[Mlir-commits] [mlir] [mlir][spirv] Add definition for OpKill (PR #126554)
Igor Wodiany
llvmlistbot at llvm.org
Mon Feb 17 08:13:39 PST 2025
https://github.com/IgWod-IMG updated https://github.com/llvm/llvm-project/pull/126554
>From 960ca478c003b44e813450cc75c910eb77f0091d Mon Sep 17 00:00:00 2001
From: Igor Wodiany <igor.wodiany at imgtec.com>
Date: Thu, 6 Feb 2025 14:37:30 +0000
Subject: [PATCH] [mlir][spirv] Add definition for OpKill
Although the operation is deprecated in the most recent version
of the SPIR-V spec, it is still used by older shaders, so having
it defined is valuable and incurs negligible maintenance overhead,
due to op simplicity.
---
.../mlir/Dialect/SPIRV/IR/SPIRVBase.td | 3 +-
.../Dialect/SPIRV/IR/SPIRVControlFlowOps.td | 42 +++++++++++++++++++
mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp | 6 ++-
.../Dialect/SPIRV/IR/control-flow-ops.mlir | 12 ++++++
.../Dialect/SPIRV/Transforms/inlining.mlir | 21 +++++++++-
mlir/test/Target/SPIRV/terminator.mlir | 6 +++
6 files changed, 87 insertions(+), 3 deletions(-)
diff --git a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVBase.td b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVBase.td
index 1eacc564655a8..cafe140469570 100644
--- a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVBase.td
+++ b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVBase.td
@@ -4445,6 +4445,7 @@ def SPIRV_OC_OpSelectionMerge : I32EnumAttrCase<"OpSelectionMerge
def SPIRV_OC_OpLabel : I32EnumAttrCase<"OpLabel", 248>;
def SPIRV_OC_OpBranch : I32EnumAttrCase<"OpBranch", 249>;
def SPIRV_OC_OpBranchConditional : I32EnumAttrCase<"OpBranchConditional", 250>;
+def SPIRV_OC_OpKill : I32EnumAttrCase<"OpKill", 252>;
def SPIRV_OC_OpReturn : I32EnumAttrCase<"OpReturn", 253>;
def SPIRV_OC_OpReturnValue : I32EnumAttrCase<"OpReturnValue", 254>;
def SPIRV_OC_OpUnreachable : I32EnumAttrCase<"OpUnreachable", 255>;
@@ -4574,7 +4575,7 @@ def SPIRV_OpcodeAttr :
SPIRV_OC_OpAtomicAnd, SPIRV_OC_OpAtomicOr, SPIRV_OC_OpAtomicXor,
SPIRV_OC_OpPhi, SPIRV_OC_OpLoopMerge, SPIRV_OC_OpSelectionMerge,
SPIRV_OC_OpLabel, SPIRV_OC_OpBranch, SPIRV_OC_OpBranchConditional,
- SPIRV_OC_OpReturn, SPIRV_OC_OpReturnValue, SPIRV_OC_OpUnreachable,
+ SPIRV_OC_OpKill, SPIRV_OC_OpReturn, SPIRV_OC_OpReturnValue, SPIRV_OC_OpUnreachable,
SPIRV_OC_OpGroupBroadcast, SPIRV_OC_OpGroupIAdd, SPIRV_OC_OpGroupFAdd,
SPIRV_OC_OpGroupFMin, SPIRV_OC_OpGroupUMin, SPIRV_OC_OpGroupSMin,
SPIRV_OC_OpGroupFMax, SPIRV_OC_OpGroupUMax, SPIRV_OC_OpGroupSMax,
diff --git a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVControlFlowOps.td b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVControlFlowOps.td
index cc2f0e4962d8a..ade20f915c0c3 100644
--- a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVControlFlowOps.td
+++ b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVControlFlowOps.td
@@ -242,6 +242,48 @@ def SPIRV_FunctionCallOp : SPIRV_Op<"FunctionCall", [
// -----
+def SPIRV_KillOp : SPIRV_Op<"Kill", [Terminator]> {
+ let summary = [{
+ Deprecated (use OpTerminateInvocation or OpDemoteToHelperInvocation).
+ }];
+
+ let description = [{
+ Fragment-shader discard.
+
+ Ceases all further processing in any invocation that executes it: Only
+ instructions these invocations executed before OpKill have observable
+ side effects. If this instruction is executed in non-uniform control
+ flow, all subsequent control flow is non-uniform (for invocations that
+ continue to execute).
+
+ This instruction must be the last instruction in a block.
+
+ This instruction is only valid in the Fragment Execution Model.
+
+ <!-- End of AutoGen section -->
+
+ #### Example:
+
+ ```mlir
+ spirv.Kill
+ ```
+ }];
+
+ let availability = [
+ MinVersion<SPIRV_V_1_0>,
+ MaxVersion<SPIRV_V_1_6>,
+ Extension<[]>,
+ Capability<[SPIRV_C_Shader]>
+ ];
+
+ let arguments = (ins);
+ let results = (outs);
+ let assemblyFormat = "attr-dict";
+ let hasVerifier = 0;
+}
+
+// -----
+
def SPIRV_LoopOp : SPIRV_Op<"mlir.loop", [InFunctionScope]> {
let summary = "Define a structured loop.";
diff --git a/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp b/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp
index 48be287ef833b..0cf5f0823be63 100644
--- a/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp
+++ b/mlir/lib/Dialect/SPIRV/IR/SPIRVDialect.cpp
@@ -84,7 +84,11 @@ struct SPIRVInlinerInterface : public DialectInlinerInterface {
// TODO: we need to filter OpKill here to avoid inlining it to
// a loop continue construct:
// https://github.com/KhronosGroup/SPIRV-Headers/issues/86
- // However OpKill is fragment shader specific and we don't support it yet.
+ // For now, we just disallow inlining OpKill anywhere in the code,
+ // but this restriction should be relaxed, as pointed above.
+ if (isa<spirv::KillOp>(op))
+ return false;
+
return true;
}
diff --git a/mlir/test/Dialect/SPIRV/IR/control-flow-ops.mlir b/mlir/test/Dialect/SPIRV/IR/control-flow-ops.mlir
index 8496448759f0c..1d1e2840a579a 100644
--- a/mlir/test/Dialect/SPIRV/IR/control-flow-ops.mlir
+++ b/mlir/test/Dialect/SPIRV/IR/control-flow-ops.mlir
@@ -789,3 +789,15 @@ func.func @unreachable() {
// expected-error @+1 {{cannot be used in reachable block}}
spirv.Unreachable
}
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// spirv.Kill
+//===----------------------------------------------------------------------===//
+
+// CHECK-LABEL: func @kill
+func.func @kill() {
+ // CHECK: spirv.Kill
+ spirv.Kill
+}
diff --git a/mlir/test/Dialect/SPIRV/Transforms/inlining.mlir b/mlir/test/Dialect/SPIRV/Transforms/inlining.mlir
index bd3c665013136..8eb48a34e61e8 100644
--- a/mlir/test/Dialect/SPIRV/Transforms/inlining.mlir
+++ b/mlir/test/Dialect/SPIRV/Transforms/inlining.mlir
@@ -1,4 +1,4 @@
-// RUN: mlir-opt %s -split-input-file -pass-pipeline='builtin.module(spirv.module(inline{default-pipeline=''}))' | FileCheck %s
+// RUN: mlir-opt %s --split-input-file --pass-pipeline='builtin.module(spirv.module(inline{default-pipeline=''}))' | FileCheck %s
spirv.module Logical GLSL450 {
spirv.func @callee() "None" {
@@ -246,5 +246,24 @@ spirv.module Logical GLSL450 {
}
}
+// -----
+
+spirv.module Logical GLSL450 {
+ // CHECK-LABEL: @callee
+ spirv.func @callee() -> () "None" {
+ // CHECK-NEXT: spirv.Kill
+ spirv.Kill
+ }
+
+ // CHECK-LABEL: @do_not_inline_kill
+ spirv.func @do_not_inline_kill() -> () "None" {
+ // CHECK-NOT: spirv.Kill
+ // CHECK-NEXT: spirv.FunctionCall @callee() : () -> ()
+ spirv.FunctionCall @callee() : () -> ()
+ // CHECK-NEXT: spirv.Return
+ spirv.Return
+ }
+}
+
// TODO: Add tests for inlining structured control flow into
// structured control flow.
diff --git a/mlir/test/Target/SPIRV/terminator.mlir b/mlir/test/Target/SPIRV/terminator.mlir
index 065b68b9bdfbb..8338a575681f1 100644
--- a/mlir/test/Target/SPIRV/terminator.mlir
+++ b/mlir/test/Target/SPIRV/terminator.mlir
@@ -24,4 +24,10 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
// CHECK-NOT: spirv.Unreachable
spirv.Unreachable
}
+
+ // CHECK-LABEL: @kill
+ spirv.func @kill() -> () "None" {
+ // CHECK: spirv.Kill
+ spirv.Kill
+ }
}
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