[llvm] [NFC][AMDGPU] New test for untested case in SILowerSGPRSpills (PR #189426)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: ambergorzynski

<details>
<summary>Changes</summary>

[This case](https://github.com/llvm/llvm-project/blob/f380a878d515024fe02662471e81cd72a8b3eb93/llvm/lib/Target/AMDGPU/SILowerSGPRSpills.cpp#L343-L345) is not covered by any existing tests (checked using code coverage and by inserting an `abort` at that line). I propose a new test that tests this line.

This is demonstrated by showing that it is the only test that fails in the presence of the `abort`.

---
Full diff: https://github.com/llvm/llvm-project/pull/189426.diff


1 Files Affected:

- (modified) llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills.mir (+57) 


``````````diff
diff --git a/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills.mir b/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills.mir
index 2de7d86223eb2..163f0a480c260 100644
--- a/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills.mir
+++ b/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills.mir
@@ -1,3 +1,4 @@
+# NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
 # RUN: llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs -run-pass=si-lower-sgpr-spills -o - %s | FileCheck %s
 
 # CHECK-LABEL: name: empty_entry_block
@@ -18,3 +19,59 @@ body: |
     renamable $sgpr36_sgpr37 = S_XOR_B64 renamable $vcc, -1, implicit-def dead $scc
     $sgpr34_sgpr35 = S_AND_SAVEEXEC_B64 $sgpr36_sgpr37, implicit-def $exec, implicit-def $scc, implicit $exec
     S_ENDPGM 0
+...
+---
+name:            lane-vgpr-spill-ncd
+tracksRegLiveness: true
+
+stack:
+  - { id: 0, type: spill-slot, size: 8, stack-id: sgpr-spill }
+machineFunctionInfo:
+  hasSpilledSGPRs: true
+  stackPtrOffsetReg: '$sgpr32'
+
+body:             |
+  ; CHECK-LABEL: name: lane-vgpr-spill-ncd
+  ; CHECK: bb.0:
+  ; CHECK-NEXT:   successors: %bb.2(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   S_BRANCH %bb.2
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   $sgpr6 = SI_RESTORE_S32_FROM_VGPR %0, 0, implicit-def $sgpr6_sgpr7
+  ; CHECK-NEXT:   $sgpr7 = SI_RESTORE_S32_FROM_VGPR %0, 1
+  ; CHECK-NEXT:   $sgpr4 = S_MOV_B32 32
+  ; CHECK-NEXT:   $sgpr4_sgpr5 = S_LSHR_B64 $sgpr6_sgpr7, killed $sgpr4, implicit-def dead $scc
+  ; CHECK-NEXT:   $sgpr4 = COPY $sgpr4, implicit killed $sgpr4_sgpr5
+  ; CHECK-NEXT:   $sgpr5 = COPY $sgpr6, implicit killed $sgpr6_sgpr7
+  ; CHECK-NEXT:   $vgpr0 = COPY killed $sgpr5
+  ; CHECK-NEXT:   $vgpr1 = COPY killed $sgpr4
+  ; CHECK-NEXT:   SI_RETURN implicit killed $vgpr0, implicit killed $vgpr1
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.2:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   $sgpr4_sgpr5 = S_MOV_B64 0
+  ; CHECK-NEXT:   [[DEF:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
+  ; CHECK-NEXT:   [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr4, 0, [[DEF]], implicit-def $sgpr4_sgpr5, implicit $sgpr4_sgpr5
+  ; CHECK-NEXT:   [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR killed $sgpr5, 1, [[DEF]], implicit killed $sgpr4_sgpr5
+  ; CHECK-NEXT:   S_BRANCH %bb.1
+  bb.0:
+    S_BRANCH %bb.2
+
+  bb.1:
+    $sgpr6_sgpr7 = SI_SPILL_S64_RESTORE %stack.0, implicit $exec, implicit $sgpr32 :: (load (s64) from %stack.0)
+    $sgpr4 = S_MOV_B32 32
+    $sgpr4_sgpr5 = S_LSHR_B64  $sgpr6_sgpr7, killed  $sgpr4, implicit-def dead $scc
+    $sgpr4 = COPY  $sgpr4, implicit killed $sgpr4_sgpr5
+    $sgpr5 = COPY  $sgpr6, implicit killed $sgpr6_sgpr7
+    $vgpr0 = COPY killed  $sgpr5
+    $vgpr1 = COPY killed  $sgpr4
+    SI_RETURN implicit killed $vgpr0, implicit killed $vgpr1
+
+  bb.2:
+    $sgpr4_sgpr5 = S_MOV_B64 0
+    SI_SPILL_S64_SAVE killed $sgpr4_sgpr5, %stack.0, implicit $exec, implicit $sgpr32 :: (store (s64) into %stack.0)
+    S_BRANCH %bb.1
+## NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+# CHECK: {{.*}}

``````````

</details>


https://github.com/llvm/llvm-project/pull/189426