[llvm] 0be3f13 - [DirectX] only allow intrinsics defined in DXIL.td (#128613)

[via llvm-commits]

Author: Farzon Lotfi
Date: 2025-02-25T16:09:41-05:00
New Revision: 0be3f134c3b0bea0a3f32db55258c776caf616fb

URL: https://github.com/llvm/llvm-project/commit/0be3f134c3b0bea0a3f32db55258c776caf616fb
DIFF: https://github.com/llvm/llvm-project/commit/0be3f134c3b0bea0a3f32db55258c776caf616fb.diff

LOG: [DirectX] only allow intrinsics defined in DXIL.td (#128613)

Fixes #128071
The current behavior lets intrinsics that don't map to a DXILOP slip
through. Nothing catches this until we hit the DXIL validator. This
change fails earlier so we don't encode invalid llvm intrinsics that can
slip through because of clang builtins like `__builtin_reduce_and`
example:
https://hlsl.godbolt.org/z/13rPj18vn

Added: 
    llvm/test/CodeGen/DirectX/unsupported_intrinsic.ll

Modified: 
    llvm/lib/Target/DirectX/DXILOpLowering.cpp
    llvm/test/CodeGen/DirectX/clamp.ll
    llvm/test/CodeGen/DirectX/discard.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/DirectX/DXILOpLowering.cpp b/llvm/lib/Target/DirectX/DXILOpLowering.cpp
index 83cc4b18824c7..efcd9970a4652 100644
--- a/llvm/lib/Target/DirectX/DXILOpLowering.cpp
+++ b/llvm/lib/Target/DirectX/DXILOpLowering.cpp
@@ -770,8 +770,20 @@ class OpLowerer {
         continue;
       Intrinsic::ID ID = F.getIntrinsicID();
       switch (ID) {
-      default:
+      // NOTE: Skip dx_resource_casthandle here. They are
+      // resolved after this loop in cleanupHandleCasts.
+      case Intrinsic::dx_resource_casthandle:
+      // NOTE: llvm.dbg.value is supported as is in DXIL.
+      case Intrinsic::dbg_value:
+      case Intrinsic::not_intrinsic:
         continue;
+      default: {
+        DiagnosticInfoUnsupported Diag(
+            F, "Unsupported intrinsic for DXIL lowering");
+        M.getContext().diagnose(Diag);
+        HasErrors |= true;
+        break;
+      }
 #define DXIL_OP_INTRINSIC(OpCode, Intrin, ...)                                 \
   case Intrin:                                                                 \
     HasErrors |= replaceFunctionWithOp(                                        \

diff  --git a/llvm/test/CodeGen/DirectX/clamp.ll b/llvm/test/CodeGen/DirectX/clamp.ll
index 6345abc1789bc..54c6aa5040c4a 100644
--- a/llvm/test/CodeGen/DirectX/clamp.ll
+++ b/llvm/test/CodeGen/DirectX/clamp.ll
@@ -286,7 +286,7 @@ declare <3 x half> @llvm.dx.nclamp.v3f16(<3 x half>, <3 x half>, <3 x half>)
 declare <4 x float> @llvm.dx.nclamp.v4f32(<4 x float>, <4 x float>, <4 x float>)
 declare <2 x double> @llvm.dx.nclamp.v2f64(<2 x double>, <2 x double>, <2 x double>)
 declare <4 x i32> @llvm.dx.sclamp.v4i32(<4 x i32>, <4 x i32>, <4 x i32>)
-declare <3 x i16> @llvm.dx.uclamp.v3i32(<3 x i16>, <3 x i32>, <3 x i16>)
+declare <3 x i16> @llvm.dx.uclamp.v3i16(<3 x i16>, <3 x i16>, <3 x i16>)
 declare <4 x i32> @llvm.dx.uclamp.v4i32(<4 x i32>, <4 x i32>, <4 x i32>)
 declare <2 x i64> @llvm.dx.uclamp.v2i64(<2 x i64>, <2 x i64>, <2 x i64>)
 

diff  --git a/llvm/test/CodeGen/DirectX/discard.ll b/llvm/test/CodeGen/DirectX/discard.ll
index 2a9ec59156e7c..81a96d577ba1a 100644
--- a/llvm/test/CodeGen/DirectX/discard.ll
+++ b/llvm/test/CodeGen/DirectX/discard.ll
@@ -1,4 +1,4 @@
-; RUN: opt -passes='function(scalarizer),module(dxil-op-lower,dxil-intrinsic-expansion)' -S -mtriple=dxil-pc-shadermodel6.3-pixel %s | FileCheck %s
+; RUN: opt -passes='function(scalarizer),module(dxil-intrinsic-expansion,dxil-op-lower)' -S -mtriple=dxil-pc-shadermodel6.3-pixel %s | FileCheck %s
 
 ; CHECK-LABEL: define void @test_scalar
 ; CHECK: call void @dx.op.discard(i32 82, i1 %0)

diff  --git a/llvm/test/CodeGen/DirectX/unsupported_intrinsic.ll b/llvm/test/CodeGen/DirectX/unsupported_intrinsic.ll
new file mode 100644
index 0000000000000..d703f2f04c494
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/unsupported_intrinsic.ll
@@ -0,0 +1,11 @@
+; RUN: not opt -S -dxil-op-lower -mtriple=dxil-pc-shadermodel6.3-library %s 2>&1 | FileCheck %s
+
+; CHECK: error: <unknown>:0:0: in function llvm.vector.reduce.and.v4i32 i32 (<4 x i32>): Unsupported intrinsic for DXIL lowering
+define i32 @fn_and(<4 x i32> %0) local_unnamed_addr #0 {
+  %2 = tail call i32 @llvm.vector.reduce.and.v4i32(<4 x i32> %0)
+  ret i32 %2
+}
+
+declare i32 @llvm.vector.reduce.and.v4i32(<4 x i32>)
+
+attributes #0 = { convergent norecurse nounwind "hlsl.export"}