[llvm] [SPIRV] Addition of spe-constant-length-array.ll, bit_reverse_small_type.ll, var_undef.ll test files (PR #151645)

Thu Jul 31 23:15:55 PDT 2025

llvmbot wrote:




@llvm/pr-subscribers-backend-spir-v

Author: Aadesh Premkumar (aadeshps-mcw)

<details>
<summary>Changes</summary>

--Test for support for specialization constant-based variable-length 
--Test for ensuring that encoding of variable with undef initializer has correct 
--Test for bitreverse intrinsic with small types

---
Full diff: https://github.com/llvm/llvm-project/pull/151645.diff


3 Files Affected:

- (added) llvm/test/CodeGen/SPIRV/SpecConstants/spec-constant-length-array.ll (+56) 
- (added) llvm/test/CodeGen/SPIRV/llvm-intrinsics/bitreverse_small_type.ll (+92) 
- (added) llvm/test/CodeGen/SPIRV/var_undef.ll (+31) 


``````````diff

diff --git a/llvm/test/CodeGen/SPIRV/SpecConstants/spec-constant-length-array.ll b/llvm/test/CodeGen/SPIRV/SpecConstants/spec-constant-length-array.ll
new file mode 100644
index 0000000000000..fccddd7966e9e
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/SpecConstants/spec-constant-length-array.ll
@@ -0,0 +1,56 @@
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_variable_length_array %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_variable_length_array %s -o - -filetype=obj | spirv-val %}
+
+; CHECK: OpCapability VariableLengthArrayINTEL
+; CHECK: OpExtension "SPV_INTEL_variable_length_array"
+
+; CHECK-DAG: OpDecorate %[[#]] SpecId 0
+; CHECK-DAG: OpDecorate %[[#]] SpecId 1
+; CHECK-DAG: OpDecorate %[[#]] SpecId 2
+; CHECK-DAG: OpDecorate %[[#A0:]] Alignment 4
+; CHECK-DAG: OpDecorate %[[#A1:]] Alignment 2
+; CHECK-DAG: OpDecorate %[[#A2:]] Alignment 16
+
+; CHECK: %[[#VOID_TY:]] = OpTypeVoid
+; CHECK: %[[#FUNC_TY:]] = OpTypeFunction %[[#VOID_TY]]
+; CHECK-DAG: %[[#I64:]] = OpTypeInt 64 0
+; CHECK-DAG: %[[#I32:]] = OpTypeInt 32 0
+; CHECK-DAG: %[[#I8:]] = OpTypeInt 8 0
+; CHECK-DAG: %[[#F64:]] = OpTypeFloat 64
+; CHECK-DAG: %[[#STRUCT_TY:]] = OpTypeStruct %[[#F64]] %[[#F64]]
+; CHECK-DAG: %[[#PTR_STRUCT:]] = OpTypePointer Function %[[#STRUCT_TY]]
+; CHECK-DAG: %[[#PTR_I8:]] = OpTypePointer Function %[[#I8]]
+; CHECK-DAG: %[[#F32:]] = OpTypeFloat 32
+; CHECK-DAG: %[[#PTR_F32:]] = OpTypePointer Function %[[#F32]]
+
+; CHECK-DAG: %[[#SC0:]] = OpSpecConstant %[[#I64]] 1
+; CHECK-DAG: %[[#SC1:]] = OpSpecConstant %[[#I32]] 2
+; CHECK-DAG: %[[#SC2:]] = OpSpecConstant %[[#I8]] 4
+
+; CHECK: %[[#]] = OpFunction %[[#VOID_TY]] None %[[#FUNC_TY]]
+; CHECK: %[[#LABEL:]] = OpLabel
+
+; CHECK: %[[#A0]] = OpVariableLengthArrayINTEL %[[#PTR_F32]] %[[#SC0]]
+; CHECK: %[[#A1]] = OpVariableLengthArrayINTEL %[[#PTR_I8]] %[[#SC1]]
+; CHECK: %[[#A2]] = OpVariableLengthArrayINTEL %[[#PTR_STRUCT]] %[[#SC2]]
+
+%struct_type = type { double, double }
+
+define spir_kernel void @test() {
+ entry:
+  %length0 = call i64 @_Z20__spirv_SpecConstantix(i32 0, i64 1), !SYCL_SPEC_CONST_SYM_ID !0
+  %length1 = call i32 @_Z20__spirv_SpecConstantii(i32 1, i32 2), !SYCL_SPEC_CONST_SYM_ID !1
+  %length2 = call i8 @_Z20__spirv_SpecConstantic(i32 2, i8 4), !SYCL_SPEC_CONST_SYM_ID !2
+  %scla0 = alloca float, i64 %length0, align 4
+  %scla1 = alloca i8, i32 %length1, align 2
+  %scla2 = alloca %struct_type, i8 %length2, align 16
+  ret void
+}
+
+declare i8 @_Z20__spirv_SpecConstantic(i32, i8)
+declare i32 @_Z20__spirv_SpecConstantii(i32, i32)
+declare i64 @_Z20__spirv_SpecConstantix(i32, i64)
+
+!0 = !{!"i64_spec_const", i32 0}
+!1 = !{!"i32_spec_const", i32 1}
+!2 = !{!"i8_spec_const", i32 2}
diff --git a/llvm/test/CodeGen/SPIRV/llvm-intrinsics/bitreverse_small_type.ll b/llvm/test/CodeGen/SPIRV/llvm-intrinsics/bitreverse_small_type.ll
new file mode 100644
index 0000000000000..77b8c5118e59b
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/llvm-intrinsics/bitreverse_small_type.ll
@@ -0,0 +1,92 @@
+;; Check that llvm.bitreverse.* intrinsics are lowered for
+;; 2/4-bit scalar and vector types.
+
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_arbitrary_precision_integers %s -o - | FileCheck %s
+; TODO: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_arbitrary_precision_integers %s -o - -filetype=obj | spirv-val %}
+
+; CHECK: OpCapability ArbitraryPrecisionIntegersINTEL
+; CHECK: OpExtension "SPV_INTEL_arbitrary_precision_integers"
+
+; CHECK: %[[#I4:]] = OpTypeInt 4 0
+; CHECK: %[[#I2:]] = OpTypeInt 2 0
+; CHECK: %[[#Z4:]] = OpConstantNull %[[#I4]]
+; CHECK: %[[#Z2:]] = OpConstantNull %[[#I2]]
+; CHECK: %[[#V2I2:]] = OpTypeVector %[[#I2]] 2
+; CHECK: %[[#V2I4:]] = OpTypeVector %[[#I4]] 2
+; CHECK: %[[#V3I2:]] = OpTypeVector %[[#I2]] 3
+; CHECK: %[[#V3I4:]] = OpTypeVector %[[#I4]] 3
+; CHECK: %[[#V4I2:]] = OpTypeVector %[[#I2]] 4
+; CHECK: %[[#V4I4:]] = OpTypeVector %[[#I4]] 4
+; CHECK: %[[#V8I2:]] = OpTypeVector %[[#I2]] 8
+; CHECK: %[[#V8I4:]] = OpTypeVector %[[#I4]] 8
+; CHECK: %[[#V16I2:]] = OpTypeVector %[[#I2]] 16
+; CHECK: %[[#V16I4:]] = OpTypeVector %[[#I4]] 16
+
+
+; CHECK: %[[#]] = OpBitReverse %[[#I2]] %[[#Z2]]
+; CHECK: %[[#]] = OpBitReverse %[[#I4]] %[[#Z4]]
+; CHECK: %[[#]] = OpBitReverse %[[#V2I2]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V2I4]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V3I2]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V3I4]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V4I2]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V4I4]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V8I2]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V8I4]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V16I2]] %[[#]]
+; CHECK: %[[#]] = OpBitReverse %[[#V16I4]] %[[#]]
+
+define spir_kernel void @testBitRev() {
+entry:
+  %call2 = call i2 @llvm.bitreverse.i2(i2 0)
+  %call4 = call i4 @llvm.bitreverse.i4(i4 0)
+  ret void
+}
+
+define spir_kernel void @testBitRevV2(<2 x i2> %a, <2 x i4> %b) {
+entry:
+  %call2 = call <2 x i2> @llvm.bitreverse.v2i2(<2 x i2> %a)
+  %call4 = call <2 x i4> @llvm.bitreverse.v2i4(<2 x i4> %b)
+  ret void
+}
+
+define spir_kernel void @testBitRevV3(<3 x i2> %a, <3 x i4> %b) {
+entry:
+  %call2 = call <3 x i2> @llvm.bitreverse.v3i2(<3 x i2> %a)
+  %call4 = call <3 x i4> @llvm.bitreverse.v3i4(<3 x i4> %b)
+  ret void
+}
+
+define spir_kernel void @testBitRevV4(<4 x i2> %a, <4 x i4> %b) {
+entry:
+  %call2 = call <4 x i2> @llvm.bitreverse.v4i2(<4 x i2> %a)
+  %call4 = call <4 x i4> @llvm.bitreverse.v4i4(<4 x i4> %b)
+  ret void
+}
+
+define spir_kernel void @testBitRevV8(<8 x i2> %a, <8 x i4> %b) {
+entry:
+  %call2 = call <8 x i2> @llvm.bitreverse.v8i2(<8 x i2> %a)
+  %call4 = call <8 x i4> @llvm.bitreverse.v8i4(<8 x i4> %b)
+  ret void
+}
+
+define spir_kernel void @testBitRevV16(<16 x i2> %a, <16 x i4> %b) {
+entry:
+  %call2 = call <16 x i2> @llvm.bitreverse.v16i2(<16 x i2> %a)
+  %call4 = call <16 x i4> @llvm.bitreverse.v16i4(<16 x i4> %b)
+  ret void
+}
+
+declare i2 @llvm.bitreverse.i2(i2)
+declare i4 @llvm.bitreverse.i4(i4)
+declare <2 x i2> @llvm.bitreverse.v2i2(<2 x i2>)
+declare <2 x i4> @llvm.bitreverse.v2i4(<2 x i4>)
+declare <3 x i2> @llvm.bitreverse.v3i2(<3 x i2>)
+declare <3 x i4> @llvm.bitreverse.v3i4(<3 x i4>)
+declare <4 x i2> @llvm.bitreverse.v4i2(<4 x i2>)
+declare <4 x i4> @llvm.bitreverse.v4i4(<4 x i4>)
+declare <8 x i2> @llvm.bitreverse.v8i2(<8 x i2>)
+declare <8 x i4> @llvm.bitreverse.v8i4(<8 x i4>)
+declare <16 x i2> @llvm.bitreverse.v16i2(<16 x i2>)
+declare <16 x i4> @llvm.bitreverse.v16i4(<16 x i4>)
diff --git a/llvm/test/CodeGen/SPIRV/var_undef.ll b/llvm/test/CodeGen/SPIRV/var_undef.ll
new file mode 100644
index 0000000000000..f6ccda8b76a43
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/var_undef.ll
@@ -0,0 +1,31 @@
+; Ensure that encoding of variable with undef initializer
+; has correct wordcount
+
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv32-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK: OpName %[[#FOO_VAR:]] "foo"
+; CHECK: OpName %[[#BAR_VAR:]] "bar"
+;; foo variable has optional initializer (OpUndef)
+; CHECK: %[[#FOO_VAR]] = OpVariable %[[#]] Workgroup
+;; bar variable does not have optional initializer
+;; word count must be 4
+; CHECK: %[[#BAR_VAR]] = OpVariable %[[#]] Workgroup
+
+%anon = type { %range }
+%range = type { %array }
+%array = type { [2 x i64] }
+
+ at foo = internal addrspace(3) global %anon undef, align 8
+ at bar = internal unnamed_addr addrspace(3) global %range undef, align 8
+
+define void @use_globals() {
+entry:
+  ; Use the globals in a no-op way to ensure they’re not optimized out
+  %foo_ptr = addrspacecast %anon addrspace(3)* @foo to %anon*
+  %bar_ptr = addrspacecast %range addrspace(3)* @bar to %range*
+  call void @llvm.donothing()
+  ret void
+}
+
+declare void @llvm.donothing()

``````````

</details>


https://github.com/llvm/llvm-project/pull/151645
