[DirectX] Remove llvm.assume intrinsic

[farzonl]

fixes #165051

This change reverts the experiment we did for #165311

While some backends seem to support llvm.assume without validation The validator itself does not so it makes more sense to just remove it.

[llvmbot]

@llvm/pr-subscribers-backend-directx

Author: Farzon Lotfi (farzonl)

Changes

fixes #165051

This change reverts the experiment we did for #165311

While some backends seem to support llvm.assume without validation The validator itself does not so it makes more sense to just remove it.

---

Full diff: https://github.com/llvm/llvm-project/pull/166697.diff

4 Files Affected:

• (modified) llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp (+4)
• (modified) llvm/lib/Target/DirectX/DXILOpLowering.cpp (-2)
• (added) llvm/test/CodeGen/DirectX/llvm_assume.ll (+9)
• (removed) llvm/test/tools/dxil-dis/llvm_assume.ll (-11)

diff --git a/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp b/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp
index ebb7c2607c0c8..e0d2dbde92150 100644
--- a/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp
+++ b/llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp
@@ -197,6 +197,7 @@ static Value *expand16BitIsNormal(CallInst *Orig) {
 
 static bool isIntrinsicExpansion(Function &F) {
   switch (F.getIntrinsicID()) {
+  case Intrinsic::assume:
   case Intrinsic::abs:
   case Intrinsic::atan2:
   case Intrinsic::exp:
@@ -988,6 +989,9 @@ static bool expandIntrinsic(Function &F, CallInst *Orig) {
   case Intrinsic::abs:
     Result = expandAbs(Orig);
     break;
+  case Intrinsic::assume:
+    Orig->eraseFromParent();
+    return true;
   case Intrinsic::atan2:
     Result = expandAtan2Intrinsic(Orig);
     break;
diff --git a/llvm/lib/Target/DirectX/DXILOpLowering.cpp b/llvm/lib/Target/DirectX/DXILOpLowering.cpp
index 8720460cceb20..e46a393e50906 100644
--- a/llvm/lib/Target/DirectX/DXILOpLowering.cpp
+++ b/llvm/lib/Target/DirectX/DXILOpLowering.cpp
@@ -904,8 +904,6 @@ class OpLowerer {
       case Intrinsic::dx_resource_casthandle:
       // NOTE: llvm.dbg.value is supported as is in DXIL.
       case Intrinsic::dbg_value:
-      // NOTE: llvm.assume is supported as is in DXIL.
-      case Intrinsic::assume:
       case Intrinsic::not_intrinsic:
         if (F.use_empty())
           F.eraseFromParent();
diff --git a/llvm/test/CodeGen/DirectX/llvm_assume.ll b/llvm/test/CodeGen/DirectX/llvm_assume.ll
new file mode 100644
index 0000000000000..d739592b75d78
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/llvm_assume.ll
@@ -0,0 +1,9 @@
+; RUN: opt -S -dxil-intrinsic-expansion -mtriple=dxil-pc-shadermodel6.3-library %s | FileCheck %s
+
+define void @test_llvm_assume(i1 %0)  {
+; CHECK-LABEL: test_llvm_assume
+; CHECK-NEXT: ret void
+tail call void @llvm.assume(i1 %0)
+ret void
+}
+
diff --git a/llvm/test/tools/dxil-dis/llvm_assume.ll b/llvm/test/tools/dxil-dis/llvm_assume.ll
deleted file mode 100644
index f5be66c0d192f..0000000000000
--- a/llvm/test/tools/dxil-dis/llvm_assume.ll
+++ /dev/null
@@ -1,11 +0,0 @@
-; RUN: llc --filetype=obj %s -o - | dxil-dis -o - | FileCheck %s
-
-target triple = "dxil-pc-shadermodel6.7-library"
-
-define void @test_llvm_assume(i1 %0)  {
-; CHECK-LABEL: test_llvm_assume
-; CHECK-NEXT: tail call void @llvm.assume(i1 %0)
-tail call void @llvm.assume(i1 %0)
-ret void
-}
-

[spall]

nit: would CHECK-NOT llvm.assume be more clear?

[farzonl]

I was thinking next would be better in the event someone comes along later and makes a transformation for llvm.assume. A transformation should break this test. Causing someone to come here and consider why they are doing a transformation but check-not would pass a transformation.

[llvm-ci]

LLVM Buildbot has detected a new failure on builder ppc64le-mlir-rhel-clang running on ppc64le-mlir-rhel-test while building llvm at step 6 "test-build-check-mlir-build-only-check-mlir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/129/builds/32631

Here is the relevant piece of the build log for the reference

Step 6 (test-build-check-mlir-build-only-check-mlir) failure: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
6.713 [0/1/0] Running the MLIR regression tests
command timed out: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1207.393432