFlag(uint32_t Version, uint32_t FlagsVal);
bool verifyRangeType(uint32_t Type);
bool verifyDescriptorRangeFlag(uint32_t Version, uint32_t Type,
uint32_t FlagsVal);
diff --git a/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp b/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp
index 6c238e0f04468..48d6b8639b2dc 100644
--- a/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp
+++ b/llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp
@@ -32,7 +32,24 @@ bool verifyRegisterSpace(uint32_t RegisterSpace) {
return !(RegisterSpace >= 0xFFFFFFF0 && RegisterSpace <= 0xFFFFFFFF);
}
-bool verifyDescriptorFlag(uint32_t Flags) { return (Flags & ~0xE) == 0; }
+bool verifyRootDescriptorFlag(uint32_t Version, uint32_t FlagsVal) {
+ using FlagT = dxbc::RootDescriptorFlags;
+ FlagT Flags = FlagT(FlagsVal);
+ if (Version == 1)
+ return FlagsVal == FlagT::DataVolatile;
+
+ assert(Version == 2 && "Provided invalid root signature version");
+
+ // The data-specific flags are mutually exclusive.
+ FlagT DataFlags = FlagT::DataVolatile | FlagT::DataStatic |
+ FlagT::DataStaticWhileSetAtExecute;
+
+ if (popcount(llvm::to_underlying(Flags & DataFlags)) > 1)
+ return false;
+
+ // Only a data flag or no flags is valid
+ return (FlagsVal & ~0xE) == 0;
+}
bool verifyRangeType(uint32_t Type) {
switch (Type) {
diff --git a/llvm/lib/Target/DirectX/DXILRootSignature.cpp b/llvm/lib/Target/DirectX/DXILRootSignature.cpp
index edad63bfe7ea7..37a60075514ef 100644
--- a/llvm/lib/Target/DirectX/DXILRootSignature.cpp
+++ b/llvm/lib/Target/DirectX/DXILRootSignature.cpp
@@ -432,7 +432,8 @@ static bool validate(LLVMContext *Ctx, const mcdxbc::RootSignatureDesc &RSD) {
return reportValueError(Ctx, "RegisterSpace", Descriptor.RegisterSpace);
if (RSD.Version > 1) {
- if (!llvm::hlsl::rootsig::verifyDescriptorFlag(Descriptor.Flags))
+ if (!llvm::hlsl::rootsig::verifyRootDescriptorFlag(RSD.Version,
+ Descriptor.Flags))
return reportValueError(Ctx, "DescriptorRangeFlag", Descriptor.Flags);
}
break;
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