[Mlir-commits] [mlir] [mlir][SPIR-V] Support spirv.selection_control attribute on scf.if (PR #196510)
Arseniy Obolenskiy
llvmlistbot at llvm.org
Sat May 9 12:03:40 PDT 2026
https://github.com/aobolensk updated https://github.com/llvm/llvm-project/pull/196510
>From db2817def623bdc817e99905e9782fbddaa65e87 Mon Sep 17 00:00:00 2001
From: Arseniy Obolenskiy <arseniy.obolenskiy at amd.com>
Date: Fri, 8 May 2026 13:10:37 +0200
Subject: [PATCH 1/3] [mlir][SPIR-V] Support spirv.selection_control attribute
on scf.if
---
.../mlir/Dialect/SPIRV/IR/TargetAndABI.h | 3 +++
mlir/lib/Conversion/SCFToSPIRV/SCFToSPIRV.cpp | 8 +++++--
mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp | 4 ++++
mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp | 4 ++++
mlir/test/Conversion/SCFToSPIRV/if.mlir | 22 +++++++++++++++++++
5 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/mlir/include/mlir/Dialect/SPIRV/IR/TargetAndABI.h b/mlir/include/mlir/Dialect/SPIRV/IR/TargetAndABI.h
index 7e11eb653c126..6e302542bde35 100644
--- a/mlir/include/mlir/Dialect/SPIRV/IR/TargetAndABI.h
+++ b/mlir/include/mlir/Dialect/SPIRV/IR/TargetAndABI.h
@@ -112,6 +112,9 @@ ResourceLimitsAttr getDefaultResourceLimits(MLIRContext *context);
/// Returns the attribute name for specifying loop control.
StringRef getLoopControlAttrName();
+/// Returns the attribute name for specifying selection control.
+StringRef getSelectionControlAttrName();
+
/// Returns the attribute name for specifying SPIR-V target environment.
StringRef getTargetEnvAttrName();
diff --git a/mlir/lib/Conversion/SCFToSPIRV/SCFToSPIRV.cpp b/mlir/lib/Conversion/SCFToSPIRV/SCFToSPIRV.cpp
index a9c6f7db847d3..d5140f3faa6ff 100644
--- a/mlir/lib/Conversion/SCFToSPIRV/SCFToSPIRV.cpp
+++ b/mlir/lib/Conversion/SCFToSPIRV/SCFToSPIRV.cpp
@@ -249,8 +249,12 @@ struct IfOpConversion : SCFToSPIRVPattern<scf::IfOp> {
// Create `spirv.selection` operation, selection header block and merge
// block.
- auto selectionOp = spirv::SelectionOp::create(
- rewriter, loc, spirv::SelectionControl::None);
+ auto selectionControl = spirv::SelectionControl::None;
+ if (auto attr = ifOp->getAttrOfType<spirv::SelectionControlAttr>(
+ spirv::getSelectionControlAttrName()))
+ selectionControl = attr.getValue();
+ auto selectionOp =
+ spirv::SelectionOp::create(rewriter, loc, selectionControl);
auto *mergeBlock = rewriter.createBlock(&selectionOp.getBody(),
selectionOp.getBody().end());
spirv::MergeOp::create(rewriter, loc);
diff --git a/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp b/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp
index 2b5e7a571f42d..5821391b426cb 100644
--- a/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp
+++ b/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp
@@ -1054,6 +1054,10 @@ LogicalResult SPIRVDialect::verifyOperationAttribute(Operation *op,
if (!isa<spirv::LoopControlAttr>(attr))
return op->emitError("'")
<< symbol << "' must be a spirv::LoopControlAttr";
+ } else if (symbol == spirv::getSelectionControlAttrName()) {
+ if (!isa<spirv::SelectionControlAttr>(attr))
+ return op->emitError("'")
+ << symbol << "' must be a spirv::SelectionControlAttr";
} else {
return op->emitError("found unsupported '")
<< symbol << "' attribute on operation";
diff --git a/mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp b/mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp
index 270cb6df20415..c604fd087ba46 100644
--- a/mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp
+++ b/mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp
@@ -167,6 +167,10 @@ spirv::getDefaultResourceLimits(MLIRContext *context) {
StringRef spirv::getLoopControlAttrName() { return "spirv.loop_control"; }
+StringRef spirv::getSelectionControlAttrName() {
+ return "spirv.selection_control";
+}
+
StringRef spirv::getTargetEnvAttrName() { return "spirv.target_env"; }
spirv::TargetEnvAttr spirv::getDefaultTargetEnv(MLIRContext *context) {
diff --git a/mlir/test/Conversion/SCFToSPIRV/if.mlir b/mlir/test/Conversion/SCFToSPIRV/if.mlir
index 2c18da41dc021..0b3df9a533302 100644
--- a/mlir/test/Conversion/SCFToSPIRV/if.mlir
+++ b/mlir/test/Conversion/SCFToSPIRV/if.mlir
@@ -167,4 +167,26 @@ func.func @unsupported_yield_type(%arg0 : memref<8xi32>, %arg1 : memref<8xi32>,
return
}
+// CHECK-LABEL: @selection_flatten
+func.func @selection_flatten(%arg2 : memref<10xf32, #spirv.storage_class<StorageBuffer>>, %arg3 : i1) {
+ %value = arith.constant 0.0 : f32
+ %i = arith.constant 0 : index
+ // CHECK: spirv.mlir.selection control(Flatten) {
+ scf.if %arg3 {
+ memref.store %value, %arg2[%i] : memref<10xf32, #spirv.storage_class<StorageBuffer>>
+ } {spirv.selection_control = #spirv.selection_control<Flatten>}
+ return
+}
+
+// CHECK-LABEL: @selection_dont_flatten
+func.func @selection_dont_flatten(%arg2 : memref<10xf32, #spirv.storage_class<StorageBuffer>>, %arg3 : i1) {
+ %value = arith.constant 0.0 : f32
+ %i = arith.constant 0 : index
+ // CHECK: spirv.mlir.selection control(DontFlatten) {
+ scf.if %arg3 {
+ memref.store %value, %arg2[%i] : memref<10xf32, #spirv.storage_class<StorageBuffer>>
+ } {spirv.selection_control = #spirv.selection_control<DontFlatten>}
+ return
+}
+
} // end module
>From 63888bc31d678c24f0c26354be21e6716d1a1049 Mon Sep 17 00:00:00 2001
From: Arseniy Obolenskiy <arseniy.obolenskiy at amd.com>
Date: Sat, 9 May 2026 09:54:05 +0200
Subject: [PATCH 2/3] Add negative test
---
mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir b/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
index 63dea6af83556..7ecb8fb363f76 100644
--- a/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
+++ b/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
@@ -346,3 +346,14 @@ func.func @vce() attributes {
// CHECK: #spirv.vce<v1.0, [Shader], [SPV_KHR_storage_buffer_storage_class]>
vce = #spirv.vce<v1.0, [Shader], [SPV_KHR_storage_buffer_storage_class]>
} { return }
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// spirv.selection_control
+//===----------------------------------------------------------------------===//
+
+// expected-error @+1 {{'spirv.selection_control' must be a spirv::SelectionControlAttr}}
+func.func @selection_control_wrong_attr() attributes {
+ spirv.selection_control = 64
+} { return }
>From 5a4611bda55e5585b46dc17a69cb382c191e6d28 Mon Sep 17 00:00:00 2001
From: Arseniy Obolenskiy <gooddoog at student.su>
Date: Sat, 9 May 2026 21:03:30 +0200
Subject: [PATCH 3/3] Update mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
Co-authored-by: Jakub Kuderski <kubakuderski at gmail.com>
---
mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir b/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
index 7ecb8fb363f76..e634186d3b9a8 100644
--- a/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
+++ b/mlir/test/Dialect/SPIRV/IR/target-and-abi.mlir
@@ -353,7 +353,7 @@ func.func @vce() attributes {
// spirv.selection_control
//===----------------------------------------------------------------------===//
-// expected-error @+1 {{'spirv.selection_control' must be a spirv::SelectionControlAttr}}
+// expected-error at +1 {{'spirv.selection_control' must be a spirv::SelectionControlAttr}}
func.func @selection_control_wrong_attr() attributes {
spirv.selection_control = 64
} { return }
More information about the Mlir-commits
mailing list